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EPE 2001

1. Capacitor C3 470n min polyester film C4 560p min ceramic plate Semiconductors D3 1N4148 signal diode TRS SDP8405 npn phototransistor IC1 MC14093BCP quad 2 input NAND Schmitt trigger Miscellaneous WD1 low profile wire ended piezo sounder Printed circuit board Uniboard avail able from the EPE PCB Service code 305 multistrand connecting wire link wires solder pins solder etc Note Component designations run on from the Solar Powered Power Supply and Voltage Regulator described in the July 01 issue Approx Cost Guidance Only Everyday Practical Electronics October 2001 components is available from the EPE PCB Service code 305 Once again the Solar Powered Power Supply and Voltage Regulator components are included in this diagram Follow the same procedures as previous ly described soldering the components to the board in sequence and finally inserting ICI in its holder observing anti static precautions Note that R6 and R7 are wired in series and together make up the required value of 44 megohms One end of each of the two resistors should have their leads twisted and soldered together The opposite free ends of the resistors should be inserted in the board across pins 2 and 3 of ICI as shown in Fig 4 SETTING UP Assuming the solar power supply is active adjust the regulator s voltage to 3 6V while the Bird Scarer is sounding Remember that capacitor C2 in the r
2. P I TREASURE HUNTER The latest MAGENTA DESIGN highly stable amp sensitive with I C 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 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 KIT 842 icvsxcrinisskan cunis 22 56 68000 DEVELOPMENT TRAINING KIT e NEW PCB DESIGN e 8MHz 68000 16 BIT BUS e MANUAL AND SOFTWARE e 2 SERIAL PORTS e PIT AND I O PORT OPTIONS e 12C PORT OPTIONS KIT 621 Pe 99 95 e ON BOARD 5V REGULATOR e PSU 6 99 e SERIAL LEAD 3 99 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
3. Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail subs epemag wimborne co uk Also via the Web at Mhttp www epemag wimborne co uk Subscriptions start with the next available issue We accept MasterCard Amex Diners Club Switch 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 Amex Diners Club Switch and MasterCard accepted minimum 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 UK 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 October 2001 Editor MIKE KENWARD Deputy Editor DAVID BARRINGTON Technical Editor JOHN BECKER Business Manager DAVID J LEAVER Subscriptions MARILYN GOLDBERG Administration FAY KENWARD Editorial Admin 01202 873872 Advertisement Manager PETER J MEW F
4. 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 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
5. ple A semiconductor is calculated to be dissipating 10 watts some quick V x I cal culations told us that The first question is what is the device s ambient temperature TA likely to be This directly affects our calculation and it depends on ventilation and the proximity of any other hot devices For now let us say that it is 40 C Therefore if the maximum junction tem perature permitted is 125 C the total per missible thermal resistance from end to end is 125 40 10 Watts 8 5 C W Suddenly those heatsink ratings need scru tinising carefully Breaking it down further we would first ly pick a semiconduc tor package with an appropriate thermal resistance jc If we were using an LM320 regulator we could rule out the TO 202 pack age a 12 C W device Choosing a TO 3 pack age that accounts for 3 C W already of our total permitted thermal resistance You might also add in say 0 5 C W for sil icon grease and a 4 selection of heatsinks including types to fit integrated washer 0cs leaving circuits us with a value of 5 C W remaining for the heatsink If this value is exceeded then heat may not be dis sipated efficiently enough to prevent the junction overheating Stay Cool Clearly the likely ambient temperature surrounding the assembly directly affects the heatsink specification This factor relates to ventilation and cabinet or circuit board layout A cooler ambient figure of 25 C m
6. 20GHz 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 5 FARNELL AMM2000 Auto Mod Meter 10Hz 2 4GHz Unused 950 H P 1650B Logic Analyser 80 channel MARCONI 2035 Mod Meter 500kHz 2GHz TEKTRONIX 577 Transistor Curve Tracer ROHDE amp SCHWARZ APN 62 Synthesised 1Hz 260kHz Signal Generator Balanced unbalanced output LCD display H P 6012B DC PSU 0 60V 0 50A 1000W FARNELL AP60 50 1kW Autoranging FARNELL H60 50 0 60V 0 50A FARNELL H60 25 0 60V 0 25A Power Supply HPS3010 0 30V 0 10A FARNELL L30 2 0 30V 0 2A FARNELL L30 1 0 30V 0 1A Many other Power Supplies available Isolating Transformer 250V In Out 500VA WELLER EC3100A Temperature controlled Soldering Station 200 C 450 C Unused PORTABLE APPLIANCE TESTER Megger Pat 2 ONLY SPECTRUM ANALYSERS ADVANTEST R4131B 10kHz 3 5GHz H P 8591E 1MHz 1 8GHz 75 Ohm TEKTRONIX 492 50kHz 18GHz EATON AILTECH 757 0 001 22GHz H P 853A Dig Frame with 8559A 100kHz 21GHz H P 8558B with main frame 100kHz 1500MHz H P 3580A Audio Analyser 5Hz 50kHz as new MARCONI 2382 100Hz 400MHz
7. 2P44 CYCLE LAMP BARGAIN You can have 100 6V 0 5A MES bulbs for just 2 50 or 1 000 for 20 They are beautifully made slightly larger than the stan dard 6 3V pilot bulb so they would be ideal for mak ing displays for night lights and similar applications DOORBELL PSU This has AC voltage output so is ideal for operating most doorbells The unit is totally enclosed so perfectly safe and it plugs into a 13A socket Price only 1 Order Ref 1 30R1 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 mil liamps 3 ranges resistance and 5 amp range These instruments are ex British Telecom but in very good condition tested and guaranteed OK probably cost at least 50 each yours for only 7 50 with leads carrying case 2 extra Order Ref 7 5P4 REPAIRABLE METERS We have some of the above testers but slightly faulty not working on all ranges should be repairable we supply diagram 3 Order Ref 3P176 TWO MORE POST OFFICE INSTRUMENTS Both instruments contain lots of useful parts includ ing sub min toggle switch sold by many at 1 each They are both in extremely nice cases with battery compartment and flexible carrying handles so if you don t need the intruments themselves the case may be just right for a project you have in mind The first is Oscillator 87F This has an output con tinuous o
8. October 2001 Constructional Project e VALVE SW RECEIVER ROBERT PENFOLD Designed for valve radio enthusiasts or anyone who would like to try the nostalgic approach to shortwave listening ESPITE continuing advances in semi conductor technology the humble valve refuses to totally stand aside in favour of modern technology Audio equipment having the true valve sound has a strong following as do olde worlde electronic music equipment and radios I wish I could say that I do not remem ber the days when this type of receiver was the normal introduction to the shortwave bands but it is very much the type of set that I built as a lad in the 1960s I still remember the HAC two valve set with its pre war valves the size of 100W light bulbs and the RCS Telstar with its miniature acorn valves that really were more or less acorn shaped BATTERY POWER The design featured here follows along the same general lines as these sets with its simple chassis and front panel method of construction and regenerative detector It covers an approximate tuning range of 5MHz to 13MHz using a simple home constructed tuning coil This provides coverage of several popular shortwave broadcast bands Sets of this type were almost invariably powered from batteries and required about 90 volts for the main supply and around 1 5 to 6 volts for the heaters These were respectively the HT high tension and LT low tensio
9. 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 your 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
10. 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 or 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 ser
11. a f e t normally conducts strongly between its drain d and source s termi nals A small reverse bias must be applied to its gate g in order to make it con duct less heavily so that it can provide linear amplification This bias is pro vided by resistor R1 which ties the gate to the OV rail in con junction with the positive bias provid ed to the source s by resistor R2 The gate is therefore neg ative of the source and the required reverse bias is obtained Capacitor Cl removes the neg ative feedback that would otherwise be introduced by R2 The valve equiva lent shown in Fig lb operates in the same manner Resistor R1 biases the control grid g to the OV rail With f e t s and valves there is very little current flow at the input Consequently in both cases resistor R1 can have a high value and the circuit as a whole can have a high input imped ance Also as before resistor R2 provides Everyday Practical Electronics October 2001 a positive bias but this time to the cathode k The output signal is developed across anode a load resistor R3 CIRCUIT OPERATION The full circuit diagram for the 2 Valve SW Receiver is shown in Fig 2 Valve V1 is used in the regenerative detector and V2 operates as an audio amplifier A valve type DF91 is used for both stages and these are pentodes that are specifically designed for battery operation Inductor coil L2 tuning capacitor VC1 and ba
12. and is far more efficient because it has a much lower thermal resistance than a small heatsink of say 25 C W A typical heatsink system contains the elements described in the photo This could represent any power transistor con taining a junction or say a voltage regula tor chip such as a the TO 3 type opened up for the photograph The requirement is to ensure that the semiconductor junction temperature symbol Tj does not exceed a figure of 125 C usually a typical value specified by data sheets The junction is at the heart of the pack age but unfortunately for us various ele ments of the system hinder the passage of heat and have to be accounted for Everything possesses a thermal resistance symbol 0 theta which can be sub defined as follows jc thermal resistance between junction and the case 0cs thermal resistance between the case and heatsink Osa thermal resistance between heatsink and ambient The electronics designer will hopefully see a number of thermal resistors in series each resistor prevents heat from flowing to ambient so heatsink design implies calculating to ensure that the over all thermal resistance of the system is not so large as to prevent heat flowing away efficiently or this will result in the semi conductor junction producing more heat than can be carried away effectively A typical assembly showing how the thermal resistance is divided between the device an
13. eVDC PCB 50x73mm 3131KT 12 95 TRAIN SOUNDS 4 selectable sounds whistle blowing level crossing bell clickety clack amp 4 in sequence SG01M 6 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 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 disrupt ing 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 R019 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 thi
14. high resolution B amp K 2033R Signal Analyser H P 182 with 8557 10kHz 350MHz MARCONI 2370 30Hz 110MHz H P 141 SYSTEMS 8553 1kHz 110MHz 8554 500kHz 1250MHz H P 5372A Frequency amp Time Interval Analyser OSCILLOSCOPES TEKTRONIX TDS380 dual trace 400MHz 2G S 2000 TEKTRONIX TDS350 dual trace 200MHz 1G S Unused 1500 TEKTRONIX TDS320 dual trace 100MHz 500M S TEKTRONIX TDS310 dual trace 50MHz 200M S LECROY 9400A dual trace 175MHz 5G S TEKTRONIX TAS 485 4 ch 200MHz etc Unused 900 TEKTRONIX THS720A ditrace Icd 100MHz 500M S Unused 900 HITACHI VC 6523 d trace 20MHz 20M S delay etc Unused 600 PHILIPS PM3092 2 2 ch 200MHz delay etc 800 as new 950 PHILIPS PM3082 2 2 ch 100MHz delay etc 700 as new 800 TEKTRONIX TAS465 dual trace 100MHz delay etc 750 TEKTRONIX 2465B 4 ch 400MHz delay cursors etc 1500 TEKTRONIX 2465 4 ch 300MHz delay cursors etc 900 TEKTRONIX 2445 A B 4 ch 150MHz delay cursors etc 500 900 TEKTRONIX 468 dig storage dual trace 100MHz delay 450 TEKTRONIX 466 Analogue storage dual trace 100MHz 250 TEKTRONIX 485 dual trace 350MHz delay sweep TEKTRONIX 475 dual trace 200MHz delay sweep TEKTRONIX 465B dual trace 100MHz delay sweep PHILIPS PM3217 dual trace 50MHz delay GOULD 0 1100 dual trace 30MHz delay HAMEG HM303 4 dual trace 30MHz component testerrr 325 HAMEG HM303 dual trace 30MHz component teste
15. pollution and its effects on the environment and health including fireballs UFOs and abnormal states Many case studies and field investigations and experi ments 286 pages photos 7 50 p amp p 2 50 THE ELECTRONICS SURPLUS TRADER This is a listing of new first class com ponents books and electronic items at below trade prices Includes manufacturers surplus and overstocks Also obsolete semiconductors valves and high voltage caps and components audio components and accessories Send two first class stamps for large catalogue Dept E CHEVET SUPPLIES LTD LEM mut 157 Dickson Road BLACKPOOL FY1 2EU nace Tel 01253 751858 Fax 01253 302979 E mail chevet globalnet co uk Telephone Orders Accepted s Callers welcome Tues Thurs Fri and Sat Everyday Practical Electronics October 2001 Lea TheEa Wa abg a 7 d MELDE HELL 4 T VA ee Ra pd n a L LU nanah aa TE T www brunningsoftware co uk Mail order address 138 The ee Li leClac Clac ea Brunning Software E e CO169LS Tel 01255 862308 Everyday Practical Electronics October 2001 GENT ELECTRONI CS Tel 01283 565435 Fax 546932 http www magenta2000 co uk E mail sales 9 magenta2000 co uk LTD EE230 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
16. 1 Complete circuit diagram for the Camcorder Power Supply Charger Everyday Practical Electronics October 2001 689 from discharging back into ICI when the supply is switched off As charging progresses the current flowing into the batteries reduces to about 50mA when the charging is nearly com plete Some 90 per cent of the required charge is delivered before the current reduces significantly With the specified batteries this takes 15 to 20 hours approx imately and in most cases the batteries will then be regarded as fully charged While charging switch Slc disconnects the subsequent circuit so current does not drain into this unnecessarily ON CAMERA Camcorder operation is selected by moving switch S1 to CAM Switch Sla now disconnects the charging supply if it has been left switched on Switch S1b con nects the two 6V batteries in series so that nominally 12V appears across them which S1c then connects to the following part of the circuit As the batteries discharge their com bined terminal voltage falls slightly At 10V they may be regarded as dangerously flat The voltage and hence charge is monitored by three sections of quad op amp IC3 configured as comparators All three inverting inputs pins 2 6 and 9 are connected together and are set at 5V by voltage reference IC2 Resistor R10 limits the current flow though IC2 to ensure its correct operation The non inverting inputs pins 3 5 and
17. 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 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 Ed el ret reri pe red per pel perd
18. If the crossing detector shows that a person is a slow walker the green time on the crossing is automatically extended Motorists at crossings benefit too One is only too familiar with the exasperating situation of being stopped at a pedestrian crossing when there is no one wanting to cross The pedestrian had pressed the crossing button and subsequently decided not to cross or managed to cross during a lucky break in the traffic With SCOOT the sensors detect that the person is no longer waiting and the call is cancelled BY THE HOADSIDE The photograph shows the inside of one of those boxes that stand on the pavement at traffic junctions The box has been opened which fact will have been noted in the log so that we can see 1 the SCOOT detector This one reads data from four inductive loops placed in the road at the four exits from the junction At 2 there are the circuits for the induc tive loops on the approaches to the junction Data from 1 and 2 are relayed to the con trol room through the OTU which is item 3 in the photograph Below at 4 is the rack holding the processor cards of the local junction computer Its power supply is to the right of this Below the computer and out of sight in the photograph is the power supply for the signal lamps These are 24V lamps and receive their supply from a transformer working on the 230V a c mains The system incorporates a photosensor that detects low ambient ligh
19. Ltd 40 42 Cricklewood Broadway London NW2 3ET Tel 020 8452 0161 Fax 020 8208 1441 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 meas ures 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 identifying mark on case Test leads and handbook included Offered at a fraction of original price 47 50 p amp p 6 50 A DIGITAL HANDHELD LCR METER Measuring inductance capacitance and resistance 3 5 digit 1999 count l c d display inductance range 2MH to 20H capac itance range 2000pF to 200uF resistance range 2002 to 20 megohms Brand new and boxed with test alligator clip leads and user manual 44 3 p amp p VARIABLE 0 15V D C OUTPUT 3 amp continuous 1 stability Digital readout Attractive cabinet 29 x 126 x 164mm 39 50 Carriage 6 50 MAGNETIC CREDIT CARD READER Keyboard and laptop display system Point of sale unit Cost over 150 our price 12 50 carriage 6 50 Two units for 35 including carriage To be used for experimental purposes only No info HEAVY DUTY 80 WATT SOLDERING IRONS Extra long life Mains input Bargain price 11 95 P amp P 4 BOOKS ELECTRIC UFOs by Albert Budden A chilling exposure of electromagnetic
20. MC14093BCP 8 12 Fig 3 Circuit diagram for the Solar Powered Bird Scarer Component numbering continues on from the power supply regulator published in the July 01 issue As with the Gate Sentinel the low frequen cy oscillator Cla modulates the high fre quency oscillator IC1c and the piezo disc WDI is operated in push pull fashion for maximum volume by IC1c and IC1d An npn phototransistor TR3 is used to switch off the two oscillators in the dark ness and this should be mounted away from any night time light sources A photo transistor is used because of its high dark resistance so that it consumes less power in this position than many other devices would do The Bird Scarer is located at the centre of the area which you would like to pro tect from birds preferably tucked away among some leaves The solar panel should of course be positioned to receive full sunlight CONSTRUCTION The Solar Powered Bird Scarer is built up on the Uniboard p c b as shown in the topside component layout details of Fig 4 together with copper foil master This board minus Left Completed Bird Scarer Uniboard p c b It also includes the compo nents except the solar cell for the Solar Powered Power Supply and Regulator from the July 01 issue COMPONENTS BIRD SCARER Resistors R5 2M carbon See film D R6 R7 R9 22M metal S film 3 off R8 4M7 carbon TALK film page All 0 25W 5 or better
21. Mike was apologising for the inclusion of the PLC article in that edi tion Well he need not be so concerned I for one found it useful PLC control is making its way into the AS level syllabus as is PIC programming and the usual electronics As a Systems and Control teacher I found the PLC article very useful as it gives details of practical solutions I have a PLC to demonstrate with although Ladder Logic rep resented on its small l c d display is a little diffi cult to cope with Be encouraged with the PIC articles too We recently bought PIC Logicator as reviewed by Robert Penfold in Nov 00 and I was pleased to help one of my A Level students to hopefully success with his major project He programmed his work in MPASM including serial in out at 9600 baud with a PICI6F84 Without the encouragement of EPE I am sure we d still be using huge circuit boards and major logic networks Much of our school s work is on the technology department s website at www roul son net techweb and I feel that many would find the site worth a visit Ivan Roulson The King s School Ottery St Mary Devon via the Net Mike says that he was simply pointing out that we do not feel we can go more deeply into how PLCs work It is interesting to learn that they are part of the AS level syllabus Thank you for your observations LOW VOLTAGE PCs Dear EPE I have recently invested in a pre assembled PIC Tutorial Mar May 98 board and have
22. Receiver 150kHz 30MHz Brooadcast FM unused FARNELL AMM255 Automatic Mod Meter 1 5MHz 2GHz unused H P 3310A Function Gen 0 005Hz 5MHz Sine Sq Tri Ramp Pulse FARNELL LFM4 Sine Sq Oscillator 10Hz 1MHz low distortion TTL output Amplitude Meter 125 H P 545A Logic Probe with 546A Logic Pulser and 547A Current Tracer 0 FLUKE 77 Multimeter 3 2 digit handheld FLUKE 77 Series 11 RACAL 9008 Automatic Modulation Meter AM FM 1 5MHz 2GHz ONLY H P 8494A Attenuator DC 4GHz 0 11dB N SMA H P 8492A Attenuator DC 18GHz 0 6dB APC7 95 MANY OTHER ATTENUATORS LOADS COUPLERS ETC AVAILABLE DATRON 1061 GD HIGH QUALITY 5 DIGIT BENCH MULTIMETER True RMS 4 wire Res Current Converter IEEE TIME 1051 LOW OHM RES BOX 0 01 ohm to 1Mohm in 0 01 ohm steps GD UNUSED GENERATOR 80 kHz 1040MHz NOW ONLY MARCONI 893B No Sinad MARCONI 2610 True RMS Voltmeter Autoranging 5Hz 25MHz GOULD J3B Sine Sq Osc 10Hz 100kHz low distortion AVO 8 Mk 6 in Every Ready case with leads etc Other AVOs from GOODWILL GVT427 Dual Ch AC Millivoltmeter 10mV 300V in 12 ranges Freq 10Hz 1MHz 100 125 SOLARTRON 7150 DMM 61 digit Tru RMS IEEE 95 150 SOLARTRON 7150 Plus RACAL TRUE RMS VOLTMETERS 9300 5Hz 20MHz usable to 60MHz 10V 316V 9300B Version 9301 9302 RF Version to 1 5Hz HIGH QUALITY RACAL COUNTERS 9904 Universal Timer Counter 5OMHz 9916 Counter 10Hz 520MHz 9918 Counter 10Hz 560MHz 9
23. Sound Effect e Intruder Alarm Control Panel Part 1 e Sound Trigger e EPE Snug Bug Pet Heating Control Centre FEATURES e The Schmitt Trigger Part 6 e Practically Speaking e Ingenuity Unlimited e Circuit Surgery e Net Work The Internet Page e FREE supplement An End To All Disease MAY 01 PROJECTS e Camcorder Mixer e PIC Graphics L C D Scope D C Motor Controller e Intruder Alarm Control Panel Part 2 FEATURES e The Schmitt Trigger Part 7 e Interface e Circuit Surgery Ingenuity Unlimited e New Technology Update e Net Work The Internet Page JUNE 01 PROJECTS e Hosepipe Controller e In Circuit Ohmmeter e Dummy PIR Detector e Magfield Monitor FEATURES e Controlling Jodrell Bank e PIC1687x Extended Memory Use e Practically Speaking Ingenuity Unlimited e New Technology Update e Circuit Surgery e Net Work The Internet Page JULY 01 PROJECTS e Stereo Surround Sound Amplifier e PIC to Printer Interface e Perpetual Projects 1 Solar Powered Power Supply and Voltage Regulator e MSF Signal Repeater and Indicator FEATURES e The World of PLCs e Ingenuity Unlimited Circuit Surgery e New Technology Update e Net Work The Internet Page PROJECTS e Digitimer e Lead Acid Battery Charger e Compact Shortwave Loop Aerial e Perpetual Projects 2 L E D Flasher Double Door Buzzer FEATURES e Controlling Power Generation e Ingenuity Unlimited Interface e Circuit Surgery e New Techn
24. a problem I can t re program the PIC on it The SPECIAL OFFERS a TEKTRONIX 2445A 4 ch 150MHz delay cursors etc Supplied TAH with 2 Tektronix probes irn ak B sz MARCONI 2019A installation has been followed correctly yet the PIC continues to run the TUTTEST program as pre loaded by Magenta I have checked the soft ware installation power supply and PC printer port register correctness and I have tested that the pins can correctly change their logic levels although the voltage for Logic 1 is around 3 35V for both the pins 12 and 13 dropping back cor rectly to OV The 12V programming voltage has been checked and is found to be 11 8V d c The computer I am using is a Gateway Pentium III running Windows 98 but the PIC software still refuses to work when the computer is booted straight into DOS mode Alan Whailin via the Net In his lengthy letter Alan gave a lot of detail about the tests he had run the above is merely a summary The programming voltage being at 11 8V should be no problem I ve programmed PICs with a Vpp as low as 9V Alan s reference to 3 3V gave me the answer though it certainly was too low A num ber of computers being released now output this lower voltage and for this reason Microchip have introduced a variant of the PICI6F84 that will handle these lower voltages namely the PICI F84A I said as much to Alan who replied Thanks for your help The problem was as you
25. after some eleven years My original qualifications were in power engineering and I have always wanted to be able to troubleshoot down to component level and only at the age of 63 when I had to leave the North Sea because of ill health did I get a suitable opportunity I signed up for a City and Guilds diploma in Digital Electronics and Computer maintenance The course was excel lent but I found that I was the only one there of my own volition everyone else had been sent by the DSS And much as I applaud the Government for giving others and me the opportunity forcing people to sign up for courses is not the way to train specialists As a final point one chap who was indeed very good actually found work Making installing and fault finding computer systems He was offered a derisory wage of 150 and he was told that the DSS could give him extra to bring him in to the level at which he was then receiving from the DSS He would have had to travel buy meals etc look after his disabled wife and incur the entire extra costs involved in accepting the position Needless to say he is still unemployed I would suggest that it is not that the DSS payments are too high but the rewards for working are too low We do our selves no good by being a low wage economy Jim from Derby via the Net Jim for once I am lost for words other than to say that it is hard not to feel very despon dent about the way in which technology and its employme
26. 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 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 o
27. difference of the two signals on playback you get the true surround signal plus unfortunately any component not com mon to the original left and right signals There is no simple analogue signal processing that can eliminate this Returning to the project for most home instal lations if the reader already has a stereo setup the use of an additional amplifier is entirely unnecessary Exactly the same effect can be achieved by wiring an additional loudspeaker system to the hot outputs of the power ampli fier ignoring the ground connection With respect to the rear speakers the amplifi er is then operating in bridged mode but the phase inversion usually required for bridged mode is inherent in the recording itself This wiring method works because almost all stereo amplifiers use a common speaker ground con nection for both channels If the stereo system normally uses 802 loud speakers then a pair of rear speakers also rated 8Q and wired in series to present 16Q to the bridge amplifier provides a more or less cor rect sound volume in relation to the front speak ers The rear speakers should not be wired in parallel but in series and in the same phase If the surround volume is too high and the ambi ence effect intrusive a large 10W or so resistor or rheostat of around 8Q to 16 can be inserted to correct this The added load on the amplifier shouldn t be a problem to any self respecting commercial hi
28. digit SOLARTRON 7045 BENCH MULTIMETER 4Ye Digit bright l e d with leads It s so cheap you should have it as a spare MARCONI TF2015 AM FM sig gen 10 520MHz 175 RACAL 9008 Auto Mod Meter 1 5MHz 2GHz 200 LEVELL TG200DMP RC Oscillator 1Hz 1MHz Sine Sq Meter battery operated batts not supplied FARNELL LF1 Sine Sq Oscillator 10Hz 1MHz 75 RACAL AIM 9343M LCR Databridge Digital Auto measurement of R C L Q D HUNTRON TRACKER Model 1000 H P 5315A Universal Counter 1GHz 2 ch FLUKE 8050A DMM 4 2 digit 2A True RCS FLUKE 8010A DMM 312 digit 10A STEWART of READING 110 WYKEHAM ROAD READING BERKS RG6 1PL y 5 Telephone 0118 9268041 Fax 0118 9351696 Callers welcome 9am 5 30pm Monday to Friday other times by arrangement Everyday Practical Electronics October 2001 H P 8657A Synth sig gen 100kHz 1040MHz H P 8656B Synth sig gen 100kHz 990MHz H P 8656A Synth sig gen 100kHz 990MHz 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 8903A Distortion Analyser WAYNE KERR 3245 Inductance Analyser H P 8112A Pulse Generator 50MHz 1 DATRON AutoCal Multimeter 512 7Y2 digit 1065 1061A 1071 from 300 600 MARCONI 2440 Frequency Counter
29. diode D3 which gives reverse polarity protection to the 12V input Diodes D3 and D4 also provide isolation between the two input sources so that current from one cannot possibly drain into the other Light emitting diodes D1 Mains and D2 12V draw current direct from their SK1 PL1 12v e 230V a c MAINS IN SK1 PL1 ov Ce C2 ZRB500Y03 5V0 REF respective supply with current limiting effected by resistors R1 and R2 CHARGING VOLTAGE The rectified voltage at Cl is fed to the input pin 1 of voltage and current regula tor IC1 This is configured to provide the correct output voltage to charge the battery pack A voltage higher than that required appears at the output pin 5 Current then flows through three resistors all labelled R3 connected in parallel and the excess voltage is developed across them This forms the current limiting aspect of the regulator If the current tends to rise the voltage across resistors R3 will increase Pin 2 senses this change and turns down ICI to reduce it With a battery in a poor state of charge the difference between its own voltage and that of the charger output is significant and this drives current through the battery Without current limiting the current would be quite high due to the very small resistances involved and could be destruc tive to circuit components or to the batter ies themselves R3 2 Oja 1O The as required voltage is obtai
