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Everyday Practical Electronics - 2000.09 - Vol

1. oec rrr enne 750 Marconi 2019A 80kHz 1040MHz Synthesised Signal Generator 1000 Marconi 2111 UHF Synthesiser NEW snsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn EI OA Marconi 2185 1 5GHz Programmable Attenuator new nooo uuu uuu uuu uuuuun POA Marconi 2305 Modulation Meter RR 1750 Marconi 2337A Automatic Distortion Meter nn 150 Marconi 2610 True RMS Voltmeter 1 1n rrne nero orna na nu nuu n ua RR Ran RR RR RRRRRAR RR RR SSRRRRARRRR RAR an NAAR 700 Marconi 2871 Data Comms Anahyser seeesrrrrsssssssssrterrrrrressssssssrrrerrrrresssRRsEEEEEEEEEEEEEREREEEEEEEEEEEE 500 Marconi 2955 Radio Comms Test Set nur wn 2000 Marconi 6310 Sweep Generator Programmable new 2 20GHz 3500 Marconi 6950 6960 Power Meter amp Sensor o erre from 500 Marconi 6960 Power Meter amp Sensor from 950 Marconi 893 A F Power Meter essssstrrterrrrrreSEEEREEEEEEEEEEEEEEEEEEEREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEREEEEEEEEEEE 250 Philips PM5167 MHz Function Generator sessssesssessssseereseserErEEEEEEEEEEEEEEEEEEEREREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEN 400 Philips 5190 L F Synthesiser G P I B 1 ces eern rrr rn nnne nnnm unnm uuu u unu uuuuu unam unus nnmnnn nnan 800
2. 15 00 KT TWO VALVE AMPLIFIER GOOD VOLUME ty Fd E17 50 KB CRYSTAL SET ONE VALVER EXPERIMENTAL VALVE SOLID STATE WITH SPEAKER Ki fed E18 00 Ko ONE VALVE MW RADIO MOT REGEN SOLID STATE INCORPORATED GOOD VOLUME WITH SPEAKER SUPPLIED WORKS VERY WELL 22 50 K10 MODERN TWO VALVE RADIO WITH SOLID STATE THIS RADIO USES TWO VALVES STILL PRODUCED TODAY AND THERE ARE NO COILS TO WIND IT OPERATES ON MEDIUM WAWE AND HAS MO REGENERATION PROBLEMS ict 28 50 Kii TWO VALVE SW GENERAL RECEIVER GMHZ TO 14MHz USING MODERN SOLID STATE COMBINED WITH VALVE TECHNOLOGY THIS RADIO HAS VERY GOOD VOLUME BY USING THE ECCR3 AND ELSA VALVES Ce 21221 ES Ki TWO VALVE AMPLIFIED CRYSTAL SET RADIO SIMILAR TO THE K8 PROJECT BUT WITH MORE AMPLIFICATION THIS I8 IDEAL IF YOU ARE INTO EXPERIMENTING WITH CRYSTAL SETS AMD YOU REQUIRE LOTS OF VOLUME T 26 50 Kia TWO VALVER REGEN RADIO MW amp SW USES THE EFS1 VALVE AS A DETECTOR AND THE ECL80 FOR AUDIO AMPLIFICA TION CIRCUITHY SIMILAR TOMS SISTER THE K3 REGEN RADIO KIT AS THESE VALVES ARE VERY COMMON THIS KIT IS SLIGHTLY CHEAPER d 24 00 K14 3 VALVE RADIO MW amp SW AND WITH RF STAGE ADDED WHICH GIVES MORE SELECTIVITY ALSO COMES WITH INTERCHANGEABLE COIL FORMER ALSO RADIO GIVES GOOD VOLUME EASY TO ASSEMBLE THIS SET USES TWO EFS VALVES AND THE ECLS0 FOR AUDIO A E30 00 K15 3 VALVE RADIO NW amp SW ANOTHER DIFFERENT TYPE OF REGENERATION RADIO ALSO WITH
3. 230V a c MAINS INPUT ENS UNLIMITED Our regular round up of readers own circuits We pay between 10 and 50 for all material published depending on length and technical merit We re looking for novel applications and circuit tips not simply mechanical or Ay electrical ideas Ideas must be the readers own work and not have been submitted for publication elsewhere The circuits shown have NOT been proven by us ngenuity Unlimited is open to ALL abilities but items for consideration in this column should preferably be typed or word processed with a brief circuit description between 100 and 500 words maximum and full circuit diagram showing all relevant component values Please draw all circuit schematics as clearly as possible Send your circuit ideas to Alan Winstanley ngenuity Unlimited Wimborne Publishing Ltd Allen House East Borough Wimborne Dorset BS21 1PF They could earn you some real cash and a prize The circuit uses a standard full wave mains power supply Diode D5 and resistor R1 pro vide the charging current for battery Bl which is a standard 8 4 volt Ni Cad 9V RX22 style type The purpose of D5 is to prevent the battery from discharging back wards following a mains failure Transistor TR1 BC178 or 2N3702 is a pnp type which combines with R2 R3 and Zener diode D7 to produce a low voltage cut off to prevent deep discharge of B1 Under mains power current flows from the mains power supply thr
4. 695 STORE YOUR BACK ISSUES IN YOUR WALLET including VAT and p amp p A new way to buy EPE Back Issues our first wallet sized CD ROM is now available containing eight back issues from our EPE Online website plus bonus articles all the relevant PIC software and web links All this for just 12 45 including postage and packing NOTE This mini CD ROM is suitable for use on any PC with a CD ROM drive It requires Adobe Acrobat Reader available free from the Internet www adobe com acrobat VOL 1 CONTENTS BACK ISSUES November 1998 to June 1999 all the projects features news lUs etc from all eight issues Note No advertisements or Free Gifts are included Order on line from www epemag com or by Phone Fax E mail or Post PIC PROJECT CODES All the available codes for the a ee published in issues from November BACK ISSUES CD ROM ORDER FORM EPE ONLINE STORE Books PCBs Subscriptions l Please send me quantity BACK ISSUES VOL 1 I I I I CD ROM NOV 98 to JUNE 99 I I I I I eic I Price 12 45 approx 20 each includes postage to anywhere I in the world EXTRA ARTICLES THE LIFE WORKS OF KONRAD ZUSE a brilliant p Name cesses eene nnn nne i pioneer in the evolution of computers A bonus article M Ad reSS coco i on his life and work written by his eldest son including l i many previously unpublished photographs DL rento ote en a es ya o
5. Data etc e Fundamental principles PRACTICAL SKILLS Learn how to identify Electronic Components Avoid Static e Troubleshooting techniques Hazards Carry Out Soldering and Wiring Remove and Replace Components bog l l l e Servicing techniques TEST EQUIPMENT How to Choose and Use Test Equipment Assemble a Toolkit Set Up a Workshop and Get the Most from Your Multimeter and Oscilloscope etc e Choosing and using test equipment Reference data Easy to use format Clear and simple layout Vital safety precautions Professionally written Regular Supplements Sturdy gold blocked ring binder SERVICING TECHNIQUES The regular Supplements include vital guidelines on how to Service Audio Amplifiers Radio Receivers TV Receivers Cassette Recorders Video Recorders Personal Computers etc TECHNICAL NOTES Commencing with the IBM PC this section and the regular Supplements deal with a very wide range of specific types of equipment radios TVs cassette recorders amplifiers video recorders etc REFERENCE DATA Detailing vital parameters for Diodes Small Signal Transistors Power Transistors Thyristors Triacs and Field Effect Transistors Supplements include Operational Amplifiers Logic Circuits Optoelectronic Devices etc ELECTRONICS SERVICE MANUAL Basic Work Contains around 900 pages of information Edited by Mike Tooley BA Regular Supplements Approximately 160 page Supplements of additional information which if r
6. LOCKS How they work and how to pick them This fact filled report will teach you more about locks and the art of lock picking than many books we have seen at 4 times the price Packed with information and illustrations R008 3 50 RADIO amp TV JOKER PLANS We show you how to build three different circuits for dis rupting TV picture and sound plus FM radio May upset your neighbours amp the authorities DISCRETION REQUIRED R017 3 50 INFINITY TRANSMITTER PLANS Complete plans for building the famous Infinity Transmitter Once installed on the target phone device acts like a room bug Just call the target phone amp activate the unit to hear all room sounds Great for home office security RO19 3 50 THE ETHER BOX CALL INTERCEPTOR PLANS Grabs telephone calls out of thin air No need to wire in a phone bug Simply place this device near the phone lines to hear the conversations taking place R025 3 00 CASH CREATOR BUSINESS REPORTS Need ideas for making some cash Well this could be just what you need You get 40 reports approx 800 pages on floppy disk that give you information on setting up different busi nesses You also get valuable reproduction and duplication rights so that you can sell the manuals as you like R030 7 50 PC CONTROLLED RELAY BOARD Convert any 286 upward PC into a dedicated automatic controller to independently turn on off up to eight lights motors amp other devices around the home off
7. MasterCard or Visa No Minimum order for credit cards 5 CELIA Signature Card Exp Date Please supply name and address of cardholder if different from the address shown VISA NOTE You can also order p c b s by phone Fax E mail or via our Internet site on a secure server http www epemag wimborne co uk 709 ICTICAL CLASSIFIED FTS TRONIS years Everyday Practical Electronics reaches twice as many UK readers as any other UK monthly hobby electronics magazine our audited sales figures prove it We have been the leading independent monthly magazine in this market for the last fifteen If you want your advertisements to be seen by the largest readership at the most economical price our classified and semi display pages offer the best value The prepaid rate for semi display space is 8 VAT per single column centimetre minimum 2 5cm The prepaid rate for classified adverts is 30p VAT per word minimum 12 words All cheques postal orders etc to be made payable to Everyday Practical Electronics VAT must be added Advertisements together with remittance should be sent to Everyday Practical Electronics Advertisements Mill Lodge Mill Lane Thorpe le Soken Essex CO16 OED Phone Fax 01255 861161 For rates and information on display and classified advertising please contact our Advertisement Manager Peter Mew as above Valve Output Transformers Single ended 50mA 4 50 push pull 15W 27
8. Ni Cads are strange because they enjoy being treated somewhat badly not gently Generally it s best to let the gadget fully discharge occasionally several times a year rather than partially discharge the Ni Cad before recharging Cordless phone electric toothbrush rechargeable torch or razor owners should take note Unfortunately Ni Cads tend to self dis charge over an extended time say 10 to 20 weeks and they are useless for low drain applications such as clocks or L C D calculators If like me you use many sets of cells a good tip is to number your cells in sets using a Dymo or Brother label maker so that you know which sets are ready and which have been discharged This helps to ensure that the cells are treated consistent ly and aren t mixed up Also to avoid a fire hazard always store charged batteries safely so that they cannot be shorted out by metal objects As for when is a Ni Cad considered flat the consensus is when the voltage across a cell is approximately 0 9V it is time to recharge A 3 6V or 7 2V pack has three or six cells respectively so they are flat when they have about 2 7V or 5 4V on load There is no point continuing beyond that because the Ni Cad s capaci ty has already been spent You run the additional risk of causing polarity reversal if the cells are discharged too much Gas gauge chips It s nothing to do with spiralling gaso line prices knowing how much power remain
9. obviously it would be better to code it in and this corrected the problem David Perks Head of Electronics Graveney School London via the Net We forwarded David s query to Mark Stuart who replied Have you fitted R1 It is a pull down resistor for the display R W line and is shown in Fig 4 It is underneath the l c d I think it will solve your problem It is necessary to pull down this pin but unless you need to read from the display memory there is no need to have it connected to a port pin Mark Stuart Everyday Practical Electronics September 2000 QBASIC AND MICROSOFT Dear EPE I would like to say that in my opinion QBasic is probably the best choice for electronic pro jects Its ease of use wide availability and back ward compatibility make it my first choice for most programming problems It can be run on very old computers and I find this very useful because I use an 80386 for electronic work I suggest that while QBasic does what you want use it If some more advanced features are required then another language would have to be used but this would put projects out of the range of some readers who do not want to or cannot as is my case upgrade Getting new commer cial software can cost a lot of money and can put development and adaptation of code out of reach If you must change language at least use one that is free Another point is that in QuickBASIC not QBasic you can compile the fi
10. 5 80 O1 BASIC CRYSTAL SET Mu 65 853 PRESSURE MAT ALARM p tii B6 MW SIGNAL BOOSTER ww 1250 Di GUITAR TUNER P 195 B FAKE CAR ALARM FLASHER 500 D TOUCH ALARM B 55 Bid 2LEDFLASHER raso B5 amp SIMPLE LIGHT METER a AS Bit LOW VOLTS L ED ALARM 9V 12V fo B5 LEDCONTNUITYMETER EX 413 812 LIE DETECTOR WITH METER 1000 853 SOUND OPERATED SWITCH Eh 6 50 B13 TOY ORGAN e650 BSBA BFLASHINGLEDS bea oa Bid METRONOME LC CONTROL esoo Dep TBA E20M AUDIO AMP EIL 103 815 TOUCH SWITCH gno B TOA 030 AUDIO AMP i t95 B16 HEADS OR TAILS GAME foo Dei ELECTRONIC DCE GAME Sec Da Bi SAEN 480 BI ADVANCED THERAMIN MUSIC ID Si 818 RAIN DETECTOR 4a B64 TOUCH DELAY LAMP 15 3 819 CONTINUITY TESTER 4509 865 FISHERMAN S ROD BITE ALARM 5 00 Ba MORSE CODE OSCILLATOR 48 Be BEAM BREAK DETECTOR ALARM 8 00 Pat BURGLAR ALARM LED A SPEAKER pro B67 LATCHING BURGLAR ALARM PT B2 LOOP SECURITY ALARM Pa Des LIGHTEOPERATED RELAY ELW B23 VIBRATION ALARM Gun 863 MICROPHONE PRE AMP Er x Bas METAL DETECTOR METER 400 29 MAGNETIC ALARM MODELS 7 Si B25 HANMDTREMOR GAME 450 IG BATH OR WATER BUTT ALARM 6 80 B25 RAIN SYNTHESISER NOISE pen BO 0 18 VOLT POWER SUPPLY UNIT 6 80 B2 AUTO LIGHT DARK INDICATOR 48 874 FM BUG POWER SUPPLY 0 9 6 50 B25 ADJ LOW LIGHT INDICATOR 48 875 TRANSISTOR FM BUG 6 50 B23 DARK ACTIVATED LED FLASHER 480 Bre 2TRANSISTOR FM BUG 750 B30 LIGHT ACTIVATED TONE ALARM 4 3 77
11. Resistors R1 R2 6800 2 off 4700 R3 Capacitors C1 C2 C3 Semiconductors D1 D2 red l e d 2 off IC1 PIC16x84 microcontroller preprogrammed see text IC2 IS1U60 infra red sensor Miscellaneous SK1 9 pin D type serial connector female X1 4MHz crystal Stripboard size to suit 5V power supply see text excluding PSU Approx Cost Guidance Only Everyday Practical Electronics September 2000 LIMITER PF DEMODULATOR INTEGRATOR COMPARATOR Fig 3 Block diagram for the IS1U60 remote control IR sensor 1 2 3 1 Vour OUTPUT 2 GROUND 3 Vcc 5V Fig 4 Pinouts for the IS1U60 sensor RCS PROTOCOL The RC5 remote control code protocol was developed by Philips and is used by several other manufacturers However it is worth noting that not all products manu factured by Philips use this protocol An RC5 transmission has a duration of approximately 25 milliseconds and contains 14 bits of data A logic O is encoded by a high to low transition and a logic by a low to high transition This is called bi phase coding as illus trated in Fig 5 The arrangement of the 14 bit code is given in Fig 6 The first two bits S of the transmission are Start bits and are always transmitted as logic 1 This allows the IR receiver to adjust its automatic gain con trol to suit the infra red signal strength The Control bit C toggles whenever a new key is pressed or if a key is h
12. V Capel This book explores the various features good points and snags of speaker designs It examines the whys and where fores so that the reader can understand the principles involved and so make an informed choice of design or even design loudspeaker enclosures for him or herself Crossover units are also explained the various types how they work the distortions they produce and how to avoid them Finally there is a step by step description of the con struction of the Kapellmeister loudspeaker enclosure 148 pages Order code BP256 3 99 PREAMPLIFIER AND FILTER CIRCUITS R A Penfold This book provides circuits and background information for a range of preamplifiers plus tone controls filters mixers etc The use of modern low noise operational amplifiers and a specialist high performance audio preamplifier i c results in circuits that have excellent performance but which are still quite simple All the circuits featured can be built at quite low cost just a few pounds in most cases The preamplifier cir cuits featured include Microphone preamplifiers low impedance high impedance and crystal Magnetic car tridge pick up preamplifiers with R I A A equalisation Crystal ceramic pick up preamplifier Guitar pick up pream plifier Tape head preamplifier for use with compact cassette systems Other circuits include Audio limiter to prevent overloading of power amplifiers Passive tone controls Active tone co
13. 98 Many of the functions offered by this design are closely similar to those provided by V Scope including output of waveform data to disk and printer Frequency counting and waveform amplitude measurement are also included WIND UP TORCH FRIDGE FREEZER ieie renie the totis casa Tee ah Will commonly last only two to three hours and many bulb A LA R M filaments burn no more than a few weeks before fusing With new l e d technology it is now possible to build a torch that Many people have a sizeable amount of capital quite adequately lights the way five to ten metres in front of one In tied up in their deep freeze A long power cut or a fact since power consumption is so small it is possible to power failure of the freezer itself can lead to significant the light for a considerable length of time from a few turns of a financial loss not to mention the prospect of losing small generator and a capacitor reservoir the sole source of the delicious smoked trout from last summer s power for this torch no batteries In addition to this the white l e d fishing holiday The disaster is not discovered until used in this circuit has a life expectancy of years not weeks as in later when it s too late to do anything about it the case of a standard filament bulb Similar remarks apply to the contents of a While the light output of the Wind up Torch is modest in refrigerator though it may be more a matter of comparison with some mode
14. Black AN Blue White or Y allow 2mm Solder Plugs 2mm Chassis Sockels 4mm Plugs Solder 4mm Plugs Screw dmm Stackable Plugs 4mm Shrouded Plugs reli Ge et SE mm Binding Posts 33mm Crocedile Clips Power Connectors DE Low Vo BBBEBBBRE DC Plug 0 7ID 2 3 F DC Plug 1 31D 3 4OD 0 32 DC Plug 1 7ID 4 0OD 0 47 DC Plug 1 71D 4 75OD 0 47 DC Plug 2 1D 5 00D 0 25 8 DC Plug 2 51D 5 00D 0 24 DC Plug 3 1ID amp 3OD 0 46 DC Line Socket Z 1mm 0 57 DC Line Sockel 7 5mm 0 68 pe Neng SN 2 1mm 0 40 DC Chassis Skt 2 5mm 0 41 IEC Mains 6A 250Vuc Le F 3 Fin IEC Line Socket l OR 3 Pin IEC Line Plu 1 78 3 Fin Chassis Socket 0 55 0 72 3 Pin XE BW Plu ay in p Bi 08 ki P552 1 39 B Pin Line Plug P55 B Pin Chassis a Sub Miniaty aA 125V 1A 250V 5mm C Mounting Hale SPST 5 x 10mm SPB x l mm SPDT C Off 5 x 10mm DPDT 9 2 x 10mm Mini 6A 125V 3A 750V amp 2mm Mounting Hole SPST 8 x 13mm 0 45 2 5mm Jack PI 0 25 SPDT alae Tamm EDZO 2 5mm Line Socket 0 16 SPDT c o Biased 2 woyE0 97 4 2 5mm Chassis Socket 0 20 SPDT c o Biased l way 04 3 5mm Mono Plug 0 24 DPDT 12 x 13m KU 3 5mm Mono Line Skt 0 30 DPDT cioll 12x Tamm 20 8 3 mm Mono Chassis 0 14 PDT c o Biased 2 wayEl 28 3 5mm Stereo Plu 0 36 DPDT c o Biased wayEl 28 3 5mm Stereo Line Ski 0 37 Shanda 3 3mm Stereo Chassis 0 22 104 250V Push on terminals x Mona Plug 0 34 12mm E Cep Hole l
15. OPTIONAL 5V POWER SUPPLY POWERFUL ARGUMENTS When planning this Teach In 2000 series it was felt that expecting you to experiment with different Zener diode val ues and voltage regulators was unrealistic The Zener values you could use with a 6V supply are few and apart from check ing with your meter that the Zener does indeed limit voltages to a particular value you could not actually put this voltage con trol to good use Standard fixed voltage regulator devices are not available below 5V e g 7805 and 78L05 These typically require a mini mum input voltage of 7V and so cannot be used with a 6V battery Consequently no actual experiments with either of these device types are offered We believe though that the Tutorial and demo programs provide you with enough information to understand their nature and how you might use them in some future designs of your own creation However contrary to what we indicated earlier in the series we now offer you the option to provide your breadboard with a mains powered 5V d c regulated supply read on MAINS ADAPTION It seems likely that many of you will already possess mains adaptors battery elim inators that are suitable for connecting to a few extra components in order to produce a fully regulated and safe 5V d c supply that can be used in place of your 6V battery Such adaptors are used for example with mobile phones computer modems and personal audio equipm
16. Tektronix 2235 100MHz Dual trace c a 600 Tektronix 2335 Dual Trace 100MHz portable cc cer c r rcc eren eru u rue enean aua nuuus 600 Tektronix 2440 300MHz 500 Ms s D S O 2 Channel error nnno annu nuu nnaanannnas 2500 Tektronix 2445 150MHz A Channel DMM ssssssssnssecsssennsecnnsenessennsenesseeeseenesecnssenesecnssenesnonsseens 900 Tektronix 2445A 100MHz 4 Channel a 900 Tektronix 2476B 400MHz 4 Channel Ena 6500 Tektronix 5403 60MHz 2 or 4 Channel 255 from 150 Tektronix 7313 7603 7623 7633 100MHz 4 Channe from 225 Tektronix 7704 250MHz 4 Channel from 350 Tektronix 7904 500MHz from 400 Trio CS 1022 20MHz Dual Channel REE rnrnnarnnas 125 Other scopes available too SPECIAL OFFER HITACHI V212 20MHz DUAL TRACE ssnunsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnannnnnnnnnnnnananans E TOO HITACHI V222 20MHz DUAL TRACE ALTERNATE MAGNIFY SPECTRUM ANALYSERS Ando AC8211 Spectrum Analyser 1 7GHz Anritsu MS62B 10kHz 1700MHz Anritsu MS3401A MS3401B 10Hz 30MHz Anritsu MS610B 10kHz 2GHz Mint nro rena ann uuu anu EEN annus u uuu uu su unus uae uuuuu a 45 Anritsu MS710F 100kHz 23GHz Spectrum ey Avcom PSA65S 1000MHz Portable nneesprrress
17. When the axis of the loop or coil is pointing towards the transmitter the induced signal voltage falls in theory to zero The two nulls 180 degrees apart are extremely sharp They enable the operator to prevent interference reaching the receiv er and to separate stations operating on the same frequency It is this property which encouraged American Raymond S Moore to re intro duce the large air cored loop for serious Medium Wave listening during the 1940s The need to rotate the aerial in a hori zontal plane to optimise reception is evi dent to every owner of a transistor portable radio What is not so widely appreciat ed is the need to tilt it in the vertical if the deepest possible nulls are to be obtained Medium frequency radio waves reach the receiver by line of sight direct waves travel to it around the curvature of the earth surface waves and at night are reflected down from the ionosphere sky waves The loop must therefore tilt as well as turn in order to point its axis pre cisely at the advancing wave front Another American Gordon Nelson was probably the first designer to incorporate tilting into his Medium Wave loops i ARGE loop or frame aerials were a 672 LOOPS AND WIRES Transmitting aerials radiate electrostatic and electromagnetic fields which coexist at right angles to one another Long wire and whip aerials in conjunction with some form of earthing are acted upon by the el
18. ZEEEEEE SD emi ivit a Hise betel ala Eni 12 ma ti 3z ji des mre ne af E IN Ir ad UR ITZTETI Ja EA E E E A A i Prices fully inclusive az a a n development boards s A ee AN Covers use of interrupts and programming for JT A RH MR real time applications risit reti Eon e Hints and tips on good programming practice pa aiii wa TL Y y with the PIC d a LAC nir TINI e Full examples of debugging using FED PIC C ES are included e Included FREE on our PIC C Compiler CD ROM or available in paper copy Prices reductions for PICDESIM WIZPIC amp our programmer users C Compiler with all manuals on CD ROM 60 CD ROM with printed manuals 75 Buy with PICDESIM WIZPIC or our Programmer 45 00 CD ROM Learn to program PICs with FED PIC C paper copy 7 50 PIC Programmers including 18Cxxx WIZPIC D de Programmer PIC Visual Developmen t Handles serially programmed PIC devices in a 40 pin multi width ZIF socket 16C55X 16C6X 16C7X 16C8x 16F8X 12C508 12C509 16C72XPIC 14000 16F87X 18Cxxx etc Also In Circuit programming alude tti ZER Operates on PC serial port ncluded components support timers serial inter Price 45 kit faces 12C LCD 7 Seg displays keypads switches 50 built amp tested port controls and many more Connect software components to PIC pins by point amp PIC Introductory Programs 8 amp 18 pin devices 16C505
19. address for Readout so I sent this letter to Editorial Some guide would have been nice not meant nastily Ian Liverton 16 Sidcup Kent via the Net Thank you for contributing to the QB debate Regarding Microsoft it is concerning how its breakup might affect standardisation I have wel comed what the company appears to have done to standardise so much in the way of software functionality When I first began program writing in the late 70s there were many systems vying for acceptance and none that I swapped between during the next few years were compatible with each other Names like Commodore Apple Sinclair Tangerine Dragon Amstrad and so on come to mind I do not know the ins and outs of the legal arguments or why in this instance the existence of a large organisation and its alleged monopoly status should be regarded as contrary to public interest yet in other instances it should not Why for example should Cisco Systems be exempt from criticism If I understand their TV ads cor rectly they carry the majority of the World s Internet traffic is that not a near monopolistic situation Like lan I too would like enlightenment Knowledgeable readers are invited to comment On Jon e final point Readout does not have a separate E mail address just write to editori al epemag wimborne co uk Any correspon dence that comes in via E mail or snail mail is considered for Readout suitability MORE QBASIC FOUND Dea
20. click using the mouse 16C55X 16C61 16C62X 16C71 16C71X 16C8X 16F8X Set parameters for each component from drop down 12C508 9 12C671 2 etc 25 kit list boxes check boxes or text entry AVR AVR1200 2313 4144 8515 8535 4434 etc in ZIF 4 5V Links your code automatically into library events e g battery powered Price 40 for the kit or 45 built amp tested Button Pressed Byte Received etc Up to 10 times faster than MPLAB Supports all 14 bit core PIC s 12C67x 16C55x All our Programmers operate on PC serial interface No hard to 16C6x 16C7x 16C8x 16C87x etc handle parallel cable swapping Programmers supplied with instructions Windows 3 1 95 98 NT software Cost CD ROM with Data sheets and application notes Upgrade programmers from our web site 35 00 Floppy version 30 00 e Rapid Application Development for the PIC microcontroller e Drag and drop your software component selections on to your design WE ET x O Q O D ee O M z Forest Electronic Developments d 18C452 60 Walkford Road Christchurch Dorset BH23 5QG E mail info fored co uk or sales fored co uk i Hardware multiply 40MHz clock Web Site htip www fored co uk a 16K program words 1536 bytes 01425 274068 Voice Fax l RAM Easy to upgrade from 16F877 Prices are fully inclusive Add 3 00 for P amp P and handling to each order iz Cheques POs payable to Forest Electronic Dev
21. flexibility the PlCmicro MCU Migratable Memory path gives you socket compatible OTP ROM and FLASH MCUs and a design without limits Add world class development tools and technical support and you ve got the most complete 8 bit RISC MCU solution with FLASH Italy 39 039 689 9939 France 33 0 1 69 53 63 20 Germany 49 0 89627 1440 UK 44 0 118 921 5818 The Micrachig rame logo PIC PI Cmiero and The Embedded Contrel Zelsdons Company ane regeierd tracemarkes and Migniabls Memory and In Circust Sonal Programming are trademarks of Mierozhip Tecbnelegy Inc in tha USA and other courbes 4 15990 Mcrochip Tachnalegy ke All ha rmon od MICROCHIP The Embedded Control Solutions Company Explore the Universe of Embedded Control at www microchip com READOUT John Becker addresses some of the general points readers have raised Flave you anything interesting to say Drop us a line WIN A DIGITAL MULTIMETER A 31 5 digit pocket sized l c d multime ter which measures a c and d c volt age d c current and resistance It can also test diodes and bipolar transistors Every month we will give a Digital Multimeter to the author of the best Readout letter LETTER OF THE MONTH BETTER BIN DEC CONVERSION Dear EPE I see you have been using your old binary to decimal routine again this time in P C Gen July 00 I hate it please accept mine It is neat and fast and 24 bit but easily modified to
22. form it is only suited for construction by experienced hobbyists but a simplified and shortened version is also described and is a supply suited for use by less experienced experimenters It can provide outputs between 5V and 15V d c Note that the 13 2V supply described elsewhere in this issue is not suited for use with the Teach In breadboard circuits NEXT MONTH In the final part of Teach In 2000 next month Part 12 we take a look at 7 segment displays both light emitting diode l e d and liquid crystal 1 c d but without actual ly experimenting with them We shall also experiment with a digital to analogue con verter There are a few loose ends yet to be tied up as well which we shall try to do In the meantime may the power be with you Everyday Practical Electronics September 2000 rcodgodgoogocdooogoooagbobiabobuubDcadbaadgagaagoaogaogdgoododoLcodccocc reegen DRE PIC Real Time 0000000000 In Circuit Emulator 20MHz full speed operation PC Serial port connection Use With Microchip MPLAB Standard MPASM Language PCB with solder mask amp component ID Kit with all components PIC16F877 Solderless Breadboard Icd Serial Lead and Software Kit 900 34 99 135 Hunter Street Burton on Trent Staffs DE14 2ST Tel 01283 565435 Fax 546932 V LAGENTA http www magenta2000 co uk E mail sales magenta2000 co uk ELECTRONICS LTD All Prices include VAT Add 3 00 p amp p 6 99 next day OODOOOOOOOOOODOODOOO
23. ing a weak and ineffective dry joint The left hand joint in Fig 1 was pro duced using the transfer method It has actually produced a proper electrical connection but the lack of solder has given a physically weak joint To avoid a dry joint the tip of the soldering iron must be applied to the joint first and then some solder is fed onto the bit of the iron The solder should then flow over the surfaces to produce a strong joint and a good elec trical connection as the right hand joint of Fig 1 Everyday Practical Electronics September 2000 Modern components and solders make soldering much easier than it used to be but you may still encounter a leadout wire or integrat ed circuit pin that is clearly covered with a large amount of dirt or corro sion It is then a good idea to careful ly scrape away the contamination with the blade of a penknife or using wire wool rather than hoping that the flux will be able to deal with it Timeout The second common soldering problem is simply taking too long over each joint With experience you will be able to complete soldered joints very rapidly without having to give each one very much thought Initially things will inevitably be slower and hesitant but the bit of the iron must still be applied to each joint for no more than one or two seconds Some components are more heat resistant than others but even the more simple components such as resistors and capacitors
24. 16 or 32 bit Execution time is constant and so can be used where timing is critical I hope that some readers will make use of it I do like to see good programming techniques I got the idea from the way some processors execute a decimal adjust instruction in hard ware so did a bit of simple arithmetic and some lateral thinking The version I sent you is my generic one no real need for the subroutines unless they are called from elsewhere In the 16 bit version I expanded the two inner loops the resulting code is hardly any bigger executes faster uses only one loop counter and does not use the FSR Great for the smaller PICs Peter Hemsley via the Net To go back in time for a moment in my PIC Agoras bike computer April 97 and which I still use numerous calls to multiplication and division routines were required The PIC16x84 as used in that design does not have division or multiplication commands nor does the PIC16F87x family and I wrote special routines for these functions Being short of program space the binary to decimal conversion was performed by the same division routine Since then a modified library version has been used in all my PIC programs needing it for bin dec conversion to suit l c d readout I tried Peter s bin dec routine and was impressed it works beautifully Thank you Peter This is the listing BINDEC CALL CLRDIG MOVLW 24 MOVWF COUNTERI GOTO SHIFT1 MOVLW DIGIT1 MOVWE FSR MOVL
25. 305 1 86 Power 5 4 315 554 EI BS one Aen MA 1 71 BNC Coupler F 0 81 BNC quate y Crimper 5 68 MN Terminalar 0 78 Set Cable perm 038 ed Switches 15 25 2 90 E732 E4 76 R5232 Surge Protector 5 43 Mains Surge Protectar 11 99 15 50 While lz E EZ 16 an a yon Mini Din ES o Block amp te 20A IkV Dau i e Insulated Testers Patch Bo Boxes 10m 260 0 Ginen 7 20 Mini Taster 7 LEDs E4 72 Check Tester 18 LEDs 6 32 TII Practical AN Electronics Teach in 2000 Hardware Er Tools Normal 42 34 Teach in 2000 Componen Normal clog 103 Teach in 2000 C Normal 16 91 Electronics S Full drteik an Web sin 3mm White me mm Re 3mm Green Led dmm Yelow Led dmm Grange Led 3mm Blue 40med 3mm Blue amp med 3mm Blue 1 mcd Imm Blue 550med 5mm White 3OXmcd 5mm White 1100mcd Jmm Bi Colour 3mm Tri Colour 5mm Red L 5mm Green Led 5mm Yelow Led Dmm Grange Lad 5mm Blue 0mod 5mm Blue S med 5mm Blue 100mecd Smm Blue 450med Smm Blue 1000med 3mm Red Flashing 5mm Green Flashing 5mm Yallow Flashing 5mm Bi Colour Led 5mm Tri Colour L ment Di H reg C Caolhoda 0 56 Red C Anode 3 Red C amens MP 3mm IR Emitter 5mm IB Emitter 3mm Photo Transistor D 5mm Photo Transistor D Diode plo Coupler Se oupler 0 36 Opto Coupler 0 30 Iplo Coupler 0 94 IE Opto Coupler 0 85 37 Opto Coupler 0 Opto Coupler D Oplo Coupler 0 138 Q Coupler ED o SG SET GE ZZE lt
26. 30W 32 50W 38 100W 53 Mains Transformers Sec 220V 30mA 6V 1A 3 250V 60mA 6V 2A 5 250V 80mA 6V 2A 6 High Voltage Caps 50uF 350V 68uF 500V 150uF 385V 330uF 400V 470uF 385V all 3 ea 32 32uF 450V 5 Postage extra Record Decks and Spares BSR Garrard Goldring motors arms wheels headshells spindles etc Send or phone your want list for quote RADIO COMPONENT SPECIALISTS E _ 337 WHITEHORSE ROAD CROYDON RR SURREY CRO 2HS Tel 020 8684 1665 Lots of transformers high volt caps valves output transformers speakers in stock Phone or send your wants list for quote NOW AVAILABLE WITH Zses 128K AND 512K OZ4 ALSO SPECTRUM AND QL PARTS W N RICHARDSON amp CO PHONE FAX 01494 8713196 RAVENSMEAD CHALFONT ST PETER BUCKS SL9 ONB TIS Midlinbank Farm Ryeland Strathaven ML10 6RD Manuals on anything electronic Circuits VCR 8 CTV 6 Service Manuals from 10 Repair Manuals from 5 P amp P any order 2 50 Write or ring 01357 440280 for full details of our lending service and FREE quote for any data BTEC ELECTRONICS TECHNICIAN TRAINING GNVQ ADVANCED ENGINEERING ELECTRONIC PART TIME HND ELECTRONICS FULL TIME B Eng FOUNDATION FULL TIME Next course commences Monday 18th September 2000 FULL PROSPECTUS FROM LONDON ELECTRONICS COLLEGE Dept EPE 20 PENYWERN ROAD EARLS COURT LONDON SW5 9SU TEL 020 7373 8721 THE BRITISH AMATEUR ELEC
27. Byte grabber THRU box MIDI auto switcher Auto manual switcher Manual switcher MIDI patchbay MIDI controlled switcher MIDI lead tester Program change pedal Improved program change pedal Basic mixer Stereo mixer Electronic swell pedal Metronome Analogue echo unit 138 pages Order code PC116 9 95 705 Testing Theory Data amd Referemce SCROGGIE S FOUNDATIONS OF WIRELESS AND ELECTRONICS ELEVENTH EDITION S W Amos and Roger Amos Scroggie s Foundations is a classic text for anyone working with electronics who needs to know the art and craft of the subject It covers both the theory and practical aspects of a huge range of topics from valve and tube technology and the application of cathode ray tubes to radar to digital tape systems and optical recording techniques Since Foundations of Wireless was first published over 60 years ago it has helped many thousands of readers to become familiar with the principles of radio and electronics The original author Sowerby was succeeded by Scroggie in the 1940s whose name became synonymous with this classic primer for practitioners and students alike Stan Amos one of the fathers of modern electronics and the author of many well known books in the area took over the revision of this book in the 1980s and it is he with his son who have produced this latest version 400 pages Order code NE27 19 99 ELECTRONICS MADE SIMPLE lan Sinclair Assuming no prior knowledge
28. CHIR GENERATOR P6 80 Ban CAR ELECTRIC PROBE a 878 TONE BURST GENERATOR FB Bas SIGNAL INJECTOR 45 879 SOUND EFFECTS GENERATOR 103 B33 MOISTURE METER LED ps B8 LIGHT METER PHOTOGRAPHY CID Si B34 LEO TRANSISTOR TESTER MFN 45 B l LIGHT OSCILLAT R PHOTOGRAPHY 850 35 DIOOETESTER LED 45 B amp 2 LIGHTACTIVATED RELAY GEN BS LED TRANSISTOR TESTER PNP 45 883 DARK ACTNATED RELAY GEI AS 10555 TESTER L ED pna 864 SOUND SIREN LOUC AMPLIFIER 150 B38 0 19 MIN TIMER L ED amp SPEAKER 55 X12 AUDIO PROBE E05 B99 TOY THERAMIN MUSIC 680 X14 CHILD SPEAK LAMP PZ B4 AMPLIFIED AF PROBE METER 05 Zi SW GEN RECEIVER AREN SOLID STATE KITS P amp P 3 UK PE SEND FOR FREE de WORDWIDE P amp P 10 PAYMENT CHEQUES STERLING CATALOGUE READY BUILT KITS 5 EXTRA K1 VALVE RADIO POWER SUPPLY UNIT IDEAL PSU FOR MOST OF OUR VALVE KITS E20 00 K2 VALVE RADIO POWER SUPPLY UNIT SIMILAR TO K1 BUT OFFERS HIGHER VOLTAGE OUTPUT ON H T SIDE E2200 K3 TWO VALVER REGEN RADIO WORKS ON Mu OR SW INTERCHANGEABLE COILS KIT COMES WITH SPEAKER GOOD VOLUME 2500 K4 ONE VALVE AMPLIFIER USES THE ELA VALVE STILL MADE TODAY IDEAL SHACK AMPLIFIER GOOD STARTER KIT i i 12 00 K5 BATTERY ONE VALVER NOVICE KIT RUNS ON 38 VOLTS IDEAL EXPERIMENTAL VALVE PROJECT ALSO SOLID STATE UNIT INCORPORATED TO GIVE SPEAKER VOLUME 15 00 K ONE VALVE REGEM RADIO COMES WITH CRYSTAL EARPIECE MVW SW
29. DETAILS IN CATALOGUE VISIT OUR WEBSITE www suma designs co uk Please note Some of our part numbers are being unscrupulously used by other companies selling kits eg MTX VXT DO NOT BE MISLEAD These are NOT GENUINE SUMA KITS which are only available direct from us or our appointed distributors If you wish to collect kits direct from our office PLEASE TELEPHONE TEL FAX 01827 714476 24 HOUR ORDERLINE email sales suma designs co uk 703 ELECTRONICS TEACH IN No 7 FREE ANALOGUE AND DIGITAL SOFTWARE ELECTRONICS COURSE published by Everyday Practical Electronics Alan Winstanley and Keith Dye B Eng Tech AMIEE This highly acclaimed EPE Teach In series which includ ed the construction and use of the Mini Lab and Micro Lab test and development units has been put together in book form Additionally EPT Educational Software have devel oped a GCSE Electronics software program to compliment the course and a FREE DISK covering the first two parts of the course is included with the book An interesting and thorough tutorial series aimed specif ically at the novice or complete beginner in electronics The series is designed to support those undertaking either GCSE Electronics or GCE Advanced Levels and starts with fundamental principles If you are taking electronics or technology at school or college this book is for you If you just want to learn the basics of electronics or technology you must make sure you see it Teac
30. Electronics Made Simple presents an outline of modern electronics with an empha sis on understanding how systems work rather than on details of circuit diagrams and calculations It is ideal for students on a range of courses in electronics including GCSE C amp G and GNVQ and for students of other subjects who will be using electronic instruments and methods Contents waves and pulses passive components active components and ICs linear circuits block and circuit dia grams how radio works disc and tape recording elements of TV and radar digital signals gating and logic circuits counting and correcting microprocessors calculators and computers miscellaneous systems 199 pages large format Melia a M 12 99 TRANSISTOR DATA TABLES Hans G nther Steidle The tables in this book contain information about the pack age shape pin connections and basic electrical data for each of the many thousands of transistors listed The data includes maximum reverse voltage forward current and power dissipation current gain and forward trans admittance and resistance cut off frequency and details of applications A book of this size is of necessity restricted in its scope and the individual transistor types cannot therefore be described in the sort of detail that maybe found in some larger and considerably more expensive data books However the list of manufacturers addresses will make it easier for the prospective user to obtain f
31. MARILYN GOLDBERG Editorial Wimborne 01202 881749 Advertisement Manager PETER J MEW Frinton 01255 861161 Advertisement Copy Controller PETER SHERIDAN Wimborne 01202 882299 READERS ENQUIRIES E mail techdept 9 epemag wimborne co uk We are unable to offer any advice on the use purchase repair or modification of commercial equipment or the incorporation or modification of designs published in the magazine We regret that we cannot provide data or answer queries on articles or projects that are more than five years old Letters requiring a personal reply must be accompanied by a stamped self addressed envelope or a self addressed envelope and international reply coupons All reasonable precautions are taken to ensure that the advice and data given to readers is reliable We cannot however guarantee it and we cannot accept legal responsibility for it COMPONENT SUPPLIES We do not supply electronic components or kits for building the projects featured these can be supplied by advertisers see Shoptalk We advise readers to check that all parts are still available before commencing any project in a back dated issue ADVERTISEMENTS E mail adverts 9 epemag wimborne co uk Although the proprietors and staff of EVERYDAY PRACTICAL ELECTRONICS take reasonable precautions to protect the interests of readers by ensuring as far as practicable that advertisements are bona fide the maga zine and its Publishers cannot give
32. Q6 i CLK Fig 1 Complete circuit diagram for the Steeplechase Game Everyday Practical Electronics September 2000 The counter could be driven by a single 7555 timer integrated circuit 1 c but this circuit uses the 7556 dual timer instead shown as IC The counter is driven by the timer on the right of ICI call it Timer 2 From the values allotted to the compo nents R3 R4 VR2 and C2 we can cal culate that the clock runs at a frequency of between 7Hz and 14Hz depending on the setting of preset VR2 This allows the players to adjust the skill level of the game These frequencies are modified by the action of the other timer in ICI Timer 1 The values of R1 R2 VRI and C1 show that the frequency of this clock can range between 0 74Hz and 0 37Hz CONTROLLING TIME To understand how one timer can influ ence another we need to look more close ly at the connections In Fig 1 there is a connection between the positive plate of capacitor Cl and pin 11 of ICI Pin 11 is the control voltage CV input of Timer 2 In the more familiar single 7555 timer the control voltage input is at pin 5 and we normally ignore it Either we connect a low value capacitor between it and the 0V line or we simply leave it unconnected In this circuit it is doing something useful just for a change Vcc PIN 14 CONTROL VOLTAGE PIN 11 THRESHOLD PIN 12 COMPARATOR TO RESET TIMER Fig 2 Part of the internal cir
33. Ref 859 3 CONTACT MICRO SWITCHES operated with slightest touch Pack of 2 Order Ref 861 HIVAC NUMICATOR TUBE Hivac ref XN3 Order Ref 865 2IN ROUND LOUDSPEAKERS 5042 coil Pack of 2 Order Ref 908 5K POT standard size with DP switch good length in spindle pack of 2 Order Ref 11R24 13A PLUG fully legal with insulated legs pack of 3 Order Ref GR19 OPTO SWITCH on p c b size 2in x 1in pack of 2 Order Ref GR21 COMPONENT MOUNTING PANEL heavy Paxolin 10in x 2in 32 pairs of brass pillars for sol dering binding components Order Ref 7RC26 PEA LAMPS only 4mm but 14V at 0 04A wire ended pack of 4 Order Ref 7RC28 HIGH AMP THYRISTOR normal 2 contacts from top heavy threaded fixing underneath think amperage to be at least 25A pack of 2 Order Ref 7FC43 BRIDGE RECTIFIER ideal for 12V to 24V charg er at 5A pack of 2 Order Ref 1070 TEST PRODS FOR MULTIMETER with 4mm Sockets Good length very flexible lead Order Ref D86 LUMINOUS ROCKER SWITCH approximately 30mm square pack of 2 Order Ref D64 MES LAMP HOLDERS slide onto in tag pack of 10 Order Ref 1054 HALL EFFECT DEVICES mounted on small heatsink pack of 2 Order Ref 1022 12V POLARISED RELAY 2 changeover contacts Order Ref 1032 PROJECT CASE 95mm x 66mm x 23mm with removable lid held by 4 screws pack of 2 Order Ref 876 LARGE MICRO SWITCHES 20mm x 6mm x 10mm changeover contacts pack of 2 Order Ref 8
34. SE uno FP 55 pH Sall bt S A et E Cr Cre n 0 D Os C de Es Es es Q Cou piar en gae Pal Ur dra mme pr UL B D m D T m Th I Be e Lobo 00901 5588 jon SS De Opts trace LDR z gaf ni ORFI KJ 0 EI e TOSOTEOBO on Sr EG SE Pi gt S La SO e Ex Lh D M L Ad La Lo La La E La tala Da Da Pu Da Es ee ALS br is OG A O SS 22 22 Pack Pack Price 33 87 Pack Price 16 82 Pack f rice 14 13 Full details on our Web site A variable s DIY hobby OVA an cooled molar ed high torque tool for all those small electronic jobs 8 Unique DIN size body 21000 rpm 230V CS all standard drill stands amp atachman on the markei lied wilh o 3 2mm also stocke keyless chuck Full range of Minicraft Drills amp Accessories 0 4 3 2mm 2 A Aa Model MX Order Code 270 390 List price 59 99 inc Technical books amp CD ROMs Data Table amp Equivalent charts from ECA Characterislics pin owls Pelt hd cl A amp selector fables for semiconductors are availab books or on Sha le as Demo version D ROM CD ROMs amp full details of the completa range ore available from our web sito Full details o wide Order in UK European or World rmation a oor web site RATING ELECTRONICS TODAY INTERNATIONAL Editorial Offices EVERYDAY PRACTICAL ELECTRONICS EDITORIAL ALLEN HOUSE EAST BO
35. Sw Enamelled SET 5A 110V DPDT 12V 0 93 Jy ONG r Wire 5A 240V DPDT ey E1 76 Per 509 202 54 240V DPDT 17W 1 75 raals avaliable IOA 240V SPDT V 1 25 300g reels aval 0 97 10A 240V SPDT 12V 1 44 14 Swe Tinned t0 97 104 2407 SPOT 24V 1 44 18 SWG Tinned e097 Computer Accessories 20 SWG Tinned 1 01 Adaptors 22 SWG Tinned 1 01 pf AEs DA SW Tinned 1 03 p T 26 SWG Tinned El v b 24 SWG Tinned a 1 03 qul Black Brown Red Orange SM Gender Changer r2 13 Yellow Green Blue pum CP 9F Gender nger 2 79 Grey amp Whita Par 25M Gender Changer 2 20 solid 0 6 2 6 25F Gender Changer 2 80 Stranded oa Zmm 2 44 9 Mala 25 Female 1 90 Flex Cable emale ale ack Br m ed Yellow 9 F l l 1 90 Bl ED um den 9M 6 Mini Din Male 2 40 Green 9F 6 Mini Din Female 2 40 25m nhanc 25D lumpar Box M F 25D Patch Box M F Anti Static Wrist Strap 4 Ga vg Surg lock m Printer Laad RD Printer eon B Printer SE Printer L E 12B4 Ee L IEEET7B4 Printer L 10m Vo 1284 Bae ETA Serial Printer 25M SN Printe Printer 2 22M 3 SF 4 amp 9 Female oF Dec ta EA 25 Female 75 Female C A 1 5 2m TO ED 2m 2m 9 Female Female 4 38 DROE lo 9 amp 275F EA BB Modem Leads 25M ale to Female 4 DB ais lo ea Leg E3 7B Interlink 25M to 25M 3 88 Patch Lead 25Miale to 75Male 3 40 Male te GER E2860 Fla SCH AB KO Hard Disk 51 65 oke Se j KR 1 88 Power 55 2 x D 1 50 Power 54 2 x
36. T Thurlow 5 Danesbury Lane Welwyn Herts AL6 9SG Phone 0143 871 4357 FREE PROTOTYPE PRINTED CIRCUIT BOARDS Free prototype p c b with quantity orders Call Patrick on 028 9073 8897 for details Agar Circuits Unit 5 East Belfast Enterprise Park 308 Albertbridge Road Belfast BT5 4GX DETECT ATMOSPHERIC ACTIVITY Unique Designs Self addressed envelope PO Box 694 Saint Helier JE4 9PZ Jersey CI EPE FTP site ftp ftp epemag wimborne co uk Access the FTP site by typing the above into your web browser or by setting up an FTP session using appropriate FTP software then go into quoted sub directories PIC project source code files pub PICS PIC projects each have their own folder navigate to the correct folder and open it then fetch all the files contained within Do not try to download the folder itself EPE text files pub docs Basic Soldering Guide solder txt EPE TENS Unit user advice tens doc and tens txt Ingenuity Unlimited submission guidance ing unlt txt New readers and subscribers info epe info txt Newsgroups or Usenet users advice usenet txt Ni Cad discussion nicadfaq zip and nicad2 zip Writing for EPE advice write4us txt On line readers Try the EPE Chat Zone a virtu ally real time Internet discussion board in a simple to use web based forum Ensure you set your FTP soft ware to ASCII transfer when fetching text files or they may be unreadable Note that any file which ends in zip nee
37. Timer 1 This is a sawtooth waveform frequency around 0 6Hz ramping up from one third of the 6V supply 2V to two thirds of the supply 4V as the capacitor charges and falling sharply back to one third of the supply in each cycle as the capacitor is discharged This is a good example of frequency modulation The counter is being driven by a square wave oscillator at around 10Hz which is frequency modulated by a 0 6Hz sawtooth The depth of modulation is fairly high producing a noticeable effect on the frequency applied to the counter In terms of the horse its rate of approach to the fence is tantalizingly erratic It is not actually unpredictable but a player needs to get the feel of the timing to be success ful in jumping the fence JUMP CIRCUIT The clear jump l e d D8 is switched by transistor TR1 which is fed from the output of a set reset flip flop This is built from two NAND gates ICAb and IC4c and is triggered by a low input pulse at pin 9 supplied by NAND gate IC4a It is reset by a low pulse to the other input pin 6 produced by pressing Reset switch S2 The flip flop can be set only if both inputs of IC4a are high at exactly the same time one supplied by counter IC2 from output Q6 the other generated by the player through IC3b With the clock run ning at say 10Hz each output of IC2 is high for 0 05s The player has to produce a trigger pulse to occur within that period when only output Q6 is h