30. fact it attached itself to a quarter megabyte file which took an eternity to fetch via the EN EIE 726 Symantec s Sircam Removal Tool a familiar sight for all too many mobile which wasn t quite the flying start to mobile communica tions I had hoped for Sad to say Sircam finally found its way onto my new laptop costing me quite a few pounds in phone charges in the process Somehow or other an infected file was opened accidentally Call it lack of familiarity with Outlook Express Symantec Anti Virus did a good job of isolating the worm but what it could not do was repair any infected files In the case of my new laptop Sircam attached itself to two files stored in the restore folder of Windows ME and only by disabling the System Restore function could the infected files be quarantined losing them in the process Back to the desktop PC system then by now Sircam worms were being picked off every few hours but due to an oversight lasting several ohno seconds I accidentally double clicked an offending filename a single push of the mouse roller actually instead of scanning it and with one bound Sircam was free to roam around my network Naturally I was kicking myself at this point but I supposed that if NASA could crash a satellite into the surface of Mars due to an unfortunate mix up over units of measure ment then mere mortals like myself would double click an infected filename occasionally At least that
31. fi amplifier Most of these are rated for 82 but can happily drive a 4 2 load without stress except at close to their clipping threshold when they might overheat Because very little bass information comes through the surround channel bass is usually mono d at the recording stage that used to be done to make LPs more trackable but they seem to still do it on CDs the surround speak ers can be of a considerably lower power hand ling capacity than the front speakers Since directional hearing doesn t work at bass fre quencies this bass mono characteristic is never a problem The exception is THX videodiscs some of which carry a very large bass dispari ty component watch out for distortion or overloading I have been using this technique on a ReVox B250 and a Teac A70 amplifier for over 10 years in a home environment and have never had any overheating In fact the overall sound quality provided by this setup far exceeds that of a big brand name amp I unfortunately bought with its in board Dolby Pro Logic and multitude of dig itally sampled surround modes David Tilch M Sc via the Net Thank you for the interesting information We are pleased to share it with readers Tal RADIO POWER Dear EPE I found both the Mechanical Radio April 99 and L E D Torch Oct 00 very interest ing but wondered if some readers would be put off by having to build the generator My local electronics shop sells old fashione
32. inserting 3 TRIACs Adjustable rotation speed amp direction PCB 54x112mm 1026KT 15 95 BOX for mains opera tion 2026BX 9 00 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 28 95 FAX 07092 203496 scm Im ANIMAL SOUNDS Cat dog chicken amp cow Ideal for kids farmyard toys amp schools SG10M 5 95 3 1 2 DIGIT LED PANEL METER Use for basic voltage current displays or customise to measure temperature light weight movement sound lev els etc with appropriate sensors not supplied Various input circuit designs provided 3061KT 13 95 IR REMOTE TOGGLE SWITCH Use any TV VCR remote control unit to switch onboard 12V 1A relay on off 3058KT 10 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 12 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 52 95 PRODUCT FEATURE COMPUTER TEMPERATURE DATA LOGGER PC serial port controlled 4 channel temperature meter either deg C or F Requires no external power Allows cont
33. 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 REGULAR SUPPLEMENTS Unlike a book or encyclopedia these Manuals 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 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 Manuals RESPONDING TO YOUR NEEDS You can also contact the editors directly in writing if you have a specific technical reguest or guery We are able to provide you with the most relating to the Manuals important and popular up to date features in our b s ee ee N N PLEASE send me VEA ORDER cian pec imply complete and return t e order form with your THE MODERN ELECTRONICS MANUAL plus a FREE SUPPLEMENT payment to ihe TONoWINg address I I Wimborne Publishing Ltd Dept Y10 408 Wimborne E
34. 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 REF 651 581 150W Continuous 12V 36 39 651 578 150W Continuous 24V 36 39 651 582 300W Continuous 12V 50 64 651 585 300W Continuous 24V 50 64 651 583 600W Continuous 12V 101 59 651 593 600W Continuous 24V 101 59 651 587 1000W Continuous 12V 177 18 651 597 1000W Continuous 24V 177 18 651 602 1500W Continuous 12V 314 52 651 605 1500W Continuous 24V 314 52 651 589 2500W Continuous 12V 490 54 p 651 599 2500W Continuous 24V 490 54 AREE UY OWN1S 651 583 600W VERSION Many uses include Fetes Fairgrounds Airshows Picnics DEL Be ERG ES OCR oeecl E Ps Camping lt Caravans Boats Carnivals Field Research and Amateur ETC PRICES ARE INCLUSIVE OF V A T SALES COUNTER VISA Radio field days Powering Desktop amp Notepad Computers AND ACCESS ACCEPTED BY POST PHONE OR FAX OR EMAIL Fm US AT SALES BKELEC COM ALTERNATIVELY SEND CHEQUE 7 B K ELECTRONICS OR POSTAL ORDERS MADE PAYABLE TO BK ELECTRONICS For Full Specifications View our web site at FAX 44 0 1702 420243 PLA AL A CAR en etel HAI an En An Everyday Practical Electronics October 2001 705 SWITTE UNIT 1 COMET WAY SOUTHEND ON SEA ESSEX SS2 6TR TEL 44 0 1702 527572 New fechnology Update CCELERO
35. my powers of learning are some what diminished or as I tell my colleagues after 45 years of cramming my brain with information it is full and cannot take anymore Trevor Wilson Aberdeen via the Net Well Trevor one of my colleagues suggests that from time to time we should all have a half price clearance sale of any no longer required mental information thus making room for more a sort of defrag in computing terms The trouble is you never really know what might become useful and personally I d hate to discard anything Perhaps evolution might one day give us the equivalent of disk data compression without having to increase our brain size But there are many examples of people in excess of 50 years taking up adult education and acquiring new skills and knowledge And look at all those PIC projects I ve designed they re from a brain considerably more ancient than yours and which still loves the challenge of software Whatever your age don t ever think that you are past learning GOULD OS 300 Dual Trace 20MHz Tested with Manual TEKTRONIX 2232 Digital Storage Scope Dual Trace 100MHz 100M S with probes 525 H P 54501A Dig Oscilloscope 100MHz 4 Ch 425 H P 3312A Function Gen 0 1Hz 13MHz AM FM Sweep Tri Gate Brst etc 300 FARNELL Dual PSU XA35 2T 0 35V 0 2A Twice QMD I c d Display 180 CIRRUS CRL254 Sound Level Meter with Calibrator 80 120dB LEQ 150 EDDYSTONE 1002
36. of applications programs hardware add ons etc The main difficulty for the uninitiated is deciding on the specification that will best suit his or her needs PCs range from simple systems of limited capabilities up to complex systems that can happily run applications that would have been considered beyond the abilities of a microcomputer not so long ago It would be very easy to choose a PC system that is inadequate to run your applications efficiently or one which goes beyond your needs and consequently represents poor value for money This book explains PC specifications in detail and the subjects covered include the following Differences between types of PC XT AT 80386 etc Maths co processors Input devices keyboards mice and digitis ers Memory including both expanded EMS and extended RAM RAM disks and disk caches Floppy disk drive formats and compatibility Hard disk drives including interleave factors and access times Display adaptors including all standard PC types CGA Hercules Super VGA etc Contains everything you need to know if you can t tell your EMS from your EGA Order code BP282 5 45 270 pages 128 pages Everyday Practical Electronics October 2001 Theory and Reference Bebop To The Boolean Boogie By Clive call me Max Maxfield Specially imported by EPE Excellent value An Unconventional Guide to k Electronics Fundamentals Lal Components and Processes This boo
37. of hours Fortunately for the engi neer this can be done through a remote link to a PC in the engineer s own home 12m Controller m INDEPENDENT LIGHTS It makes sense for the signal lights situ ated in the more remote parts of Norfolk happily there are still a few such parts to be independently controlled A single road junction might have the layout shown in Fig 1 Vehicles approaching the junction are detected by inductive loops Essentially an inductive loop is a loop of cable embedded just beneath the road surface The loop is connected into an a c bridge circuit set up to measure the self inductance of the loop This changes when a massive ferromagnet ic object such as a vehicle is situated above the loop Changes in inductance change the input to the control computer that is located beside the road junction Information from the inductive loops can tell the computer the length of the traffic queue at the lights and also the speed and approximate size of vehicles approaching the lights The com puter is programmed to read this data and to use it to decide which lights are to be switched to GO and which to STOP and for how long In the centre of a small town there may be two sets of lights with a link road join ing them Each junction has its own inde pendent set of inductive loops traffic lights and computer However their programs are designed so that the action of the two computers is coord
38. or 0 10V 8 bit 20mV step All components provided including a plastic case 140mm x 110mm x 35mm with pre punched and silk screened front rear panels to give a professional and attractive finish see photo with screen printed front amp rear panels supplied Software utilities amp programming examples supplied Description 3093KT PC Data Acquisition amp Control Unit __inc VAT ea Assembled 3093 124 95 See opposite page for ordering information on these kits Everyday Practical Electronics October 2001 Number ABC Mini Hotchip Board Currently learning about microcontrollers Need to do something more than flash a LED or sound a buzzer The ABC Mini Hotchip Board is based on Atmel s AVR 8535 RISC technology and will interest both the beginner and expert alike Beginners will find that they can write and test a simple program using the BASIC programming language within an hour or two of connecting it up Experts will like the power and flexibility of the ATMEL microcontroller as well as the ease with which the little Hot Chip board can be designed in to a project The ABC Mini Board Starter Pack includes just about everything you need to get up and experimenting right away On the hardware side there s a pre assembled micro controller PC board with both parallel and serial cables for connection to your PC Windows software included on CD ROM features an Asse
39. or E mail chevet globalnet co uk regarding the availability of the DF91 valve used in the 2 Valve SW Heceiver project We were informed that it is becoming in short sup ply they only have two in stock at present but gave us some equivalents i e IT4 W17 CV785 and CV197 We have not been able to check these out You could also try contacting Bull Electrical 0871 871 1300 Cricklewood 020 8452 0161 J amp N Factors 01444 881965 or Greenweld 01277 811042 who may be able to help For the tuning capacitors we suggest you also contact the above companies plus Mainline Surplus Sales 0870 241 0810 who sometimes have these components on special offer including the cheaper solid dielectric transistor radio types mentioned in the article A small mains transformer was used for the audio output transformer and one with a high step down ratio is needed to give good results One with 3V OV 3V secondary windings was found to give the best results and was pur chased from Maplin amp 0870 264 6000 or www maplin co uk code YN12N Note the full secondary winding is used the centre tap not being required The above company also supplied the aluminium case code XB68Y open style 6 35mm mono jack socket code HF91Y and the 4 7mH r f choke for inductor L3 code UK8OB Perpetual Projects 4 Gate Sentinel Solar Powered Bird Scarer and Register As pointed out in previous parts of the Perpetual Projects and this final i
40. or a burn proof silicon lead WI has been manufactured in the UK ua 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 ANTEX NOT JUST ANY OLD IRON YOU CAN NOW BUY ANTEK EOUIPMENT ON LINE WwWW antex co uk Everyday Practical Electronics October 2001 Regular Clinic CIRCUIT SURGERY ALAN WINSTANLEY and IAN BELL 5 Out consultant troubleshooters take a look at basic heatsink calculations this month AST month we outlined some of the basic considerations related to the power and heat dissipated by components Without doubt some parts e g mains transformers can become very hot indeed even in normal operation especially if they are mounted on plastic cases which don t dissipate heat very well at all Hopefully adequate ventilation will be available to help with the throughflow of air Obviously bolting such parts to a steel or aluminium chassis will help dissipate heat The point was made last month that heatsinks are often necessary on certain devices regulator chips or power transis tors for example but if the heatsinks become very hot it s usually just a sign that the heatsink is doing its job of conveying heat from the regulator If the heatsink sys
41. power required of it Also note that reg ulator IC4 may require a heatsink at high er input voltages and output currents CONSTRUCTION Printed circuit connection and tracking details are shown in Fig 6 This board is avallable from the EPE PCB Service code 319 It is suggested that you assemble the board in order of wire links don t forget the one underneath IC3 1 c sockets and the other components in order of size or convenience Thoroughly check the board for assem bly errors before inserting the d i l devices and applying power Next check the powered board with only regulator IC4 in converter IC1 inserted as well From then fully populate with the other i c s and a chosen PIC type a PICI6F84 is suggested at this time Only one PIC should be inserted at any one time The rest is up to you and your comput er either using your existing DOS based Toolkit V2 4 software or migrating to the exciting new Toolkit TK3 for Windows software described next month s Supplement May your programming dreams be fulfilled ACKNOWLEDGEMENT The author thanks Andy Flind for suggestions regarding some of the p c b facilities included with Toolkit Mk3 type for example as used in the EPE Teach In 2000 series of Nov 99 to Oct 00 This allows additional components to be breadboarded alongside the Toolkit Mk3 board for extended circuit develop ment use Connections between the two boards can be made via solid core con
42. projects marked with an asterisk are available on 3 5 inch PC compatible disks or free from our Internet site The following disks are available PIC Tutorial Mar May 98 issues PIC Toolkit Mk2 V2 4d May Jun 99 issues EPE Disk 1 Apr 95 Dec 98 issues EPE Disk 2 Jan Dec 99 EPE Disk 3 Jan Dec 00 EPE Disk 4 Jan 01 issue to current cover date EPE Teach In 2000 EPE Interface Disk 1 October 00 issue to current cover date 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 Project Quantity Price cheque PO in sterling only to VISA Everyday D esses Practical Electronics E Switch Issue No MasterCard Amex Diners Club Visa or Switch Minimum order for cards 5 Card No Signature Card Exp Date 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 shopdoor htm 745
43. requires some additional anchor points for the components These points are provided by a five way tagstrip mounted on the underside of the chassis just to the rear of the two valveholders Note that the centre tag connects to the chassis via the tagstrips mounting bracket and that it can only be used as a chassis Earth OV con nection point Sockets SK1 to SK3 are mounted on the rear panel of the chassis as is L4 if it is used Transformer T1 is mounted on the right hand side panel and the plastic hold er for B5 is glued or bolted to the left hand side panel A couple of holes about 3mm or 4mm in diameter are drilled in the top panel of the chassis just in front of the valveholder for V2 These enable the com ponents above the chassis to be wired to the main assembly on the underside 717 TO L2 4 SK1 SK4 Fig 4 Interwiring details between the valve bases and underside components The metal chassis forms the common earth OV connection via the solder tags and centre mounting tag of the 5 way tagstrip Pin 4 of valveholder V1 is used as an anchor point for C1 and socket SK2 WIRING UP All the interwiring on the underside of the chassis is shown in Fig 4 which should be used in conjunction with Fig 3 and Fig 5 The latter shows the connections to VC1 and VC2 and is correct for most miniature solid dielectric components With other types or different styles of solid dielectric capacitor it may be neces
44. said the voltage was too little to program the PIC As I don t live near a supplier I decided to try out a circuit to take the printer pin voltages from my computer 3 3V and change them to 5 0V I placed the circuit on stripboard and fitted it to one side of a 25 way D type connector and then connected the other end to the Centronics printer cable An interesting solution but Readers if your PC does only deliver a 3V or so Logic 1 output using the PICI6F84A would seem to be the better option MARCONI 2955 2995A SCHLUMBERGER 4040 MARCONI 2024 Signal Gen 9kHz 2 4GHz MARCONI 2022E Synth AM FM sig gen 10kHz 1 01GHz l c d display etc H P 8672A Synth 2 18GHz sig gen RADIO COMMUNICATIONS TEST SETS BASIC IS EASIER Dear EPE I agree wholeheartedly with Roger Warrington Readout July 01 I too have around 25 years of programming mostly in various dialects of Basic and a little assembler I have also used Visual Basic but prefer Delphi for Windows style programs I too find Basic easier to pick up again especially for one off projects My coding skills are not great but I usually pull through Recently I tried to learn C as a means of programming PICs because I needed to time the reactions of various components in a fast moving machine and thought Basic might be a bit slow Unfortunately I hardly got off of the starting blocks partly because of problems with the environment I was using but mainly because at the age of 50
45. stage 15 Watts RF power on the air 88 108MHz Accepts open dipole Ground Plane 5 8 J or YAGI antennas 12 18VDC PCB 70x220mm SWS meter needed for alignment 1021KT 99 95 SIMILAR TO ABOVE BUT 25W Output 1031KT 109 95 STABILISED POWER SUPPLY 2 30V 5A As kit 1007 above but rated at 5Amp Requires a 24VAC 5A transformer 1096KT 27 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 2011BX 7 00 CAR ALARM SYSTEM Protect your car from theft Features vibration sensor courtesy 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 2019BX 8 00 6 PIEZO SCREAMER 110GB 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 10 95 COMBINATION LOCK Versatile electronic lock comprising main circuit amp separate keypad for remote opening of lock Relay supplied 3029KT 10 95 ULTRASONIC MOVEMENT DETECTOR Crystal locked detector frequency for stability amp reliability PCB 75x40mm houses all components 4 7m range Adjustable sensitivity Output w
46. tem has been correctly designed it will prevent the semiconductor junction from exceeding the manufacturer s maximum temperature rating Although a wide variety of parts e g 3 pin regulators have built in thermal over load protection relying on this feature is not a good way of compensating for the use of inadequate heatsinking thermal cycling between extremes of temperature may ultimately stress the device leading to premature failure over time A TO 3 can style regulator sawn off to reveal the i c chip inside 698 Thermal Resistance In this month s Circuit Surgery we describe the basic procedure for selecting the correct heatsink for a device The idea is to carry heat away from the part that matters most the semiconductor junction Or i c die Just as electric current flows through a conductor heat flows from a semiconductor chip to the outside ambient air also through a path of conductors air metals and alloys which carry the heat away through a thermal conduction action Hence anything getting in the way of this path adds to the system s overall thermal resistance preventing the heat from being conveyed so efficiently Thermal resistance is measured in C Watt it indicates how much the tem perature will increase across a thermal resistor for a given power dissipation A large expensive heatsink rated at 1 C W increases temperature by only one degree per watt of power dissipated
47. to 20MHz or one step at a time Full emulation means that all I O ports respond exactly and immediately reading and driving external hardware Features include Reset Halt on external pulse Set Breakpoint Examine and Change registers EEPROM and program memory Load program Single Step with display of Status W register Program counter and user selected Watch Window registers KIT 900 34 99 POWER SUPPLY 3 99 STEPPING MOTOR 5 99 EPE PIC Tutorial At last A Real Practical Hands On Series e Learn Programming from scrach using PIC16F84 e Start by lighting 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
48. to build the Camcorder Power Supply project The specification of diode D10 and capacitor C8 is especially important The diode BYW80 used in the prototype is a high speed fast recovery type capable of handling 8A and was purchased from Farnell 0113 263 6311 or www farnell com code 366 705 It is also listed by Maplin amp 0870 264 6000 or www maplin co uk code AH57M You will also need a semiconductor insulating kit to electrically isolate the device from the small fabricated alu minium 15mm x 40mm heatsink Capacitor C8 must have a low impedance at 100kHz and a minimum work ing voltage of 50V d c A Rubycon YXF series capacitor 2 off ordered from Farnell see above code 580 612 was used in the prototype They can only be ordered in multiples of five minimum The same company also supplied the ZRB500Y03 5V voltage reference code 302 4210 and the Newport high current 150uH 4A inductor code 432 040 The printed circuit board is available from the EPE PCB Service code 318 see page 745 PIC TOOLKIT Mk3 Most items for the PIC Toolkit Mk3 are RS components and can be ordered through any bona fide stockist including some of our advertisers If you have a credit card you can place an order with RS on 01536 444079 or through their web site rswww com The MAX662CPA charge pump d c to d c converter chip designed to pro vide 12V at 30mA from 4 5V to 5 5V inputs is currently listed by RS as code 299 575 The rest of the sem
49. was my excuse The day s work came to an abrupt halt offending files such as Sircam32 exe were deleted but when the PC was rebooted Sircam complained about that missing file and crippled the machine When the Sircam files were restored as a workaround the worm jumped in and prevented all other programs Applications from launching so the system was totally paralysed The Whys after the Event Hot footing it to another PC mercifully the Symantec web site www symantec com offered a Sircam removal tool for download This was loaded onto a floppy disk and after running it I was even tually back in business a whole lot wiser A month later I am amazed to see that the Sircam Worm is still being E mailed to me presumably by neophyte Internet users What are the lessons to be learned It should go without saying that up to date anti virus software is crucial Symantec and McAfee www mcafee com are two of the respected brands available Subscribe Do us all a service and pay for the regular downloads to keep your virus definitions up to date Obviously if you don t scan all files on the hoof then all sus picious file attachments should be quarantined for scanning before they are opened As a corporate service MessageLabs www mes sagelabs com offers a 30 day free trial of their service which inter cepts any infected mail en route before it can be delivered Worms and viruses are a fact of Internet life and they will only ev
50. which produces a stream of pulses Their frequency is determined by the value of resistor R15 and capacitor C7 connected in parallel to pin 5 oscillator With the values specified it is about 100kHz 690 COMPONENTS Resistors See R1 R2 R11 to R13 S 2 R16 680 Q 6 off H3 1Q 2 off plus 497 see text R4 R5 1k 2 off R6 91k R7 5k6 R8 R15 4k3 2 off R9 75k R10 6k8 R14 15k R17 4k7 R18 270Q All 0 6W 1 carbon film TALK page Potentiometers VR1 1k min multiturn preset top adjust 5k min multiturn preset top adjust VR2 Capacitors C1 1000u radial elect 25V C2 C3 100n ceramic 2 off C4 100u radial elect 25V C5 33n ceramic see text C6 2u2 radial elect 16V C7 2n2 polystyrene C8 220u YXF series elect 50V 0 12 2 at 100kHz 2 off see text Semiconductors REC1 W005 1 5A bridge rectifier D1 D2 D7 D12 D3 D4 3mm green l e d 4 off 1N5400 3A rectifier diode 2 off 1N5821 3A Schottky diode 2 off D8 3mm yellow l e d D9 3mm red l e d D10 BYW80 fast recovery diode see text D11 5W Zener diode see text IC1 L200CV voltage and current regulator D5 D6 The output appears at pin 7 and is smoothed by inductor L1 in conjunction with twin capacitors both labelled C8 connected in parallel During each pulse current rises relatively slowly in L1 as energy is soaked up to create the mag netic field and charge flows i
51. 03 OV 7 15V CP CP CP CP eeeccc 000606000000000 FN 12 13 14 15 o o IC4 RM1 e tae Sy NIS e ajour TP1 TP2 TP3 TP4 TP5 TP6 k IDA KDS LDS UM wD NDA k EDA DO ov IHG JOOOOODOO ej je e RIR RII RIR e IC8 e 9 9 iS a Ol EN get S R 7 6 5 ama t0 CP24 e 9 e 9 9 9 i e ay e DATA VR2 2 MC D CP23 e 9 o 9 9 9 SS MD CX T5V OV R W ov RB7 RD7 ese Teee we ein RC3 gt ony pu Pu D RD3 sin a zi Ban BREADBOARD EDGE e e e BREADBOARD Fig 6 Printed circuit board component layout and full size master track pattern for PIC Toolkit Mk3 showing positioning of optional breadboard o 6L o JW 11X001 9 i mmp iiiiiii HIP NZ 704 Everyday Practical Electronics October 2001 terminations can be connected to the 0V 5V power lines with the polarity order as required The active switch pins can be connected to any PIC data pin Lastly Fig 5d a 10kQ preset VR3 is provided with its outer connections across the 0V 5V power lines Its wiper can be used to provide a reference voltage to an A to D analogue to digital pin of any PIC that provides A to D conversion the PICIOGFS87x family for instance EXTERNAL BHEADBOARD There are terminal pin connections not electrically connected to anything which allow the p c b to be mounted firmly onto a prototyping breadboard of the same the
52. 10 are connected to points along the potential divider chain which comprises resistors R6 to R9 joined in series across the supply When the voltage at any of these inputs is higher than the reference voltage the comparator s output will be high and its associated l e d D7 to D9 turned on Respectively the turn on voltages for IC3a to IC3c and their l e d s are 10 4V 11 0V and 11 7V The l e d s represent the charge states high D7 green medium D8 yellow and low D9 red As the battery voltage falls so does the voltage at each comparator s non inverting input When the voltage falls below each threshold the relevant output goes low and its associated l e d is turned off If all three l e d s are off the voltage is below 10 4V and the batteries must be charged as soon as possible In use it will be found that high and medium charge are shown for a relatively long time but low charge is shown for only a short period CAMERA VOLTAGE The correct camcorder operating voltage is obtained from the battery supply using switching regulator IC4 Compared with the linear regulator used for charging the batteries the switching type is much more efficient by around 80 per cent or more This allows as much useful energy as pos sible to be squeezed from the batteries and so maximise the camcorder operating time At the same time less waste heat 1s produced The regulator contains an on chip oscil lator