38. Written by leading electronics experts the collected wisdom of the electronics world is at your fingertips The simple and attractive Circuits Environment is designed to allow you to find the circuit or advice notes of your choice quickly and easily using the search facility The text is written by leading experts as if they were explaining the points to you face to face Over 1 000 circuit diagrams are presented in a standardised form and you are given the option to analyse them by clicking on the Action icon The circuit groups covered are Amplifiers Oscillators Power Sensing Signal Processing Filters Measurement Timing Logic Circuits Telecommunications The analysis tool chosen is SpiceAge for Windows a powerful and intuitive application a simple version of which automatically bursts into action when selected Newnes Interactive Electronic Circuits allows you to analyse circuits using top simulation program SpiceAge test your design skills on a selection of problem circuits clip comments to any page and define bookmarks modify component values within the circuits call up and display useful formulae which remain on screen look up over 100 electronic terms in the glosary print and export netlists System Requirements PC running Windows 3 x 95 or NT on a 386 or better processor 4MB RAM 8MB disk space CD ROM 49 95 Audio ama Music An Unconventional Guide to AN INTRODUCTION TO LOUDSPEAKERS AND ENCLOSURE DESIGN
39. a UK bank or pay by credit card to Everyday Practical Electronics Allen House East Borough Wimborne Em m ARI 5 Send your card number and card expiry date plus cardholder s address Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 E mail editorial epemag wimborne co uk Web site http www epemag wimborne co uk We also accept credit card payments Mastercard Access or Visa minimum credit card order VISA Everyday Practical Electronics September 2000 A roundup of the latest Everyday electronics CAN E MAILS CARRY VIRUSES Following on from recent headline hitting virus attacks Barry Fox asks an all important question OW that most people and companies except some PR folk are waking up to the risks of sending binary files as E mail attachments the question most com monly asked is can a virus hide inside an E mail sent as plain ASCII text or in the rich text format that wordprocessors like Word provide as a save option Graham Cluley of anti virus company Sophos has tried to clear the air for us At the same time he makes positive sugges tions and warnings Text and RTF Safe Plain ASCII text is 100 per cent safe but if someone sends an HTML Web page written in plain text and the PC uses an Internet Browser to view it this could let Active X the Microsoft system which allows programs to run inside Web pages release a hidden virus This can happen if the file is delibe
40. and IC1d The oscillator provides pulses to the 14 stage binary counter divider IC2 used here effec tively as a divide by 16 384 214 counter Having reached that figure the counter resets both the latch and itself The latch and hence the timer can be manually reset by switch S2 Connection to the radio is achieved by a 3 5mm stereo socket SK1 The collar or sleeve A is connected to the uninterrupted positive supply The switched ring B interrupts the negative supply to the radio when the plug PL1 is inserted power to the radio is restored when TR1 s drain goes low Negative power is supplied to the timer via the tip of the stereo plug C The circuit TH1 BUZ71A Fig 3 Circuit diagram for the Radio Sleep Timer is switched on by plugging it into the radio obviating the need for an on off switch The period of timing is set by capacitor C3 and resistor R5 Values of 470nF and 5602 give about an hour delay A rotary switch could be used on IC2 s unused outputs to select variable timing lengths and the addi tion of another 4001 NOR gate could give touch control and a more reliable ring of three astable Driver transistor TR1 could be replaced by a junction transistor and relay or could trig ger other logic circuitry If switching any thing other than a low power battery radio sturdier connections between the circuit and radio will be needed Andrew Fisher Hitchin Herts ES B1 ev
41. and the other to the solid centre core lead of the coax cable running to pin 2 of the rotary switch section Sla Provision is not made for this component on the p c b Commence construction by mounting the smallest components first and solder the semiconductors into circuit last The use of tweezers or a crocodile clip as a heat shunt is a wise precaution when sol dering the f e t s Solder pins inserted into the board beneath the specified MOSFET leads will permit TRI to be mounted on the component side of the board Pins inserted at the p c b lead off points will ease the task of interwiring TO OUTPUT SOCKET VIA S1a 2 Vum SOA NL OUTPUT LEVEL TO EARTH SOCKET SK3 Fig 2 Printed circuit board topside component layout off board wiring and full size copper foil underside master Note capacitor C8 is mounted directly on one outer tag of VR6 and soldered to the centre core of the output screened lead Everyday Practical Electronics September 2000 TO COAXIAL OUTPUT SOCKET TO GROUND TO VR6 TO BATTERY B1 VE TO GROUND 0V RAIL 9V TO P C B TO SOCKETS HU FOR WIRE WOU AERIALS SK1 AND SK2 Fig 3 Wiring to the on off and aerial selector switch Pole letters and tag numbers match specified switch Use screened cable ordinary audio type cable will suffice for this purpose between the wire aerial input sockets the rotary switch 4 and the loop output socket Connect the metal cases of the potentio
42. and works In no event shall Maxfield amp Montrose Interactive Inc or Wimborne Publishing Ltd be responsible or liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or any other damages in connection with or arising out of furnishing performance or use of these materials and works Copyright 2000 Wimborne Publishing Ltd and Maxfield amp Montrose Interactive Inc ISSN 0262 3617 PROJECTS THEORY NEWS COMMENTS POPULAR FEATURES VOL 29 No 9 SEPTEMBER 2000 Cover illustration by Jonathan Robertson II TIILIl I NOTE NEW PUBLISHING DATE See Editorial page 651 for full details Wimborne Publishing Ltd 2000 Copyright in all drawings photographs and articles published in EVERYDAY PRACTICAL ELECTRONICS is fully pro tected and reproduction or imitations in whole or in part are expressly forbidden Our October 2000 issue will be published on Thursday 7 September 2000 See page 643 for details Everyday Practical Electronics September 2000 PRACTICALI AE NIC ELECTRONICS TODAY INTERNATIONAL http www epemag wimborne co uk Projects and Circuits STEEPLECHASE GAME by Owen Bishop 652 Another Top Tenner design how well can your horse jump the fences ACTIVE FERRITE LOOP AERIAL by Raymond Haigh 672 Superbly designed vertically and horizontally rotating reception optimiser INGENUITY UN
43. at nearly 3A price 25 Order Ref 25PG8 1 5 6V MOTOR WITH GEAR BOX Motor is mounted on the gearbox which has inter changeable gears giving a range of speeds and motor torques Comes with full instructions for changing gears and calculating speeds 7 Order Ref 7P26 TERMS Send cash PO cheque or quote credit card number orders under 25 add 3 50 service charge J amp N FACTORS Pilgrim Works Dept E E Stairbridge Lane Bolney Sussex RH17 5PA Telephone 01444 881965 685 Regular Clinic CIRCUIT SURGERY p A ALAN WINSTANLEY IS and IAN BELL Our surgeons round up a variety of readers queries and examine choices for rechargeable batteries including the latest Rechargeable Alkaline Manganese RAM and Nickel Metal Hydride cells Common ground I m a beginner in electronics and have an idea for a project using a microcon troller to interface with some components including some pumps I ve made a start by purchasing a PIC Programmer and assembler I need to know how to inte grate a PIC into a circuit which will be powered by a 12V rail and also how to switch a 12V pump from the PIC I O Ports I would like to know how to bring a 12V supply down to SV to power the microcontroller and also how to switch on a 12V device from a 5V output Thanks David Nash by E mail All you need is an ordinary three termi nal 5V regulator such as the 7805 to reduce the 12V rail to
44. be higher or lower than 10mA in some Zener diodes consult their data sheets for the recommended minimum current flow Note that some Zener diodes are specifically manufactured to have a very low minimum current requirement OTHER VALUES To establish the same value results with out using the demo program all the calcu lations can be done in simple stages using your knowledge of resistors in series Part 1 and Ohm s Law Part 3 tracing the steps we have just described Finding out likely minimum and maxi mum load currents is less straightforward One way is to calcu late them not always easy as we have said on previous occa sions Another is to first power the circuit from a variable power supply set to the required reference Zener voltage and to measure the currents However it is not likely that you will nor mally need to use Zeners in circuits that draw particularly high currents or currents that fluctuate signifi cantly There are better components voltage regulators to use in such circumstances Zeners are more likely to be used to set a fixed reference voltage to a low power circuit rather than to control high power The following section offers a midway option AMPLIFIED ZENER CURRENT From much of the foregoing it will be obvious that using a Zener is not necessar ily too easy when the characteristics of the load circuit may not be fully known for any instant of time The choic
45. breakdown voltage can be used as a reference voltage As such a Zener diode can be used to restrict power supply volt ages to a known maximum level As an aside the term Zener really only applies to certain reference diodes which exhibit the so called Zener effect beyond our scope to define this here It has 662 SENER DIODE ZENER DIODE d 1 F Ri BALLAGT _e lt 4 7 W nz LEUR Photo 11 1 Interactive demo screen which illustrates volt age control using a Zener diode Reverse current flow through the Zener D1 and to the load circuit represented by R2 is normally limited by a ballast resistor R1 in series between them and the power supply Vin The ballast resis tor is not included in the Zener package but needs to be connected as a separate item and having a value which depends on three factors The first factor depends entirely on the load circuit R2 as we have discussed in previous parts The other two factors are normal ly quoted in the Zener diode s data sheet but also see later ZENER DIODE CHARACTERISTICS Unlike ordinary diodes Zener diodes are used in a circuit with their cathodes k facing the most positive voltage so that they only conduct when the supply voltage is above their stated refer ence value Zener diodes are commonly available having reference values from 2 4V to 75V although for specialist applications diodes exist which provide much h
46. cost effective Connection to a PC gives these virtual instruments the edge over traditional oscilloscopes the ability to print and save waveforms is just one example Units are supplied with PicoScope for Windows which is powerful yet simple to use with comprehensive on line help Applications pac Features Y Video So W A fraction of the cost of comparable benchtop scopes Y Automotive ADE op n Y Oscilloscope and data logging software supplied Y Audio lino Prices from 69 excl VAT Y Electronics design Y Up to 100 MS s sampling 50 MHz spectrum analyser Y Fault finding Se a Y Education y o Tel 01480 396395 Fax 01480 396296 E mail icotech com Web www drdaq com T E L 8 CAVANS WAY BINLEY INDUSTRIAL ESTATE COVENTRY CV3 2SF Tel 01203 650702 Fax 01203 650773 Mobile 0860 400683 Premises situated close to Eastern by pass in Coventry with easy access to M1 M6 M40 M45 and M69 ELNE OSCILLOSCOPES Beckman 9020 20MHz Dual Chalco A RS RRRSRRRRSRRRRSRRRRRR 150 Gould OS ret s from 125 Hewlett Packard 180A 180C 181A 182C eee rernrnnnnnn from 150 Hewlett Packard 1740A 1741A 1744A 100MHz Dual Channel erreur from 300 Hewlett Packard 54100D 1 GHz DigitiZiN Doc 00nn 1250 Hewlett Packard 54200A 50 MHz Digitizing rre 500 Hewlett Packard 54201A 300MHz Digitizing eorr error rrr
47. cost we cannot reply to overseas orders or queries by Fax E mail dbs epemag wimborne co uk 690 VT401 61 minutes A M Radio Theory The most complete video ever produced on a m radio Begins with the basics of a m trans mission and proceeds to the five major stages of a m reception Learn how the signal is detected converted and reproduced Also covers the Motorola C QUAM a m stereo system Order Code VT401 VT402 58 minutes F M Radio Part 1 FM basics including the functional blocks of a receiver Plus r f amplifier mixer oscillator i f amplifier limiter and f m decoder stages of a typical f m receiver Order Code VT402 VT403 58 minutes F M Radio Part 2 A con tinuation of f m technology from Part 1 Begins with the detector stage output pro ceeds to the 19kHz amplifier frequency dou bler stereo demultiplexer and audio amplifier stages Also covers RDS diaital data encoding and decoding Order Code VT403 MISCELLANEOUS VT501 58 minutes Fibre Optics From the fundamentals of fibre optic technology through cable manufacture to connectors transmitters and receivers Order Code VT501 VT502 57 minutes Laser Technology A basic introduction covering some of the common uses of laser devices plus the operation of the Ruby Rod laser HeNe laser CO gas laser and semiconductor laser devices Also covers the basics of CD and bar code scanning Order Code VT502 Each video uses a mixture of animate
48. e Alan Dower Blumlein e Circuit Surgery e Interface e PhizzyB Computers 8 e Ingenuity Unlimited e Edison 3 Review e Net Work The Internet JULY 99 PROJECTS e12V Lead acid Battery Tester e L E D Stroboscope e EPE Mood Picker e Intruder Deterrent FEATURES e Practical Oscillator Designs 1 e Practically Speaking Circuit Surgery Ingenuity Unlimited e New Technology Update e Net Work The Internet e Tee EE D tx pem eer I OD Dg Po ees PROJECTS e Ultrasonic Puncture Finder e Magnetic Field Detective e Freezer Alarm e 8 Channel Analogue Data Logger 1 e Sound Activated Switch FEATURES e Practical Oscillator Designs 2 e Power Generation from Pipelines to Pylons 1 e Ingenuity Unlimited Circuit Surgery e Interface e Net Work The Internet SEPT SES PROJECTS e Loop Aerial SW Receiver e Child Guard e 8 Channel Analogue Data Logger 2 e Variable Dual Power Supply FEATURES e Practical Oscillator Designs 3 e Power Generation from Pipelines to Pylons 2 e Practically Speaking e Circuit Surgery e Ingenuity Unlimited e New Technology Update e Net Work OCT 99 PROJECTS e Interior Lamp Delay Mains Cable Detector e QWL Loudspeaker System e Micro Power Supply FEATURES e PIC16F87x Mini Tutorial e Practical Oscillator Designs 4 e Circuit Surgery Interface e Ingenuity Unlimited e Net Work The Internet NOV 99 PROJECTS e Acoustic Probe e Vibralarm e Ginormous Stopwatch 1 e Demister One
49. e e e Oe O e O e O e OO eo O OO e O OO OO O e oO e e e oO OO 0 0 L e O OO e O O e O e O e O O O OO O O e O O OO OO e O e O Oe O OO OO K LO O OO O Oe e O e e 00000000000 OO O OO e O e e e o OO 00 J O O O O O O O e O e O O e O O O O O O O O O O O e O e O e e O O O e O 0 HL O OO OO e O e O e O OO e e oO O O e O O O e O O O O O O O O O O O O O OJ G OO e e OO O e O ee e o e Oo OO OO OO e e OO OO O OO OO 6 O O O F Oe OO O 6 OO O Oe O O O O O O O O O O O O O O O O O O O e O O O O O e EI 0000000000e600000000000e090 90 O0 O e O0 OO O O O O O D O O O OO 6 O OO O O O O O O O O O O O O e O O O O O O O O O O O 6 O O O CL ooO0O00000000000000000000000000000000002090 0 BL OOOOOOO0O0O0O000000000000000000000000000070 5070 AL O O O O O 6 O O O O O O O O 6 O O O O O O O O 6 O O O O 6 O O O 6 O O O ofofo ofofo O O 006060000000000900000000000860 LOO O O O O O Ke RK O O O O Ee RK O O O O O O O O O O O 6 O O OO O e O A B C D E F G H J K L M N O P Q R S T U V W X Y Z AA BB CC DD Ogogogogogogogogogegogogogogo O O O o O O e o O O O O ogogogegogegogo egogogogogogogogo O opofopofopoO opopopo O O O gt WUOUMTATQICATZZOUTODOACS lt SX lt N gt UOU 2 A WE 5888 Fig 3 Steeplechase Game stripboard component layout and details of breaks required in the underside copper tracks Note the wire links under t
50. end The device is then fitted the right way around If the component seems very reluc tant to move you are probably lever ing the socket away from the board rather than the chip from its holder Look carefully at what you are doing when using low profile holders A popular way of damaging inte grated circuits is to pull them from their holders using your fingers If you do manage to pull the devices free it is virtually certain that one end will pull clear of the holder well ahead of the other end This produces a lot of severely bent pins The pins can usually be prised back into position with the aid of a screwdriver blade but there is a real risk of one or more pins breaking off There is also a strong possibility that as the chip comes free from the hold er it will bury some of its pins into your finger Desoldering equipment is needed to remove an integrated circuit that is soldered direct to the circuit board Everyday Practical Electronics September 2000 Even with the right equipment it can be difficult to remove multi pin com ponents There is a real risk of dam aging the component but of more importance the circuit board can also come to grief Testing Time When your latest masterpiece is finished it is tempting to immediately switch on and see if it works It is also a popular mistake that will probably not have dire consequences but costly damage cannot be ruled out It is a good idea to spend at lea
51. into circuit Low current Led D2 with its dropping resistor R7 forms an economical on off indicator TR2 VR1 47k FINE TUNING 47k 100n Fig 1 Complete circuit diagram for the Active Ferrite Loop Aerial VARICAPS Varicap diodes intended for M W tuning are widely retailed Although the minimum capacitance of these devices is higher than that of their mechanical counterparts they have a big enough maximum capacitance to ensure the required coverage Varicaps exhibit a tuning rate which reduces as frequency increases and this makes loop adjustment easier Moreover the provision of vernier or fine tuning involves no more than an additional poten tiometer They are also relatively inexpen sive Quite apart from the question of availability therefore electronic tuning has much to recommend it These semiconductor devices have a lower Q than a mechanical capacitor par ticularly at low bias settings when the capacitance is close to maximum However the inclusion of Q multiplying TUNING The loop s main winding L1 is tuned by varicap diode D1 which is connected to it via d c blocking capacitor C1 Tuning bias is applied through signal isolating resistor Potentiometer VR adjusts the bias volt age and acts as the Coarse or main tuning control Fine tuning is provided by VR2 which produces a much smaller voltage change Preset potentiometer VR3 sets the minimum bias voltage fixing the maxi mum c
52. is drawn from them than they are designed for they start to overheat their internal circuitry senses this and they shut down Once they have cooled suffi ciently they start to function again Typical fixed voltage regulators you will come across are for example the types 78L05 and 7805 The 78 prefix indicates that they are positive voltage regulators The final two digits 05 in this case then indicate that they regulate the output volt age at 5V The 7805 is designed to supply current up to 1A some manufacturers allow 1 5A for their 7805 The 78L05 can output up to 100mA Negative voltage regulators are also available typically prefixed 79 as opposed to 78 as with the 79L05 and 7905 These are the negative equivalents of the 78L05 and 7805 both supplying 5V again at 100mA and 1A respectively A list of 78 79 series regulators is shown in the centre of Photo 11 2 Pinouts for the devices are shown in Fig 11 2 TAB IDENTITY a TOP VIEW 3 2 1 SIDE VIEW TAB 12 3 TOP VIEW PIN VIEW me m Te em T 1 INPUT COMMON 1 INPUT OUTPUT 2 COMMON INPUT 2 COMMON INPUT 3 OUTPUT OUTPUT 3 OUTPUT COMMON Fig 11 2 Pinouts for the 78 79 series of voltage regulators CA 12 3 These particular devices require that the input voltage is about 2V greater than the output voltage required The maximum input voltage is about 35V see data sheets or suppliers catalogues Note though that
53. it you then need Adobe Acrobat Reader which can be downloaded free from www adobe com Alan Winstanley PIC F84 OR C84 Dear EPE Keep up the wonderful work especially with PICs Could you tell me if the code for the Multi channel Transmission System May June 00 will fit work on a PIC16C84 rather than the rec ommended PIC16F84 as I have a tube of 16C84s Gareth Evans via the Net In this instance the code will function just as well on either device As a reminder to you all code written for a PICI6C84 will always work on a PICI6F84 In many cases the reverse is also true but not always The F84 has more registers and EEP ROM capacity than the C84 which some authors including myself have sometimes taken advantage of In such instances only the F64 is suitable Gareth was quite right to check with us KIND THANKS Dear EPE Thank you for the prompt response and the accurate diagnosis of the cure for Error Number 76 when running P C Toolkit Mk2 I have now created the C ASMCNV directory and my Toolkit Mk2 is assembling and disassembling code just fine I have been collecting EPE since June 1996 and would like to make use of this opportunity to thank you all for the many informative articles which you publish at regular intervals The recent Technology Timelines series was great A special word of thanks for the free software that you give away for your PIC and other pro jects as well Some of your competit
54. light delay 2 07 1118 Time switch with triac 0 10 mins 4 14 1122 Telephone call relay 3 68 1123 Morse code generator 1 84 1126 Microphone preamplifier 4 60 1127 Microphone tone control 4 60 1128a Power flasher 12V d c 2 53 1133 Stereo sound to light 5 26 BUY ONE GET ONE FREE ULTRASONIC MOVEMENT DETECTOR Nicely cased free standing has internal alarm which can be silenced Also has connections for external speaker or light Price 10 Order Ref 10P154 CASED POWER SUPPLIES which with a few small extra components and a bit of modifying would give 12V at 10A Originally 9 50 each now 2 for 9 50 Order Ref 9 5P4 3 OCTAVE KEYBOARDS with piano size keys brand new previous price 9 50 now 2 for the price of one Order Ref 9 5P5 TOROIDAL MAINS TRANSFORMERS All with 220V 240V primary winding 24V 24V at 25VA would give 25V at 1A or 50V at 72A price 3 Order Ref 3P245 0 7V 40VA has a main winding 7V at 5A and a secondary winding 12V at 1A price 3 Order Ref 3P238 35V at 80VA price 5 0 110V 0 110V at 120VA would give you 110V at just over 1A or 220V at A price 8 Order Ref 8PG3 0 35V 0 35V at 150VA would give 35V at 4A or 70V at 2A price 8 Order Ref 8PG9 0 35V 0 35V at 220VA would give 35V at 672A or 70V at 314A price 10 Order Ref 10PG4 0 110V 0 110V at 220V would give 110V at 2A or 220V at 1A price 12 Order Ref 12PG5 0 110V 0 110V at 500VA would give 110V at 5A or 220V
55. pulse generation e Full kit with headphones amp all hardware KIT 847 PORTABLE ULTRASONIC PEsT SCARER A powerful 23kHz ultrasound generator in a compact hand held case MOSFET output drives a special sealed transducer with intense pulses via a special tuned transformer Sweeping frequency output is designed to give maximum output without any special setting up dg 22 56 I CEBREAKER OOOO0O00o0000 PIC REAL TIME IN CIRCUIT EMULATOR SEE PAGE 669 DC Motor Gearboxes Our Popular and Versatile DC motor Gearbox sets Ideal for Models Robots Buggies etc 1 5V to 4 5V Multi ratio gearbox gives wide range of speeds LARGE TYPE MGL 6 95 SMALL MGS 4 77 Stepping Motors MD38 Mini 48 step 8 65 MD35 Std 48 step 9 99 MD200 200 step 12 99 MD24 Large 200 step 22 95 MOSFET MkII VARIABLE BENCH POWER SUPPLY 0 25V 2 5A Based on our Mk1 design and preserving all the features but now with switchin pre regulator for much higher effi ciency Panel meters indicate Volts and Amps Fully variable down to zero Toroidal mains transformer Kit includes punched and printed case and all parts As featured in April 1994 EPE An essential piece of equipment 648 PIC PIPE DESCALER e SIMPLE TO BUILD e SWEPT e HIGH POWER OUTPUT FREQUENCY e AUDIO amp VISUAL MONITORING An affordable circuit which sweeps the incoming water supply with variable frequency electromagn
56. rods can then be attached with rubber bands to a cross arm fixed by a central screw close to the top of the post and again free to rotate The coil leads are taken through a hole in the top of the case Although extremely basic this arrange ment works quite well especially if a few washers are used to make the pivots turn smoothly Prototype System A more complicated mounting and the one adopted by the author is shown in Fig 6 and the photographs Built up from ply and wood blocks the internal angles are rounded with car body filler and the unit is finished with spray can paints The rods are enclosed in a pivoted box and tilt is controlled by a cord drive A spring keeps the cord under constant tension The plastic spindle which drives the cord is extended a little beyond the body of the unit in order to minimise hand capacity effects This problem is experi enced with all loops when critical null adjustments are being made A 6mm stereo phone jack plug and socket form the vertical pivot and connects the aerial loop leads to the p c b Coil connections 1 and 3 go to the jack shank 2 is wired to the tip and 4 to the jack s centre band This arrangement min imises stray capacitance OPERATING THE LOOP Communications receivers and indeed any Medium Wave receiver with aerial and earth sockets can be used with the loop Salvaged car radios often perform extremely well Connection between the Active Ferr
57. say a value of 1092 just enough to reduce the switch on current flow through the transistor but not so high as to significantly restrict current being supplied to the load ZENER AND OP AMP BUFFER A similar current buffering technique can be achieved using any normal op amp such as the LM358 or a type 741 a single op amp as opposed to a dual In Fig 11 1 the circuit is arranged so that the Zener regulated voltage is fed into the non inverting input of the op amp which is connected in unity gain buffer mode dis cussed in Part 7 The op amp thus outputs the same volt age as provided by the Zener but with Fig 11 1 Zener and op amp reference voltage buffer 663 much greater current available although usually less than can be provided via a tran sistor There is also the security of knowing that the op amp is unlikely to die if too much current is drawn from it unlike the transistor VOLTAGE REGULATORS For situations where voltage regulation is required for the supply that powers one or more circuits rather than just a sub cir cuit then a voltage regulator should used These are devices that contain circuitry which very accurately regulates their out put voltage at a fixed level below the sup ply voltage being input to it Various types offer output currents typically from about 100mA up to several amps Furthermore within quite broad limits many types are practically indestructible If more power
58. second one IC4 gives out a high level if the input is lower than the negative reference voltage The outputs of the comparators are connected to the R and S pins of the flip flop IC5 which is a type 4013 Its Q output pin forms the output sync ter minal of the circuit Fig 5 shows how a dual comparator can be used instead The operation of the circuit can be explored by simulating it with MicroCAP or similar packages Fig 6 shows the waveforms generated in such a simulation One can see that the device works properly even if the amplitude of the input signal alters To prove that it works properly when the phases of harmonics alter the frequencies were specially selected to be not exactly 2f or 3f where f is the frequency of the Ist har monic The values of the peak amplitude detector capacitors C1 C2 shown in Fig 4 are chosen to provide the lowest working fre quency equal to 200Hz This frequency also determines how much of the input signal har monics can be frequency shifted from their values of 2f 3f etc Since this frequency shift is comparable to the lowest working frequency a switchable capacitor is recommended For example 0 1C 0 33C 1C 3C could be used to increase the frequency range and to adjust the device for a certain signal if the frequencies of the harmonics are not exact multiples of the frequency Without switching the capacitors the work ing range is 200Hz to 20kHz when the ampli tude of 2nd and 3
59. selecting the waveform responses required for real life circuit designing DIFFERENTIATION In integration as we have just been discussing the waveform voltage current flows between its source and the capacitor via a resistor You have though been using several circuits over the last few Teach In parts in which the waveform voltage is applied first to a capacitor and then to a resistor Such a circuit is known as a differ entiator and its action is called differentia tion It behaves very differently to an integrator Run menu option Capacitors Differentiation and also see Photo 11 6 At the bottom right will be seen a circuit representation of a differentiator using the same terminology as before You will also see the output waveform created by an input square wave with R C and F shown at the top right It is certainly not a square wave In fact we are not sure it actually has a name but it s the sort of shape that can be produced if too low a CR value is chosen in respect of a square wave input frequency Increase the screen CR value by using the control options available same as before and see how the output waveform shape improves Decrease the CR value and observe how spiky the waveform becomes see Photo 11 7 This all confirms what we have said implied in previous parts that wave form shapes when fed through capacitively 666 Vout DIFFERENTIATE ADC IC2 PIN 2 Fig 11 5 Circuit diagram for the di
60. self contained kits Units from Programmable Logic Controllers to Engineering Computing DON T DELAY we are waiting to hear from you Contact Laura Murdoch Open Learning Co ordinator Tel 01698 283100 Ext 214 E mail Web l murdoch bell ac uk http floti bell ac uk openlearning Member of the British Association for Open Learning Preview Centre for FT Knowledge STRATHCLYDE Bell College of Technology app re is a registered charity No Sc 021179 providing quality Higher Education and Kamp PABRTIERSHIP Training opportunities for all European Social Fund GB INVESTOR IN PEOPLE SPECIAL OFFERS TEKTRONIX 244SA 4 channel 150MHz delay sweep cursors readout Ed TEKTRONIX 475 Dual trace 200MHz delay sweep AVO 8 MK 6 MULTI METER In Ever Ready Case with Leads and Batteries Other AVOs from RACAL TRUE RMS VOLTMETERS 9300 5Hz 20MHz usable to 60MHz 10V 316V 95 9300B Version 150 9301 9302 RF Version to 1 5GHz from 200 300 RACAL AIM 9343M LCR Databridge Digital Auto measurements of R C L Q D 200 HUNTRON TRACKER Model 1000 H P 5315A Universal Counter 1GHz 2 ch FLUKE 8050A DMM 4 digit 2A True RMS 75 FLUKE 8010A DMM 3 digit 10A 5 GOODWILL GFC 8010G FREQUENCY COUNTER Range 1Hz 120MHz 8 Digit Display 15mV RMS Sensitivity Unused 75 GOODWILL GVT427 DUAL CHANNEL A C MILLIVOLTMETER 10mV 300V in 12 ranges Frequency 10Hz
61. self taught amateur who is interested in electronic fault finding but finds books on the subject too mathematical or specialized The book covers Basics Voltage current and resistance Capacitance inductance and impedance Diodes and tran sistors Op amps and negative feedback Fault finding Analogue fault finding Digital fault finding Memory Binary and hexadecimal Addressing Discrete logic Microprocessor action I O control CRT control Dynamic RAM Fault finding digital systems Dual trace oscilloscope IC replacement 274 pages Order code NE22 18 99 AN INTRODUCTION TO LIGHT IN ELECTRONICS F A Wilson This book is not for the expert but neither is it for the completely uninitiated It is assumed the reader has Project ELECTRONIC PROJECT BUILDING FOR BEGINNERS R A Penfold This book is for complete beginners to electronic project building It provides a complete introduction to the practical side of this fascinating hobby including Component identification and buying the right parts resistor colour codes capacitor value markings etc advice on buying the right tools for the job soldering mak ing easy work of the hard wiring construction methods including stripboard custom printed circuit boards plain matrix boards surface mount boards and wire wrapping finishing off and adding panel labels getting problem projects to work including simple methods of fault finding In fact everything yo
62. socket red see text SK2 4mm socket black see text Stripboard 0 1 inch matrix 8 strips by 11 holes insulating mounting kit for IC 1 aluminium case 152mm x 114mm x 76mm heatsink 152mm x 94mm x 14mm plain aluminium excluding case Approx Cost Guidance Only the upper section of the box well away from the transformer and rectifier to dis tribute the heat as evenly as possible The mounting tab of regulator ICI is internally connected to the common lead so it was fitted to the aluminium sheet with an insulating washer and some heatsink compound The leads were then bent to allow them to be soldered directly to their connections on the stripboard as shown in Fig 3 This keeps the decoupling capacitors C2 and C3 close to ICI A single mounting screw with an insu lating spacer provides additional support for the stripboard The components are connected together as shown in Fig 4 Two 4mm sockets are fitted to the case for the output and Led D3 and RI are connected to these as shown Although a single pole switch was used for the mains input a double pole type would be prefer able for safety reasons so Fig 4 shows how this should be wired General component layout within the aluminium case Note the regulator and small circuit board mounted on the underside of the case cover MAINS SAFETY Where possible parts of the circuit con nected to the mains supply such as the switch and transformer c
63. the adap tor use your multimeter to check that a voltage of 5V is present at test point TP2 within a decimal point or so A much higher or lower voltage will indicate that you have made an assembly error If the voltage is correct Link X can now be inserted This routes the fully regulated 5V supply to the rest of the circuits on the breadboard RIPPLE TEST Also connect test point TP1 to the signal input of the ADC IC2 Carefully rotating VRI s wiper clockwise you can examine via your computer screen Analogue Input Waveform Display option whether any ripple voltage is present at the junction of diodes D2 and D4 OUT 1 OUT 2 OUT 3 OUT 4 OUT 5 OUT 6 OUT 7 IN4 BIT 6 AND 64 Cine XT nb 128 uv A SELECT ERROR wi BIT4 AND O SELECT INO BIT 3 AND 8 OV BIT NUMBERS REFER TO PORT INPUT REGISTER BITS 34 3 BI 36 RS ELE 37 BA E Dd 38 E EN m 7 Se iid O no Ce EH 34 HH 35 HH 36 DE 37 HH 38 B 40 s SIGNAL INPUT LINK X SEE TEXT BERATEN C D Dx Dx Dx Dx Dx eee Dd DX D Dx D3 D DX Dd vx Va c INPUT SEE TEXT Fig 11 7 Breadboard layout for the 5V power supply circuit and the revised con nections to the printer port board SK1 COMPUTER CONNECTOR oO AN Oa FW I o GND 33 THE AND VALUE IS THAT NEEDED TO ISOLATE THE BIT IN APROGRAM NOTE THAT REGISTER INVERTS BIT 7 Fig 11 8 Revised circuit diagram for the printer port board connect
64. to be amended with the l e d output routine replaced by the serial port emulation software By running the PC serial link version of the PIC software the command values of different remote control handset keys are displayed The lists which illustrate vari ous command codes are given later but can only be used as a gen eral guide to what command code a given key on the handset may generate INFRA RED SENSOR The IS1U60 remote control infra red sensor IC2 is manufactured by Sharp As can be seen from the block diagram in Fig 3 this device filters ampli fies and demodulates the infra red signal The final stage is a comparator circuit which gives a clean TTL output signal Using this device is considerably easier and cheaper than building a circuit using a separate infra red detector and amplifier Pinouts are given in Fig 4 Data output from the sensor is connect ed directly to the PIC at Port B pin RBO It could also be added to an existing PIC circuit with minimal additional wiring if a spare port pin is available With no infra red signal the output of the device is 5V logic 1 and consumes a maximum current of 4 5mA 2 8mA typi cal The recommended power supply range is 4 7V to 5 3V Ski deesse se OOOOO O OOOO O PIN 2 DATA PIN 5 GROUND VIEWED FROM SOLDER SIDE Fig 2 9 pin D type female serial connector COMPONENTS See SHOP TALK page 10uF elect 10V 33pF ceramic 2 off
65. to photograph in the future Techs often develop their own technique so I m not sure there is a totally right way of sol dering connectors I need to do some research in this respect to get a consensus However I anticipated photographing the sol dering of D type connects etc using a reflow soldering technique Also jack plugs RCA phono plugs and so on My biggest concern is that my own preferred way of soldering these items may not be seen as the preferred way by others but hopefully there will be enough common ground to produce a definitive resource It would also be handy if someone like Cannon gave me some expensive XLRs to play with You may be interested to know that I have recently released my first CD ROM of 200 colour photos of electronic components which can be used as an educational training resource The images are royalty free for printed projects More on my home page at http home pages tcp co uk alanwin Alan Winstanley ICEBREAKER DISPLAY Dear EPE I recently purchased the kit for Mark Stuart s ICEbreaker Mar 00 It is an excellent way to get started with PICs However the example pro gram sent with it to introduce the l c d module has thrown up a slight problem I have found that the R W pin on the l c d needs to be held low whilst writing to the mod ule otherwise spurious errors occur with the dis play garbage being written to the screen I corrected this by hardwiring the R W pin to 0V
66. transformers and for digital solutions it is possible to integrate the driver and receiver circuitry together with the trans former onto the same die making a very compact solution The driver encodes the input signal into a suitable a c waveform that is fed into the transformer This is very tightly coupled so that stray effects are minimised and the resilience to elec trostatic and other transient effects is minimised The output circuitry then receives the signal from the transformer and reconstructs it into the digital wave form required at the output MEMS devices offer circuit isloation using high speed magnetic techniques Illustration courtesy Analogue Devices As these magnetic digital isolators are fabricated using CMOS techniques they have short propagation delays coupled with high speeds of operation In this way they are able to provide much higher data rates than their opto equivalents Currently these devices are able to provide data rates of 100Mbps A new process called umIntegration has recently been announced by Analog Devices This represents their latest approach to integrating MEMS Microelectromechanical Systems and semiconductor technology It allows MEMS structures to be built on top of standard semiconductor wafers By pro viding interconnections between the MEMS structure and the electronic device underneath they are able to provide very high density circuits that incorporate both electronic an
67. unmade needs assembling Maplin code NV67 39 99 can be purchased built tested and ready to use or in kit form The ready built l e SE module verifies first at normal 5 volts then Book Experimenting with C amp C Maplin code NW47 24 99 with 10 volts applied and uses the Kit CP2a made up and ready to start Not from Maplin 46 00 Kit CP2u unmade needs assembling Maplin code NW48 39 99 Kit CP2t top up to add to kit 1 Maplin code NW49 22 99 built in display to show programming messages The kit version uses a simplified design which verifies only at Book Experimenting with PIC Microcontrollers 23 99 normal volts and where the display is PIC Programmer experimental module amp software 74 00 dedicated to the test PIC the status is Kit p C3u a PCB control PIC switches amp software 30 00 indicated using 2 LEDs Kit PIC3w b all other items required to build module 25 00 E The kit consists of two parts PIC3u a contains the PCB control PIC 2 slide switches software suite and a booklet containing a full parts list and construction details PIC3u b contains all the other items to build the programmer experimental module and includes a test PIC The system will also programme similar PICs 83 710 71 620 621 etc The made up module is supplied with a test PIC fitt
68. value 5 00 VAT 866 battery pack originally intended to be used with an orbitel mobile telephone it con tains 10 1 6Ah sub C batteries 42 x 22 dia the size usually used in cordless screw drivers etc the pack is new and unused and can be broken open quite easily 7 46 VAT 8 77 Please add 1 66 vat 1 95 postage amp packing per order JPG Electronics 276 278 Chatsworth Road Chesterfield S40 2BH Tel 01246 211202 Fax 01246 550959 Mastercard Visa Switch Callers welcome 9 30 a m to 5 30 p m Monday to Saturday SHERWOOD ELECTRONICS FREE COMPONENTS Buy 10 x 1 Special Packs and choose another one FREE SP1 15 x 5mm Red LEDs SP131 2 x TLO71 Op Amps SP2 12 x 5mm Green LEDs SP133 20x 1N4004 diodes SP3 12 x 5mm Yellow LEDs SP134 15 x 1N4007 diodes SP6 15 x 3mm Red LEDs SP135 6 x Min slide switches SP7 12 x 3mm Green LEDs SP136 3 x BFY50 transistors SP10 100 x 184148 diodes SP137 4 x W005 1 5A bridge rectifiers SP11 30 x 1N4001 diodes SP138 20 x 2 2 63V radial elect caps SP12 30 x 1N4002 diodes SP140 3 x W04 1 5A bridge rectifiers SP18 20 x BC182 transistors SP142 2 x CMOS 4017 SP20 20 x BC 184 transistors SP143 5 Pairs min crocodile clips SP21 20 x BC212 transistors Red amp Black SP23 20 x BC549 transistors SP145 6 x ZTX300 transistors SP24 4 x CMOS 4001 SP146 10 x 2N3704 transistors SP25 4 x 555 timers SP147 5 x Stripboard 9 strips x SP26 4 x 741 Op Amps 25 holes SP28 4 x CMOS 4011 SP151 4 x 8mm Red LEDs SP
69. via a remote control handset can easily be achieved HESOURCES The software discussed in this article is available as stated on this month s Shoptalk page 701 SURFING THE INTERNET P gt NET WORK ALAN WINSTANLEY Check the Google box N previous months I mentioned Google www google com now the most talked about search engine on the Internet It has become a personal favourite since the end of 1999 and is strongly recom mended to EPE readers as their prime search site Google is a high ly intelligent and focused database which claims to have indexed over 1000 000 000 web pages to date a figure which has quadru pled since the beginning of the year Google operates what is prob ably the world s largest Linux cluster which contains 80TB terrabytes of disk storage with a claimed aggregate I O band width of 50 gigabytes per second For many serious Internet users Google is a dream come true because it has a minimalist front end a simple box which belies its tremendously accurate searching and indexing capabilities There are no distracting banner ads or other trimmings associated with typical portal sites such as Alta Vista Lycos or Yahoo Google also has a handy trick up its sleeve if the web site to which it refers no longer exists you may be able to check Google s own cached copy to view an ear lier copy of the page All you have to do is type any topic into the search eel uc Decrees EAN eer eben f
70. 0V 5A or 35V 10A csssssessssssssesseessessnsnseeeceeseessessssneoees 200 Farnell DSG 1 Synthesised Signal Generator eeerressrerrresEEEEEEEREEEEEEEREEEEEEEEREEEEEEEEREEEEEEEREEEEEEEER 125 Farnell AP 30250A Power Supply 3V 250 A nnncccocorerr raras 1750 Feedback PFG 605 Power Function Generator e eee e nn nnne nennen nennen inna ana nan nn nn aa aaa nana a 150 Fluke 5100A Calibrator NANI RSS S RR n anna 1950 GN ELMI EPR31 PCM Signalling Recorder nicas 2000 Guildline 9152 T12 Battery Standard Cell anna 550 Hewlett Packard 1630D Logic Analyser 43 Channels enne 500 Hewlett Packard 16500A B and C Fitted with 16510A 1651A 161530A 16531A Logic Analyser EEE naaa from 2000 Hewlett Packard 331A Distortion Analyser ccce rrr rr o rn enne nnn nn nana anas anus a ues u ua 300 Hewlett Packard 333A Distortion AnalySer ennnssrrterrrrrrESERERREEEEEEEEEEEEEEERREREEEEEEEEEEEEEEREREEEEEEEEEEEEEEN 300 Hewlett Packard 334A Distortion Analyser coreano 300 Hewlett Packard 3325A 21MHz Synthesiser Function Generator 900 Hewlett Packard 3335A Synthesised Signal Generator 200Hz 81MHz 2750 Hewlett Packard 3336C Synthesised Signal Generator 10Hz 21MHZz nene 800 Hewlett Packard 3455A 67 Digit Multimeter Autocal rreeennn
71. 10mm x 20mm including microphone 3 12V operation Range up to 500m MTX Micro miniature Room Transmitter Our best selling room transmitter kit Just 17mm x 17mm including mic Extremely sensitive 3 12V operation Range up to 1000m 14 95 STX High performance Room Transmitter High performance transmitter with buffered output for greater stability and range Measures just 22mm x 22mm including mic 6 12V operation Range up to 1500M eus dona nba ACE Ene ouo eg aes 16 95 VT500 High power Room Transmitter Our most powerful room transmitter with around 250mW of output power Excellent range and penetration Size 20mm x 40mm 6 12V operation Range up to 3000M i m rhe ER ERR 17 95 VXT Voice activated Room Transmitter Triggers only when sounds are detected by on board mic Variable trigger sensitivity and on time with LED trigger indicator Very low standby current Size 20mm x 67mm 9V operation range up to HVX400 Mains Powered Room Transmitter Connects directly to 240V AC supply Ideal for long term monitoring Size 30mm x 35mm range up to 500M a vue acri eR P e ne 21 95 SCRX Subcarrier Scrambled Room Transmitter To increase the security of the transmission the audio is subcarrier modulated Receiver now requires the decoder module SCDM connected to allow monitoring Size 20mm x 67mm 9V operation up to 1000m s lt 2 ECC L 7 7 7 0m 24 95 SCDM Subcarrier Decoder for SCRX Conn
72. 1MHz SINAD MEASUREMENTS for only ae MARCONI 893C AF POWER METER 300u Watts 30 Watts 20Hz 35kHz 2 5 ohm 20 kilohms MARCONI 893C unused boxed 100 MARCONI 893B to 10 Watts max NO SINAD 30 GOULD J3B SINE SQ OSCILLATOR Low distortion Balanced metered output Attenuator SOLARTRON 7150 DMM 672 digit TRUE R M S High Accuracy IEEE HIGH QUALITY RACAL COUNTERS 9904 Universal Timer Counter 50MHz 9916 Counter 10Hz 520MHz 9918 Counter 10Hz 560MHz 9 digit MARCONI 2610 TRUE RMS VOLTMETER d Digital LCD Analogue GEN Meier 5Hz to 25MHz D C Autoranging MARCONI TF2015 AM FM sig gen 10 520MHz 175 RACAL 9008 Auto Mod Meter 1 5MHz 2GHz 200 LEVELL TG200DMP RC Oscillator 1Hz 1MHz 50 Sine Sq Meter battery operated batts not T a FARNELL LF1 Sine Sq Oscillator 10Hz 1MHz FARNELL L30 2 Bench Power Supply 0 30 Volts 0 2 Amps ONLY Constant D IC outputs Constant current MANY OTHER POWER SUPPLIES AVAILABLE STEWART of READING 110 WYKEHAM ROAD READING BERKS RG6 1PL VISA Telephone 0118 9268041 Fax 0118 9351696 Callers welcome 9am 5 30pm Monday to Friday other times by arrangement Everyday Practical Electronics September 2000 MARCONI 2022bE Syn AM FM SIG GEN 10kHz 1 01GHz Up to 10dBm output phase mod l c d display keyboard entry etc small lightweight 525 600 750 RADIO COMMUNICATIONS TEST SETS MARCONI 2955 29958 MARCONI 2955A 2960 MA
73. 26 PIEZO ELECTRIC SOUNDER also operates effi ciently as a microphone Approximately 30mm diameter easily mountable 2 for 1 Order Ref 1084 LIQUID CRYSTAL DISPLAY on p c b with ICs etc to drive it to give 2 rows of 8 characters price 1 Order Ref 1085 RECHARGEABLE 12V JELLY ACID BATTERIES Yuasa 12V 2 3AH These are 7in long 3in high and 1 in wide with robust terminals protruding through the top Price 3 50 Order Ref 3 5P11 DITTO but 12V 18AH This is 7in long 7in high and 3in wide Brand new with 12 months guaran tee price 12 50 or pack of 4 for 48 including VAT and carriage Order Ref 12 5P3 Note This battery will start a car and is ideal for golf trolleys etc CHARGER for these batteries and other sealed lead acid batteries 5 Order Ref 5P269 RECHARGEABLE NICAD BATTERIES AA size 25p each which is a real bargain considering many firms charge as much as 2 each These are in packs of 10 coupled together with an output lead so are a 12V unit but easily divideable into 2 x 6V or 10 x 1 2V 2 50 per pack 10 packs for 25 including carriage Order Ref 2 5P34 ANSWER PHONE UNIT Brand new suitable for connection to any BT line has been currently sold for around 25 You can have one at 12 Order Ref 12P38 LIGHT ALARM A circuit for this appears in the February issue however we have a rather less complicated model already made up and in a nice case price only 3 Order R
74. 29 3 x CMOS 4013 SP152 4 x 8mm Green LEDs SP31 4 x CMOS 4071 SP153 4 x 8mm Yellow LEDs SP34 20 x 1N914 diodes SP154 15 x BC548 transistors SP36 25 x 10 25V radial elect caps SP156 3 x Stripboard 14 strips x SP37 15 x 100 35V radial elect caps 27 holes SP39 10 x 470 16V radial elect caps SP160 10 x 2N3904 transistors SP40 15 x BC237 transistors SP161 10 x 2N3906 transistors SP41 20 x Mixed transistors SP165 2 x LF351 Op Amps SP42 200 x Mixed 0 25W C F resistors SP167 6 x BC107 transistors SP47 5 x Min PB switches SP168 6 x BC108 transistors SP102 20x 8 pin DIL sockets SP175 20x 1 68V radial elect caps SP103 15x 14 pin DIL sockets SP177 10 x 1A 20mm quick blow fuses SP104 15x 16 pin DIL sockets SP182 20 x 4 7 63V radial elect caps SP105 4 x 74LS00 SP183 20 x BC547 transistors SP109 15 x BC557 transistors SP187 15 x BC239 transistors SP112 4 x CMOS 4093 SP191 3 x CMOS 4023 SP114 5 x ZTX500 transistors SP192 3 x CMOS 4066 SP115 3 x 10mm Red LEDs SP193 20x BC213 transistors SP116 3 x 10mm Green LEDs SP194 8 x OA90 diodes SP118 2 x CMOS 4047 SP195 3 x 10mm Yellow LEDs SP120 3 x 74LS93 SP197 6 x 20 pin DIL sockets SP124 20x Assorted ceramic disc caps SP198 5 x 24 pin DIL sockets SP130 100 x Mixed 0 5W C F resistors 2000 Catalogue now available 1 inc P amp P or FREE with first order P amp P 1 25 per order NO VAT Orders to Sherwood Electronics 7 Williamson St Mansfield Notts NG19 6TD RESISTOR PACKS C Film RP3 5 each valu
75. 47 50 p amp p 6 50 THE ELECTRONICS SURPLUS TRADER This is a listing of new first class com ponents and electronic items at below trade prices Includes manufacturers surplus and overstocks Also obsolete semiconductors valves and high voltage caps and components Send two first class stamps for large catalogue Dept E CHEVET SUPPLIES LTD 157 Dickson Road BLACKPOOL FY1 2EU Tel 01253 751858 Fax 01253 302979 EUH m E mail chevet globalnet co uk Telephone Orders Accepted Callers welcome Tues Thurs Fri and Sat PLASTIC BOXES amp ENCLOSURES Contact us for your free catalogue S L M Model Engineers Ltd Pu oaa Website www slm uk com Telephone 01242 525488 Cheltenham GL52 5JQ Fax 01242 226288 647 GENT ELECTRONI CS Tel 01283 565435 Fax 546932 http www magenta2000 co uk E mail sales magenta2000 co uk LTD EE217 135 Hunter Street Burton on Trent Staffs DE14 2ST All Prices include V A T ADD 3 00 PER ORDER P amp P 6 99 next day MAIL ORDER ONLY e CALLERS BY APPOINTMENT EPE MICROCONTROLLER P I TREASURE HUNTER The latest MAGENTA DESIGN highly stable amp sensitive with LC control of all timing functions and advanced pulse separation techniques e High stability drift cancelling e Easy to build amp use e No ground effect works in seawater e Detects gold silver ferrous amp non ferrous metals e Efficient quartz controlled microcontroller