53. 1mm pin header strips 2 pin socket 2 off for crystal and C1 see text solder etc 29 excluding PICs Everyday Practical Electronics October 2001 B a es LLL SE GoESBLELLESECCCSECTELLUCLLIGZS3GGGGGGCC LOOG4 dG GLULLLS S X E SOQO6SEA PEPPERELL Edo 5 8 tte 2 2 a a A B amp amp Ed oa zc od d A d 5 se a Uo os s amp amp a s WS a a m P B E os o5 ik Zo 0 o d od PP m oB m m d B B amp E a GA PRO RP m oe a qe CU mn Pd A p A o onn GAS a GRO e es m RA o onto this header It is the same l c d as supplied with the p c b for PICtutor the CD ROM based PIC Tutorial and development kit If ordering this l c d from Magenta you MUST specify that it is this l c d version required you will otherwise be supplied with a connector less l c d OSCILLATOR COMPONENTS The Mk3 board includes facilities for crystal and RC resistor capacitor oscillator components Crystal X1 is used in conjunc tion with capacitors C8 and C9 It is recommended that a crystal socket is used on the p c b so that a crystal of any required fre quency may be inserted The RC oscillator generation is controlled by capacitor C7 and the total resistance across R11 and preset VR1 It is also recom mended that a p c b socket is used for C7 so that its value can be readily changed as needed Switch S2 allows crystal or RC oscillation mode to be selected It should be noted that the PIC r
54. 2 00 FR15 Prices include base MINI POWER RELAYS For p c b mounting size 28mm x 25mm x 12mm all have 16A changeover contacts for up to 250V Four versions available they all look the same but have different coils 6V Order Ref FR17 12V Order Ref FR18 24V Order Ref FR19 48V Order Ref FR20 Price 1 each less 10 if ordered in quantities of i 10 same or mixed values NOT MUCH BIGGER THAN AN OXO CUBE Another relay just arrived is extra small with a 12V coil and 6A changeover contacts It is sealed so it can be mounted in any position or on a p c b Price 75p each 10 for 6 or 100 for 50 Order Ref FR16 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 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 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 plas tic frame so can t be accidentally touched Price 3 50 Order Ref 3 5P
55. 2 e Automatic Nightlight FEATURES e Teach In 2000 Part 8 Technology Timelines 5 Circuit Surgery e Interface e New Technology Update e Ingenuity Unlimited Net Work The Internet 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 e Ingenuity Unlimited Circuit Surgery PICO DrDAQ Reviewed Net Work The Internet PROJECTS e Handy Amp e EPE Moodloop Quiz Game Indicator e Door Protector FEATURES e Teach In 2000 Part 10 e Cave Electronics Ingenuity Unlimited e Circuit Surgery e Interface e New Technology Update e Net Work The Internet SEPT 00 PROJECTS e Active Ferrite Loop Aerial e Steeplechase Game e Remote Control IR Decoder e EPE Moodloop Power Supply FEATURES e Teach In 2000 Part 11 e New Technology Update e Circuit Surgery Ingenuity Unlimited e Practically Speaking e Net Work The Internet Page OCT 00 PROJECTS e Wind Up Torch e PIC Dual Chan Virtual Scope e Fridge Freezer Alarm e EPE Moodloop Field Strength Indicator FEATURES e Teach In 2000 Part 12 e Interface e Ingenuity Unlimited e New Technology Update e Circuit Surgery e Peak Atlas Component Analyser Review e Net Work The Internet Page NOV 00 PROJECTS e PIC Pulsometer Opto Alarm System e Sample and Hold e Handclap Switch FEATURES e The Schmitt Trigger Part 1 e In
56. 20 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 1 5V 6V MOTOR WITH GEARBOX 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 MINI BLOWER HEATER 1kW ideal for under desk or airing cupboard etc needs only a simple mounting frame price 5 Order Ref 5P23 TERMS Send cash PO cheque or quote credit card number orders under 25 add 4 50 service charge J amp N FACTORS Pilgrim Works Dept E E Stairbridge Lane Bolney Sussex RH17 5PA Telephone 01444 881965 E mail jnfactors aol com Everyday Practical Electronics October 2001 A roundup of the latest Everyday electronics COMMSIM FOR EWB mem mH HII Ha WI 2 E g Tin Lol DEPT Scientific has announced the introduction of Commsim a new product from Electronics Workbench Commsim is a powerful and easy to use Windows based simulation enviro
57. 2001 677 SPECIAL SUPPLEMENT PIC TOOLKIT TK3 FOR WINDOWS The long awaited sequel to Toolkit Mk2 crafted for PIC programming enthusiasts by a PIC programming addict PIC Toolkit TK3 for Windows is the most sophisticated EPE PIC microcontroller code assembler and programmer ever published Designed explicitly for running in the desk top PC environments of Windows 95 and 98 TK3 is intuitively easy to use fast in operation has many extra features that are probably not found elsewhere and is the ideal programming aid for all who love to play with reprogrammable PICs The PIC families catered for are principally the PIC16x84 and PIC16F87x EEPROM based series whose members include C84 F84 F873 F874 F876 and F877 It is likely that TK3 can be used with other PICs that also have 14 bit program codes including F83 F84A and no doubt some other devices Written in Visual Basic 6 TK3 is run as a fully stand alone program and can be used with the new Toolkit Mk3 programming board published in this current issue or with the well established Toolkit Mk2 board of May June 99 TEACH IN 2002 Our new 10 part educational series Teach In 2002 Making Sense of the Real World gives you an insight into the world of sensors More than ever before sensors are being deployed to measure environmental parameters so Teach In 2002 demonstrates what sensors are all about and how to use them effectively Also described are some of the key circ
58. 3 If VScroll4 Value And 32 32 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 16 16 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 8 8 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 4 4 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 2 2 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 1 1 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 Out Prn3 2 Out Prn3 3 Everyday Practical Electronics October 2001 Screen shot of the demonstration program in operation Prnl and Prn 3 are variables that are set at 898 and 890 respec tively earlier in the program These are normally the output addresses for the data lines and handshake outputs of printer port 1 Both values must be changed if you are using a differ ent port or if your PC uses differ ent addresses for port 1 The routine starts by checking the state of bit 7 in the value read from the slider control This is achieved using the normal bit wise AND method Output D0 of the printer port is set high if this bit is at logic 1 or low if it is not The next two lines generate the clock pulse that loads this bit into the shift register The same basic process is then used to check the other bits write the appropriate value to bit Strobe F
59. 4562 E mail orders epemag wimborne co uk Payments must be by card or in Sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order 708 Everyday Practical Electronics October 2001 Special Feature TRAFFIC ONTROL OWEN BISHOP SCOOT systems speed the flow of road traffic and pedestrians hear much about air traffic con W but more important to our daily lives are those relatively inconspicuous systems and people who contro the flow of traffic in our busy cities This article describes how electron ics and computers are used to make their work possible INCONSPICUOUS CONTROL Anyone standing on the pavement out side the Norfolk County Council Urban Traffic Control Centre in Norwich would probably not notice the inconspicuous semi basement entrance Yet behind this door lies the UTCC under the control of a DEC ALPHAstation 255 computer run ning at 300MHz This computer keeps the traffic flowing or at least minimises the delays not only for Norwich city but also for the whole of the county of Norfolk It keeps the pedes trians flowing too for out of the 256 sig nals linked to the system about 50 per cent are pedestrian crossings The control centre is manned during the day but the computer is able to function unassisted during the evenings and night Fortunately for the motorists the computer can call on an engineer to handle emergen cies out
60. 83 565435 Fax 01283 546932 E mail sales 9 magenta2000 co uk Everyday Practical Electronics October 2001 685 ICAL STIRONIES ELECTRONICS TODAY INTERNATIONAL hile No 1 MAGAZINE FOR ELECTRONICS TECHNOLOGY amp COMPUTER PROJECTS Editorial Offices EVERYDAY PRACTICAL ELECTRONICS EDITORIAL WIMBORNE PUBLISHING LTD 408 WIMBORNE ROAD EAST FERNDOWN DORSET BH22 9ND Phone 01202 873872 Fax 01202 874562 E mail editorial epemag wimborne co uk Web Site http www epemag wimborne co uk EPE Online www epemag com EPE Online Shop www epemag wimborne co uk shopdoor htm See notes on Readers Enquiries below we regret lengthy technical enquiries cannot be answered over the telephone Advertisement Offices EVERYDAY PRACTICAL ELECTRONICS ADVERTISEMENTS MILL LODGE MILL LANE VOL 30 No 10 OCTOBER 2001 THORPE LE SOKEN ESSEX CO16 OED Phone Fax 01255 861161 E mail epeads aol com 2002 Two thousand and two is upon us well our Teach In 2002 will be next month It hardly seems any time at all since we were all worrying about how to celebrate the new millenni um and now the numbers have moved on by two Of course regular readers will know that every other year we publish a Teach In series with the intention of providing a wide range of educational material on electronics 77 2002 will be all about interfacing to the outside world and will look in some depth at sensors how they work how to u
61. B Service code 318 Assemble the board in order of compo nent size observing the correct orientation of polarity conscious components Note that the 4 7 ohm 4 27 resistor in the R3 group may need to be changed in value after the unit has been tested to adjust the limiting current To enable this to be done more easily it could be soldered between a pair of solder pins or short wire stalks It would then be a simple matter of de soldering it and replacing it with one of a different value The value of capacitor C5 33n may not be readily available Provision has therefore been made to solder two capacitors in parallel 10n and 22n to give nearly the same value There are different manufactured styles for voltage reference device IC2 Some have three leads instead of two in which case refer to the pin out of the particular device which your component supplier should have available and cut off the unwanted lead Note that IC1 IC2 and IC3 are static sensitive so touch something which is earthed such as a metal water tap before handling their pins FS2 N 8 Cp U PANEL FUSE Leave the test point TPI TP2 link unmade at this time The l e d s can be mounted directly to the p c b with their leads bent at right angles to line up with holes in the case front panel If the leads are too short extension leads can be added as was the case with the prototype A heatsink is needed for diode D10 but not s
62. C allowing you to buy programmes text graphics and sound on a CD It also describes the installation of a CD ROM drive and a sound card pointing out the common problems that arise and then shows how to use them to create a complete multimedia presentation that con tains text photos a soundtrack with your own voice recorded as a commentary even animation and edited video footage Order code PC112 12 95 HOW TO BUILD YOUR OWN PC Morris Rosenthal More and more people are building the own PCs They get more value for their money they create exactly the machine they want and the work is highly satisfying and actually fun That is if they have a unique begin ners guide like this one which visually demonstrates how to construct a state of the art computer from start to finish Through 150 crisp photographs and clear but minimal text readers will confidently absorb the concepts of computer building The extra big format makes it easy to see what s going on in the pictures For non special ists there s even a graphical glossary that clearly illustrates technical terms The author goes under the hood and shows step by step how to create a socket 7 Pentium and non intel chipsets and a Slot 1 Pentium Il computer covering What first time builders need to know How to select and purchase parts How to assemble the PC How to install Windows 98 The few existing books on this subject although badly outdated are in steady dema
63. CES 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 MICROSWITCHES 20mm x 6mm x 10mm changeover contacts pack of 2 Order Ref 826 MAINS RELAY with 15A changeover contacts Order Ref 965 COPPER CLAD PANELS size 7in x 4in pack of 2 Order Ref 973 100M COIL OF CONNECTING WIRE Order Ref 685 WHITE PROJECT BOX 78mm x 115mm x 35mm Order Ref 106 LEVER OPERATED MICROSWITCHES ex equipment batch tested any faulty would be replaced pack of 10 Order Ref 755 MAINS TRANSFORMER 12V 0V 12V 6W Order Ref 811 694 THIS MONTH S SPECIAL IT IS A DIGITAL MULTITESTER complete with backrest to stand it and hands free test prod holder This tester measures d c volts up to 1 000 and a c volts up to 750 d c cur rent up to 10A and resistance up to 2 megs Also tests transistors and diodes and has an internal buzzer for continuity tests Comes complete with test prods battery and instructions Price 6 99 Order Ref 7P29 imA 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 1mm and 0 5mm Price 1 Order Ref 129 BT PLUG WITH TWIN SOCKET Enables yo
64. DERS 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 bank Make cheques payable to Direct Book Service Visa Mastercard Amex Diners Club and Switch orders accepted please give card number card expiry date and Switch Issue No 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 Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail dbs epemag wimborne co uk Online store www epemag wimborne co uk shopdoor htm 724 RADIO 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 EM 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
65. EMBER 2001 ISSUE ON SALE THURSDAY OCTOBER 11 Everyday Practical Electronics October 2001 679 wWwWWWw QuasarElectronics comnm Established 1990 uasaR ELECTRONICS LIMITED Unit 14 Sunningdale BISHOPS STORTFORD Herts CM23 2PA TEL 01279 467799 ADD 2 00 P amp P to all orders or 1st Class Recorded 4 Next day Insured 250 7 Europe 5 00 Rest of World 10 00 We accept all major credit cards Make cheques PO s payable to Quasar Electronics Prices include 17 5 VAT MAIL ORDER ONLY FREE 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 95 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
66. ER 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 52 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 5 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 10 95 DRILL SPEED CONTROLLER Adjust the speed of your electric drill according to the job at hand Suitable for 240V AC main
67. GY FACTS The Department of Trade and Industry has recently sent information on Energy Statistics for period February to April 2001 It is interesting to note that the production of primary fuels such as coal and other solid fuels petrol gas and electricity is actually down by 6 9 per cent compared to the same period last year As to quite how this squares with the 3 9 per cent rise in consumption of the same fuels in that period is unclear pre sumably it means we are importing more For more information browse ww w dti gov energy energystats energystats htm Everyday Practical Electronics October 2001 V92 MODEMS By Barry Fox you are buying a new modem be sure it carries the telltale mark V92 Ready Otherwise you will miss out on the chance to access the Internet more quickly and do so with a single conven tional phone line without blocking speech calls A V92 modem with Quick Connect can halve tiresome logon times Modem on Hold pauses the PC while it is Internet surfing to let the user take an incoming speech call on the same phone line When the talking stops the PC clicks back to the Internet without the need to redial The International Telecommunications Union sets the V standards which ensure that modems round the world talk to each other V90 as now widely used pushes the data capacity of phone lines to their practical limit by receiving at up to 56Kbps and sending at up to 33 6Kbps Becau
68. However the same press and TV could have done everyday Internet users a service by covering a much more troublesome nuisance a plague in the shape of the Sircam worm This nasty little creature bur rows its way towards your Windows Address Book in search of tasty E mail addresses The Sircam worm also has an appetite for comput er files stored on your hard disk it likes to share them with your friends so the worm attaches itself to any one of your files private ones stored in the My Documents folder will do nicely Then using its built in SMTP engine Sircam will E mail the file to all and sundry often without the hapless owner ever knowing Being a gregarious sort of worm Sircam propagates itself using the recipient s address book but as a sup plementary diet Sircam is also said to find E mail addresses lurking in your web browser cache It could also do more severe damage to host computers filling a hard disk with junk and trashing essential files delivering its nasty payload sometime in October In practice Sircam has caused an awful lot of damage easily trouncing ILOVEYOU according to McAfee The Worm has Turned One of the benefits of using a fairly obscure E mail package Turnpike is that it uses a proprietary address book that is immune to Windows address book attacks No worm holes to be found there So what about all those incoming files My first bout of Sircam mania happened in July when strange E mail
69. ICK GUIDE TO ANALOGUE SYNTHESIS Ks lan Waugh Even though music production has moved into the digi tal domain modern synthesisers invariably use ana logue synthesis techniques The reason is simple analogue synthesis is flexible and versatile and it s rel atively easy for us to understand The basics are the same for all analogue synths and you ll quickly be able to adapt the principles to any instrument to edit exist ing sounds and create exciting new ones This book describes How analogue synthesis works The essen tial modules every synthesiser has The three steps to synthesis How to create phat bass sounds How to generate filter sweeps Advanced synth modules How to create simple and complex synth patches Where to find soft synths on the Web If you want to take your synthesiser of the hardware or software variety past the presets and program your own sounds and effects this practical and well illustrated book tells you what you need to know Order code PC118 7 45 60 pages QUICK GUIDE TO MP3 AND DIGITAL MUSIC Ks lan Waugh MP3 files the latest digital music format have taken the music industry by storm What are they Where do you get them How do you use them Why have they thrown record companies into a panic Will they make music easier to buy And cheaper Is this the future of music All these questions and more are answered in this concise and practical book which explains everything you ne
70. KIT 878 22 99 with 16F84 29 99 with 16F877 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 SOFTWARE EXTRA e PCB LEAD ALL COMPONENTS TURNED PIN SOCKETS FOR 18 28 AND 40 PIN ICs e SEND FOR DETAILED Kit 862 29 99 INFORMATION A SUPERB PRODUCT AT Power Supply 3 99 AN UNBEATABLE LOW DISASSEMBLER PRICE SOFTWARE 11 75 PIC STEPPING MOTOR DRIVER INCLUDES PCB Kit 863 18 99 PIC16F84 WITH Pak akah sata a MEN NAN DEMO PROGRAM FULL SOURCE CODE SUPPLIED INSTRUCTIONS ALSO USE FOR DRIVING OTHER AND MOTOR 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 redesigned PCB LCD fits directly on board Use as Data Logger or as a test bed for many other 16F877 projects Kit includes programmed chip 8 EEPROMs PCB case and all components KIT 877 49 95 inc 8 x 256K EEPROMS All prices include VAT Add 3 00 p amp p Next day 6 99 Tel 012
71. LECTRONICS CD ROMS ELECTRONICS CAD PACK PCB Layout Electronics CADPACK allows users to design complex circuit schematics to view circuit animations using a unique SPICE based simulation tool and to design printed circuit boards CADPACK is made up of three separate software modules ISIS Lite which provides full schematic drawing features including full control of drawing appearance automatic wire routing and over 6 000 parts PROSPICE Lite integrated into ISIS Lite which uses unique animation to show the operation of any circuit with mouse operated switches pots etc The animation is compiled using a full mixed mode SPICE simulator ARES Lite PCB layout software allows professional quality PCBs to be designed and includes advanced features such as 16 layer boards SMT components and even a fully functional autorouter C FOR PICMICRO MICROCONTROLLERS C for PlCmicro Microcontrollers is designed for students and professionals who need to learn how to use C to program embedded microcontrollers This product contains a complete course in C that makes use of a virtual C PICmicro which allows students to see code execution step by step Tutorials exercises and practical projects are included to allow students to test their C programming capabilities Also includes a complete Integrated Development Environment a full C compiler Arizona Microchip s MPLAB assembler and software that will program a PIC16F84 via
72. LECTRONICS SERVICE MANUAL plus a FREE SUPPLEMENT Road East Ferndown Dorset BH22 9ND 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 itto also require the appropriate Supplements four times a year These are billed us in good condition within 30 days for a full refund separately and can be discontinued at any time Please delete if not required Overseas buyers do have to pay the overseas postage see below Should decide not to keep the Manual s will return it them to you within 30 days for a full refund POSTAGE CHARGES FULL NAME 5 5 5 2 275 237 ai a EE SE E 203 ae PI a ja A EN Sana E he R4 PAG P i Price PER MANUAL PLEASE PRINT Postal Region Surface Air ADDRESS Jian puman jana ah aal saa Ro Seu Ga sana Te jag ana e aude eden ee edens ra ax Kain tar aa Mainland UK FREE i I Scottish Highlands l m B BOB BOB BOB BON BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB BOB nnn nnn HoONB BOB HOH BOB BOB BOB BOB HON BOB BOB HON HON NH UK Islands amp Eire 5 50 each l l Europe EU 20each l n B B B B B BH H H BH B B B H H EH BH B B BH H H EH BH B B H H H EH BH B B H H H EH BH NH B M M M M POSTCODE m m m B B BH H H H H BH BH NH H M HM Europe Non EU 20 each 26 each USA amp Canada 25 each 33 eac
73. METERS are used in many areas Ao testing Usually their operation depends on a solid mass that is allowed to move under the differing conditions of acceleration and its position monitored to give an indication of the acceleration These devices have a number of disad vantages including the difficulty of manu facturing them and using integrated circuit technology Although in recent years new micro machining techniques have been introduced that allow for accelerometers to be manufactured as integrated items However these processes involve many masks and etching steps in the manufactur ing process Not only is this complicated but it is also very expensive New Development In a new development organised by the American National Institute of Standards and Technology in Gaithersburg in Maryland USA researchers have over come the problems of incorporating an accelerometer into an integrated circuit The idea is based around a concept that has recently been proposed using the effect of acceleration on natural heat convection The device uses heat generated from con ductors that is transferred into the gas sur rounding the device It is hermetically sealed to ensure that it is not influenced by external pressure or airflow The new implementation of this idea uses standard CMOS circuitry and micro machined thermopile or thermistor sensors for temperature sensing In view of this it is possible to have a completely integrated sen
74. MODULAR CIRCUIT DESIGN 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 Essential 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 circuit symbols pinouts power supplies decoupling etc Single User 19 95 inc VAT Multiple User 34 plus VAT UK and EU customers add VAT at 17 5 6 to plus VAT prices Minimum system requirements for these CD ROMs Pentium PC CD ROM drive 32MB RAM 10MB hard disk space Windows 95 98 NT 2000 ME mouse sound card web browser CD ROM ORDER FORM i ORDERING Note The software on each ALL PRICES INCLUDE UK Please send me L Electronic Projects I I i 1 Analogue Electronics Version required version is the same unless I Digital Electronics C Hobbyist Student stated otherwise above only POSTAGE I ur the licence for use varies Filters Institutional 1 L Digital Works 3 0 Institutional 10 user Student Single User Standard Version Electronics CAD Pack Institutional price includes postage to most 1 C For PlCm
75. Overseas 34 50 standard air service 52 express airmail I enclose payment of 2 Years UK 52 00 Overseas 64 00 standard air service cheque PO in sterling only 99 express airmail Diners Club To Everyday Practical Electronics international Payable to Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East z A Ferndown Dorset BH22 9ND VISA mS mUnOCARO Tel 01202 873872 Fax 01202 874562 cared EXER Mastercard E mail subs 9 epemag wimborne co uk i Order from our online shop at www epemag wimborne co uk shopdoor htm My card number S oce se xnccanccecinsatadessnapavictaamemonsdantesqitewoiwessaaacte Please print clearly and check that you have the number correct Signature Card Ex Date Switch Issue No Subscriptions can only start with the next available issue For back numbers see the Back Issues page If you do not wish to cut your issue send a letter or a copy of this form Everyday Practical Electronics October 2001 731 Perpetual Projects 4 GATE SENTINEL THOMAS SCARBOROUGH Be on your guard against unwanted visitors CONCLUDE this month with the Wi part of our four part series of perpetual projects All are based on one small p c b called a Uniboard Each is powered around the clock perpetually by a single high quality memory back up capacitor and a small solar cell no battery Each is desig
76. USICAL DRIVE BY Barry Fox If you are driving along and your car suddenly starts singing you can probably thank Gert van der Merwe of South Africa His international patent filing WO 01 32989 tells how it s done A series of small metal ridges is built into the road like minia ture sleeping policeman speed humps The ridges are around 15mm apart and in a pattern that matches the peaks of a musical waveform So the car vibrates to play a tune If slightly different sets of ridges are formed to the left and right of the road the car vibrates in stereo sympathy The ridges can be temporary on a mat laid on the road alongside an advertising sign to play a matching jingle NRPB VIDEO Mobile Telephony and Health is the title of a 30 minute VHS video produced by NPRP National Radiological Protection Board It provides a timely digestible review of the current state of knowledge about possible health effects of mobile phone hand sets and the associated mobile transmission masts There are documentary style interviews with leading scientists in the field and members of the Independent Expert Group on Mobile Phones whose report was published last year The video has been produced professionally and contains graph ics and other material to illustrate points made For example there are useful graphic sequences showing how mobile phones work what the possible heating effects could be in the head and how people are exposed to transm
77. add a further seven turns of wire cut the wire to leave a lead about 250mm long and then thread the lead through the appropriate hole 3 in the former Try to keep the wire taut with the turns of wire closely bunched together Even with the ends of the winding held in place it is likely that the turns will tend to spring apart slightly but some pieces of tape can be used to hold them in place Use the blade of a penknife or a miniature file to scrape the insulation from the small loop of wire and then tin coat it with solder FEEDBACK WINDING The feedback winding L1 is made in the same way but it has 14 turns and no tapping The feedback winding will look rather large if you are used to semicon ductor radio circuits but valves generally have much higher output impedances than semiconductor equivalents Hence the feedback winding is much larger than it would be for a regenerative set based on transistors The completed coil can be mounted on the chassis vertically or horizontally and the simplest method is to bolt it in place in a horizontal position see photographs However a small gap is needed between the metal chassis and the coil so some spacers must be used between the chassis and the coil former A gap of around 15mm to 20mm is more than adequate SPACERS 32mm DIA TUBE CONSTRUCTION CHASSIS DETAILS Sets of this type traditionally use an open aluminium chassis construction but an outer casing is easil
78. ailable they are an expensive option CIRCUIT OVERVIEW The circuit described here is a high capacity supply with integral charger With the author s camcorder it provides over 11 hours of operation Charging may be effected either from the mains or a 12V d c source such as plugging it into the car cigar lighter socket and takes around 15 to 20 hours to recharge The author s unit is housed in a camera bag large enough to accommodate the connecting leads and various pieces of camcorder equipment On the front panel there are mains and 12V d c input plugs output socket and mode switch This latter toggles between charging CH OFF and camera operation CAM While charging one of a pair of light emitting diodes l e d s indicates whether a mains or 12V supply is connected In camera mode a further l e d operates to confirm the output In addition three charge level lI e d s provide an indication of the state of charge of the battery pack green for high yellow for medium and red for low The unit may be used to power camcorders having an operating voltage between 6V and 9 6V d c If you mea sure it the voltage will be somewhat higher than the stated nominal value when the battery is fully charged Note that a 9 6V output may not be available when the battery pack is in a poor state of charge CURRENT SITUATION The maximum current which may be drawn from the unit 1s 2 5A However for the sake of ba
79. akes life easier for the semiconduc tor it means the overall thermal resistance allowed can be raised to 10 C W A higher ambient 65 C say and you are left with a total value of 6 C W implying a heftier heatsink rating of 2 5 C W What effect would using the smaller TO 220 package have instead The higher thermal resis tance means that a better heatsink would be required There is often the need to compromise somewhere along the line Larger heatsinks are costlier and take up more space imply ing a larger and more expensive cabinet Looking at it another way if a TO 3 device is used on a 2 5 C W heatsink with silicon grease then the maximum permissible ambient temperature allowed is 65 Heatsinks might be mounted on the outside of a box with a lower ambient temperature rather than being fixed within at a much higher temperature All these aspects should be borne in mind by the budding designer Some really purposeful looking heat sinks are available which include 10in diameter fan assisted cooling to lower their thermal resistance to a staggering 0 03 C Watt unfortunately they cost near ly 250 350 without the fan Computer enthusiasts will be well aware of the need to fan cool processor and video chips and a wide variety of very impressive looking processor fans with heatsinks are now available AW CIRCUIT THERAPY Circuit Surgery is your column If you have any queries or comments please write t
80. and 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 Ta ELECTRONICS PROJECTS Electronic Projects is split into two main sections Building Electronic Projects contains comprehensive information about the components tools and techniques used in developing projects from initial concept through to final circuit board production Extensive use is made of video presentations showing soldering and construction techniques The second section contains a set of ten projects for students to build ranging from simple sensor circuits through to power amplifiers A shareware version of Matrixs CADPACK schematic capture circuit simulation and p c b design software is included The projects on the CD ROM are Logic Probe Light Heat and Moisture Sensor NE555 Timer Egg Timer Dice Machine Bike Alarm Stereo Mixer f Power Amplifier Sound Activated Switch Reaction Tester Full parts lists Logic Probe testing schematics and p c b layouts are included on the CD ROM ANALOGUE ELECTRONICS eia o a Analogue Electronics is a complete learning resource 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 circuit
81. aphics L C D Display with PICs Supp Using the LM3914 6 L E D Bargraph Drivers Multi purpose Main p c b Relay Control L E D Display A PC Audio Power Meter Doorbell Extender Transmitter MAR 01 292 Receiver 293 Trans Remote 294 Rec Relay 295 EPE Snug bug Heat Control for Pets APR 01 296 6 50 Intruder Alarm Control Panel Main Board 297 6 97 External Bell Unit 298 4 76 Camcorder Mixer MAY 01 299 6 34 300 5 07 PIC Graphics L C D Scope Hosepipe Controller JUNE 01 301 Magfield Monitor Sensor Board 302 Dummy PIR Detector 303 Ak PIC16F87x Extended Memory Software only Stereo Surround Sound Amplifier JULY 01 Perpetual Projects Uniboard 1 Solar Powered Power Supply amp Voltage Reg MSF Signal Repeater and Indicator Repeater Board Meter Board PIC to Printer Interface Lead Acid Battery Charger Shortwave Loop Aerial Digitimer Main Board R F Board Perpetual Projects Uniboard 2 L E D Flasher Double Door Buzzer Perpetual Projects Uniboard 3 SEPT 01 Loop Burglar Alarm Touch Switch Door Light and Solar Powered Rain Alarm L E D Super Torches Red Main Display Red White L E D Order Code FEB 01 Software only AUG 01 Sync Clock Driver Ak Water Monitor Camcorder Power Supply PIC Toolkit Mk3 Perpetual Projects Uniboard 4 Gate Sentinel Solar powered Bird Scarer and Solar Powered Register EPE SOFTWARE Software programs for EPE
82. 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 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 equip ment in order to get them set up properly Where any set ting up is required the procedures are very straightforward and they are described in detail Projects covered Simple MIIDI tester Message grabber 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 Order code PC116 10 95 124 pages THE INVENTOR OF STEREO THE LIFE AND WORKS OF ALAN DOWER BLUMLEIN Robert Charles Alexander This book is the definitive study of the life and works of one of Britain s most important inventors who due to a cruel set of circumstances has all but been overlooked by history Alan Dower Blumlein led an extraordinary life in which his inventive output rate easily surpassed that of Edison but whose early death during the darkest days of World War Two led to a shr
83. ash in 7 selectable patterns 3037MKT 5 95 LED FLASHER 2 Similar to above but flash in sequence or randomly Ideal for model railways 3052MKT 5 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 22 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 13 95 ATMEL 89Cx051 PROGRAMMER Simple to use yet powerful programmer for the Atmel 89C1051 89C2051 amp 89C4051 uC s Programmer does NOT require special software other than a terminal emulator program built into Windows Can be used with ANY computer operating sys tem 3121KT 24 95 6 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 5 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 16 95 ters can be received on an ordinary VHF FM radio between 88 108MHz Available in Kit Form KT or Assembled amp Teste
84. ashing Snowman Multi project PCB x Video Cleaner FEB 00 251 5 63 Find It 4 20 Ak Teach In 2000 Part 4 High Performance Regenerative Receiver EPE Icebreaker PCB257 programmed PIC16F877 and floppy disc Parking Warning System Micro PlCscope 4 44 icro APR 00 259 4 99 Garage Link Transmitter 261 Receiver 562 sel 5 87 MAY 0O 3 33 3 17 Versatile Mic Audio Preamplifier PIR Light Checker x Multi Channel Transmission System Transmitter Receiver Interface 6 34 Canute Tide Predictor PIC Gen Frequency Generator Counter JULY 00 268 5 07 Q Meter 269 4 36 EPE Moodloop AUG 00 271 5 47 Quiz Game Indicator 272 4 52 Handy Amp 273 4 52 Active Ferrite Loop Aerial SEPT 00 SANA Remote Control IR Decoder Software only X PIC Dual Channel Virtual Scope OCT 00 Lm 5 15 NOV 00 d 96 Software only Handclap Switch PIC Pulsometer Twinkling Star Festive Fader Motorists Buzz Box PiCtogram PIC Monitored Dual PSU 1 PSU Monitor Unit Static Field Detector Multi project PCB Two Way Intercom UFO Detector and Event Recorder Magnetic Anomaly Detector Event Recorder Audio Alarm Using PICs and Keypads DEC 00 JAN 01 Software only Everyday Practical Electronics October 2001 JUNE 99 231 9 51 232 8 79 SEPT 99 241 7 51 242 7 64 JAN 00 250 4 83 932 3 00 JUNE 00 3 05 PROJECT TITLE Ice Alarm Gr
85. ation intercom 10m x 2 core cable sup plied 9V operation 3021KT 15 95 kit form only TRVS TAPE RECORDER VOX SWITCH Used to automati cally operate a tape recorder not supplied via its REMOTE sock et when sounds are detected All conversations recorded Adjustable sensitivity amp turn off delay 115x19mm 3013KT 9 95 AS3013 21 95 700W power PCB 48mm x 65mm Box provided 6074KT 17 95 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 10 95 LED DICE Classic intro to electronics amp circuit analysis 7 LED s simulate dice roll slow down amp land on a number at random 555 IC circuit 3003KT 9 95 STAIRWAY TO HEAVEN Tests hand eye co ordi nation Press switch when green segment of LED lights to climb the stairway miss amp start again Good intro to several basic circuits 3005KT 9 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 6 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 11 95 LED FLASHER 1 5 ultra bright red LED s fl
86. ation published in these materials 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 ISSN 0262 3617 PROJECTS THEORY NEWS COMMENTS POPULAR FEATURES VOL 30 No 10 OCTOBER 2001 Cover illustration by Jonathan Robertson www epemag wimborne co uk EPE Online www epemag com Projects and Circuits CAMCORDER POWER SUPPLY by Terry de Vaux Balbirnie 688 Battery replacement with a lot more bottle PIC TOOLKIT Mk3 by John Becker 700 An enhanced PIC microcontroller programming development board and prelude to next month s exciting new Windows based TK3 software 2 VALVE SW RECEIVER by Robert Penfold 714 A nostalgic and simple design for valve radio enthusiasts INGENUITY UNLIMITED hosted by Alan Winstanley 730 Three way Lighting PERPETUAL PROJECTS 4 by Thomas Scarborough 732 Three more solar powered projects to complete the series Gate Sentinel Bird Scarer In Out Register Series and Features CIRCUIT SURGERY by Alan Winstanley and lan Bell 698 Heatsink calculations NEW TECHNOLOGY UPDATE by lan Poole 706 Thermocouple based accelerometers dispense with moving parts TRAFFIC CONTROL by O
87. att 14 00 callers only 6 52 inc VAT 2ft 20 watt 9 00 callers only 12in 8 watt 4 80 75p p amp p Yin 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 ce 400 WATT BLACK LIGHT BLUE UV LAMP GES Mercury Vapour lamp suitable for use with a 400W PF Ballast Only 39 95 incl p amp p amp VAT 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 amp 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
88. bats radar or accurately follow a line marked on the floor Learn to use additional types of sensors including rotation light temperature sound and ultrasonic and also explore the possibilities provid ed by using an additional third motor For the less experienced RCX code programs accompany most of the featured robots However the more adventurous reader is also shown how to write programs using Microsoft s VisualBASIC running with the ActiveX con trol Spirit OCX that is provided with the RIS kit Detailed building instructions are provided for the fea tured robots including numerous step by step pho tographs The designs include rover vehicles a virtual pet a robot arm an intelligent sweet dispenser and a colour conscious robot that will try to grab objects of a specific colour Order code BP902 298 pages ANDROIDS ROBOTS AND ANIMATRONS John Lovine Build your own working robot or android using both off the shelf and workshop constructed materials and devices Computer control gives these robots and androids two types of artificial intelligence an expert sys tem and a neural network A lifelike android hand can be built and programmed to function doing repetitive tasks A fully animated robot or android can also be built and pro grammed to perform a wide variety of functions The contents include an Overview of State of the Art Robots Robotic Locomotion Motors and Power Controllers All Types of Sensor
89. ceeds to the 19kHz amplifier frequency dou bler stereo demultiplexer and audio amplifier stages Also covers RDS digital 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 animated 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 October 2001 SURFING THE INTERNET NET WORK ALAN WINSTANLEY Arise Sircam AT an eventful month this has been for Internet users Much of the popular media prophesied an imminent meltdown of the Internet due to the CodeRed Worm alert Defeating CodeRed and CodeRed2 is a technical issue which network managers must confront
90. co uk shopdoor htm 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 M10 01 Everyday Practical Electronics October 2001 707 STORE YOUR BACK ISSUES IN YOUR WALLET THE No i 14 THE LE EF Dar PRACTICAL e ent INTERNA DEDI EASE Sease be jz Anically 1 2 45 each including VAT and p amp p E P i A great way to buy EPE Back Issues our wallet sized CD ROMs contain back issues from our EPE Online website plus bonus articles all the relevant PIC software and web links All this for just 12 45 each including postage and packing VOL 1 CONTENTS BACK ISSUES November 1998 to June 1999 all the projects features news Us etc from all eight issues Note No advertisements or Free Gifts are included PIC PROJECT CODES All the available codes for the PIC based projects published in issues from November 1998 to June 1999 VOL 2 CONTENTS Order on line from BACK ISSUES July 1999 to December 1999 all the projects www epemag wimborne co uk shopdoor htm features news IUs etc from all six issues Note No advertisements or or WWW epemag com USA prices Free Gifts are included or by phone Fax E mail or Post PIC PROJECT CODES All the available codes for the PIC based projects published in issues from Ju
91. connector male chassis mounting T1 230V mains transformer twin 6V secondary windings each 20VA min TB2 TB3 PL1 SK1 PL2 SK2 Printed circuit board available from the EPE PCB Service code 318 aluminium case 102mm x 76mm x 38mm 14 pin d i l socket fuseholder 20mm p c b mounting 2 off fuseholder 20mm panel mounting l e d clip panel mounting 5 off sheet alu minium 15mm x 40mm see text trans former primary insulating shield insulating boots for mains input plug and fuse FS2 mains lead p c b supports plastic 4 off test bulb and holder see text solder tags 2 off battery spade connectors 2 pairs materials for battery bracket 3A mains rated wire connecting wire 4 7 ohm 3W test resistor optional see text solder etc reduces the impedance These facts must be remembered if different components to those specified are used VOLTAGE STABILISATION The output voltage is connected across the potential divider consisting of fixed resistors R16 and R17 and preset poten tiometer VR2 The voltage appearing at the wiper of VR2 is connected to IC4 s feed back input pin 2 This is one input of an on chip comparator the error amplifier Its other input is internally connected to a 5 1V reference source The difference between the two voltages is the error and this controls the mark space ratio of the oscillator s output the regulator varying its operation to reduce the error
92. correspondent Brian Whittle When I was made redundant in the early seventies I found it impossible to gain employment in my field I was a qualified Electrical Engineer with an HND and a Post Advanced Diploma Redundancy carried a stigma and perhaps it still does today I was fortunate to meet up with an American who offered me a trial in Algeria He asked me what I knew of SCRs large d c motors and drilling rigs I said I had no expe rience of these but Electricity was Electricity I grossly over simplified the sub ject by stating that there were only three faults open circuits short circuits and inter mittent faults and only the intermittent were really difficult to troubleshoot On this basis I got a start in the Petroleum industry and after three weeks I was offered a full time position I have since spoken to many people in the industry and have heard the same story over and over At that time the oil indus try in the UK was in its infancy what experi enced people we had were already making their name fame and fortune working over seas Americans in the UK recruited on the basis that if you think you can do the job try and I will fire you if you cannot No one can ask for anything more This is where I believe the UK management goes wrong they are far too cautious in offer ing employment Give your applicants a chance would be my advice Do not offer low pay until you prove yourself which I must confess I have acce
93. cs covered include the basic aspects of the hobby such as operating procedures jar gon and setting up a station Technical topics covered include propagation receivers transmitters and aerials etc Order code BP257 5 49 150 pages SIMPLE SHORT WAVE RECEIVER CONSTRUCTION R A Penfold Short wave radio is a fascinating hobby but one that seems to be regarded by many as an expensive pastime these days In fact it is possible to pursue this hobby for a minimal monetary outlay if you are prepared to undertake a bit of d i y and the receivers described in this book can all be built at low cost All the sets are easy to costruct full wiring diagrams etc are provided and they are suitable for complete beginners The receivers only require simple aerials and do not need any complex alignment or other difficult setting up procedures The topics covered in this book include The broadcast bands and their characteristics The amateur bands and their characteristics The propagation of radio signals Simple aerials Making an earth connection Short wave crystal set Simple t r f receivers Single sideband recep tion Direct conversion receiver Contains everything you need to know in order to get started in this absorbing hobby Order code BP275 4 45 88 pages Computers and Computing MULTIMEDIA ON THE PC lan R Sinclair In this book you ll find out what a CD ROM is how it works and why it is such a perfect add on for a P
94. d This book explains the basic function of an oscilloscope gives a detailed explanation of all the standard controls and provides advice on buying A separate chapter deals with using an oscilloscope for fault finding on linear and logic circuits plenty of example waveforms help to illustrate the control functions and the effects of various fault conditions The function and use of various other pieces of test equipment are also covered includ ing signal generators logic probes logic pulsers and crystal calibrators Order code BP267 4 00 104 pages BOOK ORDERING DETAILS All prices include UK postage For postage to Europe air and the rest of the world surface please add 1 per book For the rest of the world airmail add 2 per book Send a PO cheque international money order sterling only made payable to Direct Book Service or card details Visa Mastercard Amex Diners Club or Switch minimum card order is 5 to DIRECT BOOK SERVICE WIMBORNE PUBLISHING LTD 408 WIMBORNE ROAD EAST FERNDOWN DORSET BH22 9ND Books are normally sent within seven days of receipt of order but please allow 28 days for delivery 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 Tel 01202 873872 Fax 01202 874562 E mail dbs epemag wimborne co uk Order from our onl
95. d AS 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 8 95 AS3016 14 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 9 95 AS3033 18 95 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 11 95 AS3055 20 95 HIGH POWER TRANSMITTERS 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 preampli fier circuit Antenna can be an open dipole or Ground Plane Ideal 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 22 95 AS1028 34 95 6 15 WATT FM TRANSMITTER PRE ASSEMBLED amp TESTED Four transistor based stages with Philips BLY 88 in final
96. d DynoTorches squeeze a lever for 10 They have an a c generator that drives a 2 5V 0 15A bulb but my digital multimeter showed it would output approximately 5V to 6V a c into a 68 resistor There is not enough room in the front of the torch for much circuitry so either a suitable box would need to be attached to the front of the torch or the DynoTorch could be fitted with a power out socket and the radio l e d torch fitted with a power in plug this would allow them to share a generator Note that the radio would require a protective 5V1 5W Zener diode across the C4 supercap and I think DI to D4 should be upgraded to fast recovery higher rated diodes such as 1N5818 Also the torch s D1 should be similarly upgrad ed and only one bridge would be required The DynoTorch is manufactured for Fascinations Seattle WA 98148 NB Alan Bradley via the Net Thanks for the info Alan Readers can search for Fascinations via the excellent web search engine www google com MORE LANGUAGE DEBATE Dear EPE So far the arguments have been on the merits and functionality of various languages C Delphi etc However this is not in my opinion the major issue in choosing a language for use in an educa tional magazine The language used for further projects I suggest should be C C for the fol lowing reasons I have just finished an HNC in electronics of which C was a core module so articles which relate to C would help those studyin
97. d as a platform on which various PIC types could be programmed via the accompanying software Whilst it provided limited access to the pins of an on board PIC16x84 microcontroller allowing it to be used in situ as the rudimentary heart of a developing hardware circuit it did not offer direct access to all pins of the larger PIC16F87x family that could be pro grammed on it This new board design is intended to rectify this situation allowing the four PIC sizes that it can accept to be hard wired not only to additional on board hardware but also external components in conjunction with an optional plug in breadboard In this context it is not only a programmer but its options are also closely allied to the facilities available on the highly successful EPE PIC Tutorial board of Mar May 98 Direct connection of the programming lines can be made to external PIC con trolled circuits under development or final completion such as published EPE PIC based designs The notable difference between the PIC Tutorial board and that of Toolkit Mk3 is that the latter like its Mk2 predecessor is under complete programming control by the connected PC compatible computer The Tutorial board you may recall had to be manually switched at different stages of the programming procedure TOOLKIT Mk3 CIRCUIT The main circuit diagram for the PIC Toolkit Mk3 board is shown in Fig 1 Electronically the circuit is essentially the same as that fo
98. d heatsink Everyday Practical Electronics October 2001 On the Case The first item 6 c corresponds to the material between the junction and the case wall The junction of a TO 3 device will be fixed to a steel base but the case might also be packed with thermal conductive grease to help improve reduce the thermal resis tance it is usually just full of fresh air though A junction mounted in a TO 202 or TO 220 device will be embedded in a plastic resin not known for its heat conducting properties but the metal tab is there to help with heatsinking Manufacturers data sheets give the val ues for the thermal resistances of different case types For comparison National Semiconductor quotes 0 c of 3 C W for a TO 3 LM320 regulator 4 C W for the TO 220 and 12 C W for the TO 202 version The differences in thermal efficiencies are obvious The next parameter Ocs relates to the thermal resistance between the case and sink heatsink This means an insulating washer as shown in the photo perhaps with a smear of thermal conductive grease You might want to allow say 0 5 C W for this Lastly Osa the thermal resistance between the heatsink and ambient temper ature which is actually the thermal resistance of the heatsink itself In some catalogues it is shown as Ry Some typical heatsinks are shown in the photo including types intended for integrated circuits Choose a Heatsink Let s now look at a typical design exam
99. deliv ers around 80 per cent of the total energy to the load The disadvantage of lead acid batteries is that they can be damaged if allowed to discharge below their low point say 5V for a nominal 6V unit and especially if left like that for a prolonged period The charge level l e d s should therefore be checked from time to time to make sure the batteries have sufficient charge Unlike nickel cadmium cells lead acid batteries may be topped up with charge as the opportunity arises because they do not suffer from the memory effect In fact doing this extends their service life Lead acid batteries also hold their charge much better than the nickel cadmium type If Everyday Practical Electronics October 2001 lead acid batteries are left charged they will not self discharge significantly over a period of several months CIRCUIT DESCRIPTION The complete circuit for the Camcorder Power Supply is shown in Fig 1 The mains supply is connected via transformer T1 The 12V a c secondary voltage is rectified by bridge rectifier RECI With mode switch S1 set to CH OFF current flows via diode D4 to smoothing capacitor Cl The capacitor charges to the trans former s peak output voltage less the for ward voltage drop of the bridge rectifier diodes and D4 With the specified trans former this gives about 15V d c under full load When a 12V d c supply is connected instead of the mains current flows into Cl via
100. dvantage of the regeneration is that it provides a greater boost in gain at the Everyday Practical Electronics October 2001 grid with higher voltage giving increased gain Control VR1 therefore controls the regeneration by altering the gain of V1 rather than adjusting the amount of feed back This method gives very precise con trol and avoids problems with tuning shifts that can occur with other systems AUDIO STAGE Valve V2 is used in a straightforward audio amplifier set up Resistor R2 is the grid bias resistor and capacitor C4 couples the output of the detector to the input of the amplifier The original sets of this type where mainly used with high impedance about 2KQ to 4k 2 headphones but these have not been produced for many years A gen uine valve output transformer might still be available from a specialist supplier of valve components but the simpler and cheaper alternative is to use a small mains 715 transformer for T1 Either way the receiv er can then be used with ordinary 8 ohm impedance headphones Although the valves are designed to operate from 90 volts they will actually work very well on much lower supply potentials Four 9V batteries B1 to B4 connected in series to give a nominal 36V supply are shown in the circuit diagram Fig 2 This is obviously well short of the designed operating voltage of the valves but it actually gives very good results In fact adding a fifth battery to take th
101. e DA4 The logic is illustrated in the block diagram in Fig 2 During programming the PIC s data and clock lines are connected to the Port s DAO and DAI lines At other times they are disconnected from the port and routed as PIC data lines to any development cir cuit connected to them This prevents the two PIC lines and the computer from being adversely affected by external circuit loads during programming The third 2 way path in IC3 controls the on board voltage converter IC1 via its SHDN shutdown pin When this pin is held low during non programming mode IC1 outputs 5V via its Voy pin to the MCLR pins of the PIC s allowing the PIC to run its loaded program During programming mode the SHDN pin is held at 5V and ICI generates a V out voltage of 12V as required by the PIC at this time Visual advice that the PIC is in programming mode is provided by Le d D8 being turned on during programming and data read back When the PIC needs to be reset port line DA3 is set high and turns on npn tran sistor TR1 This pulls the PIC MCLR pin Everyday Practical Electronics October 2001 1X9 ees cu o3 Q SY T LOH 0d H S LOH 00H mmm a LAH 08H SVH OVY a SNId HOLO3NNOO EN aro T apo ar 1 LL vajo 0gH e Sd O A mM LEE F M a P Eque vau 9 BO L NO O amp AS O XD O AOL CAN LSVYLNOO a Zu odd Sgu 08H 1N0 ZAH LNO 98H LE O Jd 1gav
102. e supply to 45V did not bring any obvious increase in performance It was found that the circuit will actually work reasonably well from three batteries giving a nominal 27V supply The HT supply current is only about 2 5mA to 3mA so there is no need to use any form of high power battery Ordinary zinc chloride PP3 batteries can be obtained for less than a pound each and are perfect ly adequate A single 1 5V cell powers the heaters and it is advisable to use a high capacity type such as a D size cell as the current consumption is around 100mA COMPONENTS In a retro design such as this it is inevitable that some of the components require further explanation The DF91 valves are available from any specialist valve supplier as are B7G chassis mount ing valveholders An equivalent valve for the DF91 is the 1T4 and is also suitable for this circuit Inductor L3 is a Maplin r f choke see Shoptalk but any inductor of about this value and for high frequency use should work just as well An audio frequency inductor having a value of a few Henries is required for L4 If a suitable component can be found it is likely to be very expensive The cheaper alternative is to use the primary winding of a small mains transformer Several types were tried and there was no obvious differ ence in performance between them The secondary voltage is irrelevant since it is unused so simply use the cheapest mains transformer you can find A smal
103. e 4 27 resistor in the R3 group until a satisfactory reading is achieved With the current limit set permanently link TP1 to TP2 Once the batteries have reached a rea sonable charge level set switch S1 to CAM Adjust preset VR2 until the cor rect voltage is obtained across the output terminals SK2 If fuse FS3 blows or reg ulator IC4 becomes hot switch off imme diately Investigate and correct the fault before proceeding Note that the presence of Zener diode D11 will limit the maximum output volt age It will also increase the current flow if IC4 tries to raise the voltage above the Zener threshold Make checks on the circuit using a fila ment bulb 6V rating for up to 7 2V and 12V for more than this and run the battery pack down to low Check all aspects of operation and make certain the unit and camcorder operate correctly Disconnect the 12V test supply and plug i FEES Internal view showing the p c b bolted to the front panel and battery bracket into the mains Check that the output volt age at SK2 is still the same Now fully charge the batteries using the mains supply After 30 minutes then at hourly intervals unplug the supply remove the lid and check that nothing is excessively hot If necessary drill ventila tion holes in the case but make sure they are small enough so that nothing conduc tive could be pushed through and touch a mains connection di Completed circuit boa