76. 5V The regulator has an advantage of being short circuit proof having a thermal shutdown func tion to prevent overheating caused by inadequate heatsinking for instance For an example see the Interior Lamp Delay project in Oct 99 EPE You can interface your 5V PIC micro controller output to a higher voltage load by ensuring that the PIC and load circuits both have a common ground as a refer ence Then use say an npn transistor to interface or buffer the PIC to the load with the emitter connected to OV The PIC output drives the transistor through a base resistor of say 4 7 kilohms 4k7 or so One side of the load is connected to the collector but the other side can be returned to a higher voltage 12V say A 1N4001 diode should be connected across the pump anode on collector to prevent back E M F spikes As long as the PIC circuit and transistor all use the same OV rail everything will be fine you just have to keep an eye on the voltages appearing across which compo nents Also consider using a MOSFET power transistor which being voltage operated will draw next to no current from the PIC ARW Beginner s Questions I m building an Led flasher circuit on stripboard and have a few questions What 686 is the best way to cut the copper strip How do I know which way round to connect l e d s Even under a magnifying glass the leads look the same all round to me One of my resistors a 4 700 one has got FI
77. 6033A Power Supply Autoranging 20V 30A sssnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 7 90 Hewlett Packard 6253A Power Supply 20V 3A Twin eren nnn uuuunuuuuuuuuuuuuuuuuuuuuuuuuuuns 200 Hewlett Packard 6255A Power Supply 40V 1 5A Turin sseesssesseseseseseeeeeeeeeEREREREEEEEKEEEEEEEEEEE 200 HEWLETT PACKARD 6261B Power Supply 20V 50A 350 Discount for Quantities Hewlett Packard 6264B Power Supply 0 20V 0 254 cec eurer rere enun nnn nun uuu uuuuuuuus 300 Hewlett Packard 6266B Power Supply 40V 5A eee e eere ee ense nennen aaa 220 Hewlett Packard 6271B Power Supply 60V 3A eee e ee eee eere eese nn aaa a uasa a nnmnnn 225 Hewlett Packard 6624A Quad Power Supply 1 creer a 2000 Hewlett Packard 6632A Power Supply 20V 5A eren nnne neni nana nana naar aria arua ara 800 Hewlett Packard 6652A 20V 25A System P S U nnesrsrrrresssEEEEEEEREEEEEEREEEEEEEEREEEEEEREREEEEEEREEEEE 750 Hewlett Packard 7475A 6 Pen Plotter nnccocononnn na 250 Hewlett Packard 7550A 8 Pen PIOtter snnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnannns EZE Hewlett Packard 778D Coax Dual Directional Coupler cce eee e enun unu uu uuuun 6 Hewlett Packard 8015A 50MHz Pulse Generator Hewlett Packard 8165A 50MHz Programmable Signal Sour
78. 9 95 Over 500 pages Large format Specially imported by EPE Excellent value An Unconventional Guide To Computers Interactive Labs Plus FREE CD ROM which includes Fully Functional Internet Ready Virtual Computer with Interactive Labs This follow on to Bebop to the Boolean Boogie is a multimedia extravagan za of information about how computers work It picks up where Bebop left off guiding you through the fascinating world of computer design and you ll have a few chuckles if not belly laughs along the way In addition to over 200 megabytes of mega cool multimedia the accompanying CD ROM for Windows 95 machines only contains a virtual microcomputer simulating the motherboard and standard computer peripherals in an extremely realistic manner In addition to a wealth of technical information myriad nuggets of trivia and hundreds of carefully drawn illustrations the book contains a set of lab experiments for the virtual microcomputer that let you recreate the expe riences of early computer pioneers If you re the slightest bit interested in the inner workings of computers then don t dare to miss this one Over 500 pages large format 29 95 Bebop BYTES Back Computers Fully Functional Interr Virtual Computer with NEWNES INTERACTIVE ELECTRONIC CIRCUITS CD ROM CD ROM Edited by Owen Bishop An expert adviser an encyclopedia an analytical tool and a source of real design data all in one CD ROM
79. ADDED ALF STAGE THIS CIRCUIT USES THE MODEL ELBA FOR AUDIO WITH THE POPULAR EFS0 VALVE FOR THE DETECTOR AND THE EFB81 FOR THE R F STAGE THIS MAKES FOR A SUPERIOR REGEM RADIO 32 00 Visit our new Website Address http www kit master co uk For your Catalogue E mail david kit master co uk VALVE KITS P amp P 6 UK WORLDWIDE P amp P 12 PAYMENT CHEQUES STERLING MAIL ORDER ONLY a PLEASE ALLOWUPTO WV 28 DAYS FOR DELIVERY MAKE POSTAL ORDERS CHEQUES PAYABLE TO DAVID JOHNS AND SEND TO 37 GOSBECKS ROAD COLCHESTER ESSEX CO2 9JR TEL 07941 252679 FAX 01206 369226 Everyday Practical Electronics September 2000 e in a variety OS models Antex thermally balanced soldering irons are fast easy to handle and very safe Plus you get a wide range of different voltages and wattages 50 race off with a fixed temperature iron or try the In Handle temperature controlled model Each one comes with a choice of a PVC or a burn proof silicon lead has been manufactured in the UK and meets CE conformity And with Antex you get a big choice of soldering bits to suit every need But while our irons sell faster than a dragster they come at a price that won t burn a hole in your pocket So visit our web site or your electronics retailer and take one for a test drive E ee aS AN TEX WUES A E O E NOT JUST ANY OLD IRON YOU CAN NOW BUY ANTEX EQUIPMENT ON LINE ALL ON LINE ORDERS OVER 20 TAKEN IN
80. AUGUST AND SEPTEMBER WILL RECEIVE A 25 DISCOUNT www antex co uk 66 EPE ETI Tutorial Series TEACH IN 2000 Part Eleven Voltage Regulation Integration Differentiation Transformers and rectifiers were the subject of the Tutorial in Part 10 last month introducing you to the con cept of safely obtaining power from the a c mains supply and converting it to a d c voltage suitable for use with electronic circuits We illustrated the discussion with examples of the waveforms produced at various stages of the process and how capacitors form an integral part of the final conversion to d c JOHN BECKER yA 7 We now take the subject a step further by discussing how d c voltages can be regulated so that they maintain a stable level even though the source voltage may fluctuate We look too at how capacitor values can be optimised in order modify waveform shapes in this and other applications We also describe a simple mains operated 5V d c power supply that you can safely assemble on your breadboard voltage of the a c mains supply and that of a transformer s secondary windings can vary unpredictably resulting in unsta ble rectified d c voltages You will have also found that the voltage supplied by your nominally 6V battery has been progres sively dropping since you started using it some months ago you may even have had to buy a new one since then The answer you must be itch I P
81. BP239 2 95 NEWNES ELECTRONICS TOOLKIT SECOND EDITION Geoff Phillips The author has used his 30 years experience in industry to draw together the basic information that is constantly demanded Facts formulae data and charts are presented to help the engineer when designing developing evaluating fault finding and repairing electronic circuits The result is this handy workmate volume a memory aid tutor and reference source which is recommended to all electronics engineers students and technicians Have you ever wished for a concise and comprehensive guide to electronics concepts and rules of thumb Have you ever been unable to source a component or choose between two alternatives for a particular application How much time do you spend searching for basic facts or manufacturer s specifications This book is the answer it covers resistors capacitors inductors semiconductors logic circuits EMC audio electronics and music telephones electronics in light ing thermal considerations connections reference data 158 pages Order code NE20 14 99 706 PRACTICAL ELECTRONIC FAULT FINDING AND TROUBLESHOOTING Robin Pain This is not a book of theory It is a book of practical tips hints and rules of thumb all of which will equip the reader to tack le any job You may be an engineer or technician in search of information and guidance a college student a hobbyist build ing a project from a magazine or simply a keen
82. BUX BUY BUZ CA CD CX CXA DAC DG DM DS DTA DTC GL GM HA HCF HD HEF ICL ICM IRF J KA KIA L LA LB LC LD LF LM M M5M MA MAB MAX MB MC MDAJ MJE MJF MM MN MPS MPSA MPSH MPSU MRF NJM NE OM OP PA PAL PIC PN RC S SAA SAB SAD SAJ SAS SDA SG SI SL SN SO STA STK STR STRD STRM STRS SV1 T TA TAA TAG TBA TC TCA TDA TDB TEA TIC TIP TIPL TEA TL TLC TMP TMS TPU U UA UAA UC UDN ULN UM UPA UPC UPD VN X XR Z ZN ZTS many others We can also offer equivalents at customers risk We also stock a full range of other electronic components Mail phone Fax Credit Card orders and callers welcome AMERICAN AESS n J Cricklewood Electronics Ltd 40 42 Cricklewood Broadway London NW2 3ET Tel 0181 452 0161 Fax 0181 208 1441 Everyday Practical Electronics September 2000 zs 1 k e IAA Get your magazine instantly anywhere in the world buy from the web TAKE A LOOK A FREE ISSUE IS AVAILABLE A one year subscription 12 issues costs just 9 99 US ELECTRONICS SURPLUS CLEARANCE SALE SCOOP PURCHASE FLUKE HAND HELD DIGITAL MULTIMETER MODEL 8024B Cancelled export order 750V AC DC 2 amp AC DC Resistance 20Megohm plus Siemens range Also measures temperature 20 C to 1265 C Temp probe not included Calibrated for K type thermocouple Peak hold facility Supplied brand new and boxed but with original purchasing organisation s small identify ing mark on case Test leads and handbook included Offered at a fraction of original price
83. Basic Work Contains over 900 pages of information Edited by John Becker Regular Supplements Approximately 160 page Supplements of additional information which if requested are forwarded to you immediately on publication four times a year These are billed separately and can be discontinued at any time Presentation Durable looseleaf system in large A4 format Price of the Basic Work 39 95 SALE PRICE 23 97 to include a recent Supplement FREE Our 30 day money back guarantee gives you complete peace of mind If you are not entirely happy with either Manual for whatever reason simply return it to us in good condition within 30 days and we will make a full refund of your payment no small print and no questions asked Overseas buyers do have to pay the overseas postage charge E an e ele Wimborne Publishing Ltd Dept Y9 Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 ELECTRONICS SERVICE MANUAL EVERYTHING YOU NEED TO KNOW TO GET STARTED IN REPAIRING AND SERVICING ELECTRONIC EQUIPMENT SAFETY Be knowledgeable about Safety Regulations Electrical Safety and First Aid UNDERPINNING KNOWLEDGE Specific sections enable you to Understand Electrical The essential work for servicing and repairing electronic equipment and Electronic Principles Active and Passive Components Circuit Diagrams Circuit Around 900 pages Measurements Radio Computers Valves and manufacturers
84. D SOFTWARE e 2 SERIAL PORTS e PIT AND I O PORT OPTIONS e 12C PORT OPTIONS Mini Lab amp Micro Lab Electronics Teach In y As featured in EPE and now published as Teach In 7 All parts are supplied by Magenta Teach In 7 is 3 95 from us or EPE Full Mini Lab Kit 119 95 Power supply extra 22 55 Full Micro Lab Kit 155 95 Built Micro Lab 189 95 Tel 01283 565435 Fax 01283 546932 Everyday Practical Electronics September 2000 649 INCLUDES PCB PIC16F84 WITH DEMO PROGRAM SOFTWARE DISC INSTRUCTIONS AND MOTOR FULL SOURCE CODE SUPPLIED ALSO USE FOR DRIVING OTHER POWER DEVICES e g SOLENOIDS Another NEW Magenta PIC project Drives any 4 phase unipolar motor up to 24V and 1A Kit includes all components and 48 step motor Chip is pre programmed with demo software then write your own and re program the same chip Circuit accepts inputs from switches etc and drives motor in response Also runs standard demo sequence from memory 8 CHANNEL DATA LOGGER As featured in Aug Sept 99 EPE Full kit with Magenta naa PCB LCD fits directly on board Use as Data Logger or as a test bed for ma Dy other 16F877 projects Kit includes programmed chip 8 EEPROMs PCB case and all components KIT 877 49 95 inc 8 x 256K EEPROMS KIT 621 99 95 e ON BOARD 5V REGULATOR e PSU 6 99 e SERIAL LEAD 3 99 All prices include VAT Add 3 00 p amp p Next day 6 99 E mail sales mag
85. DOOODOOOOOOOOD0ODO000000ag Stepping Motor amp Power Supply Extra D O O O D O O O D D D O O D D O D D O O O O O O O O 0 a O m QOOOODOODODODDOOODDORDDODODoO0000 BD A COMPLETE RANGE OF A Complete range of regulated inverters to power 220V and 240V AC INVE RTE 2 S equipment via a car lorry or boat battery Due to their high performance 29096 the inverters generate very little heat The high stability of the BK ELECTRONICS 150W TO 1000W 12V amp 24V output frequency 1 makes them equally suitable to power sensitive devices These inverters generate a modified sine wave which are considerably superior to the square waves which are produced by most other inverters Due to this superior feature they are capable of powering electrical equipment such as TV s videos microwave ovens electrical lamps pumps battery chargers etc Low Battery Alarm The inverters give an audible warning signal when the battery voltage is lower than 10 5V 21V for the 24V version The inverter automatically shuts off when the battery voltage drops below 10V 20V for the 24V version Fuse protected input circuitry Order Code Power Voltage Price 651 581 150W Continuous 12V 38 49 651 578 150W Continuous 24V 38 49 651 582 300W Continuous 12V 54 36 651 585 300W Continuous 24V 54 36 651 583 600W Continuous 12V 118 42 651 593 600W Continuous 24V 118 42 651 587 1000W Continuous 12V 174 60 651 597 1000W Conti
86. E THE NEXT TWO MONTHS ISSUES Note our UK postage costs just 1 50 no matter how many books you order Computing WINDOWS 95 EXPLAINED P R M Oliver and N Kantaris If you would like to get up and running as soon as pos sible with the Windows 95 operating system then this is the book for you The book was written with the non expert busy person in mind It explains the hardware that you need in order to run Windows 95 successfully and how to install and opti mize your system s resources It presents an overview of the Windows 95 environment Later chapters cover how to work with programs folders and documents how to control Windows 95 and use the many accessories that come with it how to use DOS programs and if necessary DOS commands and how to communicate with the rest of the electronic world 170 pages Order code BP400 5 95 EASY PC INTERFACING R A Penfold Although the internal expansion slots of a PC provide full access to the computer s buses and are suitable for user add ons making your own expansion cards requires a fair amount of expertise and equipment The built in ports pro vide what is often a much easier and hassle free way of interfacing your own circuits to a PC In particlar a PC printer port plus a small amount of external hardware provides a surprisingly versatile input output port The PC games port is less useful for general interfacing purposes but it can be useful in some appli
87. EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEER 250 Tektronix AA5001 TM5006 M F Programmable Distortion Analyser cerne nnnnnnnn 1995 Tektronix TM5003 AFG 5101 Arbitrary Function Generator eere eere nnne 1500 Tektronix Plug ins many available such as SC504 SW503 SG502 PG508 FG504 FG503 TG501 TR503 many DOE EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEREEN POA Time 9811 Programmable Heslstance ntEEEREREREREREEEEREREREREEEREEEEEEEEEEEEEEEEEREREREREREEEEEEEEEEEEEEEEEEEEEER 400 Time 9814 Voltage Calibrator EEE 550 Valhalla Scientific 2724 Programmable Resistance Standard POA Wandel amp Goltermann PFJ 8 Error Jitter Test Set 11500 Wandel Goltermann PCM4 options 9950 Wandel amp Goltermann MU30 Test Point Scanne 1500 Wayne Kerr 4225 LCR Bridge eorr 600 Wavetek 171 Synthesised Function Generator cnn 250 Wavetek 172B Programmable Signal Source 0 0001Hz 13MHIZz POA Wavetek 184 Sweep Generator 5IVIHz EEE naazaa 250 Wavetek 3010 1 1GHz Signal Generatot sssssssssssssssssssssssssssssssEEEEEEEEEEREEEEEEEEEEEEEEEEEEEEEEEEEEERERER 1250 Wiltron 6409 RF Analysers 1MHZ 2GH2Z sssseseseseseseeeeeeeeeeeeeneeeneauauauanaeueaueeueseeeeususesnnenennnssess POA Wiltron 6620S Pr
88. Geran WV Pann iru ara The leading magazine for vintage radio enthusiasts Whether your interest 1s in domestic radio and TV or in amateur radio in military aeronautical or marine communications in radar and radio navigation in instruments in broadcasting in audio and recording or in professional radio systems fixed or mobile Radio Bygones is the magazine for you Radio Bygones covers it all The magazine is published six times a year and is available by postal subscription It is not available at newsagents To take out a subscription or to request a sample copy please con tact Radio Bygones Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 E mail radiobygones wimborne co uk Web sites www radiobygones co uk www radiobygones com N R BARDWELL LTD EPE Signal Diodes 1N4148 Rectifier Diodes 1N4001 Rectifier Diodes 1N4007 WO Bridge Rectifiers 555 Timer I C s 741 Op Amps Assorted Zener Diodes 400mW Assorted 7 segment Displays 5mm l e d s red green or yellow 3mm l e d s red green or yellow Axial l e d s 2mcd red Diode Package 1 00 Asstd High Brightness l e d s var cols 1 00 BC182L Transistors BC212L Transistors BC237 Transistors BC327 Transistors BC328 Transistors BC547 Transistors BC548 Transistors BC549 Transistors BC557 Transistors BC558 Transistors BC559 Transistors 2N3904 Transistors 1nf 50V wkg Axial Capacitors 4N7 50V wkg Axia
89. LIMITED hosted by Alan Winstanley 678 PIC UPS Loudener Radio Sleep Timer Scope Synchroniser EPE MOODLOOP POWER SUPPLY by Andy Flind 682 Stably power your Moodloop and other 13 2V or 12V 1A designs REMOTE CONTROL IR DECODER by Roger Thomas 698 Allows PIC programming enthusiasts to remotely control their designs Series and Features NEW TECHNOLOGY UPDATE by lan Poole 660 Micromagnetic isolation enhances high speed data transfer TEACH IN 2000 11 Voltage Regulation Integration Differentiation by John Becker 662 Essential info for the electronics novice with breadboard experiments and interactive computer simulations CIRCUIT SURGERY by Alan Winstanley and lan Bell 686 Common Ground Beginner s Questions Shocking Stuff Ferric Disposal Assault and Ni Cad Battery Gas Gauge Chips Down with Heavy Metal RAM your Batteries PRACTICALLY SPEAKING by Robert Penfold 694 A novice s guide to project building NET WORK THE INTERNET PAGE surfed by Alan Winstanley 702 Check the Google box Regulars and Services EDITORIAL 651 NEWS Barry Fox highlights technology s leading edge 655 Plus everyday news from the world of electronics READOUT John Becker addresses general points arising 658 ELECTRONICS MANUALS 670 Essential reference works for hobbyists students and service engineers Plus digital multimeter special offer SHOPTALK with David Barrington 688 The essential guide to component buying for EPE projects ELECTRONICS
90. LINE x 16 character display data all components and software to include in your own programs Ideal development base for meters terminals calculators counters timers Just waiting for your application EPE PIC Tutorial At last A Real Practical Hands On Series e Learn Programming from scrach using PIC16F84 e Start by lightin l e d s and do 30 tutorials to Sound Generation Data Display and a Securit System e PIC TUTOR Board with Switches l e d s and on board programmer PIC TUTOR BOARD KIT Includes PIC16F84 Chip TOP Quality PCB printed with Component Layout and all components not ZIF Socket or Displays Included with the Magenta Kit is a disk with Test and Demonstration routines KIT 870 27 95 Built amp Tested 42 95 Optional Power Supply 3 99 ZIF Socket 9 99 LCD Display 7 99 LED Display Reprints Mar Apr May 98 3 00 set 3 PIC TOOLKIT V2 SUPER UPGRADE FROM V1 e 18 28 AND 40 PIN CHIPS READ WRITE ASSEMBLE amp DISASSEMBLE PICS SIMPLE POWER SUPPLY OPTIONS 5V 20V ALL SWITCHING UNDER SOFTWARE CONTROL MAGENTA DESIGNED PCB HAS TERMINAL PINS AND OSCILLATOR CONNECTIONS FOR ALL CHIPS e INCLUDES SOFTWARE AND PIC CHIP 29 99 with 16F877 KIT 878 22 99 with 16F84 SUPER PIC PROGRAMMER e READS PROGRAMS AND VERIFIES e WINDOWS SOFTWARE e PIC16C6X 7X AND 8X e USES ANY PC PARALLEL PORT e USES STANDARD MICROCHIP e HEX FILES e OPTIONAL DISASSEMBLER SOF
91. NSIVE RANGE OF TRANSFORMERS LT ISOLATION amp AUTO 110V 240V Auto transfer either cased with American socket and mains lead or open frame type Available for immediate delivery ULTRA VIOLET BLACK LIGHT BLUE FLUORESCENT TUBES 4ft 40 watt 14 00 callers only 16 45 inc VAT 2ft 20 watt 9 00 callers only 10 58 inc VAT 12in 8 watt 4 80 75p p amp p 6 52 inc VAT 9in 6 watt 3 96 50p p amp p 5 24 inc VAT 6in 4 watt 3 96 50p p amp p 5 24 inc VAT 230V AC BALLAST KIT For either 6in 9in or 12in tubes 6 05 1 40 p amp p 8 75 inc VAT The above Tubes are 3500 4000 angst 350 400um ideal for detecting security markings effects lighting amp Chemical applications Other Wavelengths of UV TUBE available for Germicidal amp Photo Sensitive applications Please telephone your enquiries 400 WATT BLACK LIGHT BLUE UV LAMP GES Mercury Vapour lamp suitable for use with a 400W PF Ballast 5 KVA ISOLATION TRANSFORMER As New Ex Equipment fully shrouded Line Noise Suppression Ultra Isolation Transformer with termi nal covers and knock out cable entries Primary 120V 240V Secondary 120V 240V 50 60Hz 0 005pF Capacitance Size L 37cm x W 19cmc x H 16cm Weight 42 kilos Price 120 VAT Ex ware house Carriage on request 24V DC SIEMENS CONTACTOR Type 3TH8022 0B 2 x NO and 2 x NC 230V AC 10A Contacts Screw or Din Rail fixing Size H 120mm x W 45mm x D 75mm Brand New Price 7 63 incl p am
92. Philips 5518 Synthesised Function Generator cra nn mu a 1500 Philips PM5519 TV Pattern Generada 350 Philips PM5716 50MHz Pulse Generator ssnannsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn EB ZE Prema 4000 6 Digit Multimeter NEW s s s ssssssssssssnsnsnseseseseseseneneneneenenensnenseenseeeoenenenenenenenenes 350 Quartzlock 2A Off Air Frequency Standard racer 200 Racal 1992 1 3GHz Frequency COUunfer sssssssssssssssssssssssssssssssssssseseseseerererEEEEEEEEEEEEEEEEEEEEEEEEEEEEER 700 Racal 6111 6151 GSM Radio Comms Test Set RARE SR NN ASS nN RIN E RE RRRRAR ARRAS UR POA Racal Dana 9081 9082 Synthesised Signal Generator 520MHd eren nnn from 400 Racal Dana 9084 Synthesised Signal Generator 104MHz rrr rrrr rrr eune 450 Racal 9301A True RMS R F Multtivoltmeter ssseeeeeeeeeeeEEEEEEEEREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE 300 Racal Dana 9302A R F Multivoltmeter new verSiOn sssssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 375 Racal Dana 9303 R F Level Meter Head ssrsrsEsrsEREEREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEREEEEEEEEEEEEEEEEEEEEER 650 Racal Dana 9917 UHF Frequency Meter 560IVI Hz creer rr rrr rrrnr nenne seen ease aura uua nnn 175 Rohde Schwarz LFM2 60MHz Group Delay Sweep Generator c cee
93. RCONI 2019 Synth AM FM sig gen 80kHz 1040MHz 475 H P 8657A Synth sig gen 100kHz 1040MHz 250 H P 8656B Synth sig gen 100kHz 990MHz H P 8656A Synth sig gen 100kHz 990MHz GIGATRONIC 7100 Synth sig gen 10MHz 20GHz MARCONI 2017 AM FM phase locked sig gen 10kHz 1024MHz good signal purity H P 8640A AM FM sig gen 500kHz 1024MHz H P 8640A AM FM sig gen 500kHz 512MHz PHILIPS PM5328 sig gen 100kHz 180MHz with 200MHz freq counter IEEE RACAL 9081 Synth AM FM sig g en 5 520MHz H P 3325A Synth function gen 21MHz MARCONI 6500 Amplitude Analyser H P 4275A LCR Meter 10kHz 10MHz H P 8903E Distortion Analyser WAYNE KERR 3245 Inductance Analyser H P 8112A Pulse Generator 50MHz DATRON AutoCal Multimeter 5 7 2 digit 1065 1061A 1071 from 300 600 MARCONI 2400 Frequency Counter 20GHz 100 H P 5350B Frequency Counter 20GHz H P 5342A 10Hz 18GHz Frequency Counter FARNELL AP100 30 Power Supply FARNELL AP70 30 Power Supply PHILIPS PM5418TN Colour TV Pattern Generator PHILIPS PM5418TX1 Colour TV Pattern Generator B amp K Accelerometer type 4366 H P 11692D Dual Directional Coupler 2MHz 18GHz H P 11691D Dual Directional Coupler 2MHz 18GHz TEKTRONIX P6109B Probe 100MHz readout unused TEKTRONIX P6106A Probe 250MHz readout unused WELLER EC3100A Temperature controlled Soldering Station 200 C 450 C Unused FARNELL AMM255 Automatic Mod Meter AM FM 1 5MHz 2GHz 3 5 digit l c d display Unused 400 Also ava
94. REE CATALOGUE with order or send 2 x 1st class stamps refundable for details of over 150 kits amp publications PROJECT KITS Our electronic kits are supplied complete with all components high quality PCBs NOT cheap Tripad strip board and detailed assembly operating instructions 2 x 25W CAR BOOSTER AMPLIFIER Connects to the output of an existing car stereo cassette player CD player or radio Heatsinks provided PCB 76x75mm 1046KT 24 95 3 CHANNEL WIRELESS LIGHT MODULATOR No electrical connection with amplifier Light modu lation achieved via a sensitive electret microphone Separate sensitivity control per channel Power handing 400W channel PCB 54x112mm Mains powered Box provided 6014KT 24 90 12 RUNNING LIGHT EFFECT Exciting 12 LED light effect ideal for parties discos shop windows amp eye catching signs PCB design allows replacement of LEDs with 220V bulbs by inserting 3 TRIACs Adjustable rotation speed amp direction PCB 54x112mm 1026KT 16 95 BOX for mains opera tion 2026KT 8 50 DISCO STROBE LIGHT Probably the most excit ing of all light effects Very bright strobe tube Adjustable strobe frequency 1 60Hz Mains powered PCB 60x68mm Box provided 6037KT 29 90 ANIMAL SOUNDS Cat dog chicken amp cow Ideal for kids farmyard toys amp schools SG10M 5 50 3 1 2 DIGIT LED PANEL METER Use for basic voltage current displays or customise to measure temperature light weight movem
95. ROUGH WIMBORNE DORSET BH21 1PF Phone Wimborne 01202 881749 Fax 01202 841692 E mail editorial epemag wimborne co uk Web Site http www epemag wimborne co uk Online Edition www epemag com See notes on Readers Enquiries below we regret lengthy YE Mo MAGAZINE FOR ELECTRONICS TECHNOLOGY A COMPUTER PROJECTS technical enquiries cannot be answered over the telephone Advertisement Offices EVERYDAY PRACTICAL ELECTRONICS ADVERTISEMENTS MILL LODGE MILL LANE VOL 29 No 9 SEPTEMBER 2000 HARD WORK You cannot please all of the people all of the time I keep a close eye on all the p c b orders that come into the office so I can quickly see which projects are the most popular Over a period of time and I ve been doing this job for over 22 years now I have built up a feeling for what will be popular but sometimes you wonder if you are going down the wrong road This morning I received a letter from a reader asking if we could include some simple projects a lot of the projects are of an advanced nature he said perhaps just a few beginners pages and projects But I thought we have been publishing Teach In 2000 for the last eleven months and our Starter Projects since the June 99 issue altogether about 10 or more pages in each issue dedicated to beginners Now we have the Top Tenner series of projects each of which can be built for around 10 AII in all I believe we cater for the beginner as well a
96. Ru 1600 Philips PM 3335 50MHz 20 Ms s D S O 2 Channe ven 950 Tektronix 455 50MHz Dual Channel oo nnn unn uu uuu uuu uuu uuu uuu Era RR SR RRRSRRRSESRRRSSRRSSRRRSRSRRSRSRRSRRRRRE 200 Tektronix 464 466 100MHz Analogue Storage from 300 Tektronix 465 465B 100MHz Dual Channel ean uuuuu unn na au uuuu uua naa a RR RR RR RR R ano RR from 300 Tektronix 468 100MHz D S O oo ne rona ununi annu unu a nuu u naa nu uuu uuuu sua nu urna auus unn auarus anas usan sanas a aasunaaas OOO Tektronix TAS 475 100MHz 4 Channel nnn annua nua nu uuu uuu uua uuu Rara n HERR RRRRRSSRRRRRRSRRSRRRRRRRRRSR 995 Tektronix 475 475A 200MHz 250MHz Dual Channel ssserrerseerrepssssretsserensssseresesreepsesrenee from 400 Tektronix 485 350MHz 2 Channel a 750 Tektronix 2211 Digital Storage 50MHZ sssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn OU Tektronix 2213 60MHz Dual Channel eoo ranma 50 Tektronix 2215 60MHz Dual Trace ooo nnn u nna nuuuunuuuuuana uu RR Saa RRRRSRRRRRSSRRRRRSENRRESSESRNRRSSRRSRRERRNRRER 375 Tektronix 2220 60MHz Dual Channel D S O ran 950 Tektronix 2221 60MHz Digital Storage 2 Channel eee RNE mu uuu RR RR RR nuu aa uuu 950 Tektronix 2225 50MHz Dual Channel 1 crono S RHRRRESERSSHSRSERERSHSRSERSRSSHSESRHSRSHER 350
97. Shot FEATURES e Teach In 2000 Part 1 e Ingenuity Unlimited e Practically Speaking e Practical Oscillator Designs 5 e Circuit Surgery e New Technology Update e Net Work The Internet FREE ldentifying Electronic Components booklet DID YOU MISS THE ELECTRONICS mmi Tes ui E 4 100 Part IER ES amaai e DEC 99 PROJECTS e PIC Micro Probe e Magnetic Field Detector e Loft Guard e Ginormous Stopwatch Giant Display 2 FEATURES e Teach In 2000 Part 2 e Practical Oscillator Designs 6 e Interface e Ingenuity Unlimited Special Circuit Surgery e Network The Internet e 1999 Annual Index JAN 00 PROJECTS e Scratch Blanker e Versatile Burglar Alarm e Flashing Snowman e Vehicle Frost Box FEATURES e Ingenuity Unlimited Teach In 2000 Part 3 e Circuit Surgery e Practically Speaking e Tina Pro Review e Net Work The Internet FEB OU Photostats Only PROJECTS e PIC Video Cleaner e Voltage Monitor e Easy Typist Tape Controller e Find It Don t Lose lt FEATURES e Technology Timelines 1 e Circuit Surgery e Teach In 2000 Part 4 e Ingenuity Unlimited e Interface e Net Work The Internet MAR 00 PROJECTS e EPElICEbreaker e High Performance Regenerative Receiver 1 e Parking Warning System e Automatic Train Signal FEATURES e Teach In 2000 Part 5 e Practically Speaking e Technology Timelines 2 e Ingenuity Unlimited e Circuit Surgery e New Technology Update Net Work The I
98. TRONICS CLUB exists to help electronics enthusiasts by personal contact and through a quarterly Newsletter For membership details write to the Secretary Mr M P Moses 5 Park View Cwmaman Aberdare CF44 6PP Space donated by Everyday Practical Electronics 710 Miscellaneous 100W and 250W SOLID STATE POWER AMPLIFIERS power supplies active crossovers and stepped attenuator p c b s kits or A amp T modules PCBs are professional grade with solder mask and component location silkscreen We also supply a wide range of top quality audiophile active and passive compo nents specialising in the latest high perfor mance Japanese transistors and UK lateral power MOSFETs Write for a free catalogue Mail order only White Noise 11 Station Road Bearsden Glasgow G61 4AW Tel 0141 942 2460 BUILDING OR PURCHASING AN AUDIO MIXING DESK Specialists in custom built fully modular mixing desks for hospital radio talking newspapers for the blind amateur dra matic groups local shoppng centres theatres etc to see and read all about our products visit our pictorial web site at http www partridge electronics co uk or phone 01268 793256 X 10 Home Automation We put you in control Why tolerate when you can automate An extensive range of 230V X 10 products and starter kits available Uses proven Power Line Carrier technology no wires required Products Catalogue available Online Worldwide delivery Philips Pr
99. TWARE EXTRA e PCB LEAD ALL COMPONENTS TURNED PIN SOCKETS FOR 18 28 AND 40 PIN ICs 29 99 Kit 862 Power Supply 3 99 DISASSEMBLER SOFTWARE 11 75 PIC STEPPING MOTOR DRIVER Kit 863 18 99 PIC 16F84 MAINS POWER 4 CHANNEL CONTROLLER amp LIGHT CHASER WITH PROGRAMMED 16F84 AND DISK WITH SOURCE CODE IN MPASM ZERO VOLT SWITCHING MULTIPLE CHASE PATTERNS OPTO ISOLATED 5 AMP OUTPUTS 12 KEYPAD CONTROL SPEED DIMMING POT e HARD FIRED TRIACS Kit 855 39 95 Now features full 4 channel chaser software on DISK and pre programmed PIC16F84 chip Easily re programmed for your own applications Software source code is fully commented so that it can be followed easily LOTS OF OTHER APPLICATIONS PIC TOOLKIT V1 e PROGRAMS PIC16C84 and 16F84 e ACCEPTS TASM AND MPASM CODE Full kit includes PIC16F84 chip top quality p c b printed with component layout turned pin PIC socket all components and software Needs QBASIC or QUICKBASIC SEND FOR DETAILED INFORMATION A SUPERB PRODUCT AT AN UNBEATABLE LOW KIT 871 1 3 99 Built and tested 21 99 PRICE ALL PARTS FOR SERIES INCLUDING PCBs Ph IZZ yj B PROGRAMMED CHIP CD ROM AND DISPLAYS MAIN BOARD FULL KIT 131 95 eut 149 95 VO PORT KIT 16 99 Gurt 24 99 Beie 12 49 POWER SUPPLY 3 99 8 BIT SWITCH LATCH 7 95 INT MODULE 10 45 DEVELOPMENT AND 6800 TRAINING KIT e NEW PCB DESIGN on e 8MHz 68000 16 BIT BUS si p e MANUAL AN
100. Toov G Eee Scope Synchroniser Patenty a Good ldea AM a graduate from the Ryazan Radio Engineering Institute of Russia The circuit of Fig 4 was invented and tested as an addi tional synchroniser for a common oscillo scope to synchronise complex shaped signals These signals could not be stopped on the screen with the plain comparator based syn chroniser because they had 2nd and or 3rd 12V TO 15V O Fig 4 Basic circuit diagram for the Scope Synchroniser 12V TO 15V O harmonics with amplitudes comparable or even higher than those of the Ist harmonic The new synchroniser perfectly stopped these signals and has the additional benefit of not needing any adjustment because it sets the threshold automatically The design has also been used successfully as an input device for a frequency counter because it perfectly 6 Everyday Practical Electronics September 2000 separated the Ist harmonic I managed to obtain a Russian patent certifying this scheme as an invention The device consists of two peak amplitude detectors one for the positive and one for the negative polarity Their output voltages are reduced by a coefficient of 0 8 after which they are compared as reference voltages to the input voltage using two comparators The first comparator IC3 gives out a high level if the input voltage is higher than the positive k IC5 CD4013 ab a R d GN 679 reference voltage and the
101. U 20each MIDI UIT POSTCODE Europe Non EU 20 each 26 each USA amp Canada 25 each 33 each I i SIGNATURE 1 33 3 3 39 3 33 83 3E didas 3 3 8 EXC 3 ER e a ETC Far East amp Australasia 31 each 35 each i enclose cheque PO payable to Wimborne Publishing Ltd Rest of World 25 each 45 each i Please charge my Visa Mastercard Please allow four working days for UK delivery l NOTE Surface mail can take over 10 weeks to some parts of l Ut Cad AAA uar cdd dvi Ya cdi iacta chc a de Card Exp Date the world Each Manual weighs about 4kg when packed esm2 Constructional Project ACTIVE AERIAL RAYMOND HAIGH FERRITE LOOP Whether you re a serious Medium Wave listener or just an inveterate band browser this compact loop aerial will be an aid to better reception common part of the 1920s domestic radio scene but their popularity waned during the thirties when an external wire became the normal means of signal pick up A decade later improved receiver sensi tivity made it possible for small loops to be enclosed within the cabinets of portable and table sets At the close of the fifties in the twilight of the valve era very high per meability ferrites were introduced Rod like cores of this material enable a tiny coil to pick up signals better than a small air cored loop and ferrite aerials are now found in most domestic receivers TILT AND TURN
102. VE stripes yellow violet black brown brown How do I read it Is there some where with a good description of the 555 timer i c Lastly what s a good source of 3V for the circuit Peter via the Internet Use a twist drill bit to break the copper strips Something like a 3 or 3 5mm diam eter held in a pin vice a handheld chuck is fine or buy the proper tool called a spot face cutter Avoid drilling right through the board Much practical advice for constructors will be found in Robert Penfold s Practically Speaking Techniques of Actually Doing It column Most l e d s have a flat on the body cir cumference to mark the cathode k lead Sometimes especially with miniature types the Led leads may be designated only by their length so you d need to check the con nection data in a catalogue Personally I look inside the l e d body almost always the cathode is the reflector cup The resistor yellow 4 violet 7 black 0 brown x 10 brown 1 so it s a 4k7 1 resistor When you ve more expe rience as soon as you see yellow and vio let stripes together you ll know it s a 47 something resistor which will tell you which end to read the colour code from but even I have to get the data books out to check those bothersome five band types sometimes Data sheets on the 555 timer abound try downloading one from the National Semiconductor or Texas Instruments web sites I commend the Nationa
103. VIDEOS Our range of educational videos 690 CD ROMS FOR ELECTRONICS 692 Filters Digital Works 3 0 Parts Gallery Electronic Circuits and Components Digital Electronics Analogue Electronics PICtutor Modular Circuit Design Electronic Components Photos see also Direct Book Service pages BACK ISSUES Did you miss these 696 DIRECT BOOK SERVICE 704 A wide range of technical books available by mail order plus more CD ROMs PRINTED CIRCUIT BOARD AND SOFTWARE SERVICE 709 PCBs for EPE projects Plus EPE software ADVERTISERS INDEX 712 Readers Services e Editorial and Advertisement Departments 651 641 NEXT MONTH PIC VIRTUAL SCOPE A dual channel virtual oscilloscope for monitoring audio frequency waveforms via a PIC microcontrolled interface and your computer Performance sits mid range between the simple scope interface of the current Teach In 2000 series and the versatile EPE Virtual Scope of 1998 Provides waveform display of two signals simultaneously at rates much higher than the TI design offers although lower than V Scope With care even less experienced hobbyists should stand an excellent chance of constructing it successfully It requires a PC compatible computer capable of running QBasic or QuickBASIC and for it to read mouse controls via those programming dialects The controlling program allows you to check on both points before purchasing any components The author has run the prototype under Windows 3 1 95 and
104. W ADVERTISEMENT OFFICES EVERYDAY PRACTICAL ELECTRONICS ADVERTISEMENTS MILL LODGE MILL LANE THORPE LE SOKEN ESSEX CO16 OED Phone Fax 01255 861161 For Editorial address and phone numbers see page 651 Published on approximately the first Friday of each month by Wimborne Publishing Ltd Allen House East Borough Wimborne Dorset BH21 1PF Printed in England by Apple Web Offset Ltd Warrington WAT 4RW Distributed by COMAG Magazine Marketing Tavistock Rd West Drayton UB7 7QE Subscriptions INLAND 27 50 and OVERSEAS 33 50 standard air service 51 express airmail payable to Everyday Practical Electronics Subs Dept Allen House East Borough Wimborne Dorset BH21 1PF E mail subs epemag wimborne co uk EVERYDAY PRACTICAL ELECTRONICS ETI is sold sub ject to the following conditions namely that it shall not without the written consent of the Publishers first having been given be lent resold hired out or otherwise disposed of by way of Trade at more than the recommended selling price shown on the cover and that it shall not be lent resold hired out or otherwise disposed of in a mutilated condition or in any unauthorised cover by way of Trade or affixed to or as part of any publication or advertising literary or pictorial matter whatsoever
105. W 7 MOVWE COUNTER2 MOVLW 3 ADJBCD SPAM Dear EPE I hesitate to suggest that Alan Winstanley could ever stand correction but possibly not for long enough I have always understood that SPAM see Network July 00 is a contraction of SPiced hAM I was told this in the forties and have heard it repeated over the years In the early seventies I was given some tins of Chinese made pork luncheon meat by a friend who had done some work for a Chinese super market The taste took me straight back to the original Spam and it did the same for him Michael Elphick via the Net Alan dropped below warp speed for half a mo and replied 658 ADJLOOP ADDWF INDF F BTFSS INDE3 SUBWF INDEF INCF FSR F DECESZCOUNTER2 E GOTO ADJLOOP CALL SLCNT MOVLW DIGITI MOVWE FSR MOVLW 8 MOVWF COUNTER2 SLDLOOP RLF INDEF BTFSC INDFEA BSF STATUS C BCF INDEA INCF FSR F DECFSZ COUNTER2 F GOTO SLDLOOP DECFSZ COUNTERI F GOTO ADJBCD RETURN RLF COUNTO F RLF COUNTI F RLF COUNT2 F RETURN CLRF DIGIT1 CLRF DIGIT2 CLRF DIGIT3 CLRF DIGIT4 CLRF DIGITS CLRF DIGIT6 CLRF DIGIT7 CLRF DIGIT8 RETURN SHIFTI SEDEG Peter s routine will have its first EPE outing with my forthcoming PIC Monitored Power Supply Nov or Dec 00 in which Peter s remmed comments will also be listed Note that on entry variables COUNTO 2 already hold the number to be decimalised and the answer goes into variables DIGIT1 8 When outpu
106. a BASIC SOLDERING GUIDE Alan Winstanley s inter EE A EE EE E Post Code dna t nationally acclaimed fully illustrated guide i I UNDERSTANDING PASSIVE COMPONENTS i C I enclose cheque P O bank draft to the value of l eg BEEN EE i Please charge my Visa Mastercard i HOW TO USE INTELLIGENT L C Ds By Julyan llett L Card Oy went e ex dos Ee oe eg Expiry Date I An utterly practical guide to interfacing and program Note Minimum order for credit cards 5 Please supply name ming intelligent liquid crystal display modules j and address of cardholder if different from that shown above PhyzzyB COMPUTERS BONUS ARTICLE 1 Signed and Unsigned Binary Numbers By Clive Max Maxfield and Alvin Brown PhyzzyB COMPUTERS BONUS ARTICLE 2 Creating an Event Counter By Clive Max Maxfield and Alvin Brown INTERGRAPH COMPUTER SYSTEMS 3D GRAPHICS A chapter from Intergraph s book that explains Send a copy of this form or order by letter if you do not wish to computer graphics technology in an interesting and cut your issue understandable way with full colour graphics 4 SEND TO Everyday Practical Electronics Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 Due to the cost we cannot reply to overseas queries or orders by Fax E mail orders epemag wimborne co uk Payments must be by credit card or i
107. a cin Aagenengf on i G i 1 e HF contro nc 3 E NEUE SC 2 Pel HL S ver E eon Ze of Cc af i OO cUOME eng ne pillar five ig nio Jue of op box Afisi Hex Zei ex alar Pug fo geil ferrite Foar cornenr rounded with b ar boety fier Hm i Loss Des secure fo bp of pillar by means of bear TRID PLAN Fig 6 Details of the tilt and turn assembly 676 Everyday Practical Electronics September 2000 Underside of the turret assembly showing four wheels set in the plywood base to relieve the strain on the jack plug The wheels are taken from curtain runners and mounted on spindles cut from a wire coat hanger The wheels are cushioned on a disc of thin leather above right to allow the turret to glide around freely and silently turn If the lowest frequencies cannot be covered even when the coil is central a turn or two should be added LOOP MOUNTING Now for the task of putting everything together to give a neat finish Two sugges tions are put forward one fairly basic and the other almost a professional work of art but not so hard to achieve as it looks Simple System The mounting of the aerial section must allow the loop to rotate and tilt and read ers will have their own ideas for this It can consist simply of a 25mm square wooden post secured by a screw driven through the top of the control unit case and free to rotate The bundle of ferrite
108. ack down to a known voltage that way or place a load across the battery and use a voltmeter Avoid merely connecting a bulb and letting it run flat Internet users can fetch a couple of inter esting old documents from our FIP site which describe some of the chemistry behind the so called memory effect Go to ftp ftp epemag wimborne co uk pub docs Down with heavy metal Today my advice would be to choose Nickel Metal Hydride NiMH types instead which are a development of the Nickel Cadmium cell They are more envi ronmentally friendly eliminating the use of heavy metals Cadmium Better still size for size NiMH cells have up to 40 per cent extra capacity though their discharge char acteristics are broadly the same as Ni Cd cells their terminal voltage runs along a plateau and then plummets suddenly I find NiMH cells indispensable for heavy loads such as my digital camera and flashguns The elimination of Cadmium also vastly reduces the cell s susceptibility to memory effect more correctly called voltage depression where the cell cannot return to the original voltage However it is strongly recommended that you never leave a NiMH battery con nected to a load such that it is allowed to completely discharge the battery or as with NiCads it may suffer voltage rever sal Always remove the load from a NiMH battery before it is too late I find this slightly disconcerting as I need to leave a set of NiMH cel
109. ail Xx D I KA Z3 re aca um i 1 F T 100 b SAS 5320 1A 2504 112 x 42 x Simm r4 18 39 x 15MM 120 x 65 x 40mm KA i Gg Gi Meg hau k Gi x 20 x mm SI on Latehin ush lo Make x x rmm ER Black PTM M CO oi Steel Aluminium Red PTM 0 40 Plastic coated steel top Blue PTM 00 60 Aluminium base qd O Pn cm atching push On push X x 51mm ack 0 65 x 127 x 63mm 5 80 Red SEN 114 x 43 x 5 mm 3 04 AL d White 60 65 a Rocker Switches Price per 305 mim 141 Miniature 10 Way Grey Ribbon 0 10 amp A 250V Solder Tags 16 Way Grey Ribbon 0 17 SPST 21 x 14 x l mm 0 67 20 Way Grey Ribbon 0 24 DPDT 21 x 24 x 22mm 0 96 n Woy Grey Ribbon 0 29 SPST Red Neon 1 02 34 Way Grey Ribbon 0 38 SPST Green Neon 7 02 40 Way Grey Ribbon 0 49 Eae Amber Neon 1 02 20 Wer y Grey qibbon YU ay Grey Ribbon d 15A 250V Push on Togs Emerme Copper Wire illo 30 x A 22mm 0 58 Par 50g 202 Rael n eis gwai vi genee on Cou erp avaible 097 GE xl mm R 4 l SW Enamelled STER DEST 30x25mm Amber 1 40 18 SWG Enamelled 0 97 DPST 30x25mm Green 1 40 0 we Ena meile So Rela name 1 01 PCB Mountin Si SWG Enameled EL Ig JA 24Vde DPDT SV 138 36 WR Enameled E122 1A tide DPDT 12V 2 00 30 Sw Enamelled E124 3A 110V SPDT amp V 0 58 35 EWG Enamelled 1 25 JA 110V SPDT 12V 0 58 44 BWG Enamelled 127 A 110V SPDT 0 72 36 SWG Enamelled 1 29 SA IHN SPOT 12V 0 72 38 SW G Enamelled 1 55 5A 110 DPDT 4 0 93 40
110. al but unusual parts that are needed to complete a project Most component suppliers now have online catalogues at their web sites and you should certainly pay these a visit if you have Internet access lgnoring the Shoptalk feature is a common error This gives at least one source of supply for any difficult to obtain parts used in EPE projects Mega Projects Building a large and exotic project is a good way to impress your family and friends but only if it works It is stating the obvious to say that beginners should choose beginners projects but some succumb to the temptation to go for something more impressive 694 Provided you choose simple projects to start with there is an excellent chance that they will all work You may have to sort out one or two simple mis takes but there should be no major dif ficulties With larger projects there are more opportunities for things to go wrong and it can be more difficult to sort things out if problems do occur Only build a project if you fully under stand its function and use Another good way to get into difficul ties is to build a project that is not nec essarily all that complex but has a highly technical or obscure function that you do not really understand At one time there was a steady trickle of letters from readers who were having problems simply because they had misunderstood the exact function of a project Thankfully this type of thing is relatively rare thes
111. als up to about 5KHz Software amp D shell case provided 3112KT 19 95 20 MHz FUNCTION GENERATOR Square tri angular and sine waveform up to 20MHz over 3 ranges using coarse and fine frequency adjust ment controls Adjustable output from 0 2V p p A TTL output is also provided for connection to a frequency meter Uses MAX038 IC Plastic case with printed front rear panels amp all components provided 7 12VAC 3101KT 54 95 30 in ONE Electronic Projects Lab Great introduction to electronics Ideal for the budding elec tronics expert Build a radio burglar alarm water detector morse code practice circuit simple computer circuits and much more NO soldering tools or previous electronics knowledge required Circuits can be built and unassembled repeatedly Comprehensive 68 page manual with explana tions schematics and assembly diagrams Suitable for age 10 Excellent for schools Requires 2 x AA batteries ONLY 17 95 phone for bulk discounts Secure Online Ordering Facilities Full Kit Listing Descriptions amp Photos Kit Documentation amp Software Downloads 644 Everyday Practical Electronics September 2000 A PAGE RTR ABEE fe A AI Experiments ideas lor DrDAQ Fackenng Lapte sb Sp Dean C honung Bs hott m car Ues neos e 1 11 A1 4 Sear dy mt fn 10640 85 275 a Viera wit Light jCH11 Bound sumatoria o mural r rgesr lus Lan decay rreergo diana Imm e La
112. any under takings in respect of statements or claims made by advertisers whether these advertise ments are printed as part of the magazine or in inserts The Publishers regret that under no circum stances will the magazine accept liability for non receipt of goods ordered or for late delivery or for faults in manufacture Legal remedies are available in respect of some of these circumstances and readers who have complaints should first address them to the advertiser TRANSMITTERS BUGS TELEPHONE EQUIPMENT We advise readers that certain items of radio transmitting and telephone equipment which may be advertised in our pages cannot be legally used in the UK Readers should check the law before buying any transmitting or telephone equipment as a fine confiscation of equipment and or imprisonment can result from illegal use or ownership The laws vary from country to country readers should check local laws 651 lop Tenners STEEPLECHASE GAME OWEN BISHOP Project 2 This short collection of projects some useful some instructive and some amusing can be made for around the ten pounds mark The estimated cost does not include an enclosure for many of them work just as well as an open board All of the projects are built on stripboard and have been designed to fit on to boards of stan dard dimensions All of the projects are battery powered so are safe to build In a few cases in which by its nature the project i
113. apacitance of the varicap and the low frequency limit of the tuning range Bypass capacitor C2 eliminates any poten tiometer noise O MULTIPLIER Dual gate MOSFET TRI amplifies the signal voltage developed across coil L1 in order to provide Q enhancing positive Everyday Practical Electronics September 2000 2N3819 feedback The gain of TRI and hence the Q multiplication is controlled by VR4 which determines the voltage on gate g2 The stage is decoupled from the supply by preset VR5 and capacitor C5 Making the decoupling resistor variable enables the operating conditions to be adjusted to suit different dual gate MOSFETs Positive feedback is applied via source bias resistor RA and its bypass capacitor C4 to coil winding L2 BUFFER The impedance of the tuned circuit is very high at resonance and most communi cations receivers have a low input imped ance typically 50 ohms Source follower stage TR2 with its high input and low out put impedance matches the loop aerial to the receiver The voltage gain of a source follower is slightly less than unity There is however a significant power gain Decoupling of the source follower stage is provided by resistor R5 and capacitor C7 and the output is developed across source POLE 5 B O S1b 60 R7 2k7 du B1 a 9V D we E gt 2mA C7 100n A OUTPUT OUTPUT 30 LEVEL Sta C6 VR6 10n 1k load resistor R6 Output level control VR6 could be conn
114. art 10 we made the point that the become common usage however for any reference diode to be referred to as a Zener diode Commonly encountered circuit diagram symbols for Zener diodes were shown in Part 4 Fig 4 4 A symbol is also shown in the screen display accessible via the Zener Diode option of the main program menu Select and run this option and also see Photo 11 1 O The maximum current that can be drawn by the load circuit it powers O The maximum current which is per mitted to flow through the diode when the load circuit is drawing least current A Zener diode requires a minimum current flow for the reverse voltage break down to occur at the correct voltage level ing to know is how we ensure that d c supplies do maintain consis tent voltage levels One answer lies in the use of Zener diodes which were men tioned in Part 4 Let s examine them next ZENER DIODE In Part 4 Panel 4 1 it is stated that all diodes have a maximum reverse breakdown voltage limit In other words you normally only exceed that limit at the diode s peril The reverse breakdown volt age however is not always disas trous and there are ways in which it can be put to good use Zener or reference diodes have their construction modified during manufacture so that the reverse current flow commences at a spe cific voltage Provided that the current flow is limited this
115. as described it gen erates a moderate amount of heat much of which seems to come from the trans former To assist with dissipation a large heatsink was screwed to the top of the box and overnight use with the EPE Moodloop results in it becoming quite warm but not too hot to touch which is quite acceptable for modern electronic components If 4mm sockets are used as shown for the output it is essential to ensure the leads are plugged in the correct way round when using it with the Moodloop as reversing the supply polarity would dam age this A later addition to the prototype which may be seen in the photographs was a concentric type power socket wired in par allel with the 4mm output sockets This was placed at the rear so that the cable was out of the way when in use The unit is capable of continuous output of up to about 1A in fact most regulators of this type can actually supply a little more than their nominal 1A output for short peri ods Momentary short circuiting of the out put should not cause damage as they also generally have internal fold back current limiting protection although for longevity prolonged short circuiting and overload of the output should obviously be avoided NEXT MONTH We present a Magnetic Field Strength Checker Ideal for indicat ing the presence or absence of force fields from the EPE Mooodloop relaxation project Aug 00 and other sources of magnetic radiati
116. ave come on the market The site uses the latest web security systems so you can order on line with complete confidence The site is at www shesto com Other contacts with Shesto Ltd can be made with them at Unit 2 Sapcote Trading Centre 374 High Road Willesden London NW10 2DH Tel 020 8451 6188 Fax 020 8451 5450 E mail sales shesto co uk Everyday Practical Electronics September 2000 655 YEDA 2000 THE 2000 Young Electronic Designer Awards ceremony took place in London on 6 July HRH The Duke of York presented the awards at the Millennium Dome during a cele bration dinner attended by 200 guests including parents teachers local dignitaries and members of the business community The Awards now in their 15th year recognise the creativity and initiative of young people using modern technology They are open to students between the ages of 12 to 25 in secondary schools colleges and universities The competition challenges young designers to invent and produce a novel electronic device that meets an everyday need The overall objective is for contestants to have fun putting their ideas into practice and in so doing to discover the exciting opportunities which a career in the electronics communications and IT industries can offer Awards were made in three categories The Duke of York s Award for the most imag inative concept a prize for the most commercially viable project and the IEE Award to the best new entrant to YEDA Th
117. beginners are welcome and you can rely on us for practical and responsible advice We try to help with general electronics related queries and offer pointers where we can but we cannot design custom circuits to order help with spares or repairs nor does this column deal with microcontroller pro gramming sorry We know that Circuit Surgery is amongst the maga zine s most popular columns There is however an increasing dearth of what we would term sensible questions many queries received are simply unanswerable and some readers hope a complete chapter will be written special ly for them and faxed E mailed by return We welcome queries from edu cation including further and higher edu cation although we cannot always promise a reply unless we intend to use it in the magazine So if you have a sensible question that you think would be of interest to other readers please write to us at the Editorial address or ask by E mail to alan epemag wimborne co uk and we ll do our best to help through the medi um of this column with David Barrington Active Ferrite Loop Aerial One or two components needed for the Active Ferrite Loop Aerial require further comment and could possibly give some readers local sourcing problems As pointed out by the author most varicap diodes designed for Medium Wave tuning with a 9V maximum bias should be OK in this circuit The one specified in the article is the KV1236 d
118. boot light voltage drop sensor and bonnet boot earth switch sensor Entry exit delays auto reset and adjustable alarm duration 6 12V DC PCB 47mm x 55mm 1019KT 11 95 Box 6 50 PIEZO SCREAMER 110dB of ear piercing noise Fits in box with 2 x 35mm piezo elements built into their own resonant cavity Use as an alarm siren or just for fun 6 9VDC 3015KT 9 95 COMBINATION LOCK Versatile electronic lock comprising main circuit amp separate keypad for remote opening of lock Relay supplied 3029KT 9 95 ULTRASONIC MOVEMENT DETECTOR Crystal locked detector frequency for stability amp reliability PCB 75x40mm houses all components 4 7m range Adjustable sensitivity Output will drive external relay circuits 9VDC 3049KT 12 95 PIR DETECTOR MODULE 3 lead assembled unit just 25x35mm as used in commercial burglar alarm systems 3076KT 8 95 INFRARED SECURITY BEAM When the invisi ble IR beam is broken a relay is tripped that can be used to sound a bell or alarm 25 metre range Mains rated relays provided 12VDC operation 3130KT 11 95 SQUARE WAVE OSCILLATOR Generates square waves at 6 preset frequencies in factors of 10 from 1Hz 100KHz Visual output indicator 5 18VDC Box provided 3111KT 8 95 PC DRIVEN POCKET SAMPLER DATA LOG GER Analogue voltage sampler records voltages up to 2V or 20V over periods from milli seconds to months Can also be used as a simple digital Scope to examine audio amp other sign
119. bot or Darlek Great fun for discos school plays theatre productions radio stations amp playing jokes on your friends when answering the phone PCB 42x71mm 1131KT 8 95 O AUDIO TO LIGHT MODULATOR Controls intensi ty of one or more lights in response to an audio input Safe modern opto coupler design Mains voltage experience required 3012KT 7 95 MUSIC BOX Activated by light Plays 8 Christmas songs and 5 other tunes 3104KT 6 95 20 SECOND VOICE RECORDER Uses non volatile memory no battery backup needed Record replay messages over amp over Playback as required to greet customers etc Volume control amp built in mic eVDC PCB 50x73mm 3131KT 11 95 O TRAIN SOUNDS 4 selectable sounds whistle blowing level crossing bell clickety clack amp 4 in sequence SG01M 5 95 FACTOR PUBLICATIONS THE EXPERTS IN RARE amp UNUSUAL INFORMATION Full details of all X FACTOR PUBLICATIONS can be found in our catalogue N B Minimum order charge for reports and plans is 5 00 PLUS normal P amp P SUPER EAR LISTENING DEVICE Complete plans to build your own parabolic dish microphone Listen to distant voices and sounds through open windows and even walls Made from readily available parts R002 3 50 TELEPHONE BUG PLANS Build you own micro beetle telephone bug Suitable for any phone Transmits over 250 metres more with good receiver Made from easy to obtain cheap components R006 2 50
120. by condensation or water leakage You were unable to pinpoint the problem so my advice is to get it looked at by a profes sional or treat yourself to a new one instead ARW Ferric Disposal If you re looking to dispose of highly corrosive Ferric Chloride etchant safely at home there is a problem In some coun tries the use of this etchant by the public is banned altogether You can t put it in the waste disposal nor bury it nor are you supposed to flush it down drains or toilets and definitely don t pour it down a sink I m told that it can be rendered safe by mixing it with Sodium Hydroxide caustic soda The sodium and chloride will com bine to make salt whilst the iron and cop per will settle but I haven t confirmed this Sodium Hydroxide is itself already useful as a developer for UV exposed boards but as a caustic product it has its own share of handling hazards An alternative suggestion is to mix Sodium Carbonate common washing soda crystals with the Ferric Chloride then mix the result in with cement or Plaster of Paris which can then safely be thrown away Comments from chemists would be welcomed ARW Assault and Ni Cad Battery From Mr D E Gardner of Yateley Hants came a query in respect of the cor rect use of Nickel Cadmium Ni Cd bat teries The increased use of digital cameras camcorders and radio control means that there are ever more Ni Cads in circulation Their life will be extended if tr
121. can be dam aged by overheating Semiconductors are much less tolerant of heat and are easily damaged by leisurely soldering It is a good idea to buy some resis tors and a piece of stripboard and use these to practice soldering before try ing to actually build your first project You will then get up to speed before you start building in earnest and any burnt sacrifices you produce initially will be of no consequence Broken Wires It is tempting for the beginner to improvise when it comes to cutting wires and stripping insulation from them Homespun methods that involve sharp knives have to be regarded as decidedly dangerous Scissors are a less dangerous option but will soon be ruined if they are used to cut wires and do not provide the sort of precision that is required A problem when using anything other than proper wire strippers is that the wires are almost invariably nicked slightly during the stripping process This seriously weakens the wires which then easily fatigue and break Use multi strand connecting wire rather than the single core vari ety that is very prone to this breaking problem A cheap pair of combination wire cutters and strippers should last many years and will avoid a lot of problems These have notches in the cutting blades see Fig 2 so that they can be adjusted to cut through the insulation without damaging the wires within Always set wire strippers for the largest aper
122. cations This book provides a number of useful PC add on cir cuits including the following Digital input output ports Analogue to digital converter Digital to Analogue Converter Voltage and Current measurement circuits Resistance meter Capacitance meter Temperature 704 measurement interface Biofeedback monitor Constant voltage model train controller Pulsed model train con trollers Position sensor optical Hall effect etc Stepper motor interface Relay and LED drivers Triac mains switching interface 179 pages Order code BP385 4 99 INTRODUCTION TO MICROPROCESSORS John Crisp If you are or soon will be involved in the use of microprocessors this practical introduction is essential reading This book provides a thoroughly readable intro duction to microprocessors assuming no previous knowl edge of the subject nor a technical or mathematical back ground It is suitable for students technicians engineers and hobbyists and covers the full range of modern microprocessors After a thorough introduction to the subject ideas are developed progressively in a well structured format All technical terms are carefully introduced and subjects which have proved difficult for example 2 s complement are clearly explained John Crisp covers the complete range of microprocessors from the popular 4 bit and 8 bit designs to today s super fast 32 bit and 64 bit versions that power PCs and engine management systems etc Co
123. ce Hewlett Packard 8180A Data Generator Hewlett Packard 8182A Data Anahtser eueessesssrrtererrrsssssssREEEEEEEEEEEESEEEREEEEEEEEEEEEEEEEREEEEEEEEEEEEE 1500 Hewlett Packard 8350B Sweep Oscillator Mainframe various plug in options available 2500 Hewlett Packard 83554A Wave Source Module 26 5 to 40GHz c cccceerereeeennn 3500 Hewlett Packard 83555A Millimeter Wave Source Module 33 50GHZ snnnnnnnnnnnnnnnnnnnnnnnnnnnn 4250 Hewlett Packard 8405A Vector Voltmeter nnsnnnnnnnnsnnas 350 Hewlett Packard 8620C Sweep Oscillator Mainframe eere eren rennen enne from 250 Hewlett Packard 8640B Signal Generator 512MHZ 1024MHZ ee ease from 850 Hewlett Packard 8642A Signal Generator 0 01 to 1050MHz High Performance Synthesiser 6500 Hewlett Packard 8656A Synthesised Signal Generator 990MHZz 850 Hewlett Packard 8656B Synthesised Signal Generator 11 cerseeeee esee a sana nun 1450 Hewlett Packard 8657A Signal Generator 100kHz 1040MHZ eere eeu uu uera nn 1900 Hewlett Packard 8660D Synthesised Signal Generator 10kHz 2600MHZz 3250 Hewlett Packard 8750A Storage Normaliser nano uuu u auus au uuu nana 295 Hewlett Packard 8756A Scalar Network AnalySet sssssssssssesssssssss
124. cessing power or memory capacity to harbour viruses There have been no viruses yet for Windows Pocket CE and Palm devices which do not support Macros Virus writers want to infect the world says Cluley They will not waste time infecting devices that cannot spread infec tion But this may change as higher speed mobile devices work hand in hand with PCs Terrestrial digital broadcaster On Digital will soon provide Internet connection via an add one module and phone line Will this leave digital receivers open to infec tion that for instance re flashes their operating system chips Tt all depends on the kind of digital sig nature they use says Cluley The box must ignore any update that arrives with out the correct digital signature it could be PGP or Verisign with private and public key But the general rule is simple the more bits the better TOOLS SITE ITE SHESTO Ltd specialist suppliers of tools and equipment for technicians and crafts men have opened their web site They describe it as an ideal way to locate hard to find and innovative tools Over 900 products can be viewed and selected via this easy to use and navigate Web site It also features the latest news on exhibitions and events of interest to model makers electronics hobby and DIY enthusiasts Each month special offers will be available at very advantageous prices as well as features on interesting new products that h
125. ctions Multi stage Amplifiers 3 sections Filters Passive Filters 10 sections Phase Shifting Networks 4 sections Active Filters 6 sections Oscillators 6 sections from Positive Feedback to Crystal Oscillators Systems 12 sections from Audio Pre Amplifiers to 8 Bit ADC plus a gallery showing representative p c b photos Complimentary output stage Twin T phase shifting network Digital Electronics builds on the knowledge of logic gates DIGITAL ELECTRONICS covered in Electronic Circuits amp Components opposite and takes users through the subject of digital electronics E DE up to the operation and architecture of microprocessors mmm e Se The virtual laboratories allow users to operate many circuits on screen Covers binary and hexadecimal numbering systems ASCII basic logic gates 5 and their operation monostable action and circuits and bistables including F min ialis ii rai n m JK and D type flip flops Multiple gate circuits equivalent logic functions and T Err ILE E Mee TT T T TT Dee specialised logic functions Introduces sequential logic including clocks and Ur em clock circuitry counters binary coded decimal and shift registers A D and D A converters and their parameters traffic light controllers memories and Virtual laboratory Traffic Lights Microprocessor microprocessors architecture bus systems and their arithmetic logic units Filters is a complete co
126. cuit of the timer Part of the internal circuit of the 7556 timer is shown in Fig 2 This is the part that is concerned with detecting when the voltage across the timing capacitor has reached two thirds of the supply voltage Vcc or VE The resistor chain has three equal value resistors and since they are all manufactured on the same chip these are very closely matched This explains why the timer i c has such good accuracy A comparator detects when the threshold voltage the voltage across the capacitor has risen to be exactly equal to two thirds of the supply At this point the comparator changes state and resets the timer Its output goes low The circuit in Fig 2 shows why it is unnecessary to connect anything to the control voltage input when using the timer in the normal way In the absence of any connection that point on the resistor chain sits at two thirds of Vcc However if an external voltage is con nected to the resistor chain through the control voltage input it is possible to pull the voltage at that point higher or lower than two thirds of supply The comparator will then reset the timer when the capaci tor charge reaches a voltage other than two thirds of the supply voltage It resets earlier or later than usual If the timer is running as an astable as in this circuit the effect is to alter its frequency In this circuit the source of the control voltage is the voltage across the capacitor of
127. d threads Over tightening the fixing nuts on smaller components can even result in the front section breaking off com pletely Tighten mounting nuts enough to fix the components securely in place but do not necessarily go on turning them until you cannot force them any further Bit of Advice The EPE web site www epemag wimborne co uk is the place to go if you would like to Know how to sol der properly There you will find a comprehensive and fully illus trated guide to soldering There are two common mis takes that newcomers tend to make when they first try their hand at soldering The obvi ous way to solder is to first melt the solder on the tip of the iron and to then transfer the molten solder to the sur faces that are to be joined Unfortunately in this case the obvious method is definitely the wrong way of doing things The type of solder used for electrical work has cores of flux which help the solder to flow over the wires copper pads etc so that a good electrical connection and a physically strong joint are produced The problem with apply ing the solder to the bit first and the joint second is that the flux tends to burn away before the solder reaches the joint Another problem is that the solder is applied to a cold joint and it tends to solidify as soon as it touches any of the cold metal surfaces This factor plus the lack of flux results in the solder not flowing over the surfaces properly giv
128. d by Farnell 0113 263 6311 or www farnell com code 438 029 and Maplin 0870 264 6000 or www maplin co uk code AR80B The 20VA mains transformer with two independent 15V sec ondary windings is an RS product and can be ordered through any bona fide RS stockist or through Electromail Ex 01536 304555 or 688 http rswww com their mail order outlet It carries the order code 805 079 Any readers who experience difficulty finding a suitable 10 000uF 35V working radial electrolytic capacitor will find one stocked by Maplin under their HC series code AU23A At nearly 4 it seems a bit on the high side but capacitors do appear to be more expensive nowadays The same company also supplied the flat type undrilled aluminium heatsink code FL42V Most of our components advertisers should be able to supply a suitably sized two piece alu minium box Remote Control IR Decoder We have only been able to trace one source for the IS1U60 sen sor used in the Remote Control IR Decoder project This is a complete 3 pin infra red remote control receiver com plete with integral lens and EMI shielding manufactured by Sharp and was purchased from Electromail Ex 01536 204555 or http rswww com code 577 897 It can also be ordered through any bona fide RS Components stockists The chip also contains enough processing circuits to convert the incoming modulated sig nal to a logic pulse train output Unprogrammed PIC16x84s are n
129. d current flow in circuits plus text plus cartoon instruc tion etc and a very full commentary to get the points across The tapes are imported by us and originate from VCR Educational Products Co an American supplier We are the worldwide distributors of the PAL and SECAM versions of these tapes All videos are to the UK PAL stan dard on VHS tapes unless you specifically request SECAM versions Everyday Practical Electronics September 2000 Bell College Almada Street Hamilton Scotland ML3 OJB Tel 01698 283100 Fax 01698 282131 Make your Expertise pay In today s world you need qualifications to obtain and keep employment Our open learning courses make obtaining those qualifications as convenient as possible BTEC PROFESSIONAL Choose from our dozens of SQA accredited units either DEVELOPMENT CERTIFICATE singly to update your skills or as a group to obtain a Higher National Certificate o Learn at your own pace in your own home Support from professional engineers via phone FAX and the Internet Courses from Introductory Bridging Modules to HNC Electronics BELIS College XM e hbe DISTANCE LEARNING COURSES in Analogue and Digital Electronics Fibre Optics Fault Diagnosis Mechanics Mathematics and Programmable Logic Controllers leading to a Suitable for beginners and those wishing to update their knowledge and practical skills Courses are very practical and delivered as
130. d example of waveform modifica tion when examining the waveforms generat ed by the oscillator and its variants first discussed in Part 4 Fig 4 2 In the oscillator the waveform feeding into its resistance path is a square wave alternating between OV and 6V as sup plied by the output of Cla pin 2 yet the waveform at the junction of the resistance and the capacitor is approximately triangu lar and having an amplitude swing of much less than this With this oscillator of course as soon as the voltage on the capacitor reaches certain thresholds so the inverting gate s output changes its logic state SLOPING OFF Let s examine what happens if the oscil lator gate s output is also fed into two sep arate resistance capacitance circuits Modify the oscillator circuit on your bread board so that it matches the layout in Fig 11 3 The equivalent circuit diagrams and component values are given in Fig 11 4 and Fig 11 5 later It is the circuit of Fig 11 4 that we shall discuss first Connect the junction of C2 and VR2 V Out Integrate to the input of the ADC IC2 pin 2 as indicated Set the wiper of VR2 fully clockwise minimum resistance Adjust VR1 until the oscillator Led flash es at about once per second Run the Analogue Input Waveform Display program and observe the wave form displayed At this time there is no significant resistance between ICla pin 2 and capaci tor C2 and the waveform seen will be t
131. d loop tuned to a strong transmission the receiver s signal strength meter should be driven hard over Turn down Level control VR6 until the signal strength meter reads about half scale Advancing the Q multiplier control VR4 should now drive the pointer hard over again Loop tuning has to be very precise at high O levels and it may be necessary to use Fine tuning control VR2 to bring loop and receiver into perfect alignment Check that the loop can be tuned over the required frequency range and adjust preset VR3 until the low frequency limit is reached with VR2 at minimum resistance Set preset VR5 so that the loop just glides into oscillation with Q control VR4 at maximum when tuned to a station near the low frequency end of the band Sliding the coil along the ferrite rods will change its inductance and coverage can be adjusted in this way If it has to be located very close to the end remove a 675 ACTUVIE FERRITE LOOP ABRIAL o Aoc or un shal box quaa ode at E og arial 37 372 Zen wierna Fi gU y a Gi L aoe b E Nylon erue cord d Ft FRA Mee gh Pus pista e 212 brass e es SECTION Fo pereo PNE AIE Drive COE WOE e f ene ern around 3n Mood pillars gloed and uev dE GC Seon m Omnm da ase COIS Sam AG Ino peice WoT Connenr rounded C ww ser body f Mer So SS y AFAN aca hack Sage we hene o pvp dio di A e 0 er me eA 6 Am tre Dad 3 Jveecor FEY
132. d mechanical or electro mechanical features The umlsolation device consists of two CMOS die assembled into a common package Wires then provide the connec tions to the coil on the output of the CMOS circuitry This coil has a high Q and is fab ricated on the top of the receiver die A second coil is also fabricated with an insu lating oxide layer between it and the first coil so that inductive coupling between the two coils enables the signals to be trans mitted across the insulating layer The cir cuitry connected to the second coil again fabricated using CMOS technology recon stitutes the signal in its original form The coil insulation and circuitry are all contained within the same monolithic assembly The design of the chip is such that there is sufficient isolation for Operation up to 2500 volts r m s Advantages The new umlsolation inte grated circuits offer many advantages to the electronics designer requiring high speed data transmission over an isolated link Not only is it possible to use a single chip to perform this function but the fact that the coils are tightly coupled means that there are no cross talk and interference concerns This aspect can be developed to allow several isolator channels to be incorporated within the same package allowing a large number of data lines to be coupled This provides further size and cost savings when it is compared to other opto coupler implementations A furt
133. d to the OV power line the voltage at its junction with the capacitor C3 would swing above and below OV The ADC cannot be fed with a negative going voltage and so the wave form is referenced to 3V instead As you did with the integrator circuit once more experiment with different values of capacitance resistance and frequency and observe the waveforms on your com puter screen Additionally if you feel adventurous use an op amp to buffer amplify the now you know it s not triangular waveform from Cla pin 1 and then experiment with the resulting output connected to the differ entiator and integrator in place of the square wave output from Cla pin2 Op amp IC3a pins 1 2 and 3 is currently unused on your breadboard and you can connect it in the fashion described when we discussed op amps Parts 7 and 8 PANEL 11 1 THEY LEAK A BIT In your various experiments using the oscillator around ICla you may have found that large values of capacitance and or resistance can prevent the oscilla tor from functioning It s now opportune to comment on why large values of C and R may inhibit oscil lation An important thing to know about electrolytic capacitors is that they are a bit leaky the charge on one plate tends to leak across to the other progressively dis charging the capacitor With large values of R the rate at which the resistor allows the capacitor to charge up could be slower than the rate at which t
134. ddurl html Yahoogle Search engines represent a whole industry technology in them selves If Google doesn t carry advertising why is it free Apart from the streamlined front end with which many of us are familiar its database is sold to firms who are looking for a search engine perhaps to embed within a portal site Yahoo www yahoo com is perhaps the best known on line directory as distinct from an open search engine Its contents are 702 Hein arci Sorte ica hips Check viep gas dn baci bna A ee uim pags Jose LES ee ae SOT e mH ee mus A 28 645 900 Here uo te O ENEE Me hom controlled by Yahoo editors who decide what is entered into the Yahoo database Yahoo thinks highly of its users and wants them to have the best search experience so Yahoo prefers to index reliable and corporate looking web resources rather than scrappy personal home pages that might disappear or completely change content overnight This reminds me of an E mail from an American reader who informed me that one of the web links listed in my Net Work A Z listing www epemag wimborne co uk netwkaz htm had changed from an electronics related resource to one showing a photo of a topless blonde female not that he was complaining For the same sort of reason Yahoo is choosy about the sites it enters in its directory and web designers place considerable importance in the black art of getting a good placing in Yahoo What is le
135. dents outside the UK add 5 for airmail postage per order Electronic Circuits amp Components The Parts Gallery Note The PICtutor CD ROM is L PlCtutor Development Kit Deluxe L Deluxe Export not included in the Kit prices L Electronic Components Photos Modular Circuit Design Single User Modular Circuit Design Multiple User Note The software on each version is I I I I I I I I I I I I I I 1 L PlCtutor Development Kit Standard I I I I I I I the same only the licence for use varies I I I I I I I gif uU PCT Pn EE wey Boone bia Rhee pied SEROUS dci p xd Rs ER Sega ue ara dad dE eR d O E E E E E E E E E E E Kee Post code o socorro tes TONOS Souto potes tens l O eas i enclose cheque PO in sterling payable to WIMBORNE PUBLISHING LTD for l L Please charge my Visa Mastercard Card expiry date i card No e e e e NEE be hehe de a EE eee S l I Please supply name and address of cardholder if different to the delivery address ee50b PRACTICALLY SPEAKING Robert Penfold looks at the Techniques of Actually Doing It THEORY at any rate summer should be nearing its end when this maga zine is on the bookstalls and thoughts should be turning away from outdoor pursuits towards indoor activities such as project build
136. ds unzipping before use Unzip utilities can be downloaded http www epemag wimborne co uk wwwboard from Or buy EPE Online www epemag com http www winzip com or http www pkware com Everyday Practical Electronics September 2000 TRAIN TODAY FOR A BETTER FUTURE Electrical Contracting amp Installation Electrical Engineering C amp G ICS Basic Electronic Engineering C amp G ICS Basic Mechanical Engineering TV and Video Servicing Radio and Hi Fi Servicing Refrigeration Heating amp Air Conditioning Motorcycle Maintenance Now you can get the skills and qualifications you need for career success with an ICS Home Study Course Learn in the comfort of your own home at the pace and times that suit you ICS is the world s largest most experienced home study school Over the past 100 years ICS have helped nearly 10 million people to improve their job prospects Find out how we can help YOU Post or phone today for FREE INFORMATION on the course of your choice FREEPHONE 0500 581 557 Or write to International Correspondence Schools FREEPOST 882 8 Elliot Place Clydeway Skypark Glasgow G3 8BR Tel 0500 581 557 or Tel Fax Dublin 285 2533 A A A SENS WE WO END Please send me my Free Information on your Electronics Courses Mr Mrs Ms Miss BLOCK CAPITALS PLEASE From time to time we permit other carefully screened organisations to write to you about products and services If you would pref
137. dual trace 50MHx 20MS s 450 H P 54200A Digitising 50MHz 200MS s PHILIPS PM3217 Dual Trace 50MHz Delay VERY GOOD OSCILLOSCOPE Incl 2 probes pouch amp Front cover THIS IS THE BEST CHEAP SCOPE ED BUY GOULD 0S1100 Dual Trace 30MHz Delay Very bright Supplied with manual and two probes TEKTRONIX 400 SERIES 468 Digital Storage Dual Trace 100MHz Delay 466 Analogue Storage Dual Trace 100MHz Delay 485 Dual Trace 350MHz Delay Sweep 475 Dual Trace 200MHz Delay Sweep 465 Dual Trace 100MHz Delay Sweep Used Equipment GUARANTEED Manuals supplied This is a VERY SMALL SAMPLE OF STOCK SAE or Telephone for lists Please check availability before ordering CARRIAGE all units 16 VAT to be added to Total of Goods and Carriage 691 Everyday Practical Electronics are pleased to be able to offer all readers these ELECTRONICS CD ROMS Analogue Electronics is a complete learning resource ANALOGUE ELECTRONICS for this most difficult branch of electronics The CD ROM includes a host of virtual laboratories animations diagrams photographs and text as well as a SPICE electronic circuit simulator with over 50 pre designed circuits Sections on the CD ROM include Fundamentals Analogue Signals 5 sections Transistors 4 sections Waveshaping Circuits 6 sections Op Amps 17sections covering everything from Symbols and Signal Connections to Differentiators Amplifiers Single Stage Amplifiers 8 se
138. e total 3650 25W 2 85 RP7 10 each value total 730 0 25W 4 10 RP10 1000 popular values 0 25W 5 85 RP4 5 each value total 365 0 5W 3 80 RP8 10 each value total 730 0 5W 6 45 RP11 1000 popular values 0 5W 8 15 Millions of quality components at lowest ever prices Plus anything from bankruptcy theft recovery frustrated orders over productions etc Send 54p stamped self addressed label or envelope for clearance lists Brian J Reed 6 Queensmead Avenue East Ewell Epsom Surrey KT17 3EQ Tel 07775 945386 or 0208 393 9055 Mail Order UK only Lists are updated and only 40 are sent out every 2 weeks This normally ensures that orders can be fulfilled where only a few thousands of an item is available Payment is returned if sold out do not deal in credit notes ADVERTISERS INDEX A L ELECTRONICS N R BARDWELL BELL COLLEGE B K ELECTRONICS BRIAN J REED BRUNNING SOFTWARE BULL ELECTRICAL CHEVET SUPPLIES CRICKLEWOOD ELECTRONICS CROWNHILL ASSOCIATES DAVID JOHNS DISPLAY ELECTRONICS EPT EDUCATIONAL SOFTWARE ESR ELECTRONIC COMPONENTS FOREST ELECTRONIC DEVELOPMENTS 707 J amp N FACTORS JPG ELECTRONICS MAGENTA ELECTRONICS MICROCHIP NATIONAL COLLEGE OF TECHNOLOGY PEAK ELECTRONIC DESIGN PICO TECHNOLOGY QUASAR ELECTRONICS SERVICE TRADING CO SHERWOOD ELECTRONICS SLM MODEL ENGINEERS SQUIRES STEWART OF READING SUMA DESIGNS TELNET VERONICA KITS ADVERTISEMENT MANAGER PETER J ME
139. e infra red SIRC signal In most respects these transmissions are easier to decode than RC5 Several of the routines and variables used in the SIRC decoding program are similar to the ones used in the RCS program The command word is made up of 12 bits and consists of a 5 bit device code fol lowed by a 7 bit command code see Fig 8 This SIRC format uses pulse width modulation of the infra red signal to transmit the data The SIRC transmission is preceded by a single start bit unlike the RC5 code The SIRC decoding software waits for this start bit of 2 4 milliseconds When it is correctly received the START variable is set to 1 to allow the rest of the transmis sion to be decoded Using a unique signal as a start bit helps prevent the software trying to decode an incomplete transmission The infra red sensor uses this start pulse to set its auto matic gain control Everyday Practical Electronics September 2000 The SIRC command sequence is usual ly transmitted at least three times and for some reason best known to Sony the data is sent in reverse order There is no equiv alent to the control toggle bit as used in the RC5 protocol Like the RCS transmission there is no additional information trans mitted to allow for error detection The SIRC data consists of either pulses of 0 6ms or 1 2ms duration meaning logic O and logic 1 respectively Each pulse is preceded by a 0 6ms pause The pulse length is measured by the fal
140. e switches on and off as phone is used Power is drawn from line Output frequency 173 225 MHz Designed for use with ORX180 receiver Size 32mm x 37mm Range up to 500m 39 95 ORX180 Crystal Controlled FM Receiver Specifically designed for use with any of the SUMA O range kits High sensitivity design Complex RF front end section supplied as pre built and aligned sub assembly so no difficult setting up Headphone output PCB size 60MM x 75MM 9V operation aeos xu ko e e a n EA 69 95 TKX900 Signalling Tracking Transmitter Transmits a continuous stream of audio bleeps Variable pitch and bleep rate Ideal for signalling alarm or basic tracking uses High power output Size 25mm x 63mm 9 12V operation up to 2000m range 23 95 MBX 1 Hi Fi Micro Broadcaster Connects to headphone socket of CD player Walkman or Hi Fi and broadcasts your favourite music around house and garden up to 250m Size 27mm x 60mm 9V operation 4 25 26655 RR ERE eos 22 95 DLTX RX Radio Remote Switch System Two kits transmitter sends a coded signal 256 selectable codes when button pressed Receiver detects signal checks code and activates relay Can be set to be momentary or toggle on off operation Range up to 100m 9V operation on both units TX 45mm x 45mm RX 35mm x 90mm SEND 2 x 1st CLASS STAMPS FOR OUR 2000 KIT CATALOGUE CONTAINING FULL DETAILS OF THESE AND OTHER KITS A BUILD UP SERVICE IS AVAILABLE ON ALL OF OUR KITS
141. e New Technology Update e Net Work The Internet BACK ISSUES ONLY 3 00 each inc UK p amp p Overseas prices 3 50 each surface mail 4 95 each airmail We can also supply issues from earlier years 1992 except March April June to Sept and Dec 1993 except Jan to March May Aug Dec 1994 except April to June Aug Oct to Dec 1995 No Issues 1996 except Jan to May July Aug Nov 1997 except Feb and March 1998 except Jan March to May July Nov Dec 1999 We can also supply back issues of ETI prior to the merger of the two magazines for 1998 9 Vol 27 Nos 1 to 13 and Vol 28 No 1 We are not able to supply any material from ETI prior to 1998 Please put ETI clearly on your order form if you require ETI issues Where we do not have an issue a photostat of any one article or one part of a series can be provided at the same price ORDER FORM BACK ISSUES PHOTOSTATS INDEXES Send back issues dates Send photostats of article title and issues date Send copies of last five years indexes 3 00 for five inc p amp p Overseas 3 50 surface 4 95 airmail L_ I enclose cheque P O bank draft to the value of L Please charge my Visa Mastercard Card PT T Card Expiry Date Note Minimum order for credit cards 5 Please supply name and address of cardholder if different from that shown above SEND TO Everyday Practical Electronics Allen House East Borough Wimbor
142. e days Fig 1 A dry joint on the left and a good joint on the right Kid Gloves When I start on some do it yourself jobs around the house it takes a while to adjust to doing things on a larger scale am used to producing and working on intricate circuit boards not dealing with huge sheets of MDF and drilling large holes through walls Many people have the opposite prob lem when starting electronic project construction Most project cases are made from thin and relatively soft alu minium or plastics that are either soft or brittle Fibreglass circuit boards are quite tough but boards made from other materials are less durable Some makes of stripboard are quite brittle Applying the hammer and tongs approach to project construction is a good way to end up with a collection of battered and cracked cases and circuit boards Always proceed slowly and carefully using no more than moderate pressure For electronic project work hand tools or small cordless power tools are more appropriate than large power tools You also need to go at things in a restrained way when mounting compo nents on a front panel Most front panel components are mounted via a thread ed bush and a fixing nut Even with the larger components that have metal bushes tightening the nuts as if they were wheel nuts on a car could cause damage With the smaller components and those that have plastic bushes it would certainly produce some sheare
143. e of ballast resis tor and Zener wattage value can be critical in cases where higher currents are demand ed by the load There is a simple way of improving the Zener control by using a transistor to amplify the current available through the Zener s ballast resistor and then to power the load circuit using that amplified current In Part 9 we demonstrated how a transis tor could amplify current That technique is used in the Zener buffer circuit shown at the left of Photo 11 2 Remember that the transistor connection letters of c b and e are abbreviations for collector base and emitter The Zener diode is chosen to have a ref erence value of 0 7V above the load s sup ply voltage required from the emitter of transistor TRI This is to compensate for the 0 7V or so as discussed in Part 9 volt age drop between the silicon transistor s base and emitter The current which is required to flow through resistor R1 now only needs to be a fraction of that required by the load In fact it is typically chosen to be about the value of the load current divided by the gain of the transistor allowing a bit of margin in case somewhat greater currents than antici pated are drawn by the load and in case the gain is not necessarily known precisely remember that there is a spread of values that it can be for any individual transistor The minimum Zener current must also be taken into account Naturally the transistor type an npn d
144. eated prop erly but how do you do that Let s look at rechargeable battery options including the latest rechargeable alkaline types I would like to know how best to treat rechargeable Ni Cad batteries I guess I must have five different battery systems for my radio control models each battery needing a specific time for charging How far must a battery discharge before recharging There seem to be no proper facilities for discharging these battery packs so is there a simple way to do it Whilst queuing in an electronics store a customer walked in with a cordless phone which had suddenly stopped working The phone looked like new but it wouldn t work at all Dodgy rechargeable batteries were diagnosed and with a new set installed the phone sprang into life AII the previous two week s missed calls sud denly came in Ahem Constant trickle charging coupled with light use in between times is a sure way of shortening the working life of a Ni Cad which is the main reason why there is a thriving trade in replacement cordless phone batteries Ni Cad cells dislike repeated shallow discharges and of course everyone knows about the so called memory effect which is defined by Eveready as the characteristic attributed to nickel cadmium cells wherein the cell retains the characteristics of the previous cycling That is after repeated shallow depth discharges the cell will fail to pro vide a satisfactory full depth discharge
145. ected as the source load However the arrangement shown ensures that the impedance presented to the receiv er is reasonably constant Capacitors C6 and C8 block the flow of d c COMPONENTS Resistors 100k See 120k Oye 2M2 S 47 TALK 1k page 2k7 All 0 25W 5 carbon film Potentiometers VR1 47k rotary carbon lin VR2 1k rotary carbon lin VR3 47k enclosed carbon preset horizontal VR4 10k rotary carbon VR5 100k enclosed carbon preset horizontal VR6 1k rotary carbon log law if obtainable Capacitors C1 10n polycarbonate or Mylar 100n disc ceramic 4 off 1n disc ceramic 10n disc ceramic C2 C3 Semiconductors D1 KV1236 dual varicap diode Ye of D2 3mm or 5mm red l e d low current 2mA TH1 BF981 n channel dual gate MOSFET TR2 2N3819 n channel field effect transistor Miscellaneous L1 L2 ferrite loop aerial wound using 28s w g enamelled copper wire see text S1 3 way 4 pole rotary switch plastic cased Lorlin screw terminal post with 4mm socket top 2 off coaxial socket chassis mounting 2 off stereo jack socket and plug for linking ferrite aerial to main unit optional SK1 SK3 SK2 SK4 SK5 PL1 Printed circuit board available from the EPE PCB Service code 274 ferrite rod 9mm dia at least 150mm long 7 off see text instrument case for control unit size 170mm x 150mm x 50mm diecast screening box for p c b o
146. ectrostatic field Signal voltages are induced in loop aerials by the magnetic field Signal pick up by a long 20 metres plus high 8 metres plus wire and a decent earth will usually exceed that from even a large loop A coil wound on a 150mm x 9mm diameter ferrite rod will develop signal volt ages around Tia 18dB below those induced in a one metre square Mair cored loop A loop of these dimensions mounted so that 1t can tilt and turn is cumbersome and more than a little out of place in a domes tic setting However by increasing the size of the ferrite rod amplifying the output and multiplying the Q of the coil a ferrite loop can be made to outperform its bigger air cored brother This approach has been adopted in the design of the very compact unit which is described here FERRITE RODS Because of the high permeability of the ferrite the magnetic field radiated by the transmitter is concentrated in the rod and the signal induced in the coil wound around it greatly increased Bigger rods provide more signal pick up Some early ferrite loops produced for Medium Wave listening had rods more than a metre long This rather defeats the advantage of compactness and experi ments have shown that bundling the rods together to increase the overall diameter is as effective as placing them end to end to increase length Loops incorporating up to thirty rods have been produced Signal pick up i
147. ects to earphone socket on receiver and provides decoded audio output to headphones Size 32mm x 70mm 9 12V operation 27 95 UTLX Ultra miniature Telephone Transmitter Smallest kit available Connects onto telephone line switches on and off automatically as phone is used All conversations transmitted Size 10mm x 20mm powered from line up to 500m range 13 95 TLX700 Micro miniature Telephone Transmitter Best selling kit Performance as UTLX but easier to assemble as PCB is 20mm ALO bass es oe ek oe ee a ee eee TET 14 95 STLX High performance Telephone Transmitter High performance transmitter with buffered output for greater stability and range Connects onto telephone line and switches on and off automatically as phone is used Both sides of conversation transmitted up to 1000m Powered from line Size 22mm x 22mm TO ORDER Post fax or telephone your order direct to our sales office Payment can be Credit card Visa or Mastercard Postal Order cash please send registered or cheques Kits despatched same day cheques need clearing All orders sent by recorded or registered post Please add postage as follows ORDER UP TO 30 00 To UK 2 50 To EUROPE 5 50 All other 7 50 ORDERS OVER 30 00 To UK 3 65 To EUROPE 7 50 All others call Overseas customers please use credit cards or send sterling cheque or bank draft p m SUMA DESIGNS Everyday Practical Electronics September 2000 Dept EE The Wo
148. ed Two PP3 batteries are also required these are not supplied UK postage free for orders above 40 otherwise add 3 per order Prices include VAT where applicable Mame nnn BREBUZNIGEEUEBEESEUZSTERERSHUT ee ee Bg ol P TTR POSDOdE ron risa Ds oir ire Telephone for Mail order address Brunning Goftware 138 The Street Little Clacton Clacton on sea Essex CO16 9LS Tel 01255 862308 708 Everyday Practical Electronics September 2000 PCB SERVICE Printed circuit boards for most recent EPE constructional projects are available from the PCB Service see list These are fabricated in glass fibre and are fully drilled and roller tinned All prices include VAT and postage and packing Add 1 per board for airmail outside of Europe Remittances should be sent to The PCB Service Everyday Practical Electronics Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 E mail orders epemag wim borne co uk Cheques should be crossed and made payable to Everyday Practical Electronics Payment in sterling only NOTE While 95 of our boards are held in stock and are dispatched within seven days of receipt of order please allow a maximum of 28 days for delivery overseas readers allow extra if ordered by surface mail Back numbers or photostats of articles are available if required see the Back Issues page for details Please check price and availab
149. ed inputs Designed for use in various con trol amp sensing applications e g load switching exter nal switch input sensing contact closure amp external voltage sensing Controlled via serial port amp a termi nal emulator program built into Windows Can be used with ANY computer operating system Plastic case with printed front rear panels amp all components except cable provided 3108KT 49 95 UNIPOLAR STEPPER MOTOR DRIVER for any 5 6 8 lead motor Fast slow amp single step rates Direction control amp on off switch Wave 2 phase amp half wave step modes 4 LED indicators PCB 50x65mm 3109KT 14 95 PC CONTROLLED STEPPER MOTOR DRIVER Control two unipolar stepper motors 3A max each via PC printer port Wave 2 phase amp half wave step modes Software accepts 4 digital inputs from exter nal switches amp will single step motors PCB fits in D shell case provided 3113KT 17 95 12 BIT PC DATA ACQUISITION CONTROL UNIT Similar to kit 3093 above but uses a 12 bit Analogue to Digital Converter ADC with internal analogue multiplexor Reads 8 single ended channels or 4 dif ferential inputs or a mixture of both Analogue inputs read 0 4V Four TTL CMOS compatible digital input outputs ADC conversion time lt 10uS Software C QB amp Win extended D shell case amp all compo nents except sensors amp cable provided 3118KT 49 95 WEB http www QuasarElectronics com email epesales QuasarElectro