104. ectronics October 2001 FINALLY When the unit is not in use remember to return the mode switch to CH OFF When in use the batteries need recharging when only the red l e d remains on or when all l e d s are off The unit should be removed from the camera bag while charging This is because the bag would insulate the case and could cause the unit to overheat C Front panel component positioning 693 1 BARGAIN PACKS Selected Items 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 i c s etc to drive it to give 2 rows of 8 figures or letters with data Order Ref 1085 30A PANEL MOUNTING TOGGLE SWITCH Double pole Order Ref 166 SUB MIN TOGGLE SWITCHES Pack of 3 Order Ref 214 HIGH POWER 3in SPEAKER 11W 8o0hm Order Ref 246 MEDIUM WAVE PERMEABILITY TUNER Its 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 win spin dies Pack of 10 Order Ref 295 CERAMIC WAVE CHANGE SWITCH 12 pole 3 way with in 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 p
105. ed to know about MP3s in a simple and easy to understand manner It explains How to play MP3s on your computer How to use MP3s with handheld MP3 players Where to find MP3s on the Web How MP3s work How to tune into Internet radio stations How to create your own MP3s How to record your own CDs from MP3 files Other digital audio music formats Whether you want to stay bang up to date with the lat est music or create your own MP3s and join the on line digital music revolution this book will show you how 60 pages Order code PC119 7 45 AN INTRODUCTION TO LOUDSPEAKERS AND ENCLOSURE DESIGN V Capel This book explores the various features good points and snags of speaker designs It examines the whys and wherefores so that the reader can understand the princi ples 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 Temporarily out of print ELECTRONIC MUSIC AND MIDI PROJECTS R A Penfold Whether you wish to save money boldly go where no musi cian has gone before rekindle the pioneering spirit or sim ply have fun building some electronic music gadgets the designs featured in this book should suit your needs The projects
106. een period to allow the vehicle to clear the junction On the other hand if further data input shows that the vehicle is speeding up the exten sion of green time can be automatically cancelled In the longer term SCOOT also accu mulates traffic data at a given junction over a period of time and then amends the green times on different branches so as to min imise waiting times Changes of the cur rent sequencing plan at each junction are noted on the log as they come into effect 33 J C Centre mW e 33 5536 261 MP ae Di 236 A fi astie i ia 11 rem S ine EL D c E roure Beds eit y B 4 a p _ 6 2 br re Ef pe i Br t ms E NN E 3 Fig 3 The control room of the Norfolk UTCC has a large scale map showing the current state of all the traffic lights in Norwich including pedestrian crossings Everyday Practical Electronics October 2001 recognise such a situation and ignores the misleading data The flexibility of the system is such that it can receive input from the emer gency services A signal from the Fire Station for example can bring about a green wave Along a number of select ed routes the green wave puts the lights at green in an expanding zone cen tred on the Fire Station The emergency vehicles are thus given priority on their way to the fire Pedestrians too benefit from the flexibil ity and intelligence of SCOOT
107. egula tor circuit causes a short delay to any adjustments that are made to the voltage Current consumption is less than 1uA at night and fluctuates between about 10uA and 30pA when it is in operation VE TO SOLAR CELL OV 1 50in 88mm 305 2in 61mm Fig 4 Uniboard component layout and full size foil master for the Bird Scarer Includes power supply components July 01 Note top end leads of R6 and H7 are soldered together SOLAR POWERED REGISTER s there anyone at home UR FINAL Perpetual Project is a Or This device is useful espe cially to indicate whether a person is in or out It will flash Green if a person is In and Red if a person is Out A series of these devices together in a hallway could inform residents of a small digs as to who is in and who is out residents would sim ply touch a touchswitch as they passed to indicate that they were coming or going Alternatively it could send secret mes sages to the street from your bedroom win dow A green flashing l e d might indicate See you at the bowling alley tonight while a red flashing l e d might indicate Tm grounded CIRCUIT DETAILS The complete circuit diagram for the Solar Powered Register is shown in Fig 5 Like all the previous circuits the component numbering follows on from the voltage reg ulator published in the July 01 issue Both l e d s are pulsed in order to con serve power Do
108. ent to give good results If you were looking forward to a nostal gic wait for the valves to warm up fol lowed by a glow from the filaments you will be disappointed The combined heaters and cathodes give an almost instant warm up and there is no obvious light out put from the valves REGENERATION With Regeneration control VR1 well backed off in a counter clockwise direction it may be possible to receive a few of the stronger broadcast stations by adjusting Tuning control VCI If not advance VR1 in a clockwise direction and try again If there is a lack of reception switch off at once and recheck the wiring Band conditions vary according to vari ous factors such as the time of day the time of year and sunspot activity Normally at least one broadcast band with in the tuning range of the receiver will be open and the strength of the signals will be such that the broadcast bands will not be difficult to find It is important to realise that VR1 is not a volume control It can be backed off slightly if the volume becomes excessive but it must otherwise be adjusted close to the point at which oscillation occurs It is readily apparent when the detector is oscil lating because there is a change in the background noise level and notes of vary ing pitch will be heard as the set is tuned across stations OSCILLATION With some regenerative receivers there is a tendency for the detector to slide into oscillation a
109. eo 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 The essential work for servicing and repairing electronic equipment Around 900 pages Fundamental principles Troubleshooting techniques Servicing techniques Choosing and using test equipment Reference data Easy to use format Clear and simple layout Vital safety precautions Professionally written Regular Supplements 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 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 Sturdy gold blocked ring binder ORDER BOTH MANUALS TOGETHER AND SAVE ANOTHER 8 A mass of well organised and clearly explained information
110. equires its Configuration bits set to different logic values in relation to the oscillator type used UNCOMMITTED DPTIONS Several uncommitted components can be included on the p c b The components are shown in Fig 5 They comprise four npn transistors TR2 to TRI with 10kQ ballast resistors R13 to R16 on their bases Fig 5a Their emitters are grounded and you may connect their open collectors to other circuits that require currents greater than the PIC can provide about 100mA maximum per transistor compared to about 25mA per PIC pin see PIC data sheets for more infor mation on the currents permitted The bases can be connected to any PIC pin as required via the ballast resistors provided Eight uncommitted l e d s Fig 5b can be included D7 to DO numbered in this way to simplify PIC connection numbering when all are connected to the same port They all have 470 2 bal last resistors module RM1 in series providing enough current for adequate brilliance without overloading the PIC Referring to Fig 5c four uncommitted parallel switches S3 to S6 can also be added They are normally open pushbuttons with 10kQ resistors R17 to R20 in series Their commoned outer Everyday Practical Electronics October 2001 UNCOMMITTED OUTPUTS UNCOMMITTED INPUTS UNCOMMITTED CONNECTIONS CP5 CP4 CP3 CP2 CP22 SEE TEXT OV CP CONNECTION POINT CP21 Fig 5 The uncommitted component options 7
111. er get worse especially with the gradual uptake of always on Internet access cable satellite and DSL This will make it much easier for worms to propagate quickly without the knowledge of the user Another essential tool is an anti intrusion program such as the freeware Zone Alarm www zonelabs com to guard against nternet background noise to quote Steve Gibson of grc com Note that in the writer s system as an added bonus Zone Alarm also padlocked Sircam infected files ready for scanning quarantining Intrusion attempts are commonplace expect a few dozen every day Check your system today and get your anti virus and anti intrusion software up to date this minute You can contact the writer at alanQ epemag co uk Everyday Practical Electronics October 2001 with David Barrington E commence this month with the news that Electromail the mail order arm of RS Components no longer exists However the good news is that RS components can still be purchased on a one off order basis via their RS New Business Reception by telephone on 01536 444079 or through their web site at rswww com A goods must be ordered by Credit Card only They did indicate that a post and packing charge will be incurred and is as follows orders up to 30 4 60 p amp p over 30 to 79 99 2 95 over 80 1 75 Camcorder Power Supply It is important that readers keep to the specified types for some of the components needed
112. ers in the book Radio Today Yesterday and Tomorrow Radio Waves and Propagation Capacitors Inductors and Filters Modulation Receivers Transmitters Antenna Systems Broadcasting Satellites Personal Communications Appendix Basic Calculations 263 pages Order code NE30 15 99 PROJECTS FOR RADIO AMATEURS AND S W L S R A Penfold This book describes a number of electronic circuits most of which are quite simple which can be used to enhance the performance of most short wave radio systems The circuits covered include An aerial tuning unit A simple active aerial An add on b f o for portable sets A wavetrap to combat signals on spurious responses An audio notch filter A parametric equaliser C W and S S B audio filters Simple noise limiters A speech processor A volume expander Other useful circuits include a crystal oscillator and RTTY C W tone decoder and a RTTY serial to parallel converter A full range of interesting and useful circuits for short wave enthusiasts Order code BP304 4 45 92 pages AN INTRODUCTION TO AMATEUR RADIO I D Poole Amateur radio is a unique and fascinating hobby which has attracted thousands of people since it began at the turn of the century This book gives the newcomer a com prehensive and easy to understand guide through the subject so that the reader can gain the most from the hobby It then remains an essential reference volume to be used time and again Topi
113. fold SINGLE CHIP 32 BIT OUTPUT PORT REVIOUS Interface articles have described analogue to digital and dig ital to analogue converters that use a form of serial interfacing This method has the advantage of providing eight or 12 bit resolution using only about three lines to provide the interfacing to the PC The same basic method can be applied where simple interfacing is required but a large number of digital inputs or outputs are required It is an output port that is featured here but similar techniques could no doubt be applied to a digital input port Of course you do not get something for nothing by using serial interfacing The price that is paid for the lack of wires from the PC to the interface is added complica tion in the software and a lack of speed Where an application needs to update the output port every microsecond or so the serial approach is unlikely to be suitable Of course in many practical applications the output ports are only altered relative ly infrequently and the serial method is then eminently suitable Single chip The circuit featured here uses a three line interface to a PC printer port and provides some 32 output lines Further more the circuit uses just two compo nents and one of these is a supply decoupling capacitor This is made possible by using the UCN5818AF serial interfacing chip which is essentially just a 32 bit shift reg ister It would probably be cheaper to use
114. for full PIC All hardware is supplied fully built and tested and includes a PIC16F84 details Also contains a FREE 30 day PiCtutor CD ROM HARDWARE evaluation of Paint Shop Pro 6 Hobbyist Student 45 inc VAT Standard Development Kit 47 inc VAT Paint Shop Pro image editing tips Institutional Schools HE FE Industry 99 plus VAT Deluxe Development Kit 99 plus VAT and on line help included Institutional 10 user Network Licence 199 plus VAT Deluxe Export Version 96 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices ELECTRONICS IN CONTROL Two colourful animated courses for students on one CD ROM These cover Key Stage 3 and GCSE syllabuses Key Stage 3 A pictorial look at the Electronics section featuring animations and video clips Provides an ideal introduction or revision guide including multi choice questions with feedback GCSE Aimed at the Electronics in many Design amp Technology courses it covers many sections of GCSE Electronics Provides an ideal revision guide with Homework Questions on each chapter Worked answers with an access code are provided on a special website Single User 29 inc VAT Multiple User 39 plus VAT Student copies available only with a multiple user copy 6 plus VAT UK and EU customers add VAT at 17 5 6 to plus VAT prices Price 19 95 inc VAT Deluxe PlICtutor Hardware ELECTRONIC CIRCUITS am
115. g electronics The C books I have read show very little on how to use C to interface with the rest of the world or use it to program microcontrollers There are C compilers cheaply available for all computer plat forms and for all types of microprocessor C is also very often the chosen language for many electronics companies in industry C has been around for a long time and is well understood by a great many therefore requests for problem solving and improving published designs should be forth coming Stuart McGhee Norwich via E mail Thank you Stuart It s interesting how various camps are now becoming apparent We con tinue to keep an open mind about whether or not we should embrace any particular new route Anyone wishing to know how C can be used when writing PIC code is recommended to con sider buying the C For PICmicro Microcontrollers CD ROM as advertised on our CD ROM pages SOLDERING TIP Dear EPE Referring to the letter from Arthur Green in July 01 and Alan s reply The device that I have used for twenty or more years requires only a mains voltage rated diode having a suitable current passing capability The diode is connected in series with the soldering iron and in parallel with the diode is a microswitch Mechanically the hardware is arranged so that the iron when not in use is hung on a rest Mine was made from a wire coat hanger the end of which actuates the microswitch to become open t
116. genuity Unlimited PIC Toolkit Mk2 Update V2 4 e Circuit Surgery e New Technology Update e Net Work The Internet e FREE Transistor Data Chart DEC 00 PROJECTS e PIC Monitored Dual PSU Part1 e Static Field Detector e Motorists Buzz Box e Twinkling Star e Christmas Bubble e Festive Fader e PilCtogram FEATURES e The Schmitt Trigger Part 2 e Ingenuity Unlimited e Interface e Circuit Surgery e New Technology Update e Quasar Kits Review Net Work The Internet e 2000 Annual Index JAN 01 PROJECTS e Versatile Optical Trigger e UFO Detector and Event Recorder e Two Way Intercom e PIC Monitored Dual PSU Part 2 FEATURES e Using PICs and Keypads e The Schmitt Trigger Part 3 e New Technology Update e Circuit Surgery e Practically Speaking Ingenuity Unlimited e CIRSIM Shareware Review e Net Work The Internet DID YOU MISS THESE PROJECTS e Ice Alert e Using LM3914 6 Bargraph Drivers e Simple Metronome e PC Audio Power Meter FEATURES e The Schmitt Trigger Part 4 e Ingenuity Unlimited Circuit Surgery e New Technology Update Net Work The Internet e Free 16 page supplement How To Use Graphics L C D s With PICs LIE 24813 PROJECTS e Doorbell Extender e Body Detector e DIY Tesla Lightning Circuit Tester FEATURES e Understanding Inductors e The Schmitt Trigger Part 5 e Circuit Surgery e Interface e New Technology Update e Net Work The Internet Page APRIL 01 PROJECTS e Wave
117. h SIGNATURE m m a BH B B BH H BH H BH B B BH H H H HB BH BH H H BH BH EH BH H H H H H BH BH H H H H BH BH BH H BH H BH NH NH BH H BH H EH NH BH H M H NH EH NH NN Far East amp Australasia 31 each 935 each enclose cheque PO payable to Wimborne Publishing Ltd Rest of World 25 each 45 each Please charge my Visa Mastercard Amex Diners Club Switch Switch Issue No Please allow four working days for UK delivery l NOTE Surface mail can take over 10 weeks to some parts of l Card NO issue see oye ose os eee ee oe ae haces Card Exp Date the world Each Manual weighs about 4kg when packed Online Shop www epemag wimborne co uk shopdoor htm l i jawah an Hi n o uu Ml jara esm2 iL 4 i fa PE TEACH IN 2000 CD ROM The whole of the 12 part Teach In 2000 series by John Becker published in EPE Nov 99 to Oct 2000 is now available on CD ROM Plus the Teach In 2000 interac tive software covering all aspects of the series and Alan Winstanley s Basic Soldering Guide including illustrations and Desoldering Teach In 2000 covers all the basic principles of elec tronics from Ohm s Law to Displays including Op Amps Logic Gates etc Each part has its own section on the inter active software where you can also change component values in the various on screen demonstration circuits The series gives a hands on approach to electronics
118. he diode is now in circuit putting the soldering iron to half power Lift the iron off its rest and the switch closes to short the diode and give full power to the iron which will heat up to correct temperature within seconds I cannot claim to be the originator of the above idea The original article was printed in the long 22 time defunct Radio Constructor magazine many years ago Mike Trueblood via the Net Thank you Mike We too published something similar many years ago we also published in Sept 97 Bart Trepak s Soldering Iron Controller TIME MACHINE Dear EPE I have always been interested in time and have built your PIC Time Machine Nov 97 Having taken early retirement some years ago I took on the task of looking after the clock in the parish church It had gone through many stages of mod ification up to 1998 when I built a church clock control system around your Time Machine design The clock has been developed a bit since it was installed and now adds subtracts the BST rings the angelus one two or three times each day and can ring the bell three times on com mand from the pulpit about 30 metres below The control system drives an a c motor to ring the bell and a photoswitch counts the rings one per rev The fingers about four metres diameter are driven from a small a c motor through a worm box a photoswitch gives one count per rev which is 30 seconds on the fingers Every 30 sec onds the co
119. he high volume levels available from this receiver with its great ly reduced HT voltage surprised the author With most headphones it was found to be necessary to back off VR1 on strong signals in order to keep the volume down to a reasonable level A two transis tor receiver would be unlikely to provide a similar problem The precision with which the regenera tion level can be set aids the level of performance which is certainly very creditable for such a simple receiver The shortwave broadcast bands have plenty of English language transmissions from countries all over the world Some dabbling with the 2 Valve SW Receiver over a weekend produced sta tions from across Europe and into Asia and North America With skill patience and the right propagation conditions it would probably be possible to receive broadcasts from anywhere in the world 719 READOUT E mail editorial epemag wimborne co uk John Becker addresses some of the general points readers have raised Have 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 amp MORE ON ELECTRONICS SHORTAGE Dear EPE I fully concur with your Readout Aug 01
120. here are faders wipers and effects units which will add sparkle and originality to your video recordings an audio mixer and noise reducer to enhance your sound tracks and a basic computer control interface Also there s a useful selection on basic video production techniques to get you started Complete with explanations of how the circuit works shop ping lists of components advice on construction and guid ance on setting up and using the projects this invaluable book will save you a small fortune Circuits include video enhancer improved video enhancer video fader horizontal wiper improved video wiper negative video unit fade to grey unit black and white keyer vertical wiper audio mixer stereo headphone amplifier dynamic noise reducer automatic fader pushbut ton fader computer control interface 12 volt mains power supply 124 pages 10 95 PC MUSIC THE EASY GUIDE Ks Robin Vincent How do make music on my PC Can record music onto my PC Whats a sequencer How can get my PC to print a music score What sort of a soundcard do need What hardware and software do need How do connect a key board to my PC Just a few of the questions you ve probably asked Well you ll find the answers to all these questions and many more in this book It will show you what can be done what it all means and what you will need to start creating your own music on your PC It s an easy read it s fully illustra
121. hotostats of articles are available if required see the Back Issues page for details Please check price and availability in the latest issue Boards can only be supplied on a payment with order basis PROJECT TITLE Order Code Light Alarm FEB 99 Wireless Monitoring System Transmitter Receiver PIC MIDI Sustain Pedal Software only Wireless Monitoring System 2 F M Trans Rec Adaptors 219a 220a x Time and Date Generator 221 Auto Cupboard Light 222 lroning Board Saver APR 99 Voice Record Playback Module Mechanical Radio pair Versatile Event Counter PIC Toolkit Mk2 MAY 99 227 8 95 A M F M Radio Remote Control Transmitter 228 3 00 Receiver 229 3 20 Musical Sundial PC Audio Frequency Meter EPE Mood PICker JULY 99 233 12V Battery Tester 234 Intruder Deterrent 235 L E D Stroboscope Multi project PCB 932 Ultrasonic Puncture Finder AUG 99 kk 8 Channel Analogue Data Logger Buffer Amplifier Oscillators Pt 2 Magnetic Field Detective Sound Activated Switch Freezer Alarm Multi project PCB Child Guard Variable Dual Power Supply Micro Power Supply OCT 99 243 3 50 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 Ginormous Stopwatch Part 1 246 7 82 Ginormous Stopwatch Part 2 DEC 99 Giant Display 247 7 85 Serial Port Converter 248 3 96 Loft Guard 249 Scratch Blanker Fl
122. hown in the photograph and this may be a piece of sheet aluminium having min imum dimensions of 15mm by 40mm bent through right angles and attached so as to maintain a clear gap with all internal parts The diode s integral tab must not make metallic contact with anything else so as a precaution fit a mounting kit so that the tab is electrically isolated from the heatsink Solder 15cm pieces of stranded connect ing wire of 3A rating minimum to switch S1 pads Use different colours to avoid errors later BOXING UP This circuit must be mounted in an Earthed metal box Note that the metal Work is used as a heatsink for the regula tors so these must be placed flat against EARTHING SOLDER TAG ON ONE SECTION OF CASE the box It is very important that no part of the circuit makes contact with the case The 12V input and output connectors may be of any polarised type but must be sufficiently rated for the expected load The 12V and camcorder connectors must be of a different pattern so that the cables cannot be interchanged Mount the p c b vertically on plastic stand off insulators as shown in the photographs Using a suitable mounting bracket attach the batteries securely in position Make sure there is a clear space between the terminals and everything else Partially discharged batteries should be used initial ly to allow correct testing of the charging circuit Refer to Fig 3 and complete the wiring using stra
123. i nated They are linked by a data cable and they both run accord ing to clocks driven by the mains frequency Thus their action is synchronised and takes into account the time delay of traffic leaving one junction and proceeding along the link road to the other junction Although their local computers indepen dently control these single and double junctions their action is monitored remotely Fig 1 At an independently controlled road junction each by dedicated BT tele approach lane has three inductive loops 710 phone line to the UTCC Here the operator can call up the data for any particular junction The monitor screen displays a plan of the junction or junctions and pedestrian crossing too The plan shows the state of the inductive loops the state of the lights and the state of the pedestrians pushbutton on the crossing Sitting in the UTCC in Norwich an operator can check that all of the signals systems in Norfolk are operat ing correctly SCOOT In a larger town where there are more than two junctions close together the junc tion computers are connected to and con trolled by the central computer at the UTCC Connection is through an Outstation Transmission Unit OTU which comprises a modem wired to BT telephone lines The kerbside computer controls the lights at the junction but is under the supervision of the control com puter in the UTCC The main computer runs traffic co
124. iagrams how radio works disc and tape record ing elements of TV and radar digital signals gating and logic circuits counting and correcting micro processors calculators and computers miscellaneous systems Order code NE23 13 99 SCROGGIE S FOUNDATIONS OF WIRELESS AND ELECTRONICS ELEVENTH EDITION S W Amos and Roger Amos Scroggie s Foundations is a classic text for anyone work ing 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 199 pages 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 Order code NE27 21 99 GETTING THE MOST FROM YOUR MULTIMETER R A Penfold This book is primarily aimed at beginners and those of limited experience of electronics Chapter 1 covers the basics of ana
125. ications and q circuit designs not simply mechanical electrical or software ideas Ideas must be the reader s own work and must 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 circuit description between 100 and 500 words maximum and INGENUITY lt this column should be typed or word processed with a brief 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 408 Wimborne Road East Ferndown Dorset BH22 9ND We do not accept sub missions for U via E mail Your ideas could earn you some cash and a prize 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 Three way Lighting Logically 1 three way lighting circuits in which a lamp can be operated using any one of three switche
126. iconductor devices should be readily available There should not be any problems finding the optional 2 line 16 character per line alphanumeric l c d module as connection details are included for two possible formats The one used in the authors model came from Magenta Electronics 01283 565435 or www magenta2000 co uk f ordering from Magenta you should specify that you wish to purchase one with a pin connec tor attached MODEL amp CRAFT TOOLS A COMPREHENSIVE RANGE OF MINIATURE HAND AND POWER TOOLS AND AN EXTENSIVE RANGE OF ELECTRONIC COMPONENTS FEATURED IN A FULLY ILLUSTRATED 532 PAGE MAIL ORDER CATALOGUE Note If you have ordered from 2001 copy you will receive the new catalogue automatically SAME DAY DESPATCH FREE POST AND PACKAGING Catalogues FREE OF CHARGE to addresses in the UK Overseas CATALOGUE FREE postage at cost charged to credit card Squires 100 London Road Bognor Regis West Sussex PO21 1DD TEL 01243 842424 FAX 01243 842525 rt ul SHOP NOW OPEN VISA Everyday Practical Electronics October 2001 The printed circuit board is available from the EPE PCB Service code 319 see page 745 Incidentally if you browse through our component advertisers pages you will soon find that PICs are now widely stocked and should not Cause any sourcing problems 2 Valve SW Receiver Being a little out of touch with valve circuit requirements we asked Gerald Myers of Chevet Supplies 01253 751858
127. icro Microcontrollers site licence countries in the world D PlCtutor EU residents outside the UK add 5 L Electronic Circuits amp Components V2 0 pom Cub for airmail postage per order I PPT EPA i PlCtutor Development Kit Standard Note The CD ROM is not included 1 D PlCtutor Development Kit Deluxe Deluxe Export in the Development Kit prices I i Electronic Components Photos 1 L Electronics In Control Single User Note The software on each version is Electronics In Control Multiple User the same only the licence for use varies i Modular Circuit Design Single User LJ Modular Circuit Design Multiple User Full name a aaa a aa a aa a a aaa aaa aa aa aa a aaa ne Ge aaa aaa aaa aa l quoc ci radias yrat as ra aha e y na kae ana kae p a Ra a BR BER E BA WAN A I i EEG Roa CUR de RE Ja LORD E E ee ee Be ROW JR Bo RECO UE OCURRE ORE we ae UD i CAI RD URS COE RODEADO oU docu We RC ee pde Postcode Tel NO 2 2 ee SONICS P r o L I enclose cheque PO in sterling payable to WIMBORNE PUBLISHING LTD for Please charge my Visa Mastercard Amex Diners Club Switch Card expiry date Dr ee50b 3 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 appl