150. ef 3P155 FOR QUICK HOOK UPS You can t beat leads with a croc clip each end You can have a set of 10 leads 2 each of 5 assorted colours with insulated crocodile clips on each end lead length 36cm 2 per set Order Ref 2P459 1MA PANEL METER Approximately 80mm x 55mm front engraved 0 100 Price 1 50 each Order Ref 1 16R2 VERY THIN DRILLS 12 assorted sizes vary between 0 6mm and 1 6mm Price 1 Order Ref 128 EVEN THINNER DRILLS 12 that vary between 0 1 and 0 5mm Price 1 Order Ref 129 TWIN TELEPHONE PLUG Enables you to plug 2 telephones into the one socket for all normal BT plugs price 1 50 Order Ref 1 5P67 D C MOTOR WITH GEARBOX Size 60mm long 30mm diameter Very powerful operates off any voltage between 6 and 24 D C Speed at 6V is 200 rpm speed controller available Special price 3 each Order Ref 3P108 FLASHING BEACON Ideal for putting on a van a tractor or any vehicle that should always be seen Uses a Xenon tube and has an amber coloured dome Separate fixing base is included so unit can be put away if desirable Price 5 Order Ref 5P267 MOTOR SPEED CONTROLLER These are suit able for D C motors for voltage up to 12 and any power up to 1 6 h p They reduce the speed by intermittent full voltage pulses so there should be no loss of power In kit form these are 12 Order Ref 12P34 Or made up and tested 20 Order Ref 20P39 MOST USEFUL POWER SUPPLY Rated at 9V 1A this
151. eld down and a repeated transmission is made every 113 milliseconds A4 A3 A2 A1 AO C5 C4 C3 C2 Cl CO COMMAND CODE nal START CONTROL ADDRESS CODE Fig 6 RC5 code format Next is the Address A4 to AO of the equipment that is to respond to the com mand transmitted With five bits there are 32 different devices that can be addressed Some of the more common addresses are given in Table 1 Note that the software of the decoder described here does not actu ally decode the device address but the pro gram could be altered to do so After the address come the six Command code bits C5 to CO giving a total of 64 different commands that can be transmitted Some of the more common commands are listed in Table 2 Commands 0 to 17 are used mostly to con trol a TV receiver commands 41 to 46 are used for teletext and 47 to 55 used to con trol a video tape recorder LOGIC 0 LOGIC 1 Fig 5 RC5 timing of logic O and logic 1 data ACS DECODING SOFTWARE RCS transmissions are relatively slow in comparison to the operation of the PIC microcontroller However due to the bi phase encoding a more complicated decoding algorithm is needed than might be expected The decoding software works by using the falling edge of the RCS5 signal to generate an inter rupt The 8 bit inter RTCC Real Time Clock Counter timer value Everyday Practical Electronics September 2000 Table 1 Example RC5 de
152. elopments or phone with j 18C452 JW 20 00 credit card details 118C452 OTP 8 00 New architecture more instructions http Everyday Practical Electronics September 2000 707 Assembler The first book Experimenting with PC Computers with its kit is the easiest way ever to lear assembly language programming simple circuit design and interfacing to a PC If you have enough intelligence to understand the English language and you can operate a PC computer then you have all the necessary background knowledge Flashing LEDs digital to analogue converters simple oscilloscope charging _ Curves temperature graphs and audio digitising C amp CH The second book Experimenting with C amp C Programmes uses a similar approach It teaches the user to programme by using C to drive the simple hardware circuits built using the materials supplied in the kit of parts The experimental circuits build up to a storage oscilloscope using relatively simple C techniques to construct a programme that is by no means simple When approached in this way C is only marginally more difficult than BASIC and infinitely more powerful C programmers are always in demand Ideal for absolute beginners and experienced programmers The Kits The kits contain the prototyping board lead assemblies components and programming software to do all the experiments The made up kits are supplied ready to start the first experim
153. ember 2000 D1 TO D4 1N4001 Fig 11 6 Suggested experimental 5V power supply POWER SUPPLY ASSEMBLY Re arrange the right hand side of your breadboard to match the layout in Fig 11 7 ensuring that the orientations of ICI Cl and D1 to D4 are correctly followed Do not insert Link X top right until we tell you Note that the breadboard space available has prevented the use of a small value non electrolytic capacitor in parallel with C2 a recommendation discussed in the Tutorial You will notice that the computer inter face resistors R1 to R10 installed in Part 4 have been removed and the five data inputs INO to IN4 are now linked direct ly to the printer port terminals on the print ed circuit board The revised circuit diagram is shown in Fig 11 8 Because of this direct connection from hereon your breadboard MUST ONLY be operated at 5V as supplied by the circuit you are now assembling To use the 6V battery instead could be damaging to your computer without those attenuating inter face resistors in place It does not matter which way round the battery adaptor and its socket are connect ed to the breadboard The diodes D1 to 667 D4 automatically route the voltage polari ty correctly Before plugging in the adaptor ensure that your 6V battery cannot be connected remove its crocodile clip connection pins from the breadboard Turn the wiper of VRI fully anti clockwise With mains power supplied via
154. ent The unmade Kits require the prototyping board and leads to be assembled and soldered before you can start The top up kit CP2t is for readers who have purchased a kit to go with the fist book and contains all the components and programming software but not the prototyping board or leads Hardware required All three systems assume you have a PC 386 or better and a printer lead New PIC Kit Version Experimenting with PIC Microcontrollers HWPICA a I ith are F mem Prr dre i n j b l d Lhe area ier ETT a Raw tre ke aai BER uc Afi ivy WL AE fi LE Experimenting with PIC Microcontrollers This third release in our series teaches how to programme and interface to the PIC16F84 and PIC16C711 microcontrollers and consists of the book an integrated suite of programmes to run on a PC and a programmer experimental module The book with its abundance of flow diagrams and circuit diagrams is the heart of the system and the software is the brains A text editor with word processing power is the key stone supporting the assembler disassembler simulator and programming software As the text is typed in the assembler works in the background testing each line so that errors are immediately highlighted When the typing is done the simulator can be used to single step or run the programme Boxes pop up showing the contents of registers and t
155. ent The basic requirement is that the adaptor should have an output which falls into one the two following ranges other types are not suitable 6V a c to 9V a c O0 9V d c to 12V d c see later The circuit with on which either type can be used interchange AO ably is shown in Fig 11 6 with its breadboard layout given in Fig 11 7 You will additional ly need to obtain the following inexpensive components O Socket into which the adaptor can be plugged to connect to the breadboard O 73L05 100mA 5V voltage regulator IC1 O 220uF 25V electrolytic capacitor with radial leads C1 It is possible you might already have one amongst the com ponents you bought for Part 1 We speci fied that a minimum working voltage of 10V was required but your supplier may have provided you with one rated at 25V check your stock ones rated lower than 25V are not suitable re read the Tutorial of Part 10 if you re not sure why You should already have the 1N4001 rectifier diodes D1 to D4 the 100nF capacitor C2 and the 10k preset VR1 Readers who do not have a suitable mains adaptor and have no intention of getting one should leave their existing breadboard assembly unchanged ignoring the remainder of this Experimental section Next month s experiments can be done using either the existing breadboard with 6V battery or the modified version about to be described Everyday Practical Electronics Sept
156. ent sound lev els etc with appropriate sensors not supplied Various input circuit designs provided 3061KT 12 95 IR REMOTE TOGGLE SWITCH Use any TV VCR remote control unit to switch onboard 12V 1A relay on off 3058KT 9 95 SPEED CONTROLLER for any common DC motor up to 100V 5A Pulse width modulation gives maximum torque at all speeds 5 15VDC Box provided 3067KT 14 95 3 x 8 CHANNEL IR RELAY BOARD Control eight 12V 1A relays by Infra Red IR remote control over a 20m range in sunlight 6 relays turn on only the other 2 toggle on off 3 oper ation ranges determined by jumpers Transmitter case amp all components provided Receiver PCB 76x89mm 3072KT 44 95 PRODUCT FEATURE 4 WATT FM TRANSMITTER Small but powerful 4 Watt 88 108MHz FM trans mitter with an audio preamplifier stage and 3 RF stages Accepts a wide variety of input sources the electret microphone supplied a tape player or for more professional results a sepa rate audio mixer like our 3 Input Mono Mixer kit 1052 Can be used with an open dipole or ground plane antenna Supply 12 15V DC 0 5A PCB 45 x 145mm ORDERING INFO Kit 1028KT 23 95 OPTIONAL EXTRAS 3 Input Mono Mixer Kit 1052KT 17 95 SOUND EFFECTS GENERATOR Easy to build Create an almost infinite variety of interesting unusu al sound effects from birds chirping to sirens 9VDC PCB 54x85mm 1045KT 8 95 ROBOT VOICE EFFECT Make your voice sound similar to a ro
157. enta2000 co uk Su ab 4s sd ER Eo oad Cullercoats Ze ne amp Wear NE30 4PQ IS E 2 O EC e 3 zu All pne Credit cards Pier EE sme 26 Prices Exclude Vot 217 Add 1 25 UK od carriage amp Vat to all orders Cheques F Posta W payable to ESR Electronic Components Vt Ou eds Transistion Headers 10 Way Transistion 042 E 14 Way Transistion 0 42 LA ie Way Tratin EOAR a ramnmsisiieon XL Stamped Pin 26 Way Transislion 0 52 Cin uit 03 E006 3 Way Transistion 0 36 in d ay Transistion 0 14 Pin DIL 0 3 0 11 50 Way Transistion 0 84 16 Pin DIL Q 3 0 11 18 Pin DIL 0 3 20 12 Large Range of Connec St D ee Pin 12 our EE a ZZ Pd pin D Type Connectors 8 Pin DIL 0 37 0 11 14 Pin DIL 0 3 0 20 bt Dh im i mm 20 Pin DIL 0 3 028 Solder Bucket 24 Pin DIL 0 6 0 35 F Way Male Plu 20 24 BPinDILO 039 9 War Female Sockel 0 24 40 Pin DIL 0 6 0 44 12 wor Male Pi Si 5 IIF Sockets 12 E HE Pe ockal Eer Sockets 15 Way HD Sedet 0 44 28 Way 0 30 6 640 23 Way Male lug 0 44 Way 0 3 0 6 75 23WayFemale Socket 0 50 eg Way 0 3 0 6 893 29 Way Male Plu 0 36 25 Way Female Ski 0 37 ransistor Sockets IDC Ribbon Mountin Var 4 Base Socket Zen 24 9 Way Male PI TOS Base Sockel IDE Cable Sockets 26 Way Socket 34 Way Socket 40 Way Socket 50 Way Sockat IBC Cable ig Way Straight 4 Way Straight Way Straight Way Straight way Straight y Straight aj straight ay S
158. equested are forwarded to you immediately on publication four times a year These are billed separately and can be discontinued at any time Presentation Durable looseleaf system in large A4 format Price of the Basic Work 39 95 SALE PRICE 23 97 to include a recent Supplement FREE ORDER BOTH MANUALS TOGETHER AND SAVE ANOTHER 8 A mass of well organised and clearly explained information is brought to you by expert editorial teams whose combined experience ensures the widest coverage Regular Supplements to these unique publications each around 160 pages keep you abreast of the latest technology and techniques if required you feel is superfluous to your needs You can also purchase a range of past Supplements to extend your Base Manual on subjects of particular interest to you Supplements Our unique system is augmented by readers requests for new information Through this service you are able to let us know exactly what information you require in your Manuals REGULAR SUPPLEMENTS Unlike a book or encyclopedia these Manuals are living works continuously extended with new material If requested Supplements are sent to you approximately every three months Each Supplement contains around 160 pages all for only 23 50 2 50 p amp p You can of course return any Supplement within ten days which RESPONDING TO YOUR NEEDS You can also contact the editors directly in writing if you have a specific tech
159. er minor voltage fluctuations It is advisable to precede their inputs and follow their out puts with non electrolytic capacitors Typical values are between about 100nF and 330nF for the input and 100nF for the output The input capacitor here is in addi tion to the power supply s electrolytic smoothing capacitor OTHER REGULATORS Other voltage regulators exist for a vari ety of purposes Some allow the output voltage to be varied by other component values for example There are also low drop out regulators which operate with a voltage differential of less than 2V Still others consume less control current than the standard devices There are also sophisticated switch mode devices which regulate power supplies by other techniques SMOOTHING CAPACITORS Capacitors were first discussed in Part 2 We demonstrated how they could be charged and dis charged at different VE EE C3 D3 current controlling resistor is repeatedly changing its value i e it has been a wave form of some sort In such situations the capacitor does not necessarily attain its fully charged or discharged condition This is especially so when the capacitor is used as the smoothing or reservoir component in a power supply As a result the waveform which appears at the C R junction may not retain the shape of the waveform applied to the resistor and of course in a power supply you do not want any waveform to remain You have already seen a goo
160. er not to hear from such organisations please tick box Dept ZEEE 040800 _ eee Occupation Tel No J Professional 88 108MHz FM Broadcasting Kits Detailed Instructions with Schematics High Quality Screen Printed PCBs High Quality Components Our Product Range Includes Transmitters from 0 05W to 35W FM Stereo Coders Audio Compressor Limiters Antennas RF Power Amps Our Kits Are Also Available Fully Assembled And Tested 1W Professional PLL FM Transmitter for Licenced Use in the UK Date of Birth y VARIABLE VOLTAGE TRANSFORMERS INPUT 220V 240V AC 50 60Hz OUTPUT 0V 260V PANEL MOUNTING Price P amp P 0 5KVA 2 5 amp max 33 00 6 00 45 84 inc VAT 45 25 7 00 61 39 inc VAT 1KVA 5 amp max SHROUDED 0 5KVA 2 5 amp max 34 00 6 00 47 00 inc VAT 46 25 7 00 62 57 inc VAT 65 00 8 50 86 36 inc VAT 86 50 8 50 111 63 inc VAT 150 00 Carriage amp VAT 1KVA 5 amp max 2KVA 10 amp max 3KVA 15 amp max 5KVA 25 amp max Buy direct from the Importers Keenest prices in the country 500VA ISOLATION TRANSFORMER Input lead 240V AC Output via 3 pin 13A socket 240V AC continuously rated mounted in fibreglass case with handle Internally fused Price 35 00 carriage paid VAT 41 13 TOROIDAL L T TRANSFORMER Primary 0 240V AC Secondary 0 30V 0 30V 600VA Fixing bolt supplied Price 25 00 carriage paid VAT 29 38 COMPREHE
161. erate how printed circuit boards are fabricated and what the innards of memory ICs look like You ll also gain a working knowledge of Boolean Algebra and Karnaugh Maps and understand what Reed Muller logic is and how it s used And there s much MUCH more including a recipe for a truly great seafood gumbo Hundreds of carefully drawn illustrations clearly show the important points of each topic The author s tongue in cheek British humor makes it a delight to read but this is a REAL technical book extremely detailed and accurate A great reference for your own shelf and also an ideal gift for a friend or family member who wants to understand what it is you do all day 470 pages large format 24 95 DIGITAL ELECTRONICS A PRACTICAL APPROACH FREE With FREE Software Number One Systems EASY PC Professional XM and Pulsar Limited Functionality Richard Monk Covers binary arithmetic Boolean algebra and logic gates combination logic sequential logic including the design and construction of asynchronous and synchronous circuits and register circuits Together with a considerable prac tical content plus the additional attraction of its close association with computer aided design including the FREE software There is a blow by blow guide to the use of EASY PC Professional XM a schematic drawing and printed circuit board design computer package The guide also conducts the reader through logic circuit simulation using Pul
162. ere were also three special prizes one each for the Senior Intermediate and Junior categories The Duke of York s Award went to Martin Rosinski pictured above of Ponteland Community High School Ponteland Newcastle upon Tyne Martin 15 years old invent ed Smartlink the world s smallest data logger developed for stress measurement in dif ficult industrial applications where existing systems cannot be used His efforts were rewarded with a magnificent crystal trophy which he can keep for a year a special cer tificate signed by the Duke 1000 and an IBM Thinkpad courtesy of IBM Information on the other award winners and details of the annual Awards scheme can be obtained from The YEDA Trust 60 Lower Street Pulborough W Sussex RH20 2BW Tel 01798 875559 Fax 01798 873550 E mail yeda cix co uk PICO CATALOGUE PICO Technology s latest catalogue has been received Renowned for the excel lence and variety of their PC based Test and Measurement equipment Pico s cata logue is well worth obtaining if you are looking to upgrade your workshop facilities The PC based equipment ranges include oscilloscopes spectrum analysers and meters data acquisition temperature and humidity environment monitoring and signal conditioning A range of related accessories is offered as well Pico of course will also be well known to you for their kind sponsorship of our Ingenuity Unlimited pages To find out how you too could be a
163. etic signals May reduce scale formation dissolve existing scale and improve lathering ability by altering the way salts in the water behave Kit includes case P C B coupling coil and all components High coil current ensures maximum effect L E D monitor KIT 868 22 95 POWER UNIT 3 99 MICRO PEsT SCARER Our latest design The ultimate scarer for the garden Uses special microchip to give random delay and pulse time Easy to build reliable circuit Keeps pets pests away from newly sown areas play areas etc uses power source from 9 to 24 volts e RANDOM PULSES e HIGH POWER e DUAL OPTION IR ass uQaar resi ad i a aod PIC WATER DESCALER KIT SLAVE UNIT 32 50 WINDICATOR A novel wind speed indicator with LED readout Kit comes complete with sensor cups and weatherproof sensing head Mains power unit 5 99 extra DUAL OUTPUT TENS UNIT As featured in March 97 issue Magenta have prepared a FULL KIT for this excellent new project All components PCB hardware and electrodes are included Designed for simple assembly and testing and providing high level dual output drive 4 spare electrodes 6 50 KIT 866 Full kit including four electrodes 32 90 1000V amp 500V INSULATION TESTER Superb new design Regulated output efficient circuit Dual scale meter compact case Reads up to 200 Megohms Kit includes wound coil cut out ca
164. evice must be chosen so that it can safely supply the current that is required by the load and that it can handle the heat generated its wattage value when that current flows Everyday Practical Electronics September 2000 ft Eh BLOB gu 7BLi2 12U Prefix 9 instead of B 11414 4 D 1 itn Ce Iin d ell DUTI Fr COA ke d Rutatransfarmers do ot provide mains isolati Photo 11 2 The power supply Miscellany screen Auto transformers were described in Part 10 Note the use of capacitors Cl and C2 to smooth any slight fluctuations caused by circuit noise such as minor power line rip ple for example in the supply to the base and the supply taken by the load Typical values are 100nF for C1 and between about luF and 22uF for C2 Other values may be used if circum stances require greater smoothing Be aware though that when power is first applied C2 is fully discharged and thus the transistor initially sees a short circuit between the voltage on its collector and 0V at its emitter This short circuit is only brief while the capacitor charges up to the full Zener controlled level but for the first part of that charging the current might be greater than the transistor can safely han dle This will especially apply if C2 has a large value If C2 needs a large value it can be pru dent to insert a small value resistor between the full d c positive supply line Vdc IN and the collector
165. fall at the fence This game can be played by one person just for fun but also makes a game for two or more opponents You can make your own rules about this but as a suggestion a player may attempt ten jumps in succes sion and count the number of clear jumps scored The turn then passes to the next contestant until all have played The winner is the player with the high est score out of ten A tie results in a jump off Players take jumps alternately and drop out if they do not achieve a clear jump HOW IT WORKS Referring to the Steeplechase Game circuit diagram in Fig l C2 is a decade counter that has 1 of 10 outputs This 652 differs from an ordinary binary divider counter because only one output is high at a time The counter is incremented as the input from the timer ICI rises from logic low 0V to logic high 46V The output that is currently high goes low and the next output in order goes high There are seven l e d s driven by the RST1 RST2 VE DISCH 1 DISCH 2 THRES 1 TRIG 2 IG 1 G 2 CV1 OUTPUT NH GND RST p cv 2 AL ND 10u IC3a PIN 5 6 8 9 counter so they each go high in turn pro ducing the travelling display referred to earlier There is a gap of three counts between runs because there are no l e d s for stages 7 8 and 9 The aim of the player is to press the pushbutton switch S1 while the seventh l e d 1s lit but more about that later IC2 74HC4017
166. ffer entiation experiment coupled circuits are modified by the CR values of those circuits Use the lt W gt key to change the input waveform as before and again observe how the CR relationship changes the shape and amplitude of the output for sine and tri angle waveforms Again the CR relationship for a desired output result is difficult to calculate but it is also based on the CR formulae used in Part 2 The variants used for the demo dis play are shown at the top of the screen This demo display can also be used as a guide for real life circuit design value assess ment In many a c coupled circuits of course you will want to retain the signal shape across a particular frequency range but there are other instances where shape change is desirable such as in pulse generation or low frequency attenuation for example Return to your breadboard and connect the output of C3 and VR3 V Out Differentiate to IC2 pin 2 It is the differentiation circuit shown in Fig 11 5 that is now to be moni tored Once more observe the Analogue Input Waveform Display as you experiment with different CR and frequency values An important point to note about the cir cuit in Fig 11 5 is that we have had to refer ence the waveform at C3 VR3 to a midway voltage of 3V half the 6V battery voltage This is provided by potential divider R3 and R4 and buffered by op amp IC3b As discussed in Part 10 if the resistance VR3 were to be connecte
167. from a piece of 35mm outside diameter plastic waste pipe Everyday Practical Electronics September 2000 thirty rods twenty turns will be about right FERRITE LOOP Moving on to the loop assembly Fig 5 tightly bind the seven ferrite rods together with masking tape winding on sufficient material to ensure that the plastic coil for mer is a tight sliding fit Secure the wire to the former with a narrow strip of tape and wind on the spec ified number of turns 29 turns of 28s w g enamelled copper wire Don t try too hard to space the turns just concen trate on getting them on as tightly as pos sible they can be evenly spaced with the tip of a screwdriver after the other end of the winding has been secured Tn INITIAL TESTING Before we can get down to the nitty gritty of constructing the turret assembly we need to carry out a few initial spot tests First check the p c b for bridged copper tracks and poor soldered joints and check the orientation of the semicon ductors Wire up the potentiometers and the loop aerial Set presets VR3 and VR5 at half travel set controls VR4 at mini mum and VR6 at maximum Connect the unit to the receiver by a short length of coaxial cable then connect a 9V battery Current consumption should be approximately 5mA Assuming you are using a receiver with an in built signal strength meter proceed as follows With receiver an
168. gh with circuits of this kind and the tuning capacitor should have a swing of at least 10pF to 450pF to ensure coverage from 1720kHz down to 527kHz Air spaced variables of this value are no longer readi ly available and currently listed polythene dielectric types as used in transistor portables have a lower value even when two gangs are connected in parallel SWITCH POSITIONS 1 OFF 2 LOOP AERIAL 3 LONG WIRE OR WHIP AERIAL L1 1 TURN 28 S W G L2 29 TURNS 28 S W G AERIAL SEE TEXT FERRITE RODS Il LONG WIRE OR WHIP SK1 AERIAL SK5 PL1 10n Il lI Il 11 11 11 2 11 Il lI HIS Li Il 11 11 pq KV1236 1 2 a 3 4 COARSE TUNING circuitry avoids any loss of efficiency because of this Concern is sometimes expressed at the possibility of strong signal voltages dis turbing the diode bias and introducing cross modulation No problems of this kind have been encountered with the loop design described here CIRCUIT DETAILS The full circuit diagram for the Active Ferrite Loop Aerial is shown in Fig l The main components of the circuit are a dual gate MOSFET TR1 a field effect transistor TR2 a varicap diode D1 and of course the multi rod ferrite loop aerial Sockets SKI SK2 are provided for external aerials and SK3 is the common Earth socket Switches Sla and S1c permit an instant comparison between loop and wire aerials Another switch Slb con nects the battery
169. h In No 7 will be invaluable if you are con sidering a career in electronics or even if you are already training in one The Mini Lab and software enable the con struction and testing of both demonstration and develop ment circuits These learning aids bring electronics to life in an enjoyable and interesting way you will both see and hear the electron in action The Micro Lab microprocessor add on system will appeal to higher level students and those developing microprocessor projects 160 pages Order code TI7 3 95 Circuits ama Design ELECTRONICS PROJECTS USING FREE ELECTRONICS WORKBENCH plus FREE CD ROM M P Horsey This book offers a wide range of tested circuit modules which can be used as electronics projects part of an elec tronics course or as a hands on way of getting better acquainted with Electronics Workbench With circuits rang ing from bulbs and batteries to complex systems using integrated circuits the projects will appeal to novices stu dents and practitioners alike Electronics Workbench is a highly versatile computer sim ulation package which enables the user to design test and modify their circuits before building them and to plan PCB layouts on screen All the circuits in the book are provided as runnable Electronic Workbench files on the enclosed CD ROM and a selection of 15 representative circuits can be explored using the free demo version of the application Contents Some basic concepts P
170. h data bit with the relevant bit in CBINARY This sets the output bit called RS232 then the OP output rou tine is called and takes the pin RB3 high or low according to the value of bit RS232 Directly changing RB3 in the TXDATA routine would cause a timing error Once the RB3 output is set this data output value has to be held consequently several NOP commands are required to ensure correct timing There is no hand shaking or data transmission from the PC therefore the connection from the PIC to the serial socket has only two wires Everyday Practical Electronics September 2000 PC SOFTWARE The Windows 95 98 software does not decode the IR transmission but displays the value of the CBINARY variable sent from the PIC The program also displays if available a text message describing the key pressed This text is read from two text files called RCS TXT and SIRC TXT these files must be located in the same directory as the program The text can easily be altered using Notepad to coincide with the intended remote control handset These files store the relevant text in ascending order For example the first line is text for CBINA RY 0 the second line is for CBINARY 1 and so on Operation of the PC software is very sim ple select the serial communications port that the PIC circuit is connected to and then select the required protocol The Reload key reloads the text files if they have been changed while the program
171. hargeable battery is very much like choosing horses for courses there may be times when a RAM battery would be ideal for loads where ordinary alkaline types are used but have a moderate turnover Cost effec tiveness is often the most critical factor which determines what type of cell to use Rayovac par ticularly recommends RAM cells for applications needing high capacity and low self discharge uses I would consider them for flashlights or radios The charging method is complex and TI Benchmarq have developed some chips for recharging RAM batteries More advanced systems including microcon troller based chargers require expert advice I strongly recommend reading Rayovac s superb on line battery data available as a PDF file from www ray ovac com busoem oem specs down load shtml This is probably the best resource available and although it s intended for Original Equipment Manufacturers OEMs there is plenty of technical data there of interest to the con structor or engineer Also have a look at http data energiz er com batteryinfo for the low down on Ni Cd and NiMH cells Both this and the Rayovac web sites have good technical data and performance curves the publica tion of which has been long awaited and you will also find charging and discharg ing advice on line ARW Help us to help you Circuit Surgery has always been your column and it tries to maintain the widest possible appeal Queries from
172. have proved particularly useful in schools colleges training departments and electronics clubs as well as to general hobbyists and those following distance learning courses etc BASICS VT201 to VT206 is a basic electronics course and is designed to be used as a complete series if required VT201 54 minutes Part One D C Circuits This video is an absolute must for the begin ner Series circuits parallel circuits Ohms law how to use the digital multimeter and much more Order Code VT201 VT202 62 minutes Part Two A C Circuits This is your next step in understanding the basics of electronics You will learn about how coils transformers capacitors etc are used in common circuits Order Code VT202 VT203 57 minutes Part Three Semicon ductors Gives you an exciting look into the world of semiconductors With basic semicon ductor theory Plus 15 different semiconduc tor devices explained Order Code VT203 VT204 56 minutes Part Four Power Supplies Guides you step by step through different sections of a power supply Order Code VT204 VT205 57 minutes Part Five Amplifiers Shows you how amplifiers work as you have never seen them before Class A class B class C op amps etc Order Code VT205 VT206 54 minutes Part Six Oscillators Oscillators are found in both linear and digi tal circuits Gives a good basic background in oscillator circuits Order Code VT206 34 95 inc VAT amp postage Order 8 o
173. he same square wave as output from ICla VouT DIFFERENTIATE IC2 PIN 2 Cd Dd Dd D3 ARR eRe rates depending on their capacitance KEE E value and the value of D E Au BEBE ER e the resistor in series SE EEE EEES EH with them in other c RRE words on the CR OTE AAA T value of the circuit un L JC In both cases 1t was up S RRS le 9 19 0 i9 Ter BI D 19 9 8 18 A 4 z MENORES AE Rees assumed that the ES ES BACARA O capacitor started off BARR er DT DD either fully charged or fully discharged and we quoted the formu lae used to calculate the associated rate of voltage change Since then you have been using capacitors in circuits where the voltage applied to the D1 AR RRR o o oO oO cO CO s HH BRA RH VR2 S ee Dd Dd DJ HH Dn BARRE Vout INTEGRATE IC2 PIN 2 Fig 11 3 Breadboard layout for the waveform modification experiment circuits in Fig 11 4 and Fig 11 5 Everyday Practical Electronics September 2000 Vout INTEGRATE ADC IC2 PIN2 Fig 11 4 circuit diagram for the capac itor charge discharge experiment integration Note that the waveform may be a bit dis torted because of being connected to a capacitor without a resistor in between Now slowly adjust VR2 s wiper anti clockwise to increase the resistance between Cla pin 2 and C2 observing the waveform display as you do so Note how the waveform gradually loses its square shape becoming more triangular and reducing i
174. he capacitor self discharges Consequently oscillation can never be sustained and probably not even started There is a type of largish value capaci tor however which has a much less leaky disposition than electrolytics it is the Tantalum capacitor see Part 2 Fig 2 7 and Table 2 2 You will find Tantalums used in many circuits where lengthy or more accurately maintained timing is required They are also smaller value for value than elec trolytic capacitors Unfortunately they are more expensive than electrolytics and their maximum capacitance value is significantly lower 330uF probably being the highest you ll readily find whereas electrolytics are commonly available in many hundreds of thousands of microfarads even up to 2 farads 2F Everyday Practical Electronics September 2000 PANEL 11 2 VARIABLE CAPACITORS Still on capacitors but another subject we promised in Part 2 that we would eventually give information on variable capacitors Space is running a bit short but here is a brief description In comparison with their resistive counterparts potentiometers variable capacitors are much less common Unlike variable resistors though the term variable capacitor really does mean that the capacitance itself is vari able you cannot attach a slider to a capacitor to vary a fixed capacitance take off point Variable capacitors are available in both preset trimmer and fully vari able forms but
175. he result of any text written to a standard 2 line by 16 character display If it works correctly plug the programmer experimental module onto the end of your printer lead and test it using a real live PIC All operations work directly from the assembler text in the editor The experiments are all performed using the programmer experimental module which is already wired with LEDs push buttons and an alphanumeric liquid crystal display Flashing LEDs text display real time clock period timer beeps and music including a rendition of Beethoven s F r Elise Then there are two projects to work through building a sinewave generator covering 0 2Hz to 20kHz in five ranges and investigating measurement of the power Mail Order Form taken by domestic appliances In the space of 24 experiments two projects and 56 exercises the system works EE MEER Please make your cheque PO payable to Brunning Software and send with this form to trough MOm EECH Sener I9 Brunning Software 138 The Street Little Clacton Clacton on sea Essex COl6 9LS Your order will be processed as soon as your cheque arrives Despatch is usually the same day Software supplied on 3 5 HD discs The kits do not include the book experienced engineer level Kit or Ready Built Book Experimenting with PCs Maplin code NV68 23 99 Kit la made up and ready to start Not from Maplin 46 00 The programming experimental module Kit lu
176. he two presets VR1 VR2 flying lead connected to OV and touch it against the individual pin sockets in the socket for IC2 The l e d s should come on one at a time as the appropriate pin is grounded see Fig 1 to check which Led should light Finally assemble the timing circuits based on ICI Again check very carefully that you have cut the copper strips at the correct points Insert ICT and IC2 When the circuit is complete test the effects of altering the setting of VR1 and VR2 The overall speed of the horse is controlled by VR2 The amount by which its speed varies is controlled by VRI May the best horse win KEEP YOUR ISSUES SAFE RING US NOW This ring binder uses a special system to allow the issues to be easily removed and re inserted without any damage A nylon strip slips over each issue and this passes over the four rings in the binder thus holding the magazine in place The binders are finished in hard wearing royal blue p v c with the magazine logo in gold on the spine They will keep your issues neat and tidy but allow you to remove them for use easily The price is 5 95 plus 3 50 post and packing If you order more than one binder add 1 postage for each binder after the initial 3 50 postage charge overseas readers the postage is 6 00 each to everywhere except Australia and Papua Send your payment in s sterling cheque or PO Overseas readers send sterling bank draft or cheque drawn on
177. her advantage is that because they do not require l e d s the magnetic solution consumes considerably less power This can be of considerable importance in some applications Further Developments The same basic technology has also been used to provide a solid state relay the umRelay which provides another attrac tive option for some applications Again cost size and power consumption are lower than the mechanical counterparts whilst reliability and performance are claimed to be better Further details about these devices can be found on the Analog Devices website at www analog com industry umic isola tiontech html Everyday Practical Electronics September 2000 35 NOVICE OLLEGES SCH Gem a TELEPHONE 07941 252679 ALL KITS BUILT ONTRIPAD PCB ouer PERFECT FOR NOVICE FIRST TIME BUILD AS YOU SEE SYSTEM INSTRUCTIONS BUILDERS IN ELECTRONICS X1 210 ABA Mu RADIO 000 841 TRANSMITTER RE INDICATOR 4 60 D 1364 TRAN MW RADIO epo BA AUDIO NOISE GENERATOR 10 00 X5 ME484 4 2000 MW RADIO too B45 GENERAL TRANSISTOR AMP GEN X MXABS TUNER HW NO AMP 600 Bie La AMPLIFIER GENERAL ESSI B2 BASIC CRYSTAL SET AMPLIFIED nm B48 COMMONFRE AMP RADIO E Si B4 WORKSHOP AMPLIFIER 100 B48 PEST SCARER HIGH PITCH 120 Xil S METER de 1550 BS VARIABLE FREQ OSCILLATOR 55 fag SIMPLE HE M ATU 753 Bei AUTOMATIC NIGHT LIGHT ESH E SW TUNER GENERAL 000 B52 FROST ALARM Eer
178. how to begin building systems from modules a selection of over 25 electronic systems are described in detail covering such widely differing applications as timing home security measurement audio including a simple radio receiver games and remote control 200 pages Temporarily out of print PRACTICAL ELECTRONICS CALCULATIONS AND FORMULAE F A Wilson C G lI A C Eng F I E E F I E R E F B I M Bridges the gap between complicated technical theory and cut and tried methods which may bring success in design but leave the experimenter unfulfilled A strong practical bias tedious and higher mathematics have been avoided where possible and many tables have been included The book is divided into six basic sections Units and Constants Direct Current Circuits Passive Components Alternating Current Circuits Networks and Theorems Measurements Order code BP53 4 99 256 pages Everyday Practical Electronics Sepptember 2000 Theory ama Reference Bebop To The Boolean Boogie By Clive call me Max TTT Maxfield ORDER CODE BER Rut BOO0GE 24 95 470 pages Large format Specially imported by EPE Excellent value An Unconventional Guide to Electronics Fundamentals Components and Processes This book gives the big picture of digital electronics This indepth highly readable up to the minute guide shows you how electronic devices work and how they re made You ll discover how tran sistors op
179. i Mono Line Sockel 0 35 spsT 184 r 28 X Mono Chassis Skt 0 37 SPDT 18 Glen 1 31 44 Stereo Plug 0 40 SPDT efofi 18 x 30mm 1 43 i Stereo Line Sockel 0 38 DPDT 21 x 30mm ET i li Stereo Chassis Skt 0 58 DpDT doli 21 x 3 mm 1 58 erem Series Plug 2 61 Slide Switches Red Line Pigo 0 20 Black Line Plug 0 20 Miniature Yellow Line Plug 0 20 300mA 125V ile Line a Red Line Sockel 020 DADE y paning Hole g Black Line Socket 0 70 Standa AS EN Line Socket EM IA 125V ite Line Socke Red Chassis Socket 0 20 ee m Mounting Hola Block Chassis Socket 0 20 DPDT c o 17 x ain 00 27 gold Plated Plug Red 0 64 Gold R Series motel Plug Blackt0 65 Rotary Switches 3 Pin Lina Plu 1 46 3 Fin Line Socket 1 71 150m 3 Pin Chassis Plu 1 50 adi Xd Break 27mm E 3 Pin ssis Socket 1 49 9 8mm Mounting Hole Neutrik Line Plu 1 48 1 Pole 12 Way 00 84 Are pine ac i age 2 Pole o uo ED 24 i ale ay Neutrik Chassis Sockel 2 32 4 Pole 3 Way 50 84 Boxes amp Cases Many more sizes available e A Miniature Round L a gama MN 7B x 0 m inc m _ mm ounting Hole Non Latching Push to Make General Purpose Plastic Black PTM 0 23 75 x 36 x 29mm 0 99 Red PTM 20 23 75x 51 x 27mm 20 99 Yellow PTM 0 23 111 x 57 x 22mm 1 12 Green PTM POS 79 x amp x 40mm r1 70 Blue PTA 0 23 100 x 74x 41mm 1 79 White PIA 0 23 118 x 9B x 45mm 2 08 Hon geg Push to Break 150 x 100 x 0mm 22 77 Binck LP Squa 20 24 i0 x
180. ice laboratory or factory using 8 240VAC 12A onboard relays DOS utilities sample test program full featured Windows utility amp all components except cable provided 12VDC PCB 70x200mm 3074KT 29 95 2 CHANNEL UHF RELAY SWITCH Contains the same transmitter receiver pair as 30A15 below plus the components and PCB to control two 240VAC 10A relays also supplied Ultra bright LEDs used to indicate relay status 3082KT 27 95 TRANSMITTER RECEIVER PAIR 2 button keyfob style 300 375MHz Tx with 30m range Receiver encoder module with matched decoder IC Components must be built into a circuit like kit 3082 above 30A15 13 95 PC DATA ACQUISITION CONTROL UNIT Use your PC to monitor physical variables e g pressure tem perature light weight switch state movement relays etc process the information amp use results to control physical devices like motors sirens relays servo amp stepper motors Inputs 16 digital amp 11 analogue Outputs 8 digital amp 1 analogue Plastic case with print ed front rear panels software utilities programming examples amp all components except sensors amp cable provided 12VDC 3093KT 89 95 PIC 16C71 FOUR SERVO MOTOR DRIVER Simultaneously control up to 4 servo motors Software amp all components except servos control pots supplied 5VDC PCB 50x70mm 3102KT 14 95 PC SERIAL PORT ISOLATED UO BOARD Provides eight 240VAC 10A relay outputs amp 4 opti cally isolat
181. ield and hit Enter If your Sowa Techs EE VER search query is distinctive rather than broad based Googie t EE Pat E al OA E Mr e xiu alt Hea am d perhaps maxillo facial dad meet vereri e venam surgeons rather than den Maa lid SEO tists then you can usually frane tiena page for EE On hit the Pm feeling lucky ime Tha ppe button the chances are A high that Google will list the 242s stesse um EE d EIS ege macer io ba 7 har most relevant web pages straight away My screen shot shows what happened when I searched on just EPE we were listed as Nol amongst 27 000 results which took 0 04 seconds even though there is an unrelated EPE Home Page Google is power ful and hugely fast The Google database is a highly prized and marketable resource which works on the principle that if something is good you ll tell people about it just as I m singing its praise here If a web site is cool hot or whatever there is a good chance that there are many links already pointing to it However Google goes further by analysing the quality of these links rather than just counting the sheer number of them so a link to a site from another high ranking web site counts for a lot more than a link from somebody s lowly home page Because of this it is very difficult for a web site owner to influence Google s search engine results You can however sub mit your own URL at www google com a
182. igh Everyday Practical Electronics September 2000 Steeplechase prototype circuit board LI i AT MT a I L COMPONENTS Resistors See R1 100k R2 47k JOR 2200 2 of TALK R3 R7 R8 10k 3 off R4 R10 R5 3300 age H6 1k pas R9 4k7 All 0 25W 5 carbon film or better Potentiometers VR1 100k min preset horiz VR2 4k7 min preset horiz Capacitors C1 C2 10u radial elect 10V 2 off C3 10u axial elect 10V C4 10n polyester Semiconductors D1 to D6 5mml e d red D8 7 off D7 5mm l e d green IC1 7556 CMOS dual timer IC2 74HC4017 CMOS decade counter IC3 4001 CMOS quad 2 input NOR gate IC4 4011 CMOS quad 2 input NAND gate TE BC548 npn transistor Miscellaneous 81 S2 min push to make switch 2 off black white Stripboard 29 strips x 39 holes 6V battery and connector clip 1mm termi nal pins 2 off 14 pin d i l socket 3 off 16 pin d i l socket connecting wire solder etc 653 Approx Cost Guidance Only The trigger pulse is generated by the two NOR gates IC3a and IC3b connected to produce a high output pulse on a falling edge occurring at input pin 2 In other words the pulse is generated when the player releases pushbutton switch Sl Note that it is not possible for the player to cheat by pressing and holding the switch while the horse canters up to the fence The pulse is generated when the switch is first released It
183. igher reference voltages As with many other types of component Zener voltage values have a tolerance factor typically 5 The current which a Zener diode can conduct in its normal voltage limiting direction is not usually quoted as such Zeners are normally specified by wattage values which reflect the amount of power that the diode can safely dissipate Typical values range from 400mW to 20W or more Everyday Practical Electronics September 2000 ZENER DIODE PROGRAM To explore what happens with a typical Zener diode circuit you can experiment by changing various values through the Zener demo program From the left hand box you can change the values for R1 R2 D1 and the primary d c powering voltage Vin using the con trol keys stated on screen The results pro duced by the different values you select are given in the right hand box To use the program in a meaningful way set the Vin voltage level available from a theoretical power supply and the value of D1 for the fixed reference voltage output required The Zener values selectable are those normally available through major component suppliers ranging from 2 4V to 10V Note both voltage values With RI at the minimum value that can be set 1 2 i e as good as nil resistance adjust the value for R2 the load until the right hand box shows the estimated maxi mum current that will flow through it more on this presently choose an arbitrary va
184. ights Google s intelligence in index ing the web pages stored within its database Sometimes Google may fail to return a result though the reason being that there are insufficient links to the target web site to enable Google to index it One interesting job for a spare minute is to check all the links that point to a page perhaps I m interested in all the links to the EPE page so I would enter link www epemag wimborne co uk in Google Alta Vista does the same You can E mail me at alan epemag demon co uk See you next month Everyday Practical Electronics September 2000 Electronic Surveillance Equipment Kits from the UK s No 1 Supplier SUMA DESIGNS has been supplying professional quality electronic surveillance equipment kits for over 20 years Whether your requirement is hobbyist amateur or professional you can be sure that you are buying from a company that knows the business We ONLY sell surveillance products no alarms disco lights or computer bits All of our kits are designed for self assembly and are well tried tested and proven All kits are supplied complete with top grade components fibreglass PCB full instructions circuit diagrams and assembly details Unless otherwise stated all transmitter kits are tuneable and can be received using an ordinary VHF FM radio UTX Ultra miniature Room Transmitter At less than 1 2 the size of a postage stamp the UTX is the smallest room transmitter kit in the world Incredible
185. ilable FARNELL AMM2000 Auto Mod Meter 10Hz 2 4GHz Unused 950 MARCONI 2305 Mod Meter 500kHz 2GHz from 750 No travelling or college attendance Learning is at your own pace Each course can stand alone or be part of a modular study programme Tutor supported and BTEC certified For information contact NCT Ltd P O Box 11 Wendover Bucks HP22 6XA Telephone 01296 624270 Fax 01296 625299 Web http www nct ltd uk SPECTRUM ANALYSERS H P 8562A 1kHz 22GHz TEKTRONIX 492 50kHz 18GHz EATON AILTECH 757 0 001 22GHz ADVANTEST R3261A 9kHz 2 6GHz synthesised H P 853A Dig Frame with 8559A 100kHz 21GHz H P 8558B with main frame 100kHz 1500MHz MARCONI 2382 100Hz 400MHz high resolution B amp K 2033R Signal Analyser ADVANTEST TR4131 10kHz 3 5GHz MARCONI 2370 30Hz 110MHz H P 141 SYSTEMS 8553 1kHz 110MHz 8554 500kHz 1250MHz 8555 10MHz 18GHz UNUSED OSCILLOSCOPES TEKTRONIX TDS350 dual trace 200MHz 1GS s TEKTRONIX TAS485 4 channel 200MHz etc H P 54600B dual trace 100MHz 20MS s OSCILLOSCOPES PHILIPS PM3092 2 2 ch 200MHz delay TB etc 950 PHILIPS PM3082 2 2 ch 100MHz delay etc TEKTRONIX TAS465 dual trace 100MHz delay etc 800 TEKTRONIX 2645 4 ch 300MHz delay sweep cursors 1250 TEKTRONIX 2430 dual trace 150MHz 100MS s crsors etc 800 TEKTRONIX 2232 dual trace 100MHz 100MS s cursors etc 800 TEKTRONIX 2212 dual trace 60MHz 20MS s cursors etc 650 TEKTRONIX 2210
186. ility in the latest issue Boards can only be supplied on a payment with order basis PROJECT TITLE Ak EPE Time Machine NOV 97 171 Auto Dim Bedlight 172 Portable 12V PSU Charger 173 8 34 6 63 6 61 Safe and Sound Security Bleeper DEC 97 ELLE 174 7 64 178 8 30 Surface Thermometer Disco Lights Flasher Waa Waa Pedal Multi project PCB Virtual Scope Digital Board Analogue Board per board Water Wizard Kissometer EPE PIC Tutorial The Handy Thing Double Sided Lighting Up Reminder A Audio System Remote Controller PSU Main Board Simple Metal Detector Multi project PCB A RC Meter Security Auto Light Stereo Tone Control plus 20W Stereo Amplifier Tone Control 20W Amplifier k Dice Lott EPE Mood Changer AT89C2051 1051 Programmer Main Board Test Board A Reaction Timer Software only X PIC16x84 Toolkit 6 96 A Greenhouse Computer Control Board PSU Board 9 08 8 10 6 59 3 00 Personal Stereo Amplifier 3 00 Multi project PCB Greenhouse Radio Link A PIC Altimeter Voice Processor A Digiserv R C Expander IR Remote Control Transmitter Receiver A PIC Tape Measure Electronic Thermostat T Stat PhizzyB A PCB B CD ROM C Prog Microcontroller 15 Way IR Remote Control Switch Matrix 15 Way Rec Decoder Damp Stat Handheld Function Generator A Fading Christmas Lights PhizzyB I O Board 4 section Twinkle Twinkle Reaction Game EPE Mind PICkler PhizzyB I O Boa