128. ies 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 Digital 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 OR
129. ig 4 left The connections to the printer port are via the 25 way male D connector Pins 18 to 25 all con nect to ground D0 of the printer port and then clock the data into the serial register The value in each bitwise operation is changed to suit the bit being tested Adaptable Two extra Out instructions are used at the end of the routine and these generate a pulse on the Strobe output so that the data is latched onto the 32 output pins Note that these two instructions are only used at the end of the fourth routine when all 32 bits of the new word of data are available The program includes lines that print the current value for each port below the slider control so that it is easy to check that the outputs of the ports are responding properly to the slider settings It should not be difficult to adapt the software to suit practical applications The values for the ports can be written to vari ables that are then used in place of VScroll1 Value etc It is not necessary to use all 32 output pins but 32 bits of data must always be written to the UCN5818AF to prevent things getting out of sync Dummy data must therefore be written to any outputs that are not used 739 WHETHER ELECTRONICS IS YOUR HOBBY OR YOUR LIVELIHOOD YOU NEED THE MODERN ELECTRONICS MANUAL and the ELECTRONICS SERVICE MANUAL THE MODERN ELECTRONICS MANUAL E 3 The essential reference work for everyone studying electronics
130. ill drive external relay circuits 9VDC 3049KT 13 95 PIR DETECTOR MODULE 3 lead assembled unit just 25x85mm as used in commercial burglar alarm systems 3076KT 8 95 INFRARED SECURITY BEAM When the invisible 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 12 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 signals up to about 5KHz Software amp D shell case provided 3112KT 18 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 69 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 solder
131. including the following topics Component identification and buying the right parts resistor colour codes capacitor value markings etc advice on buying the right tools for the job soldering making easy work of the hard wiring construction meth ods including stripboard custom printed circuit boards plain matrix boards surface mount boards and wire wrap ping finishing off and adding panel labels getting prob lem projects to work including simple methods of fault finding In fact everything you need to know in order to get start ed in this absorbing and creative hobby 135 pages Order code BP392 5 49 A BEGINNER S GUIDE TO MODERN ELECTRONIC COMPONENTS R A Penfold The purpose of this book is to provide practical infor mation to help the reader sort out the bewildering array of components 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 elec tronic theory The main aim is to explain the differences between components of the same basic type e g car bon carbon film metal film and wire wound resistors so that the right component for a given application can be selected A wide range of components are included with the emphasis firmly on those components that are used a great deal in projects for the home constructor 166 pages Temporarily out of print HOW TO USE OSCILLOSCOPES AND OTHER TEST EQUIPMENT R A Penfol
132. ine shop at www epemag wimborne co uk shopdoor htm BOOK ORDER FORM Full name sasae eaaa eaaa aana Hmmm PAOS Sn TREE EE a aaa I ana ae ROO e e aaa daa Post code elis yz OT l enclose cheque PO payable to DIRECT BOOK SERVICE for Please charge my card Card Number T Telephone NO Please continue on separate sheet of paper if necessary If you do not wish to cut your magazine send a letter or copy of this form Everyday Practical Electronics October 2001 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 Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail orders epemag wimborne co uk On line Shop www epemag wimborne co uk shopdoor htm 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 p
133. ing 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 14 95 phone for bulk discounts Everyday Practical Electronics October 2001 Secure Online Ordering Facilities Full Kit Listing Descriptions amp Photos Kit Documentation amp Software Downloads eSVICS PACD HPVdID VOSSOEeG GLE LO ANANA Mo 1 UF Ly yo NG Youd red a fot pore aa UASAR PICALL PIC Programmer Kit will program ALL 8 18 28 and 40 pin serial AND parallel programmed PIC micro controllers Connects to PC parallel port Supplied with fully functional pre registered PICALL DOS and WINDOWS AVR software packages all components and high quality DSPTH PCB Also programs certain ATMEL AVR serial EPROM 24C and SCENIX SX devices New PIC s can be added to the software as they are released Software shows you where to place your PIC chip on the board for programming Now has blank chip auto sensing feature for super fast bulk programming A 40 pin wide ZIF socket is required to program 8 amp 18 pin devices available at 15 95 Order Ref Description o o 3117KT PICALL PIC Programmer Kit 59 95 AS3117 Assembled PICALL PIC Programmer 69 95 84 95 AS3117ZIF Asse
134. ing devices Summary In manufacture these devices only use one additional mask post processing step This makes them ideal for easy introduc tion into production This will also result in their cost not being significantly above many other specialist devices and consid erably cheaper than other accelerometers A further advantage is their robustness as they have no mechanically moving parts Further development work is still required The devices can be further opti mised and their performance needs to be characterised using different gases pres sures and temperatures Other geometries internal to the device also need to be inves tigated This new technology shows a significant amount of promise and should enable accelerometers to become cheaper smaller and more flexible in their use Everyday Practical Electronics October 2001 BACK ISSUES We can supply back issues of EPE by post most issues from the past three 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 Issues from Jan 2001 onwards are also available to download from www epemag com JUNE 00 PROJECTS Atmospheric Electricity Detector 1 e Canute Tide Predictor Multi Channel Transmission System
135. inuous temperature data logging of up to four temperature sensors located 200m from motherboard PC Ideal use for old 386 486 comput ers Users can tailor input data stream to suit their purpose dump it to a spreadsheet or write your own BASIC programs using the INPUT command to grab the readings PCB just 38mm x 38mm Sensors con nect via four 3 pin headers 4 header cables supplied but only one DS18S20 sensor Kit software available free from our website ORDERING 3145KT 23 95 kit form AS3145 29 95 assembled Additional DS18S20 sensors 4 95 each 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 robot 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 AUDIO TO LIGHT MODULATOR Cortrols intensi ty of one or more lights in response to an audio input Safe modern opto coupler design Mains voltage experience required 3012KT 8 95 MUSIC BOX Activated by light Plays 8 Christmas songs and 5 other tunes 3104KT 7 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
136. is totally new design very useful and next month we will publish a free 16 page supplement describing the new Toolkit TK3 for Windows software Don t miss next month s issue place an order with your newsagent or take out a subscription now AVAILABILITY Copies of EPE are available on subscription anywhere in the world see below from all UK newsagents distributed by COMAG and from the following electronic component retailers Omni Electronics and Yebo Electronics S Africa EPE can also be pur chased from retail magazine outlets around the world An Internet on line version can be purchased and downloaded for just 9 99 US approx 7 70 per year available from www epemag com SUBSCRIPTIONS Subscriptions for delivery direct to any address in the HI TECH LED TORCHES arre reir ad Eid anrima ir Ilo MERER lE da TARA E 5 ET TTE e 1 kab eet Pita 2d i sug cl COLE Boa aa LIL Pets bite yy UPA eT Fua Eke png de a UK 6 months 15 12 months 28 50 two years 52 Overseas 6 months 18 standard air service or 27 express airmail 12 months 34 50 standard air service or 52 express airmail 24 months 64 standard air service or 99 express airmail Online subscriptions for downloading the magazine via the Internet 9 99 US approx 7 70 for one year available from www epemag com Cheques or bank drafts in sterling only payable to Everyday Practical Electronics and sent to EPE Subs Dept
137. issions from masts NRPB felt there was a need for a video giving straightforward factual information about mobile phones and health issues There is a charge of 6 00 and copies can be obtained from Information Services NRPB Chilton Didcot Oxon OX11 ORQ or by tele phoning Jane True Jill Cook on 01235 822742 to order by major credit cards The NRPB s web site is at www nrpb org uk SONY S TECHNOLOOK Sony has announced the development of a comprehensive range of TechnoLook products following the successful introduction of its first video microscope last year The expanded TechnoLook range includes higher magnification and semi digital models tak ing the first step towards a fully digital microscope Rudy Cosjins Sony General Manager for Visual Solutions Marketing Europe comments Sony tackled a number of major issues faced by users of traditional microscopes with the introduc tion of the TechnoLook Our aim was to create an easy to use prod uct that could be connected to a PC eliminate eyestrain and reduce neck and back problems For more information contact Sony United Kingdom Pippa Copeman Hill Corporate Communications Tel 01932 816488 Fax 01932 817029 E mail pippa copeman hill 9 eu sony com Web www sony com TETRA AND HEALTH In the National news recently concerns have been raised about possible health effects of exposure to radio frequency r f radia tion via TETRA Terrestrial Trunked Radio cable
138. k 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 transistors operate 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 authors 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 20 T 0 6 du I BUNG 470 pgs large format Wela MI 26 95 DIGITAL ELECTRONICS A PRACTICAL APPROACH 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 synchro nous circuits and register circuits Together with a consid erable practical content plus the additional attraction of its close association with computer aided design includi
139. l mains transformer is also used for T1 but in this case the secondary volt age is very important A very high step down ratio is needed in order to give good performance and a 3V 0V 3V type was found to give the best results The full sec ondary winding is used to drive the head phones with the centre tap being left unused VARIABLE CAPACITORS Ideally the tuning and bandspread capacitors would be high quality air spaced types but these are now very expensive If you can salvage suitable components from the spares box or obtain surplus compo nents Any value from about 200pF to 400pF should be all right for VC1 and a value of around 10pF to 30pF will suffice for VC2 The alternative is to use modern minia ture components having a solid dielectric For VCI the two a m gangs are wired in parallel and should provide a maximum value of 250pF or more The component used for VC2 must be a type that includes low value sections about 20pF intended for use in a f m receiver Either of these 716 COMPONENTS Resistors H1 39k see text R2 2M7 All 0 25W 5 carbon film see text See Potentiometer VH1 100k rotary carbon linear page Capacitors C1 22p ceramic plate or polystyrene C2 u radial elect 100V C3 150p ceramic plate or polystyrene C4 1n5 polystyrene VC1 300p air spaced variable see text VC2 25p air spaced variable see text VC3 10p to 40p ceramic or 5 5p to 65p foil trimmer Valve
140. ld tell you everything you are ever likely to want to know about hobby electronics but did not know where to ask or refer Comprehensive contents pages makes it easy to quickly locate the data you require The subjects covered include Common circuits and related data including helpful graphs and tables of val ues Colour codes for resistors capacitors and inductors Pinout details for a wide range of CMOS and TTL devices plus basic data on the various logic families Pinout details and basic data for a wide range of operational amplifiers Data and leadout information for a wide range of transistors FETs power FETs triacs thyristors diodes etc General data including MIDI message coding radio data ASCII Baudot coding decibel ratios etc 242 pages Order code BP396 6 45 50 SIMPLE LED CIRCUITS R N Soar Contains 50 interesting and useful circuits and applica tions covering many different branches of electronics using one of the most inexpensive and freely available components the light emitting diode LED Also includes circuits for the 707 common anode display 64 pages Order code BP42 2 99 CIRCUIT SOURCE BOOK 1 A Penfold Written to help you create and experiment with your own electronic designs by combining and using the various standard building block circuits provided Where applic able advice on how to alter the circuit parameters is given The circuits covered in this book are mainly co
141. le avoid it The present project could also be called an Electronic Scarecrow was given to a farmer to test on his grapes and proved very effective over a radius of three to four metres In fact the farmer was quite excited about the results Having said this however after about three weeks the birds grew accustomed to the sound and it was a sorry looking farmer who asked the author whether he could get the Bird Scarer working again This did not mean that it had malfunc tioned as the author imagined the birds merely paid no more attention to it Thus the Bird Scarer would be particu larly useful for the temporary protection of seedlings or fruit CIRCUIT DETAILS since this project will only be needed during the daylight hours most birds go to roost in the darkness we can allow a higher current consumption during the day and put the circuit to sleep at night This circuit is more power hungry than the rest mainly because its two oscilla tors ICla and ICIb run continuously during the day Again both of the oscilla tors need to be switched off simultane ously in this case at night The full circuit diagram for the Solar Powered Bird Scarer is shown in Fig 3 The component references follow on from the supply voltage regulator circuit July 01 T HAS been shown that birds particularly 734 SOLAR POWERED BIRD SCARER ICla MC14093BCP IC1b ia MC 14093BCP ICic ICid MC14093BCP
142. le to use a stereo jack socket and it does not seem to make much difference whether the phones are driven in series or parallel The circuit will also work quite well with medium impedance headphones of the type sold as replacements for personal stereo units Socket SK4 should then be a 3 5mm jack type and results are best with the phones driven in parallel TESTING AND USE Give the wiring a thorough check before testing the finished receiver In particular make sure that the HT and LT supplies have not been accidentally swapped over at the On Off switch S1 Components soldered directly to the valveholder pins and wiring to the 5 way tagstrip Note the earthing solder tags secured to the chassis by the mounting bolts of the valve bases Main assembly underside general component layout and interwiring details Note the two transformers and battery holder mounted on the chassis internal side panels The valves should plug into the holders quite easily Do not try forcing them into place if fitting them proves to be difficult Examine the pins and carefully straighten any that are significantly bent out of position Long aerials do not generally work well with a set of this type They tend to load the tuned circuit making it difficult to obtain sufficient regeneration and very strong signals overload the detector About 0 5 to 1 metre of wire connected to socket SK2 or about 2 to 5 metres connected to SKI is suffici
143. lerometer In the device using thermocouples a polysilicon heater encapsulated in a glass passivation is suspended in air The ther mocouple junctions are then located either side and close to the heater A thermocou ple requires a second junction at a different temperature and this cold junction is located above the base silicon material Whilst it would be possible to use a sin gle pair of junctions either side of the heater greater sensitivity can be achieved by using several thermouples in series In the development examples twelve thermo couples were used in series on either side of the heater giving far greater level of output and hence sensitivity A different configuration was used for the thermistor based devices see Fig 2 Here two parallel polysilicon resistors were sus pended but with an air gap between them These were connected in a Wheatstone bridge circuit with two reference or cold resistors that were not suspended Two heaters then heated the suspended resistors These heaters were microma chined to give exactly the required conditions When the circuit experienced acceleration the convection pattern was RESISTORS ELLE REFERENCE Al Y POLYSILICON SENSE RESISTORS NT N Og NNNNNNNN N AAA SUBSTRATE Fig 2 Concept of thermistor based accelerometer The latest acce erometer technology promises to speed up their introduction into many areas reports lan Poole dis
144. logue and digital multimeters discussing the relative merits and the limitations of the two types In Chapter 2 various methods of component checking are described including tests for transistors thyristors resis tors capacitors 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 experi ence is assumed Using these simple component and cir cuit testing techniques the reader should be able to con fidently tackle servicing of most electronic projects Order code BP239 3 45 DIGITAL GATES AND FLIP FLOPS lan R SInclair This book intended for enthusiasts students and techni cians seeks to establish a firm foundation in digital elec tronics by treating the topics of gates and flip flops thor oughly and from the beginning Topics such as Boolean algebra and Karnaugh map ping are explained 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 elec tronics 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 microprocessor techniques as applied to digital logic Order code PC106 9 95 400 pages 96 pages 200 pages Music Audio and Video QU
145. lt Load Supply d Serial Output Q B UCN581 8AF Blanking C Ground Q 2 Fig 1 The UCN5818AF 32 bit latched serial input source driver pinout details 738 CMOS or TTL shift registers to provide the same function but the UCN5818AF provides a very neat and reliable way of handling things This chip is produced by Allegro Microsystems Inc and is available in the UK from the usual RS outlets The pinout configuration for the UCNB8I18AF is shown in Fig 1 Pin 40 is the normal supply pin while pin 1 is the load supply input This chip is primarily intended for operation with vacuum fluo rescent displays where it is necessary to control loads operating at relatively high voltages However it can operate at normal 5V logic levels Clock throughout and it is just a matter of connecting both supply pins to the 5V logic supply The cur rent consumption of the chip itself is only a few mil liamps but over all current drain is somewhat higher if the outputs are used to provide significant output currents Data from the PC is applied to the seri al input at pin 39 There is also a serial output at pin 2 that permits two or more devices to be cascaded if 32 outputs are not enough There are three control inputs but in normal operation only two of these are used IC UCN581 8AF The timing diagram of Fig 2 helps to illustrate the normal method of interfac ing this chip First
146. ly to December 1999 VOL 3 CONTENTS BACK ISSUES January 2000 to June 2000 all the projects features news IUs etc from all six issues Note No advertisements or Free Gifts are included I I I I I I I PIC PROJECT CODES All the available codes for the PIC based projecis published in issues from January to June 2000 I I I I I I I I I I BACK ISSUES CD ROM ORDER FORM Please send me quantity BACK ISSUES CD ROM VOL 1 Please send me quantity BACK ISSUES CD ROM VOL 2 Please send me quantity BACK ISSUES CD ROM VOL 3 Please send me quantity BACK ISSUES CD ROM VOL 4 Price 12 45 each includes postage to anywhere in the world VOL 4 CONTENTS BACK ISSUES July 2000 to Dec 2000 all the projects features news lUs etc from all six issues Note No Free Gifts are included PROJECT CODES All the available codes for the programmable PLAINS asl Spurius quss quie op us GC ain IN cit l projects from July to Dec 2000 Address een EXTRA ARTICLES ON ALL VOLUMES 223 T PUER aaa kag a a Ba A gka a aba ha mba an l BASIC SOLDERING GUIDE Alan Winstanley s internationally JH PostCode acclaimed fully illustrated guide UNDERSTANDING PASSIVE COMPONENTS Introduction to the basic principles of passive components HOW TO USE INTELLIGENT L C Ds By Julyan llett An utterly practi cal guide to interfacing and programming intelligent liquid crystal di
147. m 06211 PINS e Volume 3 Issue 10 October 2001 Copyright 2001 Wimborne Publishing Ltd Allen House East Borough Wimborne Dorset BH21 1PF UK 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 make a backup copy of the downloaded file and 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 inform
148. mains transformer Kit includes punched and printed case and all parts As featured in April 1994 EPE An essential piece of equipment 684 PIC PIPE DESCALER e SIMPLE TO BUILD e SWEPT e HIGH POWER OUTPUT FREQUENCY e AUDIO 8 VISUAL MONITORING An affordable circuit which sweeps the incoming water supply with mc WATER variable frequency electromagnetic DESCALER 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 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 ie ore eT eee ee dna x ee POWER UNIT 3 99 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 si
149. mbled PICALL PIC Programmer c w ZIF socket ATMEL AVR Programmer Powerful programmer for Atmel AT90Sxxxx AVR micro controller fam ily All fuse and lock bits are program mable Connects to serial port Can be used with ANY computer and operat ing system Two LEDs to indicate pro gramming status Supports 20 pin DIP AT90S1200 amp AT90S2313 and 40 pin DIP AT90S4414 amp AT90S8515 devices NO special software required uses any terminal emulator program built into Windows The programmer is supported by BASCOM AVR Basic Compiler software see website for details NB ZIF sockets not included Description O OOOO 3122KT ATMEL AVR Programmer Assembled 3122 39 95 Atmel 89Cx051 and 89xxx programmers also available PC Data Acquisition amp Control Unit With this kit you can use a PC parallel port as a real world interface Unit can be connected to a mixture of analogue and digital inputs from pressure temperature movement sound light intensity weight sensors etc not supplied to sensing switch and relay states It can then process the input data and use the information to control up to 11 physical devices such as motors sirens other relays servo motors amp two stepper motors FEATURES 6 8 Digital Outputs Open collector 500mA 33V max 16 Digital Inputs 20V max Protection 1K in series 5 1V Zener to ground 11 Analogue Inputs 0 5V 10 bit bmV step 1 Analogue Output 0 2 5V
150. mbler BASIC compiler and in system programmer The pre assembled boards only are also available separately _OrderRef NN Tc ine VATea ABCMINISP ABC MINI Starter Pack 64 95 ABC MINI Board Only Advanced Schematic Capture and Simulation Software ena ante v1 ime E amp lese peame pper Tae dos Hip iO gaam hmc T oanmy r gaiii Advanced Schematic Capture Simulation PCB Layout Advanced Hierarchial Schematic Capture Incrudes xx A Graphicu Library Breer aci Decor Serchar Davime Library Gorter Sees and PCE Meta Generates Chor TODO BE deve models Model import Ward abres soa bo deremiead and import models om deos manufacturers web page LR LLLI Advanced 32 bit Anales Cipin and Minsi Mode Simpitaean Virtua Imtramente Gn aage urieni Poser Mult mete ieu cnmplim Valage Guttent Phare Magntude e Bat in amp lb Channel Aol Timi Virtual Oscilloscope That in Digital Logis Arcalyper alkrem you 12 se kria pois Soop Advanced BEBAN BEMA and SO Models A Dela aaa Ty Pee including a anced Mosis Cares ROB design up io 285 aser 3274327 bowed DGI resolution amp utaftouter Autaplacement Virwer Thousands of Paris BEL ov WVigual amp pice Sefteware Purchasing Opiera Personal dition E74 05 Professional Edition 224 05 soo web or call dor Tull denis Serial Port Isolated I O Controller Kit provides eight 240VAC 12A 110VAC 15A rated relay outputs and four
151. mple assembly and testing and providing high level dual output drive KIT 866 Full kit including four electrodes 32 90 1000V amp 500V INSULATION TESTER Superb new design Hegulated output efficient circuit Dual scale meter compact case Reads up to 200 Megohms 4 spare electrodes 6 50 Kit includes wound coil cut out case meter scale PCB amp ALL components KIT 848 32 95 EPE PROJECT PICS Programmed PICs for all EPE Projects 16C84 18F84 16C71 All 5 90 each 10 inc VAT amp postage 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 e EFFICIENT 100V TRANSDUCER OUTPUT RANGE PIC16F877 now in stock e COMPLETELY INAUDIBLE TO HUMANS some projects are copyright KIT 812 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 An innovative and exciting project E Wave the wand through the air and your message appears Programmable to hold any message up t
152. ms and their arithmetic logic units FILTERS Filters is a complete course in designing active and 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 Filter synthesis 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 Chebyshev op amp filters DIGITAL WORKS 3 0 Digital Works Version 3 0 is a graphical design tool that enables you to D construct digital logic circuits and analyze their behaviour It is so ERER RT GAGNE wmS ri simple to use that it will take you less than 10 minutes to make your tirst digital design It is so powerful that you will never outgrow its capability E
153. n supplies Suitable HT batteries are no longer produced but the design featured here will work well using three or four bog standard PP3 size 9V batteries wired in series A single 1 5V cell is needed to power the heaters By the standards of bat tery powered valve sets the unit is quite economic to run When HT batteries were available they were far from cheap In the old days the nor mal aerial for a set of this type D 714 was the longest piece of wire that your gar den could accommodate Band conditions have changed somewhat over the years and there are now many more stations on air Also they are using higher output pow ers and more efficient aerials than in the past Going for the strongest possible aerial signal these days tends to overload a Fig 1 Biasing for a f e t a is essentially the same as that for a valve b simple receiver and give poor results A short indoor antenna consisting of about one to five metres of wire is perfectly ade quate for use with this receiver The output will drive practically any type of head phones at good volume BIASED VIEW Valve circuits are substantially different to those using bipolar transistors but have strong similarities to field effect transistor f e t circuits A typical f e t amplifier has the configuration shown in Fig 1a Unlike a bipolar transistor which requires a forward bias for linear amplifi cation
154. n the power supply voltage regula tor Part 1 July 01 could support two registers in sunnier climes A few such reg isters placed in a passageway could keep track of the movements of a few people at the same time TOUCH SWITCH It was decided to use touchswitches throughout this series since the symbol ism of the perpetual might be compro mised if any mechanical switches were included A touch switch was constructed by the author from the pieces of a broken ultra sonic transducer the cavity between the switch contacts being filled with quick set putty Any home produced switch should be constructed in such a way that a finger is sure to close the gap across the two contacts It would be worth noting that touch switches can pick up static A recommend ed simple means of protecting all the cir cuits in this series against static would be to wire a one megohm resistor in series with each touchswitch This would be desirable especially if there is an expanse of carpet ing near the touchswitch CONSTRUCTION The Solar Powered Register is built up on the Uniboard p c b which may or may not already hold the regulator and d i l socket see July issue Fig 2 as shown in the topside component layout details of Fig 6 This board minus all components is avallable from the EPE PCB Service code 305 Follow the same procedures as previ ously described soldering the compo nents to the board in sequence a
155. ncerned with analogue signal processing and include Audio amplifiers op amp and bipolar transistors audio power amplifiers d c amplifiers highpass lowpass bandpass and notch filters tone controls voltage controlled ampli fiers and filters triggers and voltage comparators gates and electronic switching bargraphs mixers phase shifters current mirrors hold circuits etc Over 150 circuits are provided which it is hoped will be useful to all those involved in circuit design and applica tion be they professionals students or hobbyists 182 pages Temporarily out of print 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 integrated circuits The devices covered include gates oscillators timers flip flops dividers and decoder cir cuits Some practical circuits are used to illustrate the use of TTL devices in the real world 142 pages Order code BP332 5 45 HOW TO USE OP AMPS E A Parr This book has been written as a designers guide covering many operational amplifiers serving both as a source book of circuits and a reference book for design calculations The approach has been made as non math ematical as possible Order code BP88 4 49 CIRCUIT SOURCE BOOK 2 R A Penfold This book will help you to create and experiment with your own electronic designs by combining and using the vari ous s
156. nd This one delivers the expertise and new technology that fledgling computer builders are eagerly looking for 224 pages large format Mele fase 3 e PME 21 99 184 pages PIC YOUR PERSONAL INTRODUCTORY COURSE kang SECOND EDITION John Morton Discover the potential of the PIC micro controller through graded projects this book could revolutionise your electronics construction work A uniquely concise and practical guide to getting up and running with the PIC Microcontroller The PIC is one of the most popular of the microcontrollers that are transforming electronic project work and product design Assuming no prior knowledge of microcontrollers and introducing the PIC s capabilities through simple projects this book is ideal for use in schools and col leges It is the ideal introduction for students teachers technicians and electronics enthusiasts The step by step explanations make it ideal for self study too this is not a reference book you start work with the PIC straight away The revised second edition covers the popular repro grammable EEPROM PICs P16C84 16F84 as well as the P54 and P71 families Order code NE36 13 99 UNDERSTANDING PC SPECIFICATIONS R A Penfold Revised Edition If you require a microcomputer for business applica tions or a high quality home computer an IBM PC or compatible is often the obvious choice They are com petitively priced and are backed up by an enormous range
157. nd control outputs at separate output addresses but with suitably clever software it should be pos sible to use any three outputs of the port The 5V supply is not available from the printer port but methods of obtaining a 5V supply from a PC have been covered in many previous articles The connec tions to the printer port are made via a 25 way male D connector Connection details are provided in Fig 4 Software The demonstration program for the 32 bit output port was written using Visual BASIC 6 and it requires inpout32 dll in order to run It uses four vertical slider controls VScroll1 to VScroll4 to provide values from 0 to 255 that are output to the ports see photograph above The main routine is applied to a timer that sends a new set of data to the ports every 50 mil liseconds The whole listing is too long for inclu sion here but all the files for this program are available from the EPE web site It is also available on the Interface Disk 1 see EPE PCB Service page This includes the compiled program ia TEH Ouipri Pari E i guo pue aj 170 15 tan 00000000000040 900000000000 Data is sent to the four ports using what is basically the same routine for each port This is the last of these four routines If VScroll4 Value And 128 128 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3 3 If VScroll4 Value And 64 64 Then Out Prn1 1 Else Out Prn1 0 Out Prn3 1 Out Prn3
158. nd final ly inserting ICI observing anti static pre cautions In order to conserve space bal last resistors are wired directly to the l e d s as shown Note again that some extreme brightness l e d s also require anti static precautions SETTING UP Once the memory retention capacitor supply regulator circuit C1 has been fully charged in the sun see July 01 adjust the regulator s preset trimmer VRI until 3 6V is measured across electrolytic capacitor C2 solder pins are provided for this purpose on both sides of C2 Remember that C2 causes a short delay to any adjustments that are made to the voltage Current consumption excluding the regulator is below I5uwA If you measure more than 204A make IC1 your prime suspect A CMOS i c can be partially damaged by static while seem ing to function correctly If the i c is not the version specified in the Components list this will almost certainly be the problem IN CLOSING Among other things this series has been a demonstration of some of the recent advances in electronics technology and of the practical usefulness of such advances This series also illustrates good exam ples of using capacitance as the primary source of power with the solar panel of course replenishing the capacitor May your perpetual project which ever one you choose give life long and trouble free service Everyday Practical Electronics October 2001 INTEH 5 Robert Pen
159. nd is not stored In addition to monitoring the system the controller can call up visuals from a number of remotely controlled video cam eras mounted at strategic points in the Norfolk road system These cameras have full aiming and zooming features This allows the operator to sort out any serious problems such as might arise from a traffic accident or football crowd For an overall view of the situation the controller watches the map that covers one entire wall of the control room Fig 3 Lamps on this map indicate the status of the lights at each junction On the same wall are subsidiary maps for the two large towns Great Yarmouth and King s Lynn i A mF 4 311 f AUTOMATIC CONTROL Each junction in the system has a basic plan for the sequencing and timing of the lights Because that sequencing is done by software rather than by mechanical means or logic circuits it opens up all kinds of possibilities SCOOT allows for a large number of different plans to be available for each junction and to switch from one plan to the other as the situation demands The select ed plan at each junction may change auto matically at different times of day to cope with daily variations in traffic flow However under SCOOT the plan may be changed or modified automatically second by second For instance if signals from the induc tive loops show that a vehicle perhaps an HGV is moving slowly toward a junction SCOOT can extend the gr
160. nd the regeneration control then has to be well backed off in order to take the set out of oscillation This makes accurate control of the regeneration level almost impossible There is no such prob lem with this design and the feedback can be carefully adjusted to the optimum setting Unfortunately with sets of this type it is not possible to find a universal setting that is suitable for all reception frequencies Significant changes in the settings of the tuning controls may necessitate readjust ment of VR1 This clearly makes regener ative receivers more difficult to use but it is all part of their charm Try experimenting with trimmer capaci tor VC3 at various settings Best results will be obtained with a setting that enables oscillation to be achieved at any settings of the tuning controls but with VRI well advanced With too little feedback through VC3 it may be impossible to obtain sufficient Everyday Practical Electronics October 2001 regeneration on some bands With too much feedback through VC3 valve V1 will be operating at relatively low gains and this might adversely affect performance If VCI and VC2 have built in trimmers coverage will probably be best if they are set for minimum value However there 1s no harm in trying various settings to find the ones that provide the most useful coverage PEHFDHMANCE The simple valve receivers used in the 1960s all seemed to suffer from a lack of audio output T
161. nded mains type wire of 3A rat ing minimum Insulate all mains connec tions so that they cannot be touched Make up a lead or use a ready made one to connect the car cigar lighter socket to the 12V input observing the correct polarity It is essential for an in line fuse holder and 3A fuse to be included in this lead LINK WIRE CONNECTING 120V PRIMARY WINDINGS IN SERIES FOR 230V OPERATION LINK WIRE FOR 12V OUTPUT S1a CH OFF 9 9 POLE POLE B249 S1 C SE INN TL Ra NO Ti TP1 TE TP2 S S esgh Are 5 eo tt l Gl VS POLE CH OFF 12V INPUT PL1 SK1 CAMORDER OUTPUT SOLDER TAG ON OTHER SECTION OF CASE SEE TEXT FOR L E D WIRING I I S1 SELECT MG Fig 3 Interwiring between circuit board and off board components Use stranded mains type wire of SA rating minimum 692 Everyday Practical Electronics October 2001 ADJUSTMENTS Initial testing should be made using a 12V car battery or bench power supply Whenever a mains supply is plugged in the case must be fully enclosed so that there is no access to internal parts Switch S1 to CH OFF and connect the supply The 12V 1 e d should oper ate Adjust VR to give a voltage at test point TPI of 7 7V Connect an ammeter between test points TPI and TP2 and switch to CH OFP If the ammeter reads less than 950mA no action is needed If it is too high experi ment by increasing the value of th
162. ndspread capacitor VC2 form the tuned circuit Bandspread capacitor VC2 has a low value so that it covers only a limited range of frequencies facilitating easier fine tuning Because the input impedance at the control grid of V1 pin 6 is very high it is acceptable to couple the tuned circuit directly to the grid Coil L2 effectively provides the grid bias resistance for V1 The aerial is nor mally coupled to a low impedance tap on L2 but SK2 provides a more direct cou pling for use with very short aerials SK1 SK2 VC3 10 40p DO OOOO 0 DQUQDOOT SK3 not be possible For reasons that will be explained shortly optimum results are pro duced with the amount of feedback just below the point at which oscillation occurs The audio load for valve V1 is resistor R1 or inductor L4 Both components are shown in the circuit diagram of Fig 2 but only one or the other is actually needed Using a resistor saves money and signifi cantly reduces the cost of the receiver but it also reduces the efficiency of the circuit very noticeably It is certainly worthwhile using an inductor if available funds permit SOUND HEGENEHATION On the face of it there will be no audio output from the detector Capacitor C3 provides smoothing of the r f signal so that the audio output signal is equal to the average voltage in the r f signal With no rectification the positive and negative half cycles should cancel out one another to pr
163. necting wires soldered or pinned as required POWER SUPPLY The Toolkit Mk3 board can be powered by any d c supply of between about 7V and 12V ICA in Fig 1 regulates this sup ply down to 45V A 7805 1A device ICA is recommended to provide enough current to power the board and other development circuits connected to it The external power supply should be chosen so that it can satisfactorily handle circuit then check the power line volt ages with voltage Next Month PIC TOOLKIT TK3 for WINDOWS Software crafted for PIC programming enthusiasts by a PIC programming addict Don t miss our FREE 16 page Supplement IP A COMPLETE RANGE OF A Complete range of regulated inverters to power 220V and 240V AC 4 INVE RTE R S equipment via a car lorry or boat battery Due to their high performance e gt 90 the inverters generate very little heat The high stability of the aKHrcitoucs 150W TO 2500W 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 desktop amp notepad computers microwave ovens electrical lamps pumps battery chargers etc Low Battery Alarm The inverters give an audible warning signal when the battery voltage
164. ned at the junction of R3 R5 and is determined by the voltage difference between IC1 s limit and reference pins 2 and 4 This is set at 7 7V by the potential divider formed by R4 R5 and preset VRI Three resistors are used for R3 rather than a single unit because they are easily obtainable values and also allow for some trimming of the limiting current during setting up With the values specified the theoretical limit is approximately 14A However taking into account stray resis tance that of connecting copper tracks soldered joints and so on it is likely to be in the region of 900mA The 7 7V regulator output is applied to the pair of Schottky diodes D5 and D6 These route current to the individual 6V batteries Bl and B2 at a maximum of about 450mA each Schottky diodes are used as these have a smaller forward voltage drop than ordi nary silicon diodes This varies to some extent with the load but will be typically 0 4V rather than 0 7V Thus the voltage appearing across B1 and B2 will be about 7 3V The diodes also prevent the batteries 1 OFF 407 SEE TEXT CAMAT ENE k D4 CH OFF OUT C POLE IC1 d O GN Tr L200 D IC4 IN cn 4960 FR SOF COMP GND START OSC N BATTERY MONITOR LIMIT REF p POLE TEST POINTS O Q SEE TEXT S1c D5 LINK WIRE INGGA a TP1 TP2 du B1 c a CAM D6 1N5821 a k SET CHARGE VOLTAGE SK2 PL2 SET OUTPUT VOLTAGE Fig
165. ned to run unattended for months at a time in fact for years The solar powered power supply and regulator constructed in the first part July 01 of this series form the basis for each of the projects and it only remains for you to choose which one most appeals to you This month we cover the following three Perpetual Projects vx Gate Sentinel xx x Solar Powered Bird Scarer xx Register xx Besides these three projects suggestions are made for one variation a Break Contact Alarm All the projects are built on a low cost Uniboard printed circuit board one required for each project unless you are expert at desoldering This should also include the Solar Powered Power Supply and Voltage Regulator circuit described in Part 1 July 01 Note that all the projects may also be run Off batteries see Part 1 The solar powered supply section is only required once unless you wish to build and keep all the projects as separate modules It is now over to you to choose which specific project you would like to add to your Uniboard 192 NORMALLY vaene li CLOSED ICla MC14093BCP IC1b Ja MC140928CP ICic IC1d MC14093BCP MC14093BCP 8 12 10 Uu te d R8 WD1 4M7 PIEZO DISC Fig 1 Circuit diagram for the Gate Sentinel Component references follow on from the Solar Powered Power Supply and Voltage Regulator July 07 GATE SENTINEL The full circuit diagram for the Gate Sentinel mi
166. ng the FREE software 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 con ducts the reader through logic circuit simulation using Pulsar 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 straightfor ward 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 produc tion and project ideas especially useful 250 pages large format Meli ae a zn E 17 99 ELECTRONICS MADE SIMPLE lan Sinclair Assuming no prior knowledge 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 d
167. nment for modelling analogue digital or mixed signal networks Commsim offers hundreds of communication and maths blocks for powerful yet intuitive design so modelling and simulation can be performed say Adept without having to write a single line of code The product reflects the new system level approach currently being taught in colleges and universities throughout the world to introduce electronics and its real world applications to engineering students Consistent with the approach taken by other renowned Electronics Workbench products Commsim offers both hierarchical modelling and embed ded compound blocks facilitating rapid prototyping Once designed the system can be simulated to determine its performance under a variety of operating conditions For more information contact Anna Moorhouse Dept EPE Adept Scientific plc Amor Way Letchworth Herts SG6 1ZA Tel 01462 480055 Fax 01462 480213 E mail ewb adeptscience co uk Web www adeptscience co uk LEICESTER SHOW The 30th Leicester Amateur Radio Show LARS will be held at Donington Park on 21 and 22 September 2001 LARS is cllaimed to be the UK s largest amateur radio computing and electronics event For further information contact LARS committee member G W Dover G4AFJ 31 Newbold Road Kirkby Mallory Leics LEY 7QG Tel 01455 823344 Fax 01455 828273 E mail g4afj argonet co uk Web www lars org uk Please mention EPE when contacting ENER
168. not even think of using other types of l e d besides extreme bright ness types other types will be virtually useless A narrow viewing angle is recom mended a wider viewing angle could seriously compromise brightness In this final design we dispense with buffer gates to gain more gates to utilise in the circuit Note that the specified values for bal last resistors R7 and R10 were chosen experimentally in relation to the forward voltage Vy drop of l e d s D4 and D6 which varies with the colour typically red Vp 1 85V green Vp 22V If either oscillator fails to work experiment with different values for the respective ballast resistor BISTABLE LATCH Each of the two l e d flashers IC1a and IC1b is turned on or off respectively by a TOUCH SWITCH simple bistable latch circuit made up of IClc and ICld When touchswitch S1 is touched the input at IClc pin 8 goes low According to NAND logic the output ter minal pin 10 therefore must go high Both inputs of ICId pins 12 and 13 are thus o 14 MC140908CP ED d OUT TOUCH SWITCH Flg 5 Circuit diagram for the Solar Powered Register Note component numbering follows on from the power supply July 01 Everyday Practical Electronics October 2001 735 high its output terminal is therefore low as well as input pin 9 of ICIc When touchswitch S1 opens again IClc s output terminal remains high since one of its inpu
169. nstalment readers are advised to use the Motorola MC4093BCP version of the 4093 quad 2 input NAND Schmitt trigger i c This device is listed code 640 765 by RS Components and can be ordered through any bona fide stock ists or directly using your credit card from RS 01536 444079 or rswww com The Gate Sentinel magnet operated reed type switch has normally closed contacts which may be difficult to find The prototype uses an RS Form B type code 361 4961 and can be ordered as outlined above The same applies to the Honeywell SDP8405 phototransistor used in the Bird Scarer code 195 827 Note the code given last month was for the data sheet The phototransis tor is also listed by Farnell amp 0113 263 6311 or www farnell com code 327 505 The 5mm extreme brightness 6cd green l e d with a 15 degrees viewing angle for the Register project came from Maplin 0870 264 6000 or www maplin co uk code NR87U The Uniboard printed circuit board is obtainable from the EPE PCB Service code 305 see page 745 DISTANCE LEARNING SHORT COURSES with BTEC CERTIFICATION Analogue and Digital Electronics Fibre Optics Fault Diagnosis Mechanics Mathematics and Programmable Logic Controllers o Suitable for beginners and those wishing to update their knowledge and practical skills Courses are very practical and delivered as self contained kits No travelling or college attendance Learning is at your own pace Each course can st
170. nt opportunities seem to be suffering so greatly in this country Has anyone any positive comments to make on the subject SURROUND SOUND Dear EPE Some additional comments and information that some readers might find interesting on your Stereo Surround Sound Amplifier July 01 The technique of extracting a disparity or ambience signal from a stereo pair has been around for some time it having appeared under the trade name Dynaquad I seem to remember in the 1960s It s actually exactly the same process used by the non Prologic Dolby Surround system which goes a bit further in adding a delay of typically 20ms to the surround signal because in most home environments the listener is closer to the rear speakers than to the front speakers and adding a bit of noise reduction based on a mod ified Dolby B type processor to the L R signal Even Pro Logic uses this technique to extract the surround information but goes even further by generating steering vectors to dynamically Everyday Practical Electronics October 2001 control the levels of the surround and centre levels derived The article refers to a pseudo surround signal but the L R signal in fact contains the true surround component Dolby Stereo encod ing essentially takes the surround signal and phase shifts it by 90 and 90 before adding it to the original left and right signals respec tively to maintain a two channel recording By taking the
171. nto the capacitors and load During this time diode D10 is reverse biased and has no effect When the output pulse falls the resulting negative going current is conducted through diode D10 rather than from the inductor and the load current is maintained from the stored ener gy The process then repeats The specification of DIO and capaci tor s C8 is especially important Due to the rapid switching involved the diode must be capable of switching on and off at high speed It must therefore be of the fast recovery type and have a generous current rating 8A minimum Capacitor s C8 must have a low imped ance at 100kHz and a working voltage of 50V d c minimum Two capacitors in par allel are regarded as better than a single unit of double the value because this also Approx Cost 3 5 Guidance Only excluding batts amp case IC2 ZRB500Y03 5V voltage reference IC3 LM324 quad op amp IC4 L4960 2 5A switching regulator Miscellaneous L1 1504H inductor 3A rating minimum 20mm 2A quick blow fuse 2 off FS2 20mm 1A ceramic fuse mains rated 6V 7Ah sealed lead acid battery 2 off see text S1 3 pole 2 way toggle switch 3A FS1 FS3 B1 B2 TB1 5 way p c b screw terminal block 5mm pitch 4 way p c b screw terminal block 5mm pitch 2 way p c b screw terminal block 5mm pitch chassis plug and line socket for 12V input see text chassis socket and line plug for output see text PL3 IEC mains
172. ntrol software known as SCOOT This program is written in C and its name is short for Split Cycle and Offset Optimisation Technique The difference between SCOOT and an ordinary pre planned light sequencing controller is that the SCOOT computer responds instantly to current traffic demands SCOOT also depends on sensing traffic by means of inductive loops These are additional loops on the exits from junc tions where traffic leaves the junction to pass along a stretch of roadway to the next junction In some places there may be two loops close together to allow the speed of the vehicles to be measured Other kinds of sensor are used where appropriate On the faster roads there may be Doppler effect microwave sensors to detect the presence and speed of vehicles These register vehicles at a distance of about 50 metres Doppler effect sensors are also used on pedestrian crossings to detect the presence of people waiting to cross or actually crossing Active infrared detectors are also used on pedestrian crossings as well as sensor mats on the waiting area on the pavement ENGINEERING DATA Data collected by the control computer is available to the engineers in several ways As mentioned earlier the controller can call up a display to check the operation Everyday Practical Electronics October 2001 DIRECTION SENSING In the narrower streets of this ancient city cars may find their way blocked by vehicles parked on the left a
173. ntrol system starts the motor until one count has occurred The clock has only malfunctioned twice in the last two years Both times when the MSF signal from Rugby was down for maintenance and an update took place with no Rugby signal just on noise and a purely random time resulted It would seem that the checksum cannot always validate the data and given enough reads the occasional good data bit will be given on just the noise signal Jim Fell via the Net As I recall the software validates incoming data according to information supplied by the National Physical Laboratory Your problem has not been reported by other readers and I have not experienced it myself The only simple suggestion I can make is that the MSF receiver is switched off during Rugby maintenance periods allowing the clock to run purely under its own crystal control PIC DIVISION Dear EPE Many amateur programmers who do not fully understand binary numbers often find binary arithmetic a daunting prospect and may resort to cheating i e using multiple additions and subtractions to perform multiplication and division The following routine divides two 16 bit num bers the dividend by the divisor which have been pre loaded into dividlh and divisl h respectively and returns the result quotient in dividl h with the remainder in remdrl h The original dividend is lost being overwritten by the quotient Readers who are familiar with arithmetic routines
174. nus of course the solar pow ered supply regulator is shown in Fig 1 Note that the component references follow on from the regulator circuit published in the July 01 issue The Sentinel is intended to sound when a person enters your front gate It is not intend ed so much as an alarm but rather to give the impression You have been noticed It therefore emits a pip pip pip tone Two oscillators are employed in this proj ect the first of which a slow oscillator IC1a modulates the second a fast oscillator IC1c to produce the pip pip pip tone Diode D3 and resistor R7 provide an unequal mark space ratio for the slow oscillator Cla so that the pip pip pip tone is produced rather than a beep beep beep In order not to give the impression that this is merely a dumb device the Gate Sentinel does more than merely switch on when your gate is opened and off when it is closed in that case an intruder would know that it was directly linked to the gate It emits some ten pips after the gate has been closed so as to give the impression I m more clever than a simple on off device This is achieved with the help of capaci tor C3 When the gate is closed switch S1 Everyday Practical Electronics October 2001 VE TO SOLAR CELL 1 50in 38mm 2in 51mm Fig 2 Uniboard p c b component layout and full size copper foil master for the Gate Sentinel Includes components for the power su
175. o Alan Winstanley Circuit Surgery Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND E mail no attach ments alan epemag co uk Please indicate if your query is not for publica tion A personal reply cannot be guaranteed but we will try to publish representative answers in this column ORDER YOUR COPY NOW NEXT MONTH A FREE 16 page Supplement PIC TOOKIT TK3 for WINDOWS XPLUS EPE TEACH IN 2002 Part One NEWSAGENTS ORDER FORM Please reserve deliver a copy of Everyday Practical Electronics for me each month Post Code Everyday Practical Electronics is published on the second Thursday of each month and distributed S O R by COMAG Make sure of your copy of EPE each month cut out or photostat this form fill it in and hand it to your newsagent Everyday Practical Electronics October 2001 699 Constructional Project PIC TOOLKIT Mk3 JOHN BECKER By popular demand an enhanced PIC microcontroller programming development board HIS PIC programming printed circuit board has been designed for use with the software for the new Windows based Toolkit TK3 to be described next month and the DOS based Toolkit V2 4 originally released in May June 99 The board has been introduced follow ing readership suggestions about how the original Mk2 board could be beneficially extended to allow its greater use as a PIC design development facility The Mk2 board was principally designe
176. o 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 790 2x aca eters 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 design KIT 861 24 99 ALSO AVAILABLE Built amp Tested 39 99 p s tar E R LIE r rowk Src e UP TO 4 METRES e LOW CURRENT DRAIN Everyday Practical Electronics October 2001 SIMPLE PIC PROGRAMMER INCREDIBLE LOW PRICE Kit 857 12 99 INCLUDES 1 PIC16F84 CHIP Power Supply 3 99 SOFTWARE DISK LEAD EXTRA CHIPS CONNECTOR PROFESSIONAL PC BOARD amp INSTRUCTIONS PIC 16F84 4 84 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
177. o Hd4MOd Asie NI OSO O MOSH S LNO 9S0 O O eva ZH 03H ol O MOV AdlH3A dV3H vya sgy ogd X 19 98H OIQ 2Z8H Sv OVY Iva ovd QN9 Opodo O E zd9 O N 91 EL SNId 2OI SYY 0VH O AO Lp uooL uooL L8 S9 Yo Gay 09H u0ze eo vvu 0VH a Vc99XVIN uOzz po INOA 19 JA 001 LLO WOO Fee O ASL H AL inol VOI Ini 701 Fig 1 Main circuit diagram for the PIC Toolkit Mk3 printed circuit board Everyday Practical Electronics October 2001 COMPUTER DAS PROG V CTL PRINTER pa OGVC PORT READ VERIFY ACK BUSY CHECK POWER CABLE MULTIPLEXER BUFFER KT RBO RB5 RB6 RB7 Fig 2 Block diagram illustrating the signal connection logic PIC16x84 OSC1 CLK IN OSC2 CLK OUT RCO RCA RC2 TYPICAL RC3 8 PIN PIC OSC1 PG5 GPO CLK OSC2 PG4 GP1 DIO MCLR PG3 PIC16F 873 876 PIC16F 874 877 OSC1 CLK IN OSC2 CLK OUT RCO RC1 RC2 RC3 RDO RD1 Fig 3 Pin out identities for the PIC sockets on the p c b low which is held in reset mode until DA3 goes low again Ballast resistor R12 pre vents ICI Vout from being shorted to OV during reset The PIC may also be reset manually by pushbutton switch S1 This facility is use ful during code development allowing the PIC to be repeatedly reset in order that some programmed actions can be observed from the beginning CONNECTION POINTS The board has four PIC insertion sock et