187. ind out about and then build and test bistables crystal controlled astables counters decoders and displays All of these subsystems are carefully explained with practical work supported by easy to follow prototype board layouts Full constructional details including circuit diagrams and a printed circuit board pattern are given for a digital elec tronic clock The circuit for the First Clock is modified and developed to produce additional designs which include a Big Digit Clock Binary Clock Linear Clock Andrew s Clock with a semi analogue display and a Circles Clock All of these designs are unusual and distinctive This is an ideal resource for project work in GCSE Design and Technology Electronics Product and for project work in AS Level and A Level Electronics and Technology 194 pages A4 spiral bound Tel 3 ev P em 16 50 DOMESTIC SECURITY SYSTEMS A L Brown This book shows you how with common sense and basic do it yourself skills you can protect your home It also gives tips and ideas which will help you to maintain and improve your home security even if you already have an alarm Every circuit in this book is clearly described and illustrated and contains components that are easy to source Advice and guidance are based on the real expe rience of the author who is an alarm installer and the designs themselves have been rigorously put to use on some of the most crime ridden streets in the world The designs i
188. ing Traditionally this is the time of year when a lot of new recruits enter the hobby and this fea ture often offers advice about getting started This time we work on the basis that learning from your mistakes is good but learning from the mistakes of other people is even better and we will con sider how not to do it By avoiding the pitfalls mentioned here new recruits should find this absorbing hobby rela tively frustration free Smart Buying When building old projects we always advise checking the availability of all the components before buying any of them Otherwise you risk purchas ing 95 per cent of the parts only to discover that the other five per cent are no longer available Both manufacturers and retailers seem to have ratio nalised their ranges of com ponents in recent years resulting in many compo nents suddenly disappearing Short lived components that failed to make the grade have always been a problem but even some of the golden oldies have suddenly proved to be difficult or impossible to obtain in recent years Even with a project pub lished a few months ago it is risky to start ordering parts without first checking that they are all still available Be particularly careful about semiconductors which seem to be the worst sufferers of here today gone tomorrow syndrome Get as many catalogues and price lists as you can This maximises your chances of being able to track down any vit
189. ions Do not allow the voltage applied to 1C2 s input to exceed 5V and do not try to monitor the output of an a c adaptor If a d c adaptor is used and purely out of interest temporarily remove smoothing capacitor C1 to see if ripple is present If an a c adaptor is used lower Photo 11 9 Screen dump of the rectified but unsmoothed voltage at the junction of diodes D2 and D4 see text 668 capacitance values for C2 can be tried providing the capacitor has a working voltage of 25V or greater until a minor amount of ripple is present Try 22uF in the first instance Do not totally remove C2 otherwise IC2 will not function correctly because of maximum OV to 5V ripple being present on its power line Don t forget to rein state C2 as a 220uF component when you ve finished The waveform monitored on the author s test model is shown in Photo 11 9 ANOTHER OPTION Some of you may have a 7V d c battery charger for your mobile phone as has the author This may be used as the power source if you remove the diodes D1 to D4 and connect the posi tive output to the input Photo 11 8 Detail of the breadboard layout in Fig 11 7 of regulator IC1 and the OV output to the breadboard s OV line You must ensure that this polarity is correct WORKSHOP POWER SUPPLY UNIT In a separate constructional article to be published in the November issue a work shop power supply is described In its full
190. ircuits The Parts Gallery will help students to recognise common electronic components and their corresponding symbols in circuit diagrams Selections include Components Hobbyist Student Institutional Schools HE FE Industry 99 plus VAT Institutional 10 user Network Licence 199 plus VAT HARDWARE 45 inc VAT Standard PiCtutor Development Kit 47 inc VAT Deluxe PiCtutor Development Kit 99 plus VAT Deluxe Export Version 96 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices ELECTRONIC COMPONENTS PHOTOS A high quality selection of over 200 JPG images of electronic components This selection of high resolution photos can be used to enhance projects and presentations or to help with training and educational material They are royalty free for use in commercial or personal printed projects and can also be used royalty free in books catalogues magazine articles as well as worldwide web pages subject to restrictions see licence for full details Also contains a FREE 30 day evaluation of Paint Shop Pro 6 Paint Shop Pro image editing tips and on line help included MODULAR CIRCUIT DESIGN This CD ROM contains a range of tried and tested analogue and digital circuit modules together with the knowledge to use and interface them Thus allowing anyone with a basic understanding of circuit symbols to design and build their own projects E
191. irus writers get away with double extensions like File jpg exe Windows should also give the option to disable all Macros in a way that does not let viruses turn the option back on Outlook should by default send only ASCII currently it may reply in HTML if it receives HTML Cluley suggests that as a temporary safe guard users can remove the Windows scripting Host from Windows and disable Active X This will stop VBS batch files running and will probably make no differ ence whatsoever to normal operation of the computer But the user has to know how to burrow around inside the Windows Settings Panel to Add Remove programs and alter the Security Settings inside Internet Explorer The Internet should be getting easier and safer to use not more risky and complicated The simple solution says Cluley is for Microsoft to sell Windows in a default state that 1s safe from viruses and then let users to change risky settings if they know how and dare WAP Phone Viruses Interestingly Cluley believes that risk of WAP cellphone viruses has been greatly over exaggerated The Spanish virus Timofonica connected to a Web site which then E mailed short SMS messages to random phone numbers So it only caused irritation A side effect of the PC LoveBug virus was to make a PC send some of its code to any SMS address in the Outlook address book But it could not spread itself that way because current cell phones do not have the pro
192. is active The relevant protocol l e d should flash when data is received from the PIC circuit PIC PE IR remote display LIBE ES SIRC a pee COM RCS P reload 15 RADIO TUNER SIRC decoding Fig 12 Example PC screen display REMOTE CONTROLS A manufacturer using remote control of its equipment can allocate any command number to any key Remote controls are not required to be compatible or exchange able with equipment from another manu facturer hence the plethora of remote con trols and protocols found in most homes The author has come across a remote con trol for a portable TV that uses RC5 cod ing for some of the keys and another pro tocol not SIRC for the remaining keys As neither PIC program decodes the device address then the result is a wider choice of remote controls being available However if a suitable remote control hand set is not available then replacement remote controls are readily obtainable with a variety of functions and key layout Most of these handsets are programmable and can replace many different models therefore there is an implied choice of protocol Clearly the IR decoding program could alter a variable value or the status of a Boolean flag or control a device attached to one of the PIC ports A number of dif ferent functions could be added as the assembler code associated with the LED DISPLAY routine can be increased as necessary Numeric input to a PIC pro gram
193. ital Four DAC and ADC shows you how the computer is able to communicate with the real world You wvill learn about digital to analogue and ana logue to digital converter circuits Order Code VT304 VT305 56 minutes Digital Five Memory Devices introduces you to the technology used in many of today s memory devices You will learn all about ROM devices and then proceed into PROM EPROM EEPROM SRAM DRAM and MBM devices Order Code VT305 VT306 56 minutes Digital Six The CPU gives you a thorough understanding in the basics of the central processing unit and the input output circuits used to make the system work Order Code VT306 ORDERING Price includes postage to anywhere in the world OVERSEAS ORDERS We use the VAT portion of the price to pay for airmail postage and packing wherever you live in the world Just send 34 95 per tape All payments in sterling only send cheque or money order drawn on a UK bark Make cheques payable to Direct Book Service Visa and Mastercard orders accepted please give card number card expiry date and cardholder s address if different from the delivery address Orders are normally sent within seven days but please allow a maximum of 28 days longer for overseas orders Send your order to Direct Book Service Allen House East Borough Wimborne Dorset BH21 1PF Direct Book Service is a division of Wimborne Publishing Ltd Publishers of EPE Tel 01202 881749 Fax 01202 841692 Due to the
194. ite Loop Aerial and receiver should be by means of a length of coaxial cable This loop is not balanced with respect to ground and the two nulls are not equal or symmetrical The unit cannot therefore be used for direction finding There is one position for maximum sig nal and one for the deepest null not two 180 degrees apart as is the case with balanced loops The a g c automatic gain control sys tem of a sensitive radio will tend to mask the null but turning loop output well down will usually expose it Bearing and tilt can then be adjusted until the null is as deep as possible Null depth will vary from station to station and from time to time Some pro grammes are transmitted from different locations on the same frequency and a combination of ground and sky waves also results in multi path reception making it impossible to achieve deep nulls Notwithstanding this interference from unwanted stations and man made electrical interference can always be greatly reduced and usually eliminated To have one station completely disap pear and be replaced by another as the loop is rotated can be magical It cer tainly makes the construction of the unit very worthwhile Advancing the Q control VR4 will dramatically increase sensitivity at the expense of bandwidth At high settings the audio quality is muffled and the loop can be tuned across the received signal and centred on one or other of its sidebands Not only
195. its Create your own macros highly scalable Create your own circuits components and i c s Easy to use digital interface Animation brings circuits to life Vast library of logic macros and 74 series i c s with data sheets Powerful tool for designing and learning Macro screen Counter project PRICES Hobbyist Student 45 inc VAT Prices for each of the CD ROMs above are Institutional Schools HE FE Industry 99 plus VAT Institutional 10 user Network Licence 199 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices Interested in programming PIC microcontrollers Learn with PlCtutor by John Becker This highly acclaimed CD ROM together with the PICtutor experimental and development board will teach you how to use PIC microcontrollers with special emphasis on the PIC 16x84 devices The board will also act as a development test bed and programmer for future projects as your programming skills develop This interactive presentation uses the specially developed Virtual PIC Simulator to show exactly what is happening as you run or step through a program In this way the CD provides the easiest and best ever introduction to the subject Nearly 40 Tutorials cover virtually every aspect of PIC programming in an easy to follow logical sequence HARDWARE Whilst the CD ROM can be used on its own the physical demonstration provided by the PlCtut
196. l Semiconductor data CD ROM which I bought on line for a few dollars The man ufacturer Zetex produces an interesting low voltage variation of this timer the ZSCT1555 which operates down to 2V You can easily obtain 3V d c by placing two 1 5V cells in series using a suitable battery holder and clip Or try the idea of using a 3V lithium manganese coin cell e g the CR2450 Lastly this seems as good a time as any to introduce my new Electronic Components Photos CD ROM which contains over 200 colour JPG images of electronic components divided into cate gories It s in HTML format and runs from your web browser but you don t need an Internet connection to view it Both thumbnail and high resolution colour images are included along with a demo copy of Paint Shop Pro image edit ing software The CD ROM is intended for further education presentations parts cata logues handouts industry training per sonal projects and web sites and it is available from the publishers of EPE for only 19 99 See the CD ROM advert elsewhere in this issue You ll find all sorts of photos of resistors light emitting diodes chips and more included on the CD ROM ARW Shocking Stuff Fernando Bentes de Jesus in Portugal is a regular reader and enquires about the use of Residual Current Devices RCDs or Ground Fault Circuit Interrupters GFCIs in the States If it only takes a current of 20mA to cause uncontrollable spasms perha
197. l Capacitors 1uf 250V encapsulated radial plastic cased capacitors Asstd capacitors electrolytic Asstd capacitors 1nF to 1uF Asstd disc ceramic capacitors Asstd Skel Presets sm stand cermet 1 00 Asstd RF chokes inductors Asstd grommets Asstd solder tags p conns terminals 1 00 Asstd crystals plug in Asstd coil formers Asstd dil switches Miniature slide switches sp co Standard slide switches dp dt Asstd beads ceramic teflon fish spine 1 00 Asstd small stand offs l throughs etc 1 00 Asstd dil sockets up to 40 way TV coax plugs plastic metres very thin connecting wire red 1 00 lin glass reed switches 1 00 Magnetic ear pips with lead and plug 1 00 Any one value 4W 5 cf resistors rena 1R to 10M 0 45 7812 Voltage Regulators Prices include VAT Postage 1 45 44p stamp for Lists 288 Abbeydale Road Sheffield S7 1FL Phone 0114 2552886 Fax 0114 2500689 E mail sales Bardwells co uk Web site http www bardwells co uk Everyday Practical Electronics September 2000 DIGITAL TEST METER Built in transistor test socket and diode test position DC volts 200mV to 1000V AC volts 200V to 750V DC current 200mA to 10A Resistance 200 ohms to 2000K ohms 6 99 inci var 711 Watch Slides on TV Make videos of your slides Digitise your slides using a video capture card Liesgang diatv automatic slide viewer with built in high quality colo
198. l project for those who wish to get started in the fascinating world of FM broadcasting and want a good basic circuit to experiment with 12 18VDC PCB 44x146mm 1028KT 23 95 0 15 WATT FM TRANSMITTER PRE ASSEMBLED amp TESTED Four transistor based stages with Philips BLY 88 in final stage 15 Watts RF power on the air 88 108MHz Accepts open dipole Ground Plane 5 8 J or YAGI configuration antennas 12 18VDC PCB 70x220mm SWS meter needed for alignment 1021KT 69 95 SIMILAR TO ABOVE BUT 25W Output 1031KT 79 95 STABILISED POWER SUPPLY 3 30V 2 5A Ideal for hobbyist amp professional laboratory Very reliable amp versatile design at an extremely reason able price Short circuit protection Variable DC voltages 3 30V Rated output 2 5 Amps Large heatsink supplied You just supply a 24VAC 3A transformer PCB 55x112mm Mains operation 1007KT 17 50 Custom Designed Box 2007 34 95 STABILISED POWER SUPPLY 2 30V 5A As kit 1007 above but rated at 5Amp Requires a 24VAC 5A transformer 1096KT 29 95 Custom Designed Box 2096 34 95 MOTORBIKE ALARM Uses a reliable vibration sensor adjustable sensitivity to detect movement of the bike to trigger the alarm amp switch the output relay to which a siren bikes horn indicators or other warning device can be attached Auto reset 6 12VDC PCB 57x64mm 1011KT 11 95 Box 5 95 CAR ALARM SYSTEM Protect your car from theft Features vibration sensor courtesy
199. lasts a little less than one time constant or 10us as determined by the time constant set by R6 and C4 If the switch 1s released an instant too soon the pulse is finished before the Q6 output from IC2 goes high Thus it is essential to release the switch within the 0 05s that the output is high The circuit should be powered by a 6V battery do not use any other supply voltage CONSTRUCTION The Steeplechase Game is constructed on a piece of stripboard 39 holes wide by 29 holes strips down The layout details are shown in Fig 3 Dual in line d 1 1 sockets should be used for all i c s Note that some resistors are mounted vertically There are a lot of wire links on the board preferably use sleeving on them to prevent accidental short circuits between them Note that two links have one end beneath VR1 and VR2 Ensure that the 1 C S l e d s and electrolytic capacitors are inserted the correct way round Also ensure that all the required track cuts are made in the correct positions Begin construction with IC3 and IC4 Note that only two of the four gates of IC3 are used and only three of the four gates of IC4 In the layout shown the inputs to unused gates are connected to OV or 46V When assembling this part of the circuit solder in the lead connecting ICA to IC2 This is the wire link from N21 to S21 in Fig 3 Solder the end at S21 but leave the other end free To test this section of the circuit con nect the f
200. lated side both vary considerably with load current and it is essential to ensure that the instantaneous voltage does not dip below the minimum value required for cor rect operation of the regulator Typically this is about 2V to 3V above the regulated output voltage Transformer output voltages are usu ally stated in terms of the r m s value at full power but rise when lightly loaded and the rectified and smoothed d c output is in any case Ripple is usually reckoned to be about 700mV peak to peak for each 100mA of load current with a 1000uF smoothing capacitor so it should be about the same for a 1A output if a 10 000uF capacitor is used These were the basic factors consid ered when designing this power supply CIRCUIT DESCRIPTION The full circuit of the project is shown in Fig 1 Transformer T1 is a 20VA type with two 15V outputs which are connect ed in parallel to provide a total current capacity of about 1 3A This is full wave rectified to d c by RECI and then smoothed by the 10 000uF capacitor Cl This is used to supply regulator ICI a standard 12V 1A positive supply regulator The output voltage is raised to 13 2V by the inclusion of the two silicon diodes D1 and D2 between the regulator s common connection and the OV supply rail This serves two purposes as it both increases the output power from the EPE Moodloop and reduces the heat generated in the regulator Constructors requiring a 12V supply for wo
201. lease charge my Visa Mastercard Card Number Please send book order codes Card expiry date Please continue on separate sheet of paper if necessary Everyday Practical Electronics September 2000 New The PIC 18Cxxx series FED PIC C Compiler Version 3 0 now available e Designed to ANSI C Standards e Supports all 14 bit core PICs 12C67x 16C55x Complete development environment includes 16C6x 16C7x 16C8x 16C87x etc Editor assembler simulator waveform analyser e Will produce code for MPLAB and terminal emulator see screenshot below e Libraries include serial interfaces I2C LCD LEARN to Program PIC s in C with FED keypads delays string handling hardware etc Download FREE from our web site e Simulator runs up to 10 times faster than MPLAB allows inputs to be defined multiple With the FED introductory manual breakpoint types single stepping step over etc Learn to program PIC s with FED PIC C _ e Suitable for complete beginners to PICs or to simh LIRA lm GAI PAD the C programming language r DC si Leads through example sald mlad A e Introduces simple C programs then covers variables and casting pointers structures and unions functions etc e All examples will run fully within the simulator or on the FED 16F84 and 16F877 E 7 GL T he Ere ji PP Ada Lie dev Lil L ilsretr Wadlsi pj TA a N Fm ae besi pETT1AE
202. les into stand alone executables then if the target people do not have QBasic they can run the software any way My point is we should stick with QBasic for now and until such time as we can see what is going to happen or not it is probably the best language It is also worth asking if Microsoft is bro ken up what will happen about their software Will it be continued under other names or will just some of it be sold off and Microsoft con tinue to exist in a smaller form Please enlighten me Will we still be able to find a standard oper ating system As well as my MS DOS system I have another 80386 running Linux perfectly hap pily There are many other flavours of UNIX and Linux and this could cause compatibility prob lems if Microsoft goes under Another point about Microsoft software is that it is becoming too helpful If a new version of Visual Basic does come about will it try to for mat the screen or put in bits and pieces the way it wants just like Word 2000 I find this the most annoying feature of Microsoft it thinks it knows what you want to do and then treats you like an idiot It defeats its own object If the idea of it is to help a new user which I think it is it makes things even more complicated I have been reading EPE for four years now and have loved every issue It has been and still will be the best place from which to learn elec tronics Incidentally I could not find an E mail
203. ling edge of the waveform generating an interrupt The timer value is incremented every 16 microseconds and is read on every interrupt To work out the likely timer values divide the expected pulse width by the timer tick illustrated in Fig 9 and Fig 11 pulse width start pulse 2 4ms 150 timer 16us 16us Fig 9 SIRC timer formula 2 4ms 150 start 2 Ams 0 6ms 187 start 1 2ms 0 6ms 112 logic 1 0 6ms 0 6ms 75 logic 0 Fig 10 SIRC TIMERVAL for all pulse widths START Y IO 2 4ms 0 6 1 2ms 0 6 0 6ms Fig 11 SIRC timing details The program uses the timer value to determine the waveform For example if the value is between 90 and 150 then a logic 1 is assumed and THISBIT 1 If the value is between 50 and 90 then a logic O is assumed and THISBIT 0 The ADDBINARY routine is called and the appropriate bit within CBINARY is set to the value of THISBIT SIRC ASSEMBLER PROGRAM With the SIRC code running press the Increase Volume key on the Sony remote control and one l e d D1 will come on the other l e d D2 will be off Press the Decrease Volume key and the l e d s will invert To change which key controls the l e d select the appropriate value for the key function and use that value in the LEDDISPLAY routine Note that the remote control may generate different numbers for the same function so that the Sony equipment can distinguish between for example Play fo
204. ls in my digital camera to keep its clock running in between times but I have not noted any ill effects so far The best charging techniques are designed to avoid overcharging and pos sible damage and they use a three stage process a fast recharge to restore up to 90 per cent capacity an intermediate timed charge completely restores full capacity followed by a trickle charge to balance the cells and compensate for self discharge The electronics industry has a lot of experience of the fifty year old Ni Cd but the newer NiMH cell is now creeping on to the consumer market One wall recharger the Energiser ACCU Hi Energy Charger from Argos 982 6852 also see the identical looking priced Uniross CHX2 from Maplin UG31J will charge four cells of either type or a 9V battery at the flick of a switch I must say that the first example of this model I purchased got alarmingly hot during charging and failed altogether after a few uses but its replacement is going strong RAM your batteries The latest arrival on the battery scene is the Rechargeable Alkaline Manganese RAM cell in which Rayovac leads the 687 way see photo although they are not very widely available Rayovac claim that they have a higher initial capacity than either Ni Cd or NiMH cells though not as much as an ordinary alkaline cell which have a lower internal resistance Importantly much bet ter self discharge parameters are claimed Choosing a rec
205. lue for the moment Next increase the value for R1 ballast resistor until the current flow through the Zener is at or just above 10mA Make a note of the value for R1 Now estimate the minimum current that is likely to flow through the load circuit Adjust the value of R2 until this current is shown in the Results box You will see that the current now estimated to flow through DI will have increased From the Results box read off the power that R1 and Dl are likely to consume when the load circuit of R2 is drawing the mini mum current WATTAGE VALUES As you discovered in Part 1 resistors are manufactured to handle specific maximum power values e g 0 25W 0 5W etc similarly with Zener diodes whose typi cally available power ratings are stated near the top of the screen e g 400mW 500mW IW etc but other values exist In a real life situation from these avail able values you would select wattage val ues for RI and D1 so that they can withstand the power that they are expected to handle Choose power handling values that are well above the maximum at which the component is likely to be operated at least 5096 and preferably more Be aware that if the load circuit con sumes more current than allowed for by the resistance value of R1 the Vout value may drop below the Zener voltage and inade quate stability of the powered circuit may result Note also that the example minimum current requirement through D1 may
206. lyse it The new Peak Atlas Component Analyser UK price 60 fully inclusive Shown approx actual size To find out just what the Atlas is capable of give us a call and we ll send you our data pack Alternatively see comprehensive data on our web site PEAK Constructional Project ANDY FLIND EPE MOODLOOP POWER SUPPLY A regulated 13 2V 7A supply which may be modified for 12V output give a constant voltage output with sufficient current for the EPE Moodloop project described in last month s issue The Moodloop may be operated from a supply anywhere between 9V and 15V the only restriction being that the voltage of the supply should not vary Although the average supply current drawn at 12V is about 600mA the peak value is closer to 1A and at 15V it will be even higher Since the output frequency range of the Moodloop extends down to 1 Hz the use of large decoupling capaci tors to supply these current peaks is impracticable Instead a power supply capable of delivering the peak current con tinuously is required In some cases a suitable regulated supply may already be available but for Moodloop constructors without access to a suitable power source this project will fill the need It is compact simple and relatively inex pensive to construct and can also double as a useful source of d c power in the work shop for other applications HOTLY COMPHOMISED The design of a linear regulated power supply u
207. m 911 1749 Rh wg a A E mg Volume 2 Issue 9 September 2000 WWW epernag co Copyright 1999 Wimborne Publishing Ltd and Maxfield amp Montrose Interactive Inc PO Box 857 Madison Alabama 35758 USA All rights reserved WARNING The materials and works contained within EPE Online which are made available by Wimborne Publishing Ltd and Maxfield amp Montrose Interactive Inc are copyrighted You are permitted to download locally these materials and works and to make one 1 hard copy of such materials and works for your personal use International copyright laws however prohibit any further copying or reproduction of such materials and works or any republication of any kind Maxfield amp Montrose Interactive Inc and Wimborne Publishing Ltd have used their best efforts in preparing these materials and works However Maxfield amp Montrose Interactive Inc and Wimborne Publishing Ltd make no warranties of any kind expressed or implied with regard to the documentation or data contained herein and specifically disclaim without limitation any implied warranties of merchantability and fitness for a particular purpose Because of possible variances in the quality and condition of materials and workmanship used by readers EPE Online its publishers and agents disclaim any responsibility for the safe and proper functioning of reader constructed projects based on or from information published in these materials
208. meters to ground OV rail Details of ST the Selector switch wiring are given in Fig 3 HDUSING THE CONTROLS The photographs show how the controls and p c b are housed in a plastic instrument case which also acts as the base of the unit The p c b and jack socket SK5 are screened within a diecast box which also strengthens the case beneath the loop Screening the p c b is not essential the entire enclosure can be of wood or plastic RODS AND TURNS Seven ferrite rods represents a good com promise between cost weight and perfor mance but fewer or more rods can be used The number of turns to give the required inductance about 1604 H depends of course on the number of rods finally used For a single rod thirty seven turns should produce the required value If only one rod is used it may be necessary to increase the feedback winding L2 to two turns With a bundle of TYPE No A 92 TYPE No Fig 4 left o d Semiconductor d gs pinout details a k i a k Right VARICAP TR1 TR2 D2 Completed DIODE BF981 2N3819 2mA ferrite loop 1 2 OF UNDERSIDE L E D KV1236 aerial housed in a pivot box 29 SPACED TURNS OF 28 S W G ENAMELLED omm FERRITE RODS COPPER WIRE 35mm DIA PLASTIC WASTE PIPE FINISH START FINISH 1 TURN OF 28 S W G ENAMELLED COPPER WIRE Fig 5 Ferrite rod 7 off loop aerial winding details and dimensions The coil former is made
209. mmer does NOT require special software other than a terminal emulator program built into Windows Can be used with ANY computer operating sys tem 3121KT 34 95 3V 1 5V TO 9V BATTERY CONVERTER Replace expensive 9V batteries with economic 1 5V batter ies IC based circuit steps up 1 or 2 AA batteries to give 9V 18mA 3035KT 4 95 TELEPHONE SURVEILLANCE MTTX MINIATURE TELEPHONE TRANSMITTER Attaches anywhere to phone line Transmits only when phone is used Tune in your radio and hear both parties 300m range Uses line as aerial amp power source 20x45mm 3016KT 7 95 AS3016 13 95 TRI TELEPHONE RECORDING INTERFACE Automatically record all conversations Connects between phone line amp tape recorder not supplied Operates recorders with 1 5 12V battery systems Powered from line 50x33mm 3033KT 7 95 AS3033 16 95 O TPA TELEPHONE PICK UP AMPLIFIER WIRELESS PHONE BUG Place pick up coil on the phone line or near phone earpiece and hear both sides of the conversation 3055KT 10 95 AS3055 19 95 1 WATT FM TRANSMITTER Easy to construct Delivers a crisp clear signal Two stage circuit Kit includes microphone and requires a simple open dipole aerial 8 30VDC PCB 42x45mm 1009KT 14 95 4 WATT FM TRANSMITTER Comprises three RF stages and an audio preamplifier stage Piezoelectric microphone supplied or you can use a separate pream plifier circuit Antenna can be an open dipole or Ground Plane Idea
210. n Sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order 696 Everyday Practical Electronics September 2000 RACT CUE wa ELECTRONICS TODAY INTERNATIONAL SS EEN A T se PUDDITURTHCYIO PUT nm EM ue ad We can supply back issues of EPE by post most issues from the past five years are available An EPE index for the last five years is also available see order form Alternatively indexes are published in the December issue for that year Where we are unable to provide a back issue a photostat of any one article or one part of a series can be purchased for the same price APRIL 99 PROJECTS e Mechanical Radio Voice Record Playback Module e Versatile Event Counter e PhizzyB Computers 6 e Ironing Board Saver FEATURES e Microcontrollers e PhizzyB Computers 6 e MAX761 D C to D C Converter e Interface e Circuit Surgery e Net Work e FHEE 48 page Basic Soldering Guide booklet MAY 99 PROJECTS e MIDI Handbells e A M F M Radio Remote Control e PhizzyB Computers 7 e PIC Toolkit Mk2 1 FEATURES e PC Engines From 4004 to Pentium lll e Ingenuity Unlimited e Practically Speaking e PhizzyB Computers 7 e Circuit Surgery e New Technology Update e Net Work e FREE pull out 7400 series Pinout Data Chart JUNE 99 PROJECTS e Clipping Video Fader Starter Project e PC Audio Frequency Meter e Musical Sundial e PIC Toolkit Mk2 2 FEATURES
211. n ning Windows 95 screen where I am in the spec trum up to 30MHz This would make my day Peter McBeath Morpeth Northumberland In fact Robert and R A Penfold are one and the same although with so many designs arti cles and books to his credit anyone could be for given for wondering how just one person could be so prolific My own familiarity with Robert s work must date back to at least the early 70s Over the years he has taught many electronics enthusiasts about how to get the best out of their hobby and we greatly respect his abilities and knowledge We are pleased to know that Robert s designs have inspired you as well and have passed your letter to him LAPTOP AND TEACH IN Dear EPE I ve been trying to test the parallel port on my laptop Pentium II running Windows 98 and I do not get any responses from the parallel port when testing it with Teach In 2000 s Parallel Port Data Display Set routine Ive built the interface and checked it thor oughly and the outputs stay at OV regardless of what I select from the state shown on the Output Byte box on the computer screen I have tried all three addresses for the printer port all unsuccess ful I checked the Readout column on some issues of EPE to see if anyone had encountered this problem but could not find any Any help would be appreciated Alejandro Fubini via the Net I suggested to Alejandro that he should read Panel 9 5 of Teach In Part 9 July 00 aski
212. n trols PA filters highpass and lowpass Scratch and rumble filters Loudness filter Audio mixers Volume and balance controls Order code BP309 3 99 92 pages HIGH POWER AUDIO AMPLIFIER CONSTRUCTION R A Penfold Practical construction details of how to build a number of audio power amplifiers ranging from about 50 to 300 400 watts r m s includes MOSFET and bipolar transistor designs Order code BP277 3 99 96 pages ELECTRONIC MUSIC AND MIDI PROJECTS R A Penfold Whether you wish to save money boldly go where no Everyday Practical Electronics September 2000 musician has gone before rekindle the pioneering spirit or simply have fun building some electronic music gadgets the designs featured in this book should suit your needs The projects are all easy to build and some are so simple that even complete beginners at electronic project construction can tackle them with ease Stripboard layouts are provided for every project together with a wiring diagram The mechanical side of construction has largely been left to the individual constructors to sort out simply because the vast majority of project builders prefer to do their own thing in this respect None of the designs requires the use of any test equipment in order to get them set up properly Where any setting up is required the procedures are very straightforward and they are described in detail Projects covered Simple MIIDI tester Message grabber
213. n amplitude until it leaves an almost straight line in its place on the screen roughly midway between the maxi mum and minimum points that the wave form reached while still a square wave What is happening as you increase VR2 s resistance 1s that the CR ratio is progressive ly increasing and the capacitor has less and less time to charge or discharge between each change of voltage from Cla pin 2 set VR2 s wiper to a midway position Now vary the setting of VR1 to change the frequency being generated Again observe the screen while you do so You will see that the waveform regains some of its amplitude at lower frequencies but loses it as the frequency rises Again its all to do with the CR ratio of VR2 and C2 this time in respect of the rate of change of the controlling square wave Try the same tests with different capacitor values e g Cl at 22uF and C2 at 2 2uF so setting other CR ratios and frequency ranges There are many varied applications in which this simple resistance capacitance VR2 C2 configuration can be used from setting an oscillator s frequency as you ve E E E in Pen Gi Photo 11 3 Detail of the breadboard layout in Fig 11 3 been doing to changing waveform shapes as you ve just done removing higher fre quency signals whilst retaining those at lower frequencies as in an audio tone con trol for example and smoothing a rectified power supply voltage of course although this is a s
214. n be obtained because there 1s no feedback from the output to the input and the isolation depends upon the material that separates the l e d and the detector However one of the drawbacks of these systems is that they may not have a suffi ciently high bandwidth When a digital one is received by the opto isolator s Led it emits light This is received by the photo detector that converts the incoming light into free electrons and holes thereby allowing current to flow in the detector However when the l e d is extin guished the photo detector stops converting the light into electrons but it takes finite time for the charge to be dissipated This is particularly so because the detector is gener ally operating into a relatively high imped ance circuit and this slows down the rate at which data can be transferred A further problem is that photo detectors are particularly sensitive to electrostatic fields Unfortunately when driving large machines these are often present Often elec trostatic transients appear and these manifest themselves as additional spikes on the output of the coupler The resulting spikes can cor rupt the data being transferred providing an additional problem for the system designer 660 New technology Micromagnetic techniques offer better circuit isolation for high speed data transfer lan Poole reports Another approach is to use a magnetic isolator These are typically based around
215. nclude all elements including sensors detectors alarms controls lights video and door entry systems Chapters cover installation testing maintenance and upgrading Order code NE25 14 99 192 pages MICROCONTROLLER COOKBOOK Mike James The practical solutions to real problems shown in this cookbook provide the basis to make PIC and 8051 devices really work Capabilities of the variants are examined and ways to enhance these are shown A survey of common interface devices and a description of programming models lead on to a section on development techniques The cookbook offers an introduction that will allow any user novice or experienced to make the most of microcontrollers 240 pages Order code NE26 19 99 A BEGINNER S GUIDE TO TTL DIGITAL ICs R A Penfold This book first covers the basics of simple logic circuits in general and then progresses to specific TTL logic inte grated circuits The devices covered include gates oscilla tors timers flip flops dividers and decoder circuits Some practical circuits are used to illustrate the use of TTL devices in the real world 142 pages Order code BP332 4 95 ELECTRONIC MODULES AND SYSTEMS FOR BEGINNERS Owen Bishop This book describes over 60 modular electronic circuits how they work how to build them and how to use them The modules may be wired together to make hundreds of differ ent electronic systems both analogue and digital To show the reader
216. ncreases with each additional rod but the rate of improvement seems to fall off after about ten or so Weight and cost are also limiting factors and this design incorpo rates seven rods Fewer or more rods can of course be used and guidance on this is given later HIGH Q Tuned circuits incorporating coils wound on ferrite rods have a high Q This restricts bandwidth and can result in side band cutting which reduces treble response The application of positive feedback to the tuned circuit increases Q and signal output The price paid for this is a further reduction in bandwidth Sideband cutting becomes severe and treble response heavi ly attenuated Moreover with high levels of Q multiplication loop tuning becomes critical High selectivity ahead of a receiver cov ering a congested and noisy band can be very useful however Careful operation can restore the treble response and Everyday Practical Electronics September 2000 measures can be taken to overcome the problem of critical tuning GOING ASTHAY The Medium Wave band extends from 527kHz to 1620kHz in Europe In the USA stations operate up to 1700kHz and Australia has low powered transmitters working at 1720kHz United Kingdom coverage is from 558kHz to 1602kHz the region beyond 1602KHz being taken up by cordless phone channels In Europe Dutch Greek and Serbian pirate stations invade the seg ment above 1600kHz Stray capacitance can be relatively hi
217. ne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 E mail orders 9 epemag wimborne co uk Payments must be in sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order Send a copy of this form or order by letter if you do not wish to cut your issue Everyday Practical Electronics September 2000 697 PIC Programming Project REMOTE CONTROL IR DECODER ROGER THOMAS Allows PIC programming enthusiasts to remotely control their designs microcontroller circuits to be enhanced by the addition of a low cost infra red sensor and suitable decoding software The operation of the PIC soft ware can then be selected via a remote control handset This control option may be preferable to interfacing external switches to the PIC The circuit and program could also be used just as a simple tester to show that a remote control is working BASIC FUNCTIONS Referring to Fig 1 the Remote Control Decoder uses an infra red sensor IC2 the demodulated output from which is con nected to a PIC16x84 microcontroller IC1 for decoding Remote control handsets can use a vari ety of different protocols The PIC soft ware decodes either the RCS Philips or SIRC Sony transmission protocol as these are most likely to be used to control equipment in the home These protocols are described later so that the decoding software can be understood and incorpo rated as part of ano
218. ng him to let me know the outcome He responded Thanks for your help I can now get on with continuing the Tutorial which is the best refresher I ve had since completing my electron ics engineering degree six years ago It s amaz ing what you forget in that timespan Everyday Practical Electronics September 2000 WEB DATA SHEETS Dear EPE Following your information in Readout May 00 I have in vain tried to access data sheets for Harris Semiconductors HA12017 and also the SSM2166P used in your Versatile Mic Audio Preamplifier May 00 Please advise how it is possible to access a site with data sheets that I can print off as appropri ate to the specific chip concerned Roger Nightingale via the Net Our webmaster Alan received this query and gave Roger the following reply Links are stored on our Net Work A Z web page which also has a Google search engine Entering Harris Semiconductor into the Google search engine see Net Work May 00 brought up their address instantly www semi harris com It says that Harris Semiconductor was taken over by Intersil You could try searching www intersil com which is where Harris s web site will now send you Similarly by typing Analog Devices into the Google search engine the URL is immedi ately revealed www analog com Save any Adobe Acrobat PDF files by right clicking over the file name choose Save Target As and save to your hard disk If you haven t got
219. nical request or query We are able to provide you with the most relating to the Manuals important and popular up to date features in our d PLEASE send me l ORDER FORM l l Simply complete and return the order form with your l CT THE MODERN ELECTRONICS MANUAL plus a FREE SUPPLEMENT Wight Pub EU DOLUS AUR House I ELECTRONICS SERVICE MANUAL plus a FREE SUPPLEMENT East Borough Wimborne Dorset BH21 1PF I enclose payment of 23 97 for one Manual or 39 94 for both Manuals saving We offer a 30 day MONEY BACK GUARANTEE another 8 by ordering both together plus postage if applicable if you are not happy with either Manual simply return it to _ also require the appropriate Supplements four times a year These are billed us in good condition within 30 days for a full refund i i separately and can be discontinued at any time Please delete if not required Overseas buyers do have to pay Me overseas postage eee beliu I Should I decide not to keep the Manual s I will return it them to you within 30 days for a full refund POSTAGE CHARGES FULL NAME E EN Price PER MANUAL i PLEASE PRINT Postal Region Surface Air i ADDRESS sesos E Ra aio ado Mainland UK FREE i Scottish Highlands l DEE ee ee a ee ae a eee E eS ee ee A ee ee ee UK Islands amp Eire 5 50 each l Europe E
220. nics com SURVEILLANCE High performance surveillance bugs Room transmitters supplied with sensitive electret microphone amp battery holder clip All trans mitters can be received on an ordinary VHF FM radio between 88 108MHz Available in Kit Form KT or Assembled amp Tested AS ROOM SURVEILLANCE MTX MINIATURE 3V TRANSMITTER Easy to build amp guaranteed to transmit 300m 3V Long bat tery life 3 5V operation Only 45x18mm 3007KT 5 95 AS3007 10 95 MRTX MINIATURE 9V TRANSMITTER Our best selling bug Super sensitive high power 500m range 9V over 1km with 18V supply and better aerial 45x19mm 3018KT 6 95 AS3018 11 95 HPTX HIGH POWER TRANSMITTER High performance 2 stage transmitter gives greater stability amp higher quality reception 1000m range 6 Mili 12V DC operation Size 70x15mm 3032KT 8 95 AS3032 17 95 MMTX MICRO MINIATURE 9V TRANSMITTER The ultimate bug for its size performance and price Just 15x25mm 500m range 9V Good stability 6 18V operation 3051KT 7 95 AS3051 13 95 O VTX VOICE ACTIVATED TRANSMITTER Operates only when sounds detected Low standby current Variable trigger sensitivity 500m range Peaking circuit sup plied for maximum RF output On off switch 6V operation Only 63x38mm 3028KT 9 95 AS3028 22 95 HARD WIRED BUG TWO STATION INTERCOM Each station has its own amplifier speaker and mic Can be set up as either a hard wired bug or tw
221. nnnm 500 Hewlett Packard 3456A Digital Voltmeter nana 600 Hewlett Packard 3488A HP 1B Switch Control Unit various Plug ins available 550 Hewlett Packard 35600A Dual Channel Dynamic Signal Analyser o nnno nnns 3750 Hewlett Packard 3586A Selective Level Meter extsssrrrerrsssrrreressrrrerressrrrerssssrrerrsssrrrerusssrrrersen 800 Hewlett Packard 3711A 3712A 3791B 3793B Microwave Link Analyser 1500 Hewlett Packard 3746A Selective Measuring Set 1 c ceeseseseeeeeeeen eio o 500 Hewlett Packard 3776A PCM Terminal Test Sei etetEEEEEEEEEEEEEREREREREREEEREEEEEEEEEEEEEEEEEREEEREEEEEEE 1000 Hewlett Packard 3779A 3779C Primary Mux Analyser eere rennen nnns from 400 N E T Hewlett Packard 3784A Digital Transmission Analyser ecran nnn nnnnnnnaunnu nnus 5000 Hewlett Packard 3785A Jitter Generator Receiver cce c rece ree nennen nuuus 1250 Hewlett Packard 37900D Signalling Test Set No 7 and ISDN 55 o nona naanauan unns LAZO Hewlett Packard P382A Variable AttenuatoOr SSA RSS s RR nana 250 Hewlett Packard 4192A LF Impedance Analyser eren n nnn nuu ununi unu n uuu u unu n nuu naaa 6500 Hewlett Packard 4262A Digital LCR Meter once 950 Hewlett Packard 4342A Q Me
222. ntents The world changed in 1971 Microprocessors don t have ten fingers More counting Mathematical micros It s all a matter of logic Registers and memories A microprocessor based system A typical 8 bit micro processor Programming High level languages Micros are getting bigger and faster The Pentium The PowerPC The Alpha 21164 microprocessor Interfacing Test equipment and fault finding Order code NE31 16 99 222 pages PRACTICAL REMOTE CONTROL PROJECTS Owen Bishop Provides a wealth of circuits and circuit modules for use in remote control systems of all kinds ultrasonic infra red optical fibre cable and radio There are instructions for building fourteen novel and practical remote control pro jects But this is not all as each of these projects provides a model for building dozens of other related circuits by sim ply modifying parts of the design slightly to suit your own requirements This book tells you how Also included are techniques for connecting a PC to a remote control system the use of a microcontroller in remote control as exemplified by the BASIC Stamp and the application of ready made type approved 418MHz radio transmitter and receiver modules to remote control systems Order code BP413 5 99 160 pages DISCOVERING ELECTRONIC CLOCKS W D Phillips This is a whole book about designing and making elec tronic clocks You start by connecting HIGH and LOW logic signals to logic gates You f
223. nternet APRIL 00 PROJECTS e Flash Slave e Garage Link e Micro PlCscope e High Performance Regenerative Receiver 2 FEATURES e Teach In 2000 Part 6 e Ingenuity Unlimited e Technology Timelines 3 e Circuit Surgery e Interface e Telcan Home Video e Net Work The Internet SE BACK ISSUES MAY OU PROJECTS e Versatile Mic Audio Preamplifier e PIR Light Checker e Low Cost Capacitance Meter Multi Channel Transmission System 1 FEATURES e Teach In 2000 Part 7 e Technology Timelines 4 e Circuit Surgery e Practically Speaking Ingenuity Unlimited e Net Work The Internet e FREE Giant Technology Timelines Chart JUNE 00 PROJECTS e Atmospheric Electricity Detector 1 e Canute Tide Predictor e Multi Channel Transmission System 2 e Automatic Nightlight FEATURES e Teach In 2000 Part 8 e Technology Timelines 5 e Circuit Surgery Interface e New Technology Update e Ingenuity Unlimited Net Work The Internet ELECTRONICS T JULY 00 PROJECTS e Q Meter e Camera Shutter Timer PIC Gen Frequency Generator Counter e Atmos pheric Electricity Detector 2 FEATURES e Teach In 2000 Part 9 e Practically Speaking Ingenuity Unlimited Circuit Surgery e PICO DrDAQ Reviewed Net Work The Internet PROJECTS e Handy Amp e EPE Moodloop e Quiz Game Indicator e Door Protector FEATURES e Teach In 2000 Part 10 e Cave Electronics e Ingenuity Unlimited e Circuit Surgery e Interface
224. nuous 24V 174 60 EENG Fetes Fairgrounds Airshows ORDERS FROM SCHOOLS COLLEGES OO BEEN CN E ee Meca GE Carnivals Field ETC PRICES ARE INCLUSIVE OF V A T SALES COUNTER VISA esearch and Amateur Radio field days AND ACCESS ACCEPTED BY POST PHONE OR FAX OR EMAIL Em US AT SALES BKELEC COM ALTERNATIVELY SEND CHEQUE OR POSTAL ORDERS MADE PAYABLE TO BK ELECTRONICS id ma B K ELECTRONICS um For Full Specifications View our web site at TEL 44 0 1702 527572 FAX 44 0 1702 420043 MAA AMAN emote LLLA REG SG HTNM Everyday Practical Electronics September 2000 669 WHETHER ELECTRONICS IS YOUR HOBBY OR YOUR LIVELIHOOD YOU NEED THE MODERN ELECTRONICS MANUAL and the ELECTRONICS SERVICE MANUAL THE MODERN ELECTRONICS MANUAL 15 a The essential reference E work for everyone studying electronics Over 900 pages In depth theory Projects to build Detailed assembly instructions Full components checklists Extensive data tables Detailed supply information Easy to use format Clear and simple layout Comprehensive subject range Professionally written Regular Supplements Sturdy gold blocked ring binder EVERYTHING YOU NEED TO GET STARTED AND GO FURTHER IN ELECTRONICS The revised edition of the Modern Electronics Base Manual amplifiers car projects computer interfaces measuring contains practical easy to follow information on the following instruments workshop equipment security
225. o station intercom 10m X 2 core cable supplied 9V operation 3021KT 13 95 kit form only O TRVS TAPE RECORDER VOX SWITCH Used to automatically operate a tape recorder not supplied via its REMOTE socket when sounds are detected All conver sations recorded Adjustable sensitivity amp turn off delay 115x19mm 3013KT 7 95 AS3013 19 95 LIQUID LEVEL SENSOR RAIN ALARM Will indi cate fluid levels or simply the presence of fluid Relay output to control a pump to add remove water when it reaches a certain level 1080KT 6 95 STEREO VU METER shows peak music power using 2 rows of 10 LED s mixed green amp red moving bar display 0 30db 3089KT 10 95 AM RADIO KIT 1 Tuned Radio Frequency front end single chip AM radio IC amp 2 stages of audio amplification All components inc speaker provid ed PCB 32x102mm 3063KT 9 95 O DRILL SPEED CONTROLLER Adjust the speed of your electric drill according to the job at hand Suitable for 240V AC mains powered drills up to 700W power PCB 48mm x 65mm Box provided 6074KT 17 90 3 INPUT MONO MIXER Independent level con trol for each input and separate bass treble controls Input sensitivity 240mV 18V DC PCB 60mm x 185mm 1052KT 16 95 NEGATIVE POSITIVE ION GENERATOR Standard Cockcroft Walton multiplier circuit Mains voltage experience required 3057KT 9 95 LED DICE Classic intro to electronics amp circuit analysis 7 LED s simulate dice roll slow d
226. ogrammable Sweep Generator 3 6GHz 6 5GHZz 650 Wiltron 6747 20 Swept Frequency Synthesiser 10MHz 20GHZ ccce eere ereeennannns 3950 Yokogowa 3655 Analysing Recorder Renan POA MANY MORE ITEMS AVAILABLE SEND LARGE SAE FOR LIST OF EQUIPMENT ALL EQUIPMENT IS USED WITH 30 DAYS GUARANTEE PLEASE CHECK FOR AVAILABILITY BEFORE ORDERING CARRIAGE amp VAT TO BE ADDED TO ALL GOODS Everyday Practical Electronics September 2000 SQUIRES MODEL amp CRAFT TOOLS Fluorescent Bench Magnifier With 22W circular daylight simulation tube 5 dia glass lens x1 75 magnification Spring balanced arms for universal positioning Multi angle table clamp Robust metal construction Code LA100 Price 49 95 Post Free to UK addresses Post Telephone or Fax your orders to Tel 01243 842424 Fax 01243 842525 Shop Now Open aaa Squires 100 London Road Bognor Regis iN master West Sussex PO21 1DD VISA FRUSTRATED Looking for ICs TRANSISTORS A phone call to us could get a result We offer an extensive range and with a world wide database at our fingertips we are able to source even more We specialise in devices with the following prefix to name but a few 2N 2SA 2SB 2SC 2SD 2P 2SJ 2SK 3N 3SK 4N 6N 17 40 AD ADC AN AM AY BA BC BD BDT BDV BDW BDX BF BFR BFS BFT BFX BFY BLY BLX BS BR BRX BRY BS BSS BSV BSW BSX BT BTA BTB BRW BU BUK BUT BUV BUW
227. on ON SALE 7 Sept Everyday Practical Electronics September 2000 1 BARGAIN PACKS Selected Items CROCODILE CLIPS Small size 10 each red and black Order Ref 116 PLASTIC HEADED CABLE CLIPS Nail in type several sizes Pack of 50 Order Ref 123 30A PANEL MOUNTING TOGGLE SWITCH Double pole Order Ref 166 SUB MIN TOGGLE SWITCHES Pack of 3 Order Ref 214 HIGH POWER 3in SPEAKER 1W 80ohm Order Ref 246 MEDIUM WAVE PERMEABILITY TUNER It s almost a complete radio with circuit Order Ref 247 HEATING ELEMENT Mains voltage 100W brass encased Order Ref 8 MAINS MOTOR with gearbox giving 1 rev per 24 hours Order Ref 89 ROUND POINTER KNOBS for flatted in spin dles Pack of 10 Order Ref 295 CERAMIC WAVE CHANGE SWITCH 12 pole 3 way with Yin spindle Order Ref 303 REVERSING SWITCH 20A double pole or 40A single pole Order Ref 343 LUMINOUS PUSH ON PUSH OFF SWITCHES Pack of 3 Order Ref 373 SLIDE SWITCHES Single pole changeover Pack of 10 Order Ref 1053 PAXOLIN PANEL Approximately 12in x 12in Order Ref 1033 CLOCKWORK MOTOR Suitable for up to 6 hours Order Ref 1038 TRANSISTOR DRIVER TRANSFORMER Maker s ref no LT44 impedance ratio 20k ohm to 1k ohm centre tapped 50p Order Ref 1 23R4 HIGH CURRENT RELAY 12V D C or 24V A C operates changeover contacts Order Ref 1026 2 CORE CURLY LEAD 5A 2m Order Ref 846 3 CHANGEOVER RELAY 6V A C 3V D C Order
228. onnections should be insulated or shrouded Some heat shrink sleeving proved useful for this Where live parts are exposed care MUST be exercised whilst testing or working on the unit Temporary covering with insulating tape is often a good idea when working with such hazards Enlargement showing the regulator IC 1 bolted to the underside of the aluminium case cover It is mounted using an insulating kit and some heatsink compound TOUT STRIPBOARD Fig 4 Details of the interwiring between components The heavyweight components are mounted on the base of the aluminium box see facing photograph It is essential to earth the metalwork of the case and it will be seen that the negative output rail SK2 is also connected to earth The prototype does not have any built in fusing instead it relies on a 3A fuse in the mains plug but constructors wishing to add fuses to the input or the output for addition al safety may easily do so If the unit is to be used as a source of power for the workshop a separate switch for the output would be a useful addition as capacitor Cl stores a considerable amount of power and rapid disconnection of this from a circuit on test might occa sionally be required It would also help to spare the unit from the stress of frequent power up from the mains COMPONENT LAYOUT Apart from keeping the stripboard close to the regulator the layout of this unit is in no way critical Built
229. onto Intelligent Remote now available Laser Business Systems Ltd E Mail info laser com KOR http www laser com Tel 020 8441 9788 Fax 020 8449 0430 PRINTED CIRCUIT BOARDS QUICK SERVICE Prototype and production artwork raised from magazines or draft designs at low cost PCBs designed from schematics Production assembly wiring and software programming For details contact Patrick at Agar Circuits Unit 5 East Belfast Enterprise Park 308 Albertbridge Road Belfast BT5 4GX Phone 028 9073 8897 Fax 028 9073 1802 E mail agar argonet co uk THE BRITISH AMATEUR ELECTRONICS CLUB trading page at http members tripod com baec E trade htm is a place where electronics hob byists can buy and sell electronics components cheaply Many items are free Includes PIC FUN quality Microcontroller kit has everything needed to program the PIC16F84 from your PC 20 includ ing p amp p Details in Electronic Kits section G C S E ELECTRONIC KITS at pocket money prices S A E for FREE catalogue SIR KIT Electronics 52 Severn Road Clacton CO15 3RB PROTOTYPE PRINTED CIRCUIT BOARDS one offs and quantities for details send s a e to B M Ansbro 38 Poynings Drive Hove Sussex BN3 8GR or phone Brighton 883871 fax 01273 706670 VALVE ENTHUSIASTS Capacitors and other parts in stock For free advice lists please ring Geoff Davies Radio Tel 01788 574774 WANTED Circuit diagram of Alba chassis 50 circa 1934
230. or Development Kit plus the ability to program and test your own PIC16x84s really reinforces the lessons learned The hardware will also be an invaluable development and programming tool for future work Two levels of PICtutor hardware are available Standard and Deluxe The Standard unit comes with a battery holder a reduced number of switches and no displays This version will allow users to complete 25 of the 39 Tutorials The Deluxe Development Kit is supplied with a plug top power supply the Export Version has a battery holder all switches for both PIC ports plus l c d and 4 digit 7 segment l e d displays It allows users to program and control all functions and both ports of the PIC All hardware is supplied fully built and tested The Virtual PIC and includes a PIC16F84 PiCtutor CD ROM Price 19 95 inc var ELECTRONIC CIRCUITS amp COMPONENTS THE PARTS GALLERY Provides an introduction to the principles and application of the most common types of electronic components and shows how they are used to form complete circuits The virtual laboratories worked examples and pre designed circuits allow students to learn experiment and check their understanding Sections include Fundamentals units amp multiples electricity electric circuits alternating circuits Passive Components resistors capacitors inductors transformers Semiconductors diodes transistors op amps logic gates Passive Circuits Active C
231. ors could take a leaf from your book Many thanks from darkest Africa Graham Jacobsen Zambia via the Net We are glad to be of service Best wishes from Historic Wimborne at least 1000 years old the location not us personally WRITEOUT If you have something to say which might interest other readers and is loosely related to electronics drop us a line or send an e mail or fax addresses on the Editorial page 659 SOLATING sections of circuitry can be a very important function in some applica tions A variety of techniques and compo nents can be used to achieve this Which one is chosen depends on a variety of fac tors and each technique has its own advan tages and disadvantages With increasing demands for high speed data transmission one of the major requirements of an isolator is to maintain a very high speed path Speeds of many megabits per second are often required and designers of these systems often find that the isolator limits the performance of the whole system As a result companies are investigating new methods of providing cost effective isolators Typically these are integrated cir cuit solutions because they are able to pro vide the required speeds Opto isolators have provided an ideal solution in many respects and many suitable devices have been available for some years Being based around an Led and an optical detector photo detector very high levels of isolation ca
232. ote No construction details are given A reference book of invaluable use to all those who have any interest in electronics be they professional engineers or designers students of hobbyists Order code BP44 3 99 167 pages BOOK ORDERING DETAILS Our postage price is the same no matter how many books you order just add 1 50 to your total order for postage and packing overseas readers add 3 for countries in the EEC or add 6 for all countries outside the EEC surface mail postage and send a PO cheque international money order sterling only made payable to Direct Book Service or credit card details Visa or Mastercard minimum credit card order is 5 to DIRECT BOOK SERVICE ALLEN HOUSE EAST BOROUGH WIMBORNE DORSET BH21 1PF Books are normally sent within seven days of receipt of order but please allow 28 days for deliv ery more for overseas orders Please check price and availability see latest issue of Everyday Practical Electronics before ordering from old lists For a further selection of books see the next two issues of EPE DIRECT BOOK SERVICE IS A DIVISION OF WIMBORNE PUBLISHING LTD Tel 01202 881749 Fax 01202 841692 Due to the cost we cannot reply to overseas orders or queries by Fax E mail dbs epemag wimborne co uk BOOK ORDER FORM Ge ari e eg Post code legi E Telephone NO vias l enclose cheque PO payable to DIRECT BOOK SERVICE for P
233. ough D5 and R1 which charges the Ni Cad B1 Current also TR1 Fig 1 Circuit diagram for the uninterruptible PIC Power Supply WIN A PICO PC BASED OSCILLOSCOPE e 50MSPS Dual Channel Storage Oscilloscope e 25MHz Spectrum Analyser e Multimeter e Frequency Meter e Signal Generator If you have a novel circuit idea which would be of use to other readers then a Pico Technology PC based oscilloscope could be yours Every six months Pico Technology will be awarding an ADC200 50 digital storage oscilloscope for the best IU submission In addition two single channel ADC 40s will be presented to the runners up flows through TR1 to regulator ICT which provides a 5V output for the PIC microcon troller Following a power failure as the voltage across C1 falls D6 becomes for ward biased and D5 reverse biased so now the regulator is powered by the battery instead Should the battery voltage fall below approx 6 2V 5 6V 0 6V as set by D6 and D7 then the Zener will come out of breakdown and turn off TR1 which cuts power to the regulator until mains power returns Damien Maguire Greystones Co Wicklow INGENUITY UNLIMITED readers the benefit of your Ingenuity Share those ideas earn some cash and possibly a prize Loudener Sound activated Sleeper T circuit depicted in Fig 2 is a sound sen sitive switch which will operate a bleeper whenever a microphone detects a s
234. ound It could be used in monitoring systems or even as a novel form of doorbell The input section contains an electret microphone MICI fol lowed by an amplifier circuit around Darlington TR1 The op amp is configured as a comparator with the reference voltage applied to the inverting input pin 2 The out put of the op amp powers a Darlington driver which operates an external audible tone gen erator Detected sounds are transformed into a series of beeps or one long beep Some experimentation may be needed as the circuit when tested produced noise with some op amps but responded correctly with others M N Beg Lenasia South Africa 678 MIC1 ELECTRET Fig 2 Circuit diagram for the Sound Activated Bleeper Everyday Practical Electronics September 2000 BE INTERACTIVE 7 2 IU is your forum where 5 you can offer others CS Radio Sleep Timer Snooze Time TE circuit diagram of Fig 3 was designed as a Radio Sleep Timer to be attached to a battery operated radio Its existence was necessitated by the very poor sound quality of bedside clock radios and the realisation that sleep mode was the only use that the bed side clock was getting The circuit is based around a NOR gate R S latch ICla and IC1b which is operated by pushswitch S1 Its output drives transistor TR1 which sinks current and consequently turns on the radio The latch s inverted output gates an astable oscillator made up of IClc
235. ow quite plentiful and should be easy to obtain However for those readers unable to program their own PICs a ready programmed PIC16F84 can be purchased from Magenta Electronics E 01283 565435 or www magenta2000 co uk for the inclusive price of 5 90 over seas readers add 1 for p amp p For those who wish to program their own PICs the software is available from the Editorial Offices on a 3 5in PC compatible disk see PCB Service page It is also avail able free via the EPE website ftp ftp epemag wimborne co uk pubs PICS IRdecoder The software is written in MPASM Steeplechase Game We do not expect any component buying problems to be encoun tered when shopping for parts for the Steeplechase Game this month s Top Tenner project PLEASE TAKE NOTE Experimenter s Power Supply I U May 00 Page 343 The two programmable Zener diodes IC2 IC4 used in this circuit were wrongly identified as Texas TL431C parts They should be Zetex ZR431C devices The Zetex device has a much lower excitation current than its Texas counterpart and is essential in this application Everyday Practical Electronics September 2000 VIDEOS ON ELECTRONICS A range of videos selected by EPE and designed to provide instruc tion on electronics theory Each video gives a sound introduction and grounding in a specialised area of the subject The tapes make learning both easier and more enjoyable than pure textbook or magazine study They
236. own amp land on a number at random 555 IC circuit 3003KT 8 95 STAIRWAY TO HEAVEN Tests hand eye co ordination Press switch when green segment of LED lights to climb the stairway miss amp start again Good intro to several basic circuits 3005KT 8 95 ROULETTE LED Ball spins round the wheel slows down amp drops into a slot 10 LED s Good intro to CMOS decade counters amp Op Amps 3006KT 10 95 9V XENON TUBE FLASHER Transformer circuit steps up 9V battery to flash a 25mm Xenon tube Adjustable flash rate 0 25 2 Sec s 3022KT 10 95 LED FLASHER 1 5 ultra bright red LED s flash in 7 selectable patterns 3037MKT 4 95 LED FLASHER 2 Similar to above but flash in sequence or randomly Ideal for model railways 3052MKT 4 95 INTRODUCTION TO PIC PROGRAMMING Learn programming from scratch Programming hardware a P16F84 chip and a two part practical hands on tutorial series are provided 3081KT 21 95 SERIAL PIC PROGRAMMER for all 8 18 28 40 pin DIP serial programmed PICs Shareware soft ware supplied limited to programming 256 bytes registration costs 14 95 3096KT 14 95 PICALL SERIAL amp PARALLEL PIC PRO GRAMMER for all 8 18 28 40 pin DIP parallel AND serial PICs Includes fully functional amp registered software DOS W3 1 W95 8 3117KT 59 95 ATMEL 89Cx051 PROGRAMMER Simple to use yet powerful programmer for the Atmel 89C1051 89C2051 amp 89C4051 uC s Progra
237. p p and VAT 240V AC WESTOOL SOLENOIDS Model TT2 Max stroke 16mm 5lb pull Base mount ing Rating 1 Model TT6 Max stroke 25mm 15lb pull Base mounting Rating 1 Series 400 Max stroke 28mm 15lb pull Front mounting Rating 2 Prices inc p amp p amp VAT TT2 5 88 TT6 8 81 Series 400 8 64 AXIAL COOLING FAN 230V AC 120mm square x 38mm 3 blade 10 watt Low Noise fan Price 7 29 incl p amp p and VAT Other voltages and sizes available from stock Please telephone your enquiries INSTRUMENT CASE Brand new Manufactured by Imhof L 31cm x H 18cm x 19cm Deep Removable front and rear panel for easy assembly of your components Grey tex tured finish complete with case feet Price 16 45 incl p amp p and VAT 2 off 28 20 inclusive DIECAST ALUMINIUM BOX with internal PCB guides Internal size 265mm x 165mm x 50mm deep Price 9 93 incl p amp p amp VAT 2 off 17 80 incl 230V AC SYNCHRONOUS GEARED MOTORS Brand new Ovoid Gearbox Crouzet type motors H 65mm x W 55mm x D 35mm 4mm dia shaft x 10mm long 6 RPM anti cw 9 99 incl p amp p amp VAT 20 RPM anti cw Depth 40mm 11 16 incl p amp p amp VAT 16 RPM REVERSIBLE Croucet 220V 230V 50Hz geared motor with ovoid geared box 4mm dia shaft New manuf surplus Sold complete with reversing capacitor connect ing block and circ Overall size h 68mm x w 52mm x 43mm deep PRICE incl P amp P amp VAT 9 99 EPROM ERASURE KIT Build yo
238. pdates the value of the CBINARY command binary variable using the THISBIT variable value The BITS value must be greater than eight so that only the command part of the RC5 sequence is decoded If THISBIT 1 then the appropriate bit within the CBINARY variable byte is set to 1 This is done by logic ORing BIT VALUE and CBINARY Dividing BIT VALUE by two sets the next bit within this variable to 1 Initially the value of BITVALUE is 32 binary 100000 so dividing BITVALUE by two gives 16 binary 010000 Division by two is done by shifting the variable to the right by one place using the RRF instruction Rotate Right File If THIS BIT 0 only BITVALUE needs to be altered as the relevant bit within CBINA RY is already zero An alternative decoding method con sidered was to use a timer generated inter rupt to sample the waveform every 889 microseconds after detecting the initial waveform edge However if the RC5 transmission is faster or slower due to dif ferences between remote handsets then there is a possibility that accumulated tim ing error would cause either a pulse to be missed or the same pulse to be sampled twice START DEVICE CODE Observation of the waveform will show that if the last pulse of an RC5 transmission is zero then there is no final falling edge to enable an interrupt to read the timer With no interrupts the RTCC timer will reach 255 maximum byte value and start counting from zero This
239. pecial case since the discharge resistance is that of the load circuit and the charging resistance is virtually nil There is a term given to this simple cir cuit configuration it is known as an inte grator and its action is known as integration The term is not to be confused however with the term integrated when applied to a semiconductor integrated cir cuit i c in this latter case the term loose ly means combined INTEGRATION DEMO We can demonstrate further examples of waveform shaping using an integrator through program menu option Capacitors Integration Select and run it and also see Photo 11 4 On entry to the screen display a square wave is shown as the changing voltage being input via Vin to resistor R see the circuit diagram at bottom right With the CR and frequency values as shown at top right the second screen waveform repre senting that at the R C junction Vc is shown as having a somewhat triangular shape Press key lt W gt a few times and observe how the input waveform shape changes between square sine and triangle and how the Vc output wave form also changes Note that the pro gram has set the Vin Square wave varying between OV and a pos itive unspecified voltage whereas the Vin sine and triangle waveforms are evenly swinging above and below OV At certain CR val ues you will see that the square and triangle inputs can both result in similarly shaped OR Uc
240. plugs into a 13A socket is really nicely boxed 2 Order Ref 2P733 BT TELEPHONE EXTENSION WIRE This is proper heavy duty cable for running around the skirting board when you want to make a perma nent extension 4 cores properly colour coded 25m length Only 1 Order Ref 1067 12V 8A DC POWER SUPPLY Totally enclosed with its own cooling fan Normal mains operation Price 11 order Ref 11P6 TWIN 13A SWITCHED SOCKET Standard in all respects and complete with fixing screws White standard size and suitable for flush mounting or in a surface box Price 1 50 Order Ref 1 5P61 INSULATION TESTER WITH MULTIMETER Internally generates voltages which enable you to read insulation directly in megohms The multi meter has four ranges AC DC volts 3 ranges DC milliamps 3 ranges resistance and 5 amp range Ex British Telecom but in very good condition tested and guaranteed probably cost at least 50 each yours for only 7 50 with leads carrying case 2 each Order Ref 7 5P4 REPAIRABLE METERS We have some of the above testers but faulty not working on all ranges should be repairable we supply diagrams 3 Order Ref 3P176 BIG 12V TRANSFORMER It is 55VA so that is over 4A which is normal working intermittently it would be a much higher amperage Beautiful transformer well made and very well insulated terminals are in a plastic frame so can t be acci dentally touched Price 3 50 Order Ref 3 5P20 Everyday P
241. power level CONSTRUCTION The prototype was constructed within an inexpensive aluminium box as shown in the photographs Transformer T1 rectifier RECI and the capacitor Cl were fitted into the bottom section of the box RECI is secured with a single screw and a dab of heatsink compound no insulation being necessary GROUND T IN Fig 2 Stripboard component layout STRIPBOARD INSULATING WASHERS INSULATING ALUMINIUM SPACER CASE Fig 3 Suggested method of mounting the circuit board and regulator on the underside of the case cover Capacitor C1 is a snap in type really intended for mounting on a printed circuit board but here it 1s secured with a U shaped bracket made from a scrap of alu minium and connections are made with soldered leads Capacitors C2 C3 and C4 with the two diodes D1 and D2 were assembled on a piece of 0 1 inch pitch stripboard having 8 strips of 11 holes as shown in Fig 2 This and the regulator IC1 were then fitted to COMPONENTS See SHOP TALK page Resistor R1 560Q Capacitors C1 10 000u radial elect snap in 35V 100n ceramic resin dipped 2 off C4 470u radial elect 35V C2 C3 Semiconductors D1 D2 1N4001 rectifier diode 2 off D3 red l e d panel mounting REC1 6A 100V bridge rectifier IC1 7812 1A 12V regulator Miscellaneous T1 20VA mains transformer 15V x 2 secondaries S1 d p s t switch mains rated 4mm
242. ps rendering a person unable to release a live wire and electrocuting them how can an RCD offer protection if it typically only trips at 30mA Incidentally I have a dish washer which causes a worrying and tin gling electric shock yet the RCD checks out OK and does not trip in use This was prompted by a two part feature on electricity generation and distribution EPE Aug 99 to Sept 99 I haven t heard of any cases whereby anyone has suffered electrocution before an RCD has managed to trip The level of leakage cur rent flowing through the body is unstable because it depends on so many factors including skin moisture and the body s contact with the earth Even if a fault current of say 20mA was received this is very likely to Everyday Practical Electronics September 2000 increase and as soon as the RCD threshold is reached the device must trip There is no question of someone clinging on to a live apparatus and suffering a constant 20mA shock because in practice that fig ure just couldn t be constant If they lose muscle control and therefore grip some thing tighter the current would rise and trip the RCD A trip time of 40 millisec onds is typical far too rapid to allow the current to cause any real damage so hope fully I can put your mind at rest We can t really cover electrical repairs but your dishwasher may have developed an insulation fault perhaps in the wiring loom near the door hinge made worse
243. ptional size 120mm x 90mm x 30mm l e d holder plastic control knob 5 off 9V battery with connectors and box single core screened cable multistrand connecting wire plastic pipe for aerial coil former materials for fer rite loop aerial housing mounting fixing nuts and bolts solder tag solder etc Approx Cost Guidance Only 35 excl case and mechanics 674 COMPONENTS Most dual gate MOSFETs including the BF960 BF961 3SK81 3SK85 MFE201 and 40673 will prove satisfac tory in this circuit Likewise most j f e t s including the BF244 BF245 J310 MPF102 TIS14 and 2SK168 will be suitable for the source follower stage TR2 Case styles and leadouts vary and must be checked if these and other alter natives are substituted Most varicaps designed for Medium Wave tuning with a 9V maximum bias should prove suitable Plastic pipe for the coil former for LI L2 is available from DIY outlets and plastic and metal spindles and bushes for the loop aerial mounting are stocked by model shops CONSTRUCTION Dealing with the control box first Most parts are assembled on a small printed TO B1 VE TO B1 VE VIA S1b 5 3 1 78 7mm circuit board p c b which is available from the EPE PCB Service code 274 The topside component layout off board wiring and a full size underside copper foil master pattern are shown in Fig 2 Note that one lead of capacitor C8 is soldered directly on to one tag of VR6
244. r ately re named The original version of Microsoft Outlook allowed this to hap pen automatically it saw HTML and took over to display it as a Web page Viruses Bubble Boy and Cakworm work this way A free software patch for Outlook can be downloaded from the Microsoft site to prevent this But the PC owner must be literate and be able to handle download upgrades In its present form Outlook does not automatically open attachments That s why any system of active E mail would be horrendous says Cluley RTF in native form is safe too because it is plain text with a little fancy formatting It does not support macros But there is now a sneaky new virus called Cap which waits until you try and save a Word docu ment as RTF silently intrudes to save it as a virus infected Word file and sticks the letters RTF at the end so that it looks safe to open Because Windows treats a Word file as a Word file whatever the letters on the end the virus springs to life when the file opens Advice to Microsoft Cluley says Microsoft should change Windows so that it checks the file exten sion against the embedded file identifier and only open a file if the extension and identifier match Currently Windows ignores file extensions and relies on the embedded identifier If they don t match says Cluley this should tell Windows there is something wrong Cluley says Windows should also stop hiding file extensions which helps v
245. r EPE As requested in Readout pages this is just to confirm that I have found QBasic on the Windows 98 second edition CD I ve done a file compare with the version that came with Windows 3 1 and they re identical The trouble is that it s in a folder called D Tools oldmsdos The oldmsdos bit worries me because I ve been told that DOS disappears entirely with Win2000 so although everybody may have it now that may not be true next year month week Note that the oldmsdos folder also has the old fc exe which I used to compare Roger Warrington via the Net Thanks Roger and to all others who have kindly told us that QBasic is on their Windows 95 98 CDs Would anyone with Win2000 care to comment on QBasic s availability with that APPRECIATION Dear EPE Can I through your Readout column express my appreciation of the many contributions made by Messrs R A Penfold and Robert Penfold to your magazine I am a radio man myself and have built every set in the three paperbacks that R A Penfold produced from the 1976 edition to the January 1991 edition I ran out of space to house these many years ago Every one of them lacks one attribute however that of frequency readout I have tried numerous suggestions for this but without success Can I through your good offices ask that these two knowledgeable gentlemen produce a program and simple interface which I can attach to my radios that will show on my computer 486 ru
246. r more get one extra FREE Order 16 get two extra FREE VCR MAINTENANCE VT102 84 minutes Introduction to VCR Repair Warning not for the beginner Through the use of block diagrams this video will take you through the various circuits found in the NTSC VHS system You will follow the signal from the input to the audio video heads then from the heads back to the output Order Code VT102 VT103 35 minutes A step by step easy to follow procedure for professionally clean ing the tape path and replacing many of the belts in most VHS VCR s The viewer will also become familiar with the various parts found in the tape path Order Code VT103 DIGITAL Now for the digital series of six videos This series is designed to provide a good ground ing in digital and computer technology VT301 54 minutes Digital One Gates begins with the basics as you learn about seven of the most common gates which are used in almost every digital circuit plus Binary notation Order Code VT301 VT302 55 minutes Digital Two Flip Flops will further enhance your knowledge of digital basics You will learn about Octal and Hexadecimal notation groups flip flops counters etc Order Code VT302 VT303 54 minutes Digital Three Registers and Displays is your next step in obtaining a solid understanding of the basic circuits found in today s digital designs Gets into multiplexers registers display devices etc Order Code VT303 VT304 59 minutes Dig
247. r the CD player and Play for the tape recorder See Tables 3 to 5 As there is no error detection or data verification with either of the IR protocols errors can occur if the IR signal is not Table 3 SIRC device code Command Device TV receiver video tape recorder 1 video tape recorder 2 laser disk surround sound unit cassette deck tuner CD player equaliser Table 4 SIRC VCR FUNCTIONS Command Function 0 9 numerals O to 9 9 10 0 20 x2 play 21 power 22 eject 24 stop 25 pause 26 play 27 rewind 28 fast forward 29 record Table 5 SIRC TV FUNCTIONS Command Function 0 9 numerals O to 9 9 10 0 16 channel 17 channel 18 volume 19 volume 20 mute 21 power 22 reset 23 audio mode 24 contrast 25 contrast 26 colour 4 27 colour 30 brightness 31 brightness 38 balance left 39 balance right 47 power off received correctly Also strong sunlight falling on the sensor can generate a signal SERIAL PORT The PIC16x84 microcontroller does not have a built in serial port but one can be implemented in software Replace the entire routine LEDDISPLAY with the TXDATA code in the PIC assembler pro gram Add the two equates to the top of the assembler program and the BCF PORTB RS232 to the MAIN SIRC or START RCS procedure This enables the RB3 port pin to be used as an output In routine LOOP replace CALL LEDDIS PLAY with CALL TXDATA The TXDATA routine works by ANDing eac
248. ractical Electronics September 2000 SMART HIGH QUALITY ELECTRONIC KITS CAT NO DESCRIPTION PRICE 1005 Touch Switch 2 87 1010 5 input stereo mixer with monitor output 19 31 1016 Loudspeaker protection unit 3 22 1023 Dynamic head preamp 2 50 1024 Microphone preamplifier 2 07 1025 7 watt hi fi power amplifier 2 53 1026 Running lights 4 60 1027 NiC cad battery charger 3 91 1030 Light dimmer 2 53 1039 Stereo VU meter 4 60 1042 AF generator 250Hz 16kHz 1 70 1043 Loudness stereo unit 3 22 1047 Sound switch 5 29 1048 Electronic thermostat 3 68 1050 3 input hi fi stereo preamplifier 12 42 1052 3 input mono mixer 6 21 1053 Electronic metronome 3 22 1054 4 input instrument mixer 2 76 1059 Telephone amplifier 4 60 1062 5V 0 5A stabilised supply for TTL 2 30 1064 12V 0 5A stabilised supply 3 22 1067 Stereo VU meter with leads 9 20 1068 18V 0 5A stabilised power supply 2 53 1070 Hi fi preamplifier 7 47 1071 4 input selector 6 90 1080 Liquid level sensor rain alarm 2 30 1082 Car voltmeter with l e d s 7 36 1083 Video signal amplifier 2 76 1085 DC converter 12V to 6V or 7 5V or 9V 2 53 1086 Music to light for your car 4 60 1093 Windscreen wiper controller 3 68 1094 Home alarm system 12 42 1098 Digital thermometer with l c d display 11 50 1101 Dollar tester 4 60 1102 Stereo VU meter with 14 l e d s 6 67 1106 Thermometer with l e d s 6 90 1107 Electronics to help win the pools 3 68 1112 Loudspeaker protection with delay 4 60 1115 Courtesy
249. rafts in sterling only payable to Everyday Practical Electronics and sent to EPE Sub Dept Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 E mail subs Q epemag wimborne co uk Also via the Web at http www epemag wimborne co uk Subscriptions start with the next available issue We accept MasterCard or Visa For past issues see the Back Issues page BINDERS Binders to hold one volume 12 issues are available from the above address These are finished in blue p v c printed with the magazine logo in gold on the spine Price 5 95 plus 3 50 p amp p for overseas readers the postage is 6 00 to everywhere except Australia and Papua New Guinea which cost 10 50 Normally sent within seven days but please allow 28 days for delivery more for overseas Payment in sterling only please Visa and MasterCard accepted minimum credit card order 5 Send fax or phone your card number and card expiry date with your name address etc Or order on our secure server via our web site Overseas customers your credit card will be charged by the card provider in your local currency at the existing exchange rate Everyday Practical Electronics September 2000 THORPE LE SOKEN ESSEX CO16 OED Phone Fax 01255 861161 Editor MIKE KENWARD Deputy Editor DAVID BARRINGTON Technical Editor JOHN BECKER On Line Editor ALAN WINSTANLEY Business Manager DAVID J LEAVER Subscriptions
250. rd 4 section Alternative Courtesy Light Controller Light Alarm A Wireless Monitoring System Transmitter Receiver X PIC MIDI Sustain Pedal Software onl Wireless Monitoring System 2 F M Trans Rec Adaptors 219a 220a Time and Date Generator 221 Auto Cupboard Light 222 Smoke Absorber Ironing Board Saver Voice Record Playback Module Mechanical Radio pair amp Versatile Event Counter PIC Toolkit Mk2 A M F M Radio Remote Control Transmitter Receiver Musical Sundial PC Audio Frequency Meter XK EPE Mood PICker 12V Battery Tester 234 Intruder Deterrent 235 L E D Stroboscope Multi project PCB 932 8 32 8 15 Everyday Practical Electronics September 2000 busco o PROJECT TITLE Ultrasonic Punture Finder A 8 Channel Analogue Data Logger Buffer Amplifier Oscillators Pt 2 Magnetic Field Detective Sound Activated Switch Freezer Alarm Multi project PCB 932 Child Guard SEPT 99 Variable Dual Power Suppl 242 7 64 Micro Power Supply 243 3 50 A Interior Lamp Delay 244 7 88 Mains Cable Locator Multi project PCB 932 3 00 Vibralarm NOV 99 230 6 93 Demister One Shot 245 6 78 Ak Ginormous Stopwatch Part 1 246 7 82 A Ginormous Stopwatch Part 2 DEC 99 Giant Display 247 Serial Port Converter 248 3 96 Loft Guard 249 4 44 Scratch Blanker ELN Flashing Snowman Multi project PCB 932 3 00 Video Cleaner FEB 00 251 5 63 Find It 252 4 20 Teach In 2000 Part 4 4 52 High Pe
251. rd harmonics are both equal to amplitude of the Ist harmonic i e THR 140 The upper frequency is approximately 20 40kHz but the circuit can be used to syn chronise high frequency signals up to 50 100MHz by replacing the op amp based detectors and using high speed comparators for IC3 and ICA 12 TO 15V 12V TO 15V Dmitry Moskalenko Ryazan Russia Our compliments to Mr Moskalenko and greetings to our new found readers in Russia Fig 6 Waveforms generated to simulate the Scope Synchroniser operation using ARW MicroCAP SUBSCRIBE AND SAVE OVER 5 50 THAT S LIKE GETTING TWO ISSUES FREE enclose payment of cheque PO in sterling BEEN VISA only payable to Everyday Practical Electronics Access or Visa No SUBSCRIPTION ORDER FORM Annual subscription rates 2000 2001 Signature 1 Year UK 27 50 Overseas 33 50 standard air service 51 express airmail Card Ex Date 2 Years UK 50 00 Overseas 60 00 standard air service mM 92 50 express airmail Please supply name and address of cardholder if different from the subscription address shown below Subscriptions can only start with the next available issue For back numbers see the Editorial page To Everyday Practical Electronics Allen House East Borough Wimborne Dorset BH21 1PF Tel 01202 881749 Fax 01202 841692 680 Everyday Practical Electronics September 2000 Don t just test it Ana
252. re that on the first interrupt BITS 1 the program variables are ini tialised but the RTCC timer value is not used On the second interrupt BITS 2 the RTCC timer value of the start bit is assigned to variable TIMERVAL This value is used as a reference and all subse quent timer value calculations use it The XVALUE variables are used to set the three different TIMERVAL value ranges this determines the waveform tim ing see Listing 1 Using ranges of values rather than direct comparison to the first reading ensures that any timing discrepan cy does not affect the operation of the pro gram Small variations in the RTCC value are inevitable due to PIC interrupt latency and tolerances between different remote controls Once the TIMERVAL comparison is made the appropriate waveform time can be determined If TIMERVAL 1 then the result will be the same as the last bit value of variable LASTBIT If TIMER VAL 1 5 then the result is to invert the LISTING 1 Setting TIMERVAL values XVALUE1 z 0 5 x initial TIMERVAL XVALUE2 z 1 25 x initial TIMERVAL XVALUES 1 75 x initial TIMERVAL if current TIMERVAL XVALUE1 and XVALUE2 then TIMERVAL 1 if current TIMERVAL XVALUE2 and lt XVALUES3 then TIMERVAL 1 5 if current TIMERVAL XVALUES then TIMERVAL 2 700 last bit received If TIMERVAL 2 and the previous bit was O then the result is binary 10 The ADDBINARY routine is then called which u
253. ree end of the link to OV Pressing S1 should have no effect Led D8 remaining unlit Then connect the wire link to 6V Now pressing S1 should cause D8 to light and then pressing S2 turns it off If this part does not work correctly check all the connecting wires and also check that the copper strips have been cut at the correct points Next install the socket for IC2 l e d s D1 to D7 and resistor R5 but do not put IC2 in its socket yet Check the wiring by connect ing the terminal pin at Fl to 6V Take a EPE BINDER New Guinea which costs 10 50 each N Xx Z cao DOVOZZCACIO OO0O0 000000000e6000000e6000000e00oooeoeoeo ccl oooeeoeooeo eeooeeoooQooeoeooooooooooo B eeooe oeeooo geeooeeooot ooooooooeoeoeooo AAT 0000680060060 0e o0o0e e000 0000000000 00e 0000000 Z o0ooeoeQoeeoooQ0OoeQQoeoeoooooooooooooo y O O O O e O e O O O O O O e O e e 0000000060 O e 00 x oooceeQQoeooooceQgQeooeeoeooooooooooo w O O Oe e OO e e O e o e e o e e o oO O O O O O O O O O O OeooOoOooooOooOoOoOo0eooooooooeoooo OO0 e 000000000000000e6000000 O O O O O O O O O O O O ooje Oogegogyo e O O O O O ogogogogogye e O oeooooooeQQoeoeoco oooooooeeQQoeooooo000 LO O O O O O O O O O O O e O O O O O O O O O e e O O O e O e O O O 6 O O O LO O O O O O O O O O O O O O O e O O e O O O O O O O O e O e O O O O O O O N e O O e O e e O e oO O e e e e O O e oO O O O O O e e O e O O O O O O O MIO Oe
254. rene nnnnnemnmaaaanas 1450 Hewlett Packard 54512B 300MHz 1GS s 4 Channel eere rer nana annu u unn aa uu uuu u uuu 2250 Hewlett Packard 54501A 100MHz 100Ms s 4 Channel cer eren uu nnn nn unn 1250 Hitachi V152F V302B V302F V353F V550B VG650F 1 1e rrrr rere nana na nana uu uu uuu u uuu uu uu uu nanus from 105 Hitachi V650F 60MHz Dual Channel ssssssssssssssssnsnsnessennnnseeeneesnnnneenennnesennneenenenessennsessnenenssennessses ELOO Hitachi V1100A 100MHz 4 Channel 22555 nuu unnu nuu u sunu uuu uuu RSS aRRR RSS RRRRRSRRRRRSRRRRRESSRRRRRRRRRRRRAR 900 Intron 2020 20MHz Digital Storage NEW 450 DIETZ CEET OT E from 125 Meguro MSO 1270A 20 MHz Digital Storage NEW sssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nn 450 Lecroy 9304 AM 200MHz 100 Ms s 4 Channel oo ennnnn annu u nnn nana nasa nau uu nnna 3000 Lecroy 9450A 300MHz 400 Ms s D S O 2 Channel ecc c cce r eere eene nnnunus 2250 Philips PM 3055 50MHz Dual Timebase nene 450 Philips PM 3211 PM 3212 PM 3214 PM 3217 PM 3234 PM3240 PM 3243 PM 3244 PM 3261 PM 3262 PM 3263 PM 3540 eere rrr rrr rre enun uuu n nana uuu u uuu from 125 Philips PM 3295A 400MHz Dual Channsel eee eee re renes ees aa aaa a saura uaa uuu u uuu uuu RR RR RR RR RR RR
255. reseee sensns 950 Rohde Schwarz CMTA 94 GSM Radio Comms Analyser nonne nnn nnn nnn nu nun aa 6995 Schaffner NSG 203A Line Voltage Variation Simulator 750 Schaffner NSG 222A Interference Simulator 700 Schaffner NSG 223 Interference Generator 700 Schlumberger 2720 1250MHz Frequency Counter wz 400 Schlumberger 4031 1GHz Radio Comms Test Sel extersssssssrrrterrrrruesssssrsrtrrrrrtrEsESEEEREEEEEEEEE 4995 Schlumberger Stabilock 4040 Radio Comms Test Gel ssssssssssssssssssssssssssssssssssssseueuereserrruuen 1995 Schlumberger 7060 7065 7075 MultiMeterS nnnnnunnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn FOM 350 Stanford Research DS 340 15MHz Synthesised Function NEW and Arbitrary Waveform Generador ENEE anna 1200 Systron Donner 6030 Microwave Frequency Counter 26 5GHZz 1995 Tektronix AM503 TM501 P6302 Current Probe AMplifiCY nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 995 Tektronix PG506 TG501 SG503 TM503 Oscilloscope Calibrator 1995 Tektronix 577 Curve Traer cc ccc ccc ccr rennen nnn nnnn nasa anas seas e seas RR ERR RR RR NR NR NR RR NR R RR RR RR R RR RR RR 1150 Tektronix 1240 Logic Analyser NANA nene nene sero nn 500 Tektronix 141A PAL Test Signal Generator ssssesssssssesesessesEsEEEEEEEEEEEEEEEEEE
256. rformance Regenerative Receiver EPE Icebreaker PCB257 programmed PIC16F877 and floppy disc Parking Warning System A Micro PlCscope Garage Link Transmitter Receiver Versatile Mic Audio Preamplifier PIR Light Checker A Multi Channel Transmission System Transmitter Receiver Interface Canute Tide Predictor JUNE 00 3 05 Ak PIC Gen Frequency Generator Counter JULY 00 269 4 36 Q Meter 5 47 A EPE Moodloop AUG 00 271 Quiz Game Indicator 272 4 52 Handy Amp 273 4 52 Active Ferrite Loop Aerial SEPT 00 274 4 67 x Remote Control IR Decoder Software only EPE SOFTWARE Software programs for EPE projects marked with an asterisk are available on 3 5 inch PC compatible disks or free from our Internet site Six disks are available PIC Tutorial Mar May 98 issues PIC Toolkit Mk2 May Jun 99 issues EPE Disk 1 Apr 95 Dec 98 issues EPE Disk 2 Jan Dec 99 EPE Disk 3 Jan 00 issue to current cover date EPE Teach In 2000 The disks are obtainable from the EPE PCB Service at 3 00 each UK to cover our admin costs the software itself is free Overseas each 3 50 surface mail 4 95 each airmail All files can be downloaded free from our Internet FTP site ftp ftp epemag wimborne co uk EPE PRINTED CIRCUIT BOARD SERVICE Order Code Order Code Cost 7 85 Project Quantity Price cheque PO in sterling only to Everyday Practical Electronics
257. rkshop use can replace these two diodes with a link or even fit a switch to short them out in order to make both output voltages available Everyday Practical Electronics September 2000 Capacitor C4 provides additional decoupling for the output of IC1 whilst C2 and C3 provide high frequency decoupling for ICI s input and output The l e d D3 together with current limiting resistor R1 indicate that the unit is operating and the output is present UP TO MEASURE A few measurements taken from the prototype confirm the design considera tions just described The r m s a c voltage of the two parallel connected secondary windings of Tl was measured at 16 3V with no load and dropped to 15 5V with a load of about 1A The unregulated voltage across Cl was found to be 20 9V when unloaded but dropped to 17 6V with the 1A load Maximum ripple at this current was about 600mV peak to peak so the lowest instantaneous voltage at the bottom of the ripple waveform was just over 17V This leaves a minimum headroom of almost AV for the regulator when it is delivering 13 2V sufficient to ensure correct opera tion but low enough to minimise heat generation With a continuous load of 1A the regu lator will therefore produce about four watts of heat whilst the rectifier will add a further one watt or thereabouts so a heatsink of some kind is required The transformer was also found to generate an appreciable amount of heat at this
258. rkshops 95 Main Road Baxterley Warwickshire CV9 2LE U K Website www suma designs co uk PTS7 Automatic Telephone Recording Interface Connects between telephone line anywhere and normal cassette recorder Automatically switches recorder on and off as phone is used Both sides of any conversation recorded 9V operation size 20mm x CD400 Pocket Size Bug Detector Locator LED and piezo bleeper pulse slowly Pulse rate and tone pitch increase as signal source is approached Variable sensitivity allows pinpointing of signal source 9V operation size 45mm x 54mm CD600 Professional Bug Detector Locator Multicolour bargraph LED readout of signal strength with variable rate bleeper and variable sensitivity allows pinpointing of any signal source When found unit is switched into AUDIO CONFIRM mode to distinguish between bugging devices and legitimate signals such as pagers cellphones etc Size 70mm x 100mm 9V operation we sudazezrcxexei s 59 95 QTX180 Crystal Controlled Room Transmitter Narrow band FM crystal transmitter for ultimate in privacy Output frequency 173 225 MHz Designed for use with ORX180 receiver unit Size 20mm x 67mm 9V operation range up to 1000m QLX180 Crystal Controlled Telephone Transmitter Specifications as per OTX180 but connects onto telephone line to allow monitoring of both sides of conversations 44 95 QSX180 Line Powered Crystal Telephone Transmitter Connects onto telephone lin
259. rn torches it matches several disappointment than loss when somebody who candlepower at medium power and is thus quite serviceable It will was it leaves the door ajar and the chilled provide ample light around a camp table for walking on a footpath lemonade warms up on a summer s day or for reading The light output of the torch is continuously variable This circuit sits in the freezer and simply waits and its expected service from each full wind about a for the temperature to rise above a preset limit 30 second wind is as follows as a book light 1 hours as a Then it turns on a loud buzzer one that is loud medium power beam 40 minutes as a beam for walking enough to be heard with the freezer door shut 15 minutes NOTE NEW PUBLISHING DATE NO ONE DOES IT BETTEH TICAL DON T MISS AN EGHRONI ISSUE PLACE YOUR ORDER NOW ELECTRONICS TODAY INTERNATIONAL Demand is bound to be high OCTOBER ISSUE ON SALE THURSDAY SEPTEMBER 7 Everyday Practical Electronics September 2000 643 um TN EL a gi e n gt Established 1990 Unit 14 Sunningdale BISHOPS STORTFORD Herts CM23 2PA TEL 01279 306504 ADD 2 00 P amp P to all orders or 1st Class Recorded 4 Next day Insured 250 7 Europe 4 00 Rest of World 6 00 We accept all FAX 0870 7064222 E ve S major credit cards Make cheques PO s payable to Quasar Electronics Prices include 17 5 VAT MAIL ORDER ONLY F
260. rojects with switches LEDs relays and diodes Transistors Power supplies Op amp projects Further op amp circuits Logic gates Real logic circuits Logic gate multivibrators The 555 timer Flip flops counters and shift registers Adders compara tors and multiplexers Field effect transistors Thyristors tri acs and diacs Constructing your circuit Index 227 pages Order code NE29 14 99 A BEGINNER S GUIDE TO MODERN ELECTRONIC COMPONENTS R A Penfold The purpose of this book is to provide practical information to help the reader sort out the bewildering array of com ponents currently on offer An advanced knowledge of the theory of electronics is not needed and this book is not intended to be a course in electronic theory The main aim is to explain the differences between components of the same basic type e g carbon carbon film metal film and wire wound resistors so that the right component for a given application can be selected A wide range of compo nents are included with the emphasis firmly on those components that are used a great deal in projects for the home constructor Order code BP285 4 99 170 pages The books listed have been selected by Everyday Practical Electronics editorial staff as being of special interest to everyone involved in electronics and computing They are supplied by mail order to your door Full ordering details are given on the last book page FOR ANOTHER SELECTION OF BOOKS SE
261. roll over sets the timer overflow flag which is used to indicate the end of transmission and the LEDDISPLAY output routine is called RCS ASSEMBLER PROGRAM Once the RC5 assembler listing is pro grammed into the PIC the decoding soft ware can be tested If the key marked 1 on the remote control is pressed one l e d D1 will come on if the 2 key is pressed then the other Led D2 will come on If the 3 key is pressed then both l e d s come on To change which key alters the l e d change the CBINARY comparison value in the LEDDISPLAY routine For example using a VCR remote con trol change the three comparisons to D 53 D 54 D 55 to change from hexadecimal to decimal notation replace H nn with D nnn in the assem bler program On the remote control handset pressing the VCR Play key should generate com mand code 53 and one of the l e d s should light Pressing the Stop key should gener ate code 54 and light the other Led Pressing the Record key should generate 55 and both l e d s should be on D4 D3 D2 D1 DO C6 C5 C4 C3 C2 C1 CO COMMAND CODE Fig 8 SIRC code format SIRC PROTOCOL SIRC Serial Infra Red Control proto col is the name given to Sony s IR remote control system The 12 bit protocol is the most common format used with domestic products but there are others including 15 bit and 20 bit versions Control S pro tocol is the hard wired TTL version of th
262. rough EOCS member Martin Bates site www bate suk freeserve co uk Martin says to then click on the supermarket trolley then the Wersi logo Summery Greenweld SUMMER S here at last proclaims Greenweld s Summer 2000 catalogue Well maybe as the named seasons go but weath er wise what do you think Anyway irre spective of meteorology but Greenweld say that at least they are full of sunshine here s a summery of what s in their cat Tools galore multimeters one under a tenner new hot melt guns and Antex sol dering irons photographic films and equipment electronic components includ ing digital i c s audio visual gear motors project and computer books and more including surplus To get your copy of this 32 page bumper value cat contact Greenweld Ltd Dept EPE PO Box 144 Hoddesdon EN11 0ZG Tel 01277 811042 Fax 01277 812419 E mail service greenweld co uk Everyday Practical Electronics September 2000 Get More in a Flash Discover the power and flexibility of an 8 bit PiCmicro RISC MCU with FLASH The possibilities are endless When you incorporate self programming and two wire In Circuit Serial Programming over the entire voltage range without external components PlCmicros feature an operating voltage from 2V 10 bit A D converter with up to 8 channels RS 485 type USART up to 256 bytes high endurance EEPROM data memory and up to 5 MIPS performance For added
263. s is a big headache for laptop com puter and mobile phone manufacturers In the industry a variety of so called gas gauge chips are available from the likes of Texas Instruments who recently joined forces with specialist battery controller makers Unitrode and Benchmarq Microelectronics If you re looking for data on their current range of battery controller chips go to www bench marq com Radio control models that use 7 2V rac ing packs are notoriously abusive of Nickel Cadmium cells Battery packs can become too hot to handle after just a few minutes of hard driving but elevated tem peratures are a potential source of internal battery ruin In racing applications ensur ing that the battery has fully discharged is not a problem it usually happens just as you re winning as the batteries are sub ject to a complete discharge over a 10 minute cycle or so There is probably less risk of memory effect arising but the high temperatures caused by self heating are of concern Everyday Practical Electronics September 2000 Eveready suggest a maximum tempera ture of 45 C when discharging before cut ting the load You cannot measure the remaining capac ity of a Ni Cad by reading its off load volt age If you want a simple method of mea suring when they are nearly flat you could maybe measure the voltage at which point a particular light bulb filament ceases to glow and using that as a guide discharge a bat tery p
264. s more experienced constructors but do tell me if I ve got it wrong The interesting thing is that it is rarely these simple projects that are the most popular top of the popularity list last year by a country mile was PIC Toolkit Mk2 from the May 99 issue NEW DATES Please note that from next month our publishing date is changing The October issue will be published on Thursday September 7 and subsequent issues will be published on the second Thursday in the month This is for production reasons to fit in with other work in our typesetting and production departments I should also inform you that the cover price will increase to 2 75 next month the first rise since May 1997 If you take out a subscription the actual price you pay is under 2 30 per issue UK and that includes delivery to your door the equivalent of two free issues each year See below for subscription prices AVAILABILITY Copies of EPE are available on subscription anywhere in the world see right from all UK newsagents distributed by COMAG and from the following electronic component retailers Omni Electronics and Maplin in S Africa EPE can also be purchased from retail magazine outlets around the world An Internet on line version can be purchased from www epemag com SUBSCRIPTIONS Annual subscriptions for delivery direct to any address in the UK 27 50 Overseas 33 50 stan dard air service 51 express airmail Cheques or bank d
265. s to be run for long periods power may be provided by an inexpensive mains adaptor Again the cost of such a unit is not included because most spares boxes contain a few of these possibly pensioned off from obsolete electronic gadgets T FIRST glance this is a very simple A game There is a row of seven l e d s across the top edge of the circuit board all of them red except for the one on the right which is green A timer drives a counter that turns on the l e d s one at a time starting from the left in order The travelling display represents a horse approaching a jump which is the green l e d If the player presses the white button switch S1 at the exact moment when the green l e d is lit this counts as perfect tim ing and a clear jump is scored There is an eighth Led close to the white button to indicate when this happens However there is no time to gloat over a successful jump because the horse is already pound ing toward the next fence The travelling display repeats regularly with only short pauses between Now comes the catch Although this is a digital game which one might expect to run as regularly as clockwork a digital clock we suppose there is an element of uncertainty that taxes the skill of the play er Like most horses the steeplechaser may accelerate or hang back as it approaches and takes the jump The player must take this into account if the horse is not to jump too soon or too late and
266. sar software Chapters on p c b physics and p c b production techniques make the book unique and with its host of project ideas make it an ideal companion for the integrative assignment and common skills components required by BTEC and the key skills demanded by GNVQ The principal aim of the book is to provide a straightforward approach to the understanding of digital electronics Those who prefer the Teach In approach or would rather experiment with some simple circuits should find the book s final chapters on printed circuit board production and project ideas especially useful E SES DIGITAL GATES AND FLIP FLOPS lan R Sinclair This book intended for enthusiasts students and technicians seeks to estab lish a firm foundation in digital electronics by treating the topics of gates and flip flops thoroughly and from the beginning Topics such as Boolean algebra and Karnaugh mapping are explainend demonstrated and used extensively and more attention is paid to the subject of synchronous counters than to the simple but less important ripple counters No background other than a basic knowledge of electronics is assumed and the more theoretical topics are explained from the beginning as also are many working practices The book concludes with an explanation of micro processor techniques as applied to digital logic 200 pages 8 95 Bebop Bytes Back By Clive Max Maxfield and Alvin Brown ORDER CODE BEB2 2
267. se meter scale PCB amp ALL components KIT 848 32 95 EPE PROJECT PICS Programmed PICs for all EPE Projects TEACH IN 2000 Full set of top quality NEW components for this educa tional series All parts as specified by EPE Kit includes breadboard wire croc clips pins and all components for experiments as listed in introduction to Part 1 Batteries and tools not included TEACH IN 2000 KIT 879 44 95 MULTIMETER 14 45 SPACEWRITER YA An innovative and exciting project BA Wave the wand through the air and A your message appears Programmable to hold any message up to 16 digits long Comes pre loaded with MERRY XMAS Kit includes PCB all components amp tube plus instructions for message loading KIT 849 12V EPROM ERASER A safe low cost eraser for up to 4 EPROMS at a time in less than 20 minutes Operates from a 12V supply 400mA Used extensively for mobile work updating equipment in the field etc Also in educational situations where mains supplies are not allowed Safety interlock prevents contact with UV KIT le erae 29 90 SUPER BAT DETECTOR 1 WATT O P BUILT IN SPEAKER COMPACT CASE 20kHz 140kHz NEW DESIGN WITH 40kHz MIC A new circuit using a full bridge audio amplifier i c internal speaker and headphone tape socket The latest sensitive transducer and double balanced mixer give a stable high perfor mance superheterodyne de
268. sign KIT 861 24 99 ALSO AVAILABLE Built amp Tested 39 99 ULTRASONIC PEsT SCARER Keep pets pests away from newly sown areas fruit vegetable and flower beds children s play areas patios etc This project produces intense pulses of ultrasound which deter visiting animals e KIT INCLUDES ALL COMPONENTS PCB amp CASE ES 90 16C71 e EFFICIENT 100V e UP TO 4 METRES All 9 JU each TRANSDUCER OUTPUT RANGE PIC16F877 now in stock e COMPLETELY INAUDIBLE e LOW CURRENT 10 inc VAT amp postage TO HUMANS DRAIN Kit No 845 64 95 some projects are copyright KIT 812 lere 15 00 Everyday Practical Electronics September 2000 SIMPLE PIC PROGRAMMER INCREDIBLE LOW PRICE Kit 857 12 99 Power Supply 3 99 EXTRA CHIPS PIC 16F84 4 84 INCLUDES 1 PIC16F84 CHIP SOFTWARE DISK LEAD CONNECTOR PROFESSIONAL PC BOARD amp INSTRUCTIONS Based on February 96 EPE Magenta designed PCB and kit PCB with Reset switch Program switch 5V regulator and test L E D s and connection points for access to all A and B port pins PIC 16C84 DISPLAY DRIVER Kit 860 19 99 Power Supply 3 99 FULL PROGRAM SOURCE CODE SUPPLIED DEVELOP YOUR OWN APPLICATION INCLUDES 1 PIC16F84 WITH DEMO PROGRAM SOFTWARE DISK PCB INSTRUCTIONS AND 16 CHARACTER 2 LINE LCD DISPLAY Another super PIC project from Magenta Supplied with PCB industry standard 2
269. snenensessesessneesesssssssenenensneneness 1500 Hewlett Packard 8757A Scalar Network AnalyS f sssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 12 2 DU Hewlett Packard 8901A Modulation AnalhytSser ueesesssssrrterrrrrresRRRRREEEEEEEEEEEEEEREEEEEEEEEEEEEEREREEEER Hewlett Packard 8901B Modulation Anal ser essrerrressEEeEEEEREEEEEEEEREEEEEEEREEEEEEEEREEEEEEEREEEEEEEEEE Hewlett Packard 8903E Distortion AnalySCTnncccccc naaa Hewlett Packard 8903B Distortion Analyser Mint Hewlett Packard 8920A R F Comms Test Set Hewlett Packard 8922B G H Radio Comms Test Sets G S M Hewlett Packard 8958A Cellular Radio Interface Keytek MZ 15 EC Minizap 15kV Hand Held ESD Simulator ae Krohn Hite 2200 Lin Log Sweep Generator eeeesesesEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEN Krohn Hite 4024A Oscilator nc nnna Krohn Hite 5200 Sweep Function Generator nm namas Krohn Hite 6500 Phase Meter 111 NARRAR ARAN nnan Leader LDM 170 Distortion Mleter NENE UR RRRRRR RSS SR nnn Leader 3216 Signal Generator 100kHz 140kHz AM FM CW with built in FM stereo modulator M Nt ssssnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn OOD Marconi 1066B Demultiplexer and Frame Alignment Monitor new oorr POA Marconi 2019 80kHz 1040MHz Synthesised Signal Generator
270. ss widely known is that apart from its own directory Yahoo also uses a second database You may have seen this in action when Yahoo offers you other web page match es in its search results especially if it could not find anything in its main directory so if you ever a wondered why Yahoo offered no results and then proceeded to offer you a whole list of match es the switch to the sec ond database is the answer These other matches are maintained in a sepa rate search engine which until recently was the Inktomi database www inktomi com Inktomi is another Internet search resource which sells its technology to others looking to place a search box in say a por tal web site In mid June Yahoo announced that it was to buy its database from Google instead and sure enough some of my search engine queries are now redirected to google yahoo com E Stupp zi Get your own Google box There are some useful reader resources on the Google site including a Help page you are also shown how to add your own Google box to your web page if desired Google searches for exact matches to your query only but unlike Alta Vista does not support Boolean expressions Google will always add a logical and between all the words in your query Another option is Google Scout which will retrieve the most rel evant pages i e the sites Google ranks as equal that relate to a search result This feature highl
271. ssential information for anyone undertaking GCSE or A level electronics or technology and for hobbyists who want to get to grips with project design Over seventy different Input Processor and Output modules are illustrated and fully described together with detailed information on construction fault finding and components including Components Quiz Symbols Symbols Quiz Circuit Technology clrqult BOIS PINOUIS REENERT Hobbwiet Student 34 inc VAT Single User Version 19 95 inc VAT Institutional Schools HE FE Industry eee 89 plus VAT Multiple User Version 34 plus VAT Institutional 10 user Network Licence 169 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices UK and EU customers add VAT at 17 5 to plus VAT prices Minimum system requirements for these CD ROMs PC with 486 166MHz VGA 256 colours CD ROM drive 32MB RAM 10MB hard disk space Windows 95 98 mouse sound card web browser Piessesend me CD ROM ORDER FORM ORDERING ALL PRICES INCLUDE UK Version required POSTAGE Analogue Electronics Digital Electronics TT Hobbyist Student Note The software on each C Filters Institutional version is the same only CT Digital Works 3 0 Institutional 10 user He licence for use varies l O PiCtutor Student Single User Standard Version price includes postage to most countries in the world EU resi
272. sssssstrrterrrrrressssrertrrrreEEEEEEEEEEREEEEEEEEEEEEEEEEEEEEEEEEEEEEE 850 Hameg 8028 8038 Spectrum pel eet een lng Gen 100MHz Oscilloscope 1000 Hewlett Packard 182R with 8559A 10MHz 21QGHI cere rrr rure rre e nuu n n ena naa uuu au uu auus 2750 Hewlett Packard 182T 8558B 0 1 to 1500MHZ eren unma uaa nna ananas 1200 Hewlett Packard 853A 8558B 0 1 to 1500IM Hz enero creer res sasaannnan nnn nono aa uasa san Rams Ru 2250 Hewlett Packard 3562A Dual Channel Dynamic Sig Analyser 5750 Hewlett Packard 3580A GHz BOkKHS eeeeeserterrrrteEEEESEEEREEEEEEEEEEEEEEEEREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE 800 Hewlett Packard 3582A 0 02Hz 25 6kHz Dual Channel ss snnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 2000 Hewlett Packard 3585A 20HZ A0MHS eeteteeeeEEREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEER 4000 Hewlett Packard 8569B 0 01 to 22GHZ eeerr EEE 4250 Hewlett Packard 85046A S Parameter Test Sei enrrtrESESSREREEEEEEEEEEEEEEEEEREEEEEEEEEEEEEEEEREEEEEEEEEEE 2500 Hewlett Packard 8753A Network Analyser coccion from 3000 Hewlett Packard 8753B Network Analyser eeexrrreseseRREEEEEEEEEEEEEEEREREEEEEEEEEEEEEEEEREEEEEEEEEEEEE from 4500 IFR 7750 10kHz 1GHZ cere NN nnananaas 2000 Meguro MSA 4901 1 300GHz AS NEW 4 750 Meg
273. st a few minutes looking for any wiring errors semiconductors fitted the wrong way round swapped over com ponents and this sort of thing Be especially vigilant when looking for components that are fitted the wrong way round and do not forget to check the battery clip as well In the past semiconductors con nected the wrong way round or fed with the wrong supply polarity had a life expectancy of about one microsecond Modern devices are less easily damaged in this way but they can still be zapped by the large supply currents that often flow as a result of incorrect connection You are usually left in no doubt when a semiconductor overheats because it often explodes with a load crack Electrolytic capacitors con nected the wrong way round often suffer the same fate Always switch off at once if you detect the charac teristic smell of hot components com ing from a low power circuit Ignoring any notes on setting up and using a project is a good way of ensuring that it fails to perform prop erly even if it has been built properly Always follow any setting up instruc tions to the letter and heed any advice about using projects Do It The biggest mistake of all is to always be about to build a project but to never actually get around to it Getting started is the hardest part of any creative hobby but once under way you are unlikely to have any regrets and should be at the start of countless hours of fun
274. sually involves some compro mise Linear voltage regulators generate heat The amount of this heat can be Te power supply was designed to 682 determined from the product of the output current and the voltage difference between the regulator s input and output in watts This is why experimenters are sometimes surprised to find regulators overheating or even failing despite not being run at any where near their full current rating an excessive input voltage is often the culprit closer to the peak value which is about 1 414 times this The rectifier also introduces a small voltage drop typically about 1 2V for a silicon bridge rectifier where two diodes are in series with the output at any point during operation For a 15V transformer with a bridge rectifier and a smoothing capacitor the unregulated d c voltage is likely to exceed 20V with no load 1N4001 k a D2 1N4001 k Fig 1 Complete circuit diagram for the EPE Moodloop Power Supply Keeping this to a minimum improves efficiency and reduces the heat output which in turn allows the use of a smaller heatsink or even no heatsink at all in some cases To minimise heat generation in a mains operated supply therefore it is desirable to keep the voltage difference between the unregulated supply from the rectifier and the regulated output to a minimum It should be remembered however that the average and ripple voltage of the unregu
275. systems etc subjects The Base Manual describes 13 projects including a Theremin and a Simple TENS Unit BASIC PRINCIPLES Electronic Components and their Characteristics 16 sections from Resistors and Potentiometers to ESSENTIAL DATA Extensive tables on diodes transistors Crystals Crystal Modules and Resonators Circuits Using Passive thyristors and triacs digital and linear i c s Components 9 sections Power Supplies The Amateur Electronics Workshop The Uses of Semiconductors Digital EXTENSIVE GLOSSARY Should you come across a technical Electronics 6 sections Operational Amplifiers Introduction to word phrase or abbreviation you re not familiar with simply turn Physics Semiconductors 6 sections and Digital Instruments to the glossary included in the Manual and you ll find a 5 sections comprehensive definition in plain English CIRCUITS TO BUILD There s nothing to beat the satisfaction of The Manual also covers Safety and Suppliers creating your own project From basic principles like soldering and The most comprehensive reference work ever produced at a price making printed circuit boards to circuit building the Modern you can afford the revised edition of THE MODERN Electronics Manual and its Supplements describe clearly with ELECTRONICS MANUAL provides you with all the essential appropriate diagrams how to assemble radios loudspeakers information you need THE MODERN ELECTRONICS MANUAL Revised Edition of
276. t then looks at the part digital has to play in the ever expand ing Information Technology especially in modern transmis sion systems and television It avoids getting deeply involved in mathematics Various chapters cover Digital Arithmetic Electronic Logic Conversions between Analogue and Digital Structures Transmission Systems Several Appendices explain some of the concepts more fully and a glossary of terms is included 183 pages Order code BP376 4 95 Building 30 SIMPLE IC TERMINAL BLOCK PROJECTS R Bebbington Follow on from BP378 using ICs 117 pages Order code BP379 4 99 HOW TO DESIGN AND MAKE YOUR OWN P C B S R A Penfold Deals with the simple methods of copying printed circuit board designs from magazines and books and covers all aspects of simple p c b construction including photographic methods and designing your own p c b s 80 pages Order code BP121 3 99 IC555 PROJECTS E A Parr Every so often a device appears that is so useful that one wonders how life went on before without it The 555 timer is such a device It was first manufactured by Signetics but is now manufactured by almost every semiconductor man ufacturer in the world and is inexpensive and very easily obtainable Included in this book are over 70 circuit diagrams and descriptions covering basic and general circuits motor car and model railway circuits alarms and noise makers as well as a section on 556 558 and 559 timers N
277. t AA E zi et esi prc bti uj bon am loo fu M Acid Bare Tirecon Moral pel and Ty B s Acid sin Moors the Sl af coliscIndrait b e Exattusrnie Reaction Etre EH Te TU i Cipio chat echange F gairi bh e infrm red nemore corrmlg se Spot d e Outpt o s solar cel Pati d Heat laulamon Wap 562 Fe lob Warning list Ts W Heaters T rrougb Winders SLEG Only 591 The DrDAQ is a low cost data logger from Pico Technology It is supplied ready to use with all cables software and example science experiments DrDAQ represents a breakthrough in data logging Simply plug DrDAQ into any Windows PC run the supplied software and you are ready to collect and display data DrDAQ draws its power from the parallel port so no batteries or power supplies are required The science lab in a PC Its Output Voltage Microphone External sensors Very low cost Built in sensors for light sound level and waveforms and temperature Use DrDAQ to capture fast signals eg sound waveforms Outputs for control experiments Supplied with both PicoScope oscilloscope and PicoLog data logging software Transform your PC Into an oscilloscope spectrum analyser and multimeter The Pico Technology range of PC based oscilloscopes offer performance only previously available on the most expensive benchtop scopes By intergrating several instruments into one unit they are both flexible and
278. tember 2000 Photo 11 4 Interactive integration demo screen illustrating how a square wave input is modified by a CR ratio M Uc WesDiFF CI ERPU TACR2 DOOTsecs 100u5 M Photo 11 5 Interactive integration demo screen illustrating how CR ratios can cause signal phase shifting 665 We Pkt ELCH uber UczPketEXP t CR ubere Photo 11 6 and Photo 11 7 Interactive differentiation screens showing how different CR values can drastically affect the shape of a square wave entered the Integration display screen as in Photo 11 4 You will probably have seen similar curved slopes under some condi tions of using your Analogue Input Waveform Display to monitor other bread board waveforms in previous experiments earlier in the Teach In series No doubt you will recognise that the slopes follow the graphs generated when using the Resistor Capacitor Charging Graph displays in Part 2 Indeed the formulae which we pointed out to you then basically apply to integration cal culations as well but with a few extra factors taken into account Again we do not expect you to learn the formulae but the variants used to generate the integration demo dis plays are shown at the top of the screen The calculations are more complex for a square wave than for the sine or triangle waveforms With experience at using the Integration demo screen you will find that you can use its control options as a reasonable guide to
279. ter e errer enne eene nana annum uana aa RRRR RR RR RR RR NAAR RS RS SRRSRRARRR S RSS RR NAAR 600 Hewlett Packard 435A or B Power Meter with 8481A 84844 from 400 Hewlett Packard 436A and 437B Power Meter and Sensor from 900 Hewlett Packard 4948A TIMS Transmission Impairment My Set 1000 Hewlett Packard 4972A Lan Protocol Analyser eensussrtrrrrrrrrrESSREEREEEEEEEEEEEEEEREREEEEEEEEEEEEEEREREREEEE 1250 Hewlett Packard 5183 Waveform Recorder Sanar 1250 Hewlett Packard 5238A Frequency Counter 100lVI Hz c ecce cec r e nne nunnuus 250 Hewlett Packard 5314A NEW 100MHz Universal Counter ce erre eee u nue 250 Hewlett Packard 5316A Universal Counter IEEE sssssssssssssserseererererererEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEER 400 Hewlett Packard 5335A 200MHz High Performance Systems Counter 600 Hewlett Packard 5324A Microwave Frequency Counter 500MHz 18GHz Opts 1 3 800 Hewlett Packard 5359A High Resolution Time Synthesiser or rrr erre errem Hewlett Packard 5370B Universal Timer Counter Hewlett Packard 5384A 225MHz Frequency Counter 500 Hewlett Packard 5385A Frequency Counter 1GHz HP1B with OPTS 001 003 004 005 750 Hewlett Packard
280. the greater the differ ential between input and output voltages the greater the power that is dissipated by the device In other words it will get hotter more quickly for a given current drawn if 664 the voltage differential is large it s the P VA situation again The 1A and greater devices have metal tabs to help radiate convect conduct heat away from them The tabs can be bolted to heatsinks to aid cooling a subject beyond this series but simply bolting the devices to the metal case containing the circuit can often provide a satisfactory cooling solution Note that the tab is usually electrically con nected to the Common OV pin so they may need to be insulated from the heatsink Suitable mica or similar washers are some times supplied with the device although they may have to be purchased separately The basic circuit for using a fixed volt age regulator is also shown in the centre of Photo 11 2 The input voltage Vdc enters one pin and the regulated voltage Vout exits another while a OV connection is made to a third That s all just three pins to connect to provide an extremely well regulated fixed d c voltage supply Obviously such devices automatically remove the power supply ripple voltage referred to earlier as long as the minimum ripple voltage does not drop below the mini mum 2V nominal input output differential However such regulators are not totally immune to power line noise and oth
281. the values tend to be small less than 1000pF Schematic representations were shown in Part 2 Pis 2 5 Various forms of variable capacitor con struction are used with dielectrics which are either solid plastic film mica ceramic material or air Variable capacitors are gen erally very reliable although mechanical faults can occur with some of the cheaper solid dielectric types Air spaced variable capacitors can also be prone to problems through dust and other contaminants getting in between the inter leaved plates In earlier days the large air spaced types Type were commonly used for tuning the recep tion frequency of radios in many instances they have been replaced by semiconductor Range pF Tolerance 96 Voltage d c Stability Applications Air spaced 5 to 500 10 20 10 250V to 1kV 63V Excellent Fair Good Transmitters r f signal generators devices whose capacitance value depends on the voltage applied to them and known as Varicap or tuning diodes The preset types continue to be used for applications such as oscillator fre quency correction Characteristics of the most commonly encountered variable capacitors are shown in Table 11 1 Table 11 1 Characteristics of commonly encountered variable capacitors Plastic film 10 to 750 Ceramic 2 to 200 63V to 150V Compensation oscillator trimming Radio tuning oscillator trimming TEACH IN 2000 Experimental 11
282. ther program for a more elaborate circuit To help demonstrate the decoding process and provide programming exam ples the PIC circuit incorporates two light emitting diodes D1 and D2 connected to Port B Certain remote control key codes T design was created to enable PIC RBO OSC1 IC1 PIC16x84 Fig 1 Circuit diagram for the Remote Control IR Decoder 698 are recognised by the PIC software and used to switch these l e d s on or off Resistors R1 and R2 limit the Led cur rent from the PIC Additional l e d s with suitable current limiting resistors can be added but note that the PIC can only source a maximum current of 20mA per port pin with a maximum current total of 100mA for Port B The circuit can easily be built on strip board and requires a regulated 5V power supply No constructional details are offered Software is available as stated later SERIAL INTERFACE It can be difficult to predict what com mand code a particular remote control handset key will generate Instead of switching on or off l e d s the value of the command code generated by the remote control handset can also be serially trans mitted to a PC compatible computer To achieve this R3 1s a series current limiting resistor and connects Port B pin RB3 to pin 2 of a 9 pin D type serial port socket SK1 in Fig 2 so that the data from the PIC circuit can be sent direct to the PC s serial port In serial mode the PIC software needs
283. tive Club Ripponden Road Moorside Oldham The Club is a registered City amp Guilds Examination Centre able to host the RAE and Novice exams and welcomes external candidates For more details contact the Oldham Amateur Radio Club 196 Middleton Road Hopwood Heywood OLIO 2LH Alternatively telephone fax the Club Secretary Mike Crossley MICVL on 01706 367454 Mention EPE when responding Organ Society NEWISH readers of EPE who do not yet know that the Electronic Organ Constructors Society exists and would like to become involved in such a society are invited to contact Peter Cox the EOCS Membership Secretary 10 Victoria Street Reading Berks Rol 4NQ for more details Tel 0118 957 3865 The Society has been in existence for sev eral decades holding periodic meetings in the London South Essex and South Coast regions although anyone from any part of the world can join The Electronic Organ Magazine is the quarterly journal of the EOCS and includes articles from members and others The latest issue has recently been received at EPE HQ and as usual cov ers a diverse range of subjects including con structional features letters details of Society meetings and other pertinent matters It is interesting to note that an EOCS web site is being constructed but not yet accessible and one of its features will be a discussion forum of the type provided by ourselves News about the EOCS site progress can be accessed th
284. traight EAR IS e 39999998 gp 333333387 t Way Straight 1 Way Straight Way Siraig hi Way Straight Way Straight Way Straight Way Straight Way GE SE E 14 Way DIL 16 Way DIL 24 Way DIL 40 EE DIL SODDDBEO Log 17 4 p mun 0 0 0 0 0 ED 0 1 i Ka ss LPS E ad Cad Pad GP GO LIS G Ged had eer te m DOSOGGOBO OGBODOO EE cOCDGOGO Sessa JR EROR UR LI FS B Bootle P G LO 3 wu s OO Dh 48 DOG LP Ln a E kapinin dta tag u 9 Way Female eek 0 93 t Way Male Plu l Way Female 25 Woy Male 3 Wer Se 13 Way Male Plu a Way Female WE Way nonas go Qo Opt PRU A LATA A 25 Way Female Socket 0 CEO D Covers 9 Way Cover Gre 1 Way Cover Blac 2 uu SAD Do Ls 5 Way Cover Grey 3 Way Cover Gre 23 Way Cover Blac 25 Way Cover Gre 29 NY Cover Blac over Case 25 lo 25 Cover Case 9 to 25 Cover Case Audio Connectors 3885 Gemeen lug 5012 Solder BNC P 00 99 BNC Plug 501 Crimp 0 68 BNC Plug 754 Solder 0 95 BNC Gre 7511 Ata y 0 68 BNC C SCH 0 81 F Plug M v0 24 F Flu 20 26 TNC os 30 Solder 124 TNC Plug 5011 Comp 0 85 THE Plug 750 Solder 1 40 TNC Plug 750 Comp 1 16 UHF Plug 5mm Coble 0 53 UHF Plug 11mm Cable f Stas UHF Chassis Ski Sar UHF Chassis Skl End 8 gt Extensive range of RF con nectors in stock inc Ce SMA Mini UHF amp N Type Colours Red
285. tting the conversion data to an l c d the decimal values held in the eight DIGIT variables must be IORed with decimal 48 to convert them to ASCII In my Power Supply software an additional routine blanks leading zeros as appropriate As things turn out you are indeed correct I eventually found a manufacturer s reference to the product which originally started life as Hormel s Spiced Ham Production started in 1937 Apparently a competition was held with customers to find a new name and the winner was Spam Thanks for pointing out the mistake Alan Winstanley I too recall Spam gracing my childhood plate usually fried in batter Half a memory also tells me there was a TV program some moons ago which featured a conglomerate of Spam addicts who had formed a club to celebrate its virtues And who can forget the infamous Monty Python sketch XLR SOLDERING Dear EPE I work for Doyle Technology Consultants in Redmond Washington USA and I m putting together a training manual for our new employ ees on connector soldering techniques and would like any information you could send my way on where I could find clear photos or drawings of soldering techniques on XLR and RCA and TRS connectors Bradley J Luther via the Net The query was sent to our On line Editor Alan who replied I really don t know of anywhere at the moment This is similar to something I ve been asked for in the past and is something I could maybe attempt
286. ture that enables the sleeving to be removed This minimis es the risk of damaging the wires Holders It is tempting to leave out integrat ed circuit i c holders or d i l dual in line sockets as they are common ly referred to Why bother with the Fig 2 Inexpensive wirecutters strippers can save a lot of problems and are safe expense of an i c holder when you can solder the components directly onto the board As pointed out previously semicon ductors are vulnerable to overheat ing a problem that is made worse if there are large numbers of pins to connect Also bear in mind that many modern semiconductors are vulnera ble to damage from static charges It is not just large discharges that are the problem and even quite modest voltages can zap the inputs of some devices Soldering this type of component direct to a circuit board increases the risk of static damage and is definitely not a good idea Always heed any advice about avoiding static damage including the use of i c holders Another good reason for using holders is that the occasional mistake will inevitably occur with the integrat ed circuit being fitted the wrong way round If the device is fitted in a hold er there is no major problem There are special tools for pulling integrated circuits from their holders but it is usually possible to carefully lever one end free using a small screwdriver and to then repeat the process at the other
287. u need to know in order to get started in this absorbing and creative hobby 135 pages Order code BP392 4 95 45 SIMPLE ELECTRONIC TERMINAL BLOCK PROJECTS R Bebbington Contains 45 easy to build electronic projects that can be constructed by an absolute beginner on terminal blocks using only a screwdriver and other simple hand tools No soldering is needed Most of the projects can be simply screwed together by following the layout diagrams in a matter of minutes and readily unscrewed if desired to make new circuits A theoretical circuit diagram is also included with each pro ject to help broaden the constructor s knowledge The projects included in this book cover a wide range of interests under the chapter headings Connections and Components Sound and Music Entertainment Security Devices Communication Test and Measuring 163 pages Order code BP378 4 95 some basic knowledge of electronics After dealing with subjects like Fundamentals Waves and Particles and The Nature of Light such things as Emitters Detectors and Displays are discussed Chapter 7 details four dif ferent types of Lasers before concluding with a chapter on Fibre Optics 161 pages Order code BP359 4 95 UNDERSTANDING DIGITAL TECHNOLOGY F A Wilson C G A C Eng F I E E EL Mgt This book examines what digital technology has to offer and then considers its arithmetic and how it can be arranged for making decisions in so many processes I
288. ual type Our latest information is that this is to be replaced by the KV1235 type Both devices will of course function in this project The specified varicap and transistors are available from Bonex Ltd amp 01753 549502 or www bec co uk and JAB Electronic Components 0121 682 7045 Finding a source for the ferrite rods proved a little more problem atic as they seem to have been dropped from many components catalogues One very good deal we came across was from J amp N Factors amp 01444 881965 who are offering a pack of two ferrite rod aerials from their bargain packs for just 1 code Ref D53A At that price you can discard the coils and use the rods Another fer rite rod source is Squires Model amp Craft Tools Ex 011243 842424 code 882 000 This one has a slightly flattened profile measures 100mm long and costs 1 each If you intend to use the 6 3mm stereo jack socket and plug arrangement to link the top aerial turret to the base control unit the socket came from Maplin www maplin co uk code BW80B They also supplied the Lorlin plastic cased 3 way 4 pole rotary switch code FF76H The single side printed circuit board is available from the EPE PCB Service code 274 EPE Moodloop Power Supply As far as we can tell the 6A 100V bridge rectifier called up in the EPE Moodloop Power Supply component listing is an International Rectifier device and their code for this part is KBPC6 01 This is cur rently liste
289. ulti plier control at zero CONCLUSIONS Results were as follows With the exception of one station the signal level from the seven rod loop always matched that from the long wire The seven rod Active Ferrite Loop Aerial consistently outperformed the air cored passive loop the signal delivered being from 3dB to 6dB stronger The tilt facility made the nulls with the ferrite loop deeper than those displayed by the air cored model in some instances a decent null could be obtained with the ferrite aer ial when the null with the traditional loop was barely discernible Output from the thirty rod loop was some 3dB greater than that from the seven rod version The application of a modest amount of Q multiplication dramatically increased the output of the ferrite loops at the expense of bandwidth For a given output bandwidth with thirty rods was always greater than with seven 677 PIC UPS Keep Your PIC Powered HE purpose of the simple UPS Uninterruptible Power Supply circuit of Fig 1 is to provide a near seamless battery backup power for a PIC based circuit in the event of a mains failure It allows the circuit to be powered from the mains under normal operating conditions whilst charging a back up battery at a reasonably constant current In the event of a power failure the battery takes up the load with no spikes or delays as would be caused by a relay changing over D5 FS1 1N4001 D1 TO D4 1N4001
290. ur TV camera It has a composite video output to a phono plug SCART amp BNC adap tors are available They are in very good condition with few signs of use 91 91 VAT 108 00 Board cameras all with 512 x 582 pixels 8 5mm 1 3 inch sensor and composite video out All need to be housed in your own enclosure and have fragile exposed surface mount parts They all require a power supply of between 10V and 12V DC 150mA 47MIR size 60 x 36 x 27mm with 6 infra red LEDs gives the same illumination as a small torch but is not visible to the human eye 37 00 VAT 43 48 30MP size 32 x 32 x 14mm spy camera with a fixed focus pin hole lens for hiding behind a very small hole 35 00 VAT 41 13 40MC size 39 x 38 x 27mm camera for C mount lens these give a much sharper image than with the smaller lenses 32 00 VAT 37 60 Economy C mount lenses all fixed focus amp fixed iris VSL1220F 12mm F1 6 12 x 15 degrees viewing angle 15 97 VAT 18 76 VSL4022F 4mm F1 22 63 x 47 degrees viewing angle 17 65 VAT 20 74 VSL6022F 6mm F1 22 42 x 32 degrees viewing angle 19 05 VAT 22 38 VSL8020F 8mm F1 22 32 x 24 degrees viewing angle 19 90 VAT 23 38 Better quality C Mount lenses VSL1614F 16mm F1 6 30 x 24 degrees viewing angle 26 43 VAT 31 06 VWL813M 8mm F1 3 with iris 56 x 42 degrees viewing angle 77 45 VAT 91 00 1206 surface mount resistors E12 values 10 ohm to 1M ohm 100 of 1 value 1 00 VAT 1000 of 1
291. ur own EPROM ERASURE for a fraction ot the price of a made up unit Kit of parts less case includes 12in 8watt 2537 Angst Tube Ballast unit pair of bi pin leads neon indicator on off switch safety microswitch and circuit 15 00 2 00 p amp p 19 98 inc VAT WASHING MACHINE WATER PUMP Brand new 240V AC fan cooled Can be used for a variety of purposes Inlet 1 oin outlet 1in dia Price includes p amp p amp VAT 20 each or 2 for WE DELIVER WORLD WIDE AND ACCEPT MAJOR CREDIT CARDS Visit our Website at http www veronica co uk Contact Us Now For A Free Brochure Tel 01274 883434 Fax 01274 428665 email info veronica co uk Unit 5 6 1A Sandbeds Albert Rd Queensbury BRADFORD BD13 1AA COVERT VIDEO CAMERAS Black and White Pin Hole Board Cameras with Audio Cameras in P 1 R Radios Clocks Briefcases etc Transmitting Cameras with Receiver Wireless Cameras as above with colour Audio Surveillance Kits and Ready Built Units Bug Detector etc A L ELECTRONICS Please phone 0181 203 6008 for free catalogue Fax 0181 201 5359 E mail surveillance btclick com www uspy com New DTI approved Video Transmitters and Receivers Wireless Major credit cards now taken Only 39 95 incl p amp p amp VAT 20 50 inclusive Me SERVICE TRADING CO se a 57 BRIDGMAN ROAD CHISWICK LONDON W4 5BB Monday Friday Tel 0181 995 1560 FAX 0181 995 0549 Ample Parking Space Radio Bygones Hip e Model 471 AE CU
292. uro MSA 4912 1 1GHz AS NEW 2 1000 Rohde amp Schwarz SWOB 5 Polyskop 0 1 1300MHz 1500 Takeda Riken 4132 1 0GHz Spectrum Analyser 2100 Tektronix 7L18 with mainframe 1 5 60Ghz with external mmlverel eneen 2000 Tektronix 495P 100Hz 1 8GHz programmable e ee eee eene nn snnn snas nn nn nn Renan rn nnnnnnrnnas 4500 Tektronix 496P 1kHz 1 8GHz Spectrum ANalyS F cnc crasas 4250 MISCELLANEOUS Adret 740A 100kHz 1120MHz Synthesised Signal Generator corre eonun nuuuunun 800 Anritsu MG 3601A Signal Generator 0 1 1040MHz wn 1250 Anritsu ME 462B DF 3 Transmission Analyser 2500 Anritsu MG 645B Signal Generator 0 05 1050MHz 750 Boonton 92C R F Millivoltmeter 195 Boonton 93A True RMS Voltmeter RRE 195 Dranetz 626 AC DC Multifunction Analyser cene enne nnne nono NN nina nna En NN NN anna 500 EIP 331 Frequency Counter 180GHZ ssterrrrrrsssssRSREEEEEEEEEEEEEEERREEEEEEEEEEEEEEEREREEEEEEEEEEEEEERERREREEEEEEEEEEEEEN 450 EIP 545 Frequency Counter 18GHZz nenas 1250 EIP 575 Frequency Counter 187 ssssssssssssssssssssssssssssssseseseseseseerrreEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEER 1450 Eltek SMPS Power Supply 6G0V 30V oorr nnn onaa uana nna u nana nuu u usu uu uus o nanus DO Farnell TSV 70 MKII Power Supply 7
293. urse in designing active and FI LTE RS passive filters that makes use of highly interactive virtual laboratories and simulations to explain how filters are designed It is split into five chapters Revision which provides underpinning knowledge required for those who need to design filters Filter Basics which is a course in terminology and filter characterization important classes of filter filter order filter impedance and impedance matching and effects of different filter types Advanced Theory which covers the use of filter tables mathematics behind filter design and an explanation of the design of active filters Passive Filter Design which includes an expert system and filter synthesis tool for the design of low pass high pass band pass and band stop Bessel Butterworth and Chebyshev ladder filters Active Filter Design which includes an expert system and filter synthesis tool for the design of low pass high pass band pass and band stop Bessel Butterworth and Filter Theory Active filter synthesis Chebyshev filters based on the use of op amps Digital Works Version 3 0 is a graphical design tool that enables you to construct digital logic circuits and DIGITAL WORKS 3 0 analyze their behaviour It is so simple to use that it will take you less than 10 minutes to make your first digital DUIS design It is so powerful that you will never outgrow its beh i KEREN nears KI capability e Software for simulating digital logic circu
294. urther information if necessary Lists over 8 000 different transistors including f e t s 200 pages Order code BP401 5 95 ELECTRONIC TEST EQUIPMENT HANDBOOK Steve Money The principles of operation of the various types of test instrument are explained in simple terms with a mini mum of mathematical analysis The book covers ana logue and digital meters bridges oscilloscopes signal generators counters timers and frequency measure ment The practical uses of the instruments are also examined Everything from Oscillators through R C amp L measure ments and much more to Waveform Generators and testing Zeners Order code PC109 8 95 206 pages GETTING THE MOST FROM YOUR MULTIMETER R A Penfold This book is primarily aimed at beginners and those of lim ited experience of electronics Chapter 1 covers the basics of analogue and digital multimeters discussing the relative merits and the limitations of the two types In Chapter 2 var ious methods of component checking are described including tests for transistors thyristors resistors capaci tors and diodes Circuit testing is covered in Chapter 3 with subjects such as voltage current and continuity checks being discussed In the main little or no previous knowledge or experience is assumed Using these simple component and circuit test ing techniques the reader should be able to confidently tackle servicing of most electronic projects 96 pages Order code
295. vice addresses Adaress Device TV receiver 1 TV receiver 2 teletext video recorder 1 video recorder 2 experimental satellite preamplifier 1 tuner audio tape recorder 1 preamplifier 2 CD player audio tape recorder 2 Table 2 RC5 command codes Command Function 0 9 numerals O to 9 10 digits 11 select 12 stand by 13 mute 14 presets display volume volume page timer large reveal cancel subtitle store pause erase fast reverse fast forward rewind play stop record is read TIMERVAL after every interrupt and the RTCC timer is then set to zero and begins to count up again PIC software times the IR sensor output from falling edge to falling edge With a 4MHz crystal clock and prescaler set to 16 the timer is incremented every 16 microseconds As can be seen from the various logic combinations in Fig 7 despite the number of different waveform permutations the edge to edge timing can be one of only three different values The output from the infra red sensor is high and goes low when a signal is received so on the first interrupt the timer value is not valid Program variable BITS 699 LOGIC 00 1 0 x INITIAL TIMERVAL LOGIC 01 1 5 x INITIAL TIMERVAL LOGIC 10 DEPENDS ON LAST BIT LOGIC 11 1 0 x INITIAL TIMERVAL A LOGIC 010 2 0 x INITIAL TIMERVAL a LOGIC 110 1 5 x INITIAL TIMERVAL Fig 7 Example RC5 timing diagram is used to ensu
296. will this restore the treble response it can also shift the tuning to the side of the signal furthest from a source of interference The Selector switch S1 permits an instant comparison between the loop and the other aerial available at the listening station Band searching is best carried out with some form of wire aerial The loop can then be switched in for comparison when the station has been located This avoids the need to keep loop and receiver tuning in step Everyday Practical Electronics September 2000 Rear of the prototype model showing the tilt drive cord arrangement PERFORMANCE Performance was assessed by compar ing the seven rod active loop with other aerials The receiver used for the test has a large signal strength meter and its a g c system was switched out The aerials used were as follows 1 A long 20 metres high 10 metres wire aerial with impedance matching transformer and screened downlead The receiver was earthed when this aerial was in use 2 A passive one metre diameter air cored loop with a single turn coupling winding and no provision for tilting 1 e a traditional loop or frame aerial 3 A thirty rod version of the ferrite loop described here The test was carried out during day light in a room caged by the usual house wiring and plumbing this distorts nulls It involved ten stations spread across the Medium Wave band Loop out put was set at maximum and the Q m
297. winner of a Pico PC based scope see this month s IU pages This latest catalogue includes three new product ranges a high resolution version of the ADC 11 an EnviroMon logger with rechargeable battery pack and a vast memory and the DrDAQ data logger with built in sensors for light sound and temperature 656 For more product information contact Pico Technology Ltd Dept EPE The Mill House Cambridge Street St Neots PE19 IQB Tel 01480 396395 Fax 01480 396296 E mail post picotech com Web www picotech com Mobiles and Masts THE National Radiological Protection Board NRPB has published a report on exposure to radio waves near to mobile phone base stations a matter which is fre quently in the news and the subject of pub lic controversy The NRPB made measurements at mast sites in the vicinity of where people lived worked or had frequent access In all cases the total exposures were a small fraction of national and international guidelines Typical average exposures were 0 002 per cent of the guidelines The measurements were frequently comparable to those from TV FM radio and other transmitters See web sites www nrpb org uk and www iegmp org uk Oldham RAE Course OLDHAM Amateur Radio Club tell us that they will be starting a new RAE course beginning on 17 September 2000 The course runs until May 2001 ready for the examination Enrolment commences on 12 September at 8pm at the Moorside Conserva
298. z inHdis 1T EXPU tACH 5min outputs and at first sight the sine wave input and output shapes appear similar Note though how the relationship between the peaks and troughs shifts with various CR values In other words a phase shift occurs see Photo 11 5 The program allows control over the R C and F frequency values represented by the circuit The Scale option changes the frequency range covered by option F and amends the C and R values appropriately in order to retain waveform shapes between range changes Positive or negative d c bias not speci fied as a particular voltage just a number can be given to the input waveform and to the voltage level to which capacitor C is terminated shown as OV on entry to the program The CR time constant in respect of the C and R values is also quoted Experiment with the various options particularly C R and F and see how the Vc waveform is affected You will see how the square wave input results in a Vc waveform that closely matches what you observed on your breadboard earlier FORMULATION We have repeatedly referred to the wave form at IC1a pin 1 of the oscillator as being triangular or nearly so If you were to actually look at the waveform on an oscil loscope you would see that its shape con sisted of curved slopes more like the Vc waveform you observed when you first UinPket ERPL t CR JJ i nf 10 lora kHz Everyday Practical Electronics Sep

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