178. oduce zero output VR1 centre of the receiver s passband where the gain is already higher and less towards the edges where the gain is lower As the regen eration is increased the selectivity of the set is therefore greatly improved Instead of receiving two stations on adjacent channels simultaneously with the enhanced selectivi ty the tuning controls can be used to pick out one station or the other This factor is very important with the plethora of stations that are often to be found on the shortwave broadcast bands High sensitivity alone is not sufficient to guarantee good results It is clearly essential to have some means of accurately adjusting the level of feedback so that it can be set just below the point of oscillation where optimum results are obtained Trimmer capacitor VC3 is used to provide a preset amount of feed back but potentiometer VR1 is the Regeneration control This component provides a variable bias voltage to the screen grid of V1 pin 3 The gain obtained at the control grid depends on the bias voltage at the screen O Sila OV wor a maka 1V5 S1b fe O Fig 2 Complete circuit diagram for the 2 Valve SW Receiver Note only L4 or R1 is required not both see text Because the DF91 valve is intended for battery operation it does not use a separate cathode and heater The heating filament is also the cathode On the face of it there is no reverse bias to the control grid since one
179. 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 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 687 Constructional Project CAMCORDER POWER SUPPLY TERRY de VAUX BALBIBNIE Battery reolacement with a lot more bottle ANY camcorder users manage per fectly well with the battery sup plied with their machine If they need to extend the operating time they simply buy another battery and carry them both around A typical camcorder battery provides an operating time of 45 minutes including using the zoom lens and rewinding the tape every so often to review the results Two batteries would still only give 90 minutes of operation However serious users often need much more than this between charges pos sibly even up to 12 hours Although high capacity batteries are av
180. ole 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 cocntacts Order Ref 1026 3 CONTACT MICROSWITCHES operated with slightest touch pack of 2 Order Ref 861 HIVAC NUMICATOR TUBE Hivac ref XN3 Order Ref 865 or XN11 Order Ref 866 2IN ROUND LOUDSPEAKERS 502 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 pax olin 10in x 2in 32 pairs of brass pillars for solder ing binding components Order Ref 7RC26 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 charger at 5A pack of 2 Order Ref 1070 TEST PRODS FOR MULTIMETER with 4mm sockets Good length flexible lead Order Ref D86 LUMINOUS ROCKER SWITCH approximately 30mm square pack of 2 Order Ref D64 MES LAMPHOLDERS slide on to in tag pack of 10 Order Ref 1054 HALL EFFECT DEVI
181. ology Update e Net Work The Internet Page SEPT 01 PROJECTS e Water Monitor e L E D Super Torches e Synchronous Clock Driver Perpetual Projects 3 Loop Burglar Alarm Touch Switch Door Light Solar Powered Rain Alarm FEATURES e Controlling Flight Ingenuity Unlimited Practically Speaking Circuit Surgery e New Technology Update e Net Work The Internet Page BACK issuEs ONLY 3 30 each inc UK p amp p Overseas prices 3 80 each surface mail 5 25 each airmail We can also supply issues from earlier years 1998 except Jan to May July Nov Dec 1999 2000 except Feb 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 30 for five inc p amp p Overseas 3 80 surface 5 25 airmail L_ I enclose cheque P O bank draft to the value of i Please charge my Visa Mastercard Amex Diners Club Switch Cardi NO P U T Switch Issue No Card Expiry Date Note Minimum order for credit cards 5 SEND TO Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail orders epemag wimborne co uk On line Shop www epemag wimborne
182. ongside other insulated mains wiring the same stan dards must be followed to ensure safety Take extra precautions to ensure that there is no possibility of others mistaking low voltage signal wires for live mains wiring or vice versa ARW Kate Turner St Leonards on Sea DUT Ic IM Table 1 Truth Table S1 S2 S3 Lamp off off off off off off on on off on off on off on on off on off off on on off on off on on off off on on on on WHY NOT SEND US YOUR CIRCUIT IDEA Earn some extra cash and possibly a prize Merk LAMP AC 4 MAINS NEUTRAL Fig 1 Complete circuit diagram for the Three way Lighting system 730 Everyday Practical Electronics October 2001 m Em rimi o Masi Lair seh Trah HOTEL EPE TEACH IN 2000 Now on CD ROM The whole of the 12 part Teach In 2000 series by John Becker published in EPE Nov 99 to Oct 2000 is now available on CD ROM Plus the Teach In 2000 software covering all aspects of the series and Alan Winstanley s Basic Soldering Guide including illustrations and Desoldering Teach in 2000 covers all the basic principles of electronics from Ohm s Law to Displays including Op Amps Logic Gates etc Each part has its own section on the inter active PC software where you can also change component values in the various on screen demonstration circuits The series gives a hands on approach to electronics with numerous breadboarded circuits to
183. optically isolated inputs Can be used in a variety of control and sensing applications including load switching external switch input sensing contact closure and external voltage sensing Programmed via a computer serial port it is compatible with ANY computer amp operating system After programming PC can be disconnected Serial cable can be up to 35m long allowing remote control User can easily write batch file programs to control the kit using simple text commands NO special software required uses any terminal emulator program built into Windows All components provided including a plastic case with pre punched and silk screened front rear panels to give a professional and attractive finish see photo OrderRef Description 3108KT Serial Port Isolated I O Controller Kit 54 95 69 95 AS3108 Assembled Serial Port Isolated I O Controller Standard Edition 149 B5 681 eSVICS PACD HPOJ L A LATE CAISIHA I T 22 M 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 colour TV camera It has a composite video output to a phono plug SCART amp BNC adaptors are available They are in very good condition with few signs of use More details see www diatv co uk 91 91 VAT 108 00 Board cameras all with 512 x 582 pixels 8 5mm 1 3 inch sensor and
184. ors D3 D5 1N4148 signal diode 2 off D4 5mm extreme brightness red l e d D6 5mm extreme brightness green l e d MC14093BCP quad 2 input NAND Schmitt trigger Miscellaneous S touch switch see text Printed circuit board Uniboard avail able from the EPE PCB Service code 305 multistrand connecting wire link wires solder pins solder etc Note Component designations run on from the Solar Powered Power Supply and Voltage Regulator described in the July 01 issue Approx Cost Guidance Only 736 TO SOLAR CELL SWITCH 1 50in 38mm TOUCH SWITCH Fig 6 Uniboard component layout and full size copper foil master for the Solar Powered Register Includes power supply from Part 1 July 01 Note cathode k lead of D4 and D6 is shorter than the anode a lead IClc and ICld are fed back to one of the other inputs at pin 13 and pin 9 respective ly to serve as the most basic form of mem ory the bistable latch The subjective brightness of the two l e d s D4 and D6 may be increased con siderably by changing the values of resis tors R6 and R9 to 47 kilohms 47k to change the flashing mark space ratio However the power supply charge life span would be reduced to about fifteen hours The rate of flashing may be increased by decreasing the value of resistors R5 and R8 but this will also reduce the power sup ply effective life One Goldcap memory backup capaci tor Cl i
185. oud of secrecy which has covered his life and achievements ever since His 1931 Patent for a Binaural Recording System was so revolutionary that most of his contemporaries regard ed it as more than 20 years ahead of its time Even years after his death the full magnitude of its detail had not been fully utilized Among his 128 patents are the princi pal electronic circuits critical to the development of the world s first elecronic television system During his short working life Blumlein produced patent after patent breaking entirely new ground in electronic and audio engineering During the Second World War Alan Blumlein was deeply engaged in the very secret work of radar development and contributed enormously to the system eventually to become H25 blind bombing radar Tragically during an experi mental H2S flight in June 1942 the Halifax bomber in which Blumlein and several colleagues were flying crashed and all aboard were killed He was just days short of his thirty ninth birthday Order code NE32 15 99 420 pages Everyday Practical Electronics October 2001 VIDEO PROJECTS FOR THE ELECTRONICS CONSTRUCTOR R A Penfold Written by highly respected author R A Penfold this book contains a collection of electronic projects specially designed for video enthusiasts All the projects can be simply con structed and most are suitable for the newcomer to project construction as they are assembled on stripboard T
186. p COMPONENTS V2 0 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 Version 2 has been considerably expanded in almost every area following a review of major syllabuses GCSE GNVQ A level and HNC It also contains both European and American circuit symbols 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 Circuits The Parts Gallery will help students to recognise common electronic components and their corresponding symbols in circuit diagrams Selections include Components Components Quiz Symbols Symbols Quiz Circuit Technology Included in the Institutional Versions are multiple choice questions exam style questions fault finding virtual laboratories and investigations worksheets Hobbyist Student Rr RE XR ERR ERES 45 inc VAT Institutional Schools HE FE Industry 99 plus VAT Institutional Site Licence 499 plus VAT UK and EU customers add VAT at 17 5 6 to plus VAT prices Circuit simulation screen
187. 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 11 in outlet in dia Price includes p amp p amp VAT 11 20 each or 2 for 20 50 inclusive My SERVICE TRADING CO LES 57 BRIDGMAN ROAD CHISWICK LONDON W4 5BB FAX 020 8995 0549 Nona Friday Tel 020 8995 1560 682 Ample Parking Space 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 28A 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 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 PATE PULA j Cricklewood Electronics
188. pecified in all the author s recent since 1998 alphanumeric l c d based PIC designs Magenta Electronics supply 2 line x 16 character per line l c d s which have pre connected sockets intended for plugging Approx Cost Guidance Only COMPONENTS Resistors R1 to R4 See R10 R11 1k 6 off R5 to R8 100k 4 off S R9 R13 to R20 10k 9 off R12 4709 page RM1 47002 commoned 8 resistor module Potentiometers VR1 500k cermet preset round VR2 VR3_ 10k cermet preset round 2 off Capacitors Ci C2 220n ceramic disc 2 off C3 C6 4u7 radial elect 16V 2 off 100n ceramic disc 2 off see text 10p ceramic disc 2 off Semiconductors DOtoD8 redl e d 9 off TR1 to TR5 BC549 or similar npn transistor IC1 MAX662A 12V 30mA Flash memory programming supply IC2 4050 non inverting hex buffer IC3 4053 triple 2 channel analogue multiplexer IC4 7805 5V 1A voltage regulator IC5 to IC8 PIC microcontroller see text Miscellaneous S1 S8to min s p push to make S6 switch S2 s p d t slide switch p c b mounting SK1 36 way Centronics female parallel printer connector p c b mounting X1 crystal see text Printed circuit board available from the EPE PCB Service code 319 alpha numeric l c d see text 8 pin d i l socket 2 off 16 pin d i socket 2 off 18 pin d i l or ZIF socket 28 pin d i l or ZIF sock et 40 pin d i or ZIF socket
189. pen quite easily 7 46 VAT 8 77 Please add 1 66 vat 1 95 postage amp packing per order oe JPG Electronics Shaws Row Old Road Chesterfield S40 2RB Tel 01246 211202 Fax 01246 550959 Mastercard Visa Switch Callers welcome 9 30 a m to 5 30 p m Monday to Saturday 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 1KVA 5 amp max 45 25 61 39 inc VAT SHROUDED 0 5KVA 2 5 amp max 34 00 6 00 47 00 inc VAT 46 25 7 00 62 57 inc VAT 1KVA 5 amp max 2KVA 10 amp max 65 00 86 36 inc VAT 86 50 8 50 111 63 inc VAT 150 00 Carriage amp VAT 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 COMPREHENSIVE 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 16 45 inc VAT 10 58 inc VAT 4ft 40 w
190. perd ed rend per perd perd ped rer perl pe perd perl rer peri pe red perl red perd pel red perd per perd perd ed perd perl ed ped ped rer perl pe perd per ed peri pe re perl ped perd perl red perd per ed perd ed perd perl ed per pel red perd e perd perl ed perd pe red perl pe perd perl red rer per perd per red perd perl re perd perl red peri e perd perl ed perd pe red perl pe perd pel red reri per red pel ret re perl re perd perl reri pel fe Wimborne Publishing Ltd Dept Y10 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 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 and Electronic Principles Active and Passive Components Circuit Diagrams Circuit Measurements Radio Computers Valves and manufacturers Data etc PRACTICAL SKILLS Learn how to identify Electronic Components Avoid Static Hazards Carry Out Soldering and Wiring Remove and Replace Components 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 SERVICING TECHNIQUES The regular Supplements include vital guidelines on how to Service Audio Amplifiers Radio Receivers TV Receivers Cassette Recorders Vid
191. pins PIC 16C84 DISPLAY DRIVER INCLUDES 1 PIC16F84 WITH Kit 860 19 99 DEMO PROGRAM SOFTWARE Power Supply 3 99 DISK PCB INSTRUCTIONS AND 16 CHARACTER 2 LINE E eae LCD DISPLAY YOUR OWN APPLICATION Another super PIC project from Magenta Supplied with PCB industry standard 2 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 PIC 16F84 MAINS POWER 4 CHANNEL CONTROLLER amp LIGHT CHASER e WITH PROGRAMMED 16F84 AND DISK WITH SOURCE CODE IN MPASM e ZERO VOLT SWITCHING ae bed full pia d MULTIPLE CHASE PATTERNS Fe nroqrammed DIC IePBA e OPTO ISOLATED hip Easily re programmed 5 AMP OUTPUTS for your own applications e 12 KEYPAD CONTROL Software source code is fully e SPEED DIMMING POT So Le Mea that it can be e HARD FIRED TRIACS Dres asi Kit 855 39 95 LOTS OF OTHER APPLICATIONS I CEBREAKER nooooooo0o0n PIC Real Time In Circuit Emulator Icebreaker uses PIC16F877 in circuit debugger Links to Standard PC Serial Port lead supplied Windows 95 Software included Works with MPASM and MPLAB Microchip software 16 x 2 L C D Breadboard Relay I O devices and patch leads supplied As featured in March 00 EPE Ideal for beginners AND advanced users Programs can be written assembled downloaded into the microcontroller and run at full speed up
192. pply regulator see photograph is held open by the proximity magnet mounted on the gate When the gate is opened S1 reverts to its normal closed state and capacitor C3 charges up through the switch taking ICla pin 1 high logic 1 thus triggering the Sentinel When the gate is closed again and switch S1 is held open by the proximity magnet mounted on the gate capacitor C3 requires a short period to discharge through resistor R5 This introduces a delay before the Gate sentinel again falls silent To increase the period for which the Sentinel sounds after closing your gate increase the value of C3 SWITCHED OFF A normally closed magnet operated reed type switch would be ideal for S1 These switches are harder to come by than normally open switches of the same type so it would be worth noting that a magnet may be glued strategically to the side of a normally open switch of this type to convert it to a normally closed switch A continuity tester will quickly show where the magnet should be glued Any number of normally closed switch es microswitches included which are cheaper may be wired in series with switch S1 These open when the gate is closed Normally open vibration switches would also be well suited in this position closing briefly when the gate is opened A special challenge of this project was to switch off both oscillators simultaneously when switch S1 opened so that no oscilla tor would be left r
193. pted many years ago Do not employ via agencies which many do and the agency takes a good proportion of what should go to the employee Simply give one a chance to prove oneself My son faced the same problem as many UK University graduates He has a first class Honours degree in Computer Science from a PIC TO DISK Dear EPE I found the PIC to Printer Interface in the July issue very interesting a good use for redundant printers On a similar vein is it possible to interface a PIC to a 3 5 inch floppy disk drive With all those old PCs that get outdated rapidly there must be a lot of drives about and the additional long term storage would be very useful for any number of PIC projects Obviously it would be best if the data record ed was readable on a PC and in that event a PC could be used for formatting Roger Warrington via the Net Thank you Roger it probably would be feasi ble but I can t offer to do it as I do not have a spare drive nor indeed do I know the command protocol for accessing drives Does anyone know how easy it might be prestigious University He had many inter views sometimes even up to three and some months later the positions were still being advertised The usual response was he had no experience or that he was overqualified for the position He took the opportunity to work on a very short contract in Switzerland and shortly afterwards he was offered a staff position He is still there
194. r HAMEG HM203 7 dual trace 20MHz component tester 250 FARNELL DTV20 dual trace 20MHz component tester 180 RACAL RECEIVER RA1772 50kHz 30 MHz LED Display GC Basically working 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 723 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 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
195. r interrupted of 1kHz It is in a plastic box size 115mm wide 145mm high and 50mm deep Price only 1 Order Ref 7R1 The other is Amplifier Ref No 109G This is in a case size 80mm wide 130mm high and 35mm deep Price 1 Order Ref 7R2 HEAVY DUTY POT Rated at 25W this is 20 ohm resistance so it could be just right for speed controlling a d c motor or device or to control the output of a high current amplifier Price 1 Order Ref 1 33L 1 STEPPER MOTOR Made by Philips as specified for the wind up torch in the Oct 00 Practical Electronics is still available price 2 Order Ref 2P457 SOLDERING IRON super mains powered with long life ceramic element heavy duty 40W for the extra special job complete with plated wire stand and 245mm lead 3 Order Ref 3P221 RELAYS We have thousands of relays of various sorts in Stock so if you need any thing special give us a ring A few new ones that have just arrived are spe cial in that they are plug in and come complete with a special base which enables you to check volt ages of connections of it without having to go underneath We have 6 different types with varying coil voltages and contact arrange ments All contacts are rated at 10A 250V AC Coil Voltage Contacts Price Order Ref 12V DC 4 pole changeover 2 00 FR10 24V DC 2 pole changeover 1 50 FR12 24V DC 4 pole changeover 2 00 FR13 240V AC 1 pole changeover 1 50 FR14 240V AC 4 pole changeover
196. r the Mk2 board Connections between the PC compatible computer and the board are made via the parallel printer port and a standard Typical main screen display of the controlling software described in the 16 page Free supplement to be published next month 700 connector cable The connections are buffered by IC2a to IC2e ensuring that the input and output signals are maintained at optimum logic levels The input signals also have ballast and pull down resistors R1 to R8 The ballast resistors protect the connected computer output lines when the board is unpowered The pull down resistors provide a OV bias to the buffer inputs when the computer is unpowered or the port connector is unplugged Data and clock signals are brought in via printer port lines DAO and DAI Reset control of the PIC is via port line DA3 and programming mode control via DA4 A fifth port line connection ACK sends signals back to the computer during PIC data reading such as is required in code verification and disassembly modes A new sixth connection has been added between IC2 pin 2 and the BUSY line at connector pin 11 This allows the software to check that the printer port cable is con nected and the p c b power is switched on MULTIPLEXER Multiplexer IC3 is a 3 channel 2 way changeover switch and routes the PIC s data and clock connections according to the programming or non programming mode which is controlled by port lin
197. rd Note the l e d extension wires at the front EPE BINDERS KEEP YOUR MAGAZINES 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 New Guinea which costs 10 50 each Send your payment in s sterling cheque or PO Overseas readers send sterling bank draft or cheque drawn on a UK bank or pay by card to Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail editorial 9 epemag wimborne co uk Web site http www epemag wimborne co uk Order on line from www epemag wimborne co uk shopdoor htm We also accept card payments Mastercard Visa Amex Diners Club or Switch minimum card order 5 Send your card number and card expiry date plus Switch Issue No with your order Everyday Practical El
198. rest value alone The subjects covered include Magnetic field detector Basic Hall effect compass Hall effect audio isolator Voice scrambler descrambler Bat detector Bat style echo loca tion Noise cancelling LED stroboscope Infra red torch Electronic breeze detector Class D power amplifier Strain gauge amplifier Super hearing aid 138 pages Order code BP371 5 45 PRACTICAL FIBRE OPTIC PROJECTS R A Penfold While fibre optic cables may have potential advantages over ordinary electric cables for the electronics enthusiast it is probably their novelty value that makes them worthy of exploration Fibre optic cables provide an innovative interesting alternative to electric cables but in most cases they also represent a practical approach to the problem This book provides a number of tried and tested circuits for projects that utilize fibre optic cables The projects include Simple audio links F M audio link P W M audio links Simple d c links P W M d c link P W M motor speed control RS232C data links MIDI link Loop alarms R P M meter All the components used in these designs are readily available none of them require the constructor to take out a second mortgage 132 pages Order code BP374 5 45 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 practi cal side of this fascinating hobby
199. rinton 01255 861161 Advertisement Copy Controller PETER SHERIDAN 01202 873872 On Line Editor ALAN WINSTANLEY EPE Online Internet version Editors CLIVE MAX MAXFIELD and ALVIN BROWN 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 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 any under takings in respect
200. rupted such that the bridge conditions were altered Test Conditions The accelerometers were tested under a variety of conditions One crucial test was that of investigating how the devices oper ated when they were inclined to the hori zontal Their operation was tested between plus and minus 90 degrees and for acceler ations between zero and 7g They were also tested over a range of vibration frequencies from 30Hz to 3kHz The accelerometers showed very good levels of linearity Errors of less than 0 5 were achieved under tilt conditions of up to 9 degrees and less than two per cent for accelerations of less than 7g The sensitivity was also good and was found to be almost a linear function of the heater power Using a heater running at 100mW sensi tivity levels of just over 1004 V per g were achieved for the thermocouple devices Values of 25uV per g were obtained for thermistor devices sensitivity is of considerable impor tance If values fall too low then the output voltage can become lost in the noise A typ ical thermocouple device with a resistance of 64 kilohms produced a noise voltage of 32nV Hz 32 nanovolts per square root Hertz and for a thermistor device with a resistance of 4 kilohms the value was about a quarter of this It was also found that the thermistor device had a higher frequency response than the thermocouple This is thought to result from the significantly smaller spac ing between the sens
201. s Sections on the CD ROM include Fundamentals Analogue Signals 5 sections Transistors 4 sections Waveshaping Circuits 6 sections Op Amps 17 sections covering everything from Symbols and Signal Connections to Differentiators Amplifiers Single Stage Amplifiers 8 sections Multi stage Amplifiers 3 sections Filters Passive Filters 10 m i sections Phase Shifting Networks 4 sections Active Filters 6 sections SiS COSC Oscillators 6 sections from Positive Feedback to Crystal Oscillators Complimentary output stage Systems 12 sections from Audio Pre Amplifiers to 8 Bit ADC plus a gallery showing representative p c b photos DIGITAL ELECTRONICS Digital Electronics builds on the knowledge of logic gates covered in Electronic Circuits amp Components opposite and takes users through the subject of digital electronics up to the operation and architecture of microprocessors The virtual laboratories allow users to operate many circuits on screen Covers binary and hexadecimal numbering systems ASCII basic logic gates monostable action and circuits and bistables including JK and D type flip flops Multiple gate circuits equivalent logic functions and specialised logic functions Introduces sequential logic including clocks and clock circuitry counters binary coded decimal and shift registers A D and D A converters traffic light controllers memories and microprocessors architecture bus syste
202. s TETRA is the new digital radio system for use by commercial organisations and the emergency services Its operation results in pulse modulation of the r f signal at a low frequency 17 6Hz The National Radiological Protection Board NRPB has sent us the following statement on behalf of AGNIR the NRPB Advisory Group on Non ionising Radiation Agnir has reviewed the features of operation of the TETRA sys tem the likely levels of exposure of people and studies relevant to the assessment of any biological effects It has noted that the sig nals from base stations are not pulsed whereas those from hand portables and from terminals built into vehicles are Agnir has concluded that although areas of uncertainty remain about the biological effects of low level rf radiation in general including modulated signals current evidence suggests that it is unlikely that the special features of signals from TETRA hand porta bles and terminals mounted in vehicles pose a hazard to health For more information contact NRPB Chilton Didcot Oxon OX11 ORQ Tel 01235 822744 Fax 01235 822746 Web www nrpb org uk 696 Tome n ei variety of 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 So race off with a fixed temperature iron or try the In Handle temperature controlled model Each one comes with a choice of a PVC
203. s Tilt Bump Road and Wall Detection Light Speech and Sound Recognition Robotic Intelligence Expert Type Using a Single Board Computer Programmed in BASIC Robotic Intelligence Neutral Type Using Simple Neural Networks Insect Intelligence Making a Lifelike Android Hand A Computer Controlled Robotic Insect Programmed in BASIC Telepresence Robots With Actual Arcade and Virtual Reality Applications A Computer Controlled Robotic Arm Animated Robots and Androids Real World Robotic Applications Order code MGH1 14 99 224 pages 22 99 742 DIRECT BOOK SERVICE NOTE ALL PRICES INCLUDE UK POSTAGE The books listed have been selected by Everyday Practical Electronics editorial staff as being of special interest to everyone involved in elec tronics and computing They are supplied by mail order to your door Full ordering details are given on the last book page For a further selection of books see the next two issues of EPE BASIC RADIO PRINCIPLES AND TECHNOLOGY lan Poole Radio technology is becoming increasingly important in today s high technology society There are the traditional uses of radio which include broadcasting and point to point radio as well as the new technologies of satellites and cellular phones All of these developments mean there is a growing need for radio engineers at all levels Assuming a basic knowledge of electronics this book provides an easy to understand grounding in the topic Chapt
204. s V1 V2 sections can be used for VC2 and the other three sections of the component are left unused Trimmer capacitor VC3 can be any type having a maximum value of around 40pF to 65pF A 10 40pF ceramic component is used on the prototype but a 5 5 65pF foil type was found to work just as well COIL DETAILS Plug in coils are no longer made and those coils that are still available are not SHOP TALK DF91 or 1T4 pentode 2 off Approx Cost 39 Guidance Only excluding batts amp headphones Miscellaneous B1 to B4 9V battery PP3 size 4 off B5 1 5V D size battery L1 L2 see text L3 4 7mH r f choke L4 small mains transformer see text T1 230V mains primary 3V 0V 3V secondary S1 d p s t rotary or toggle switch SK1 SK2 4mm socket red 2 off SK3 4mm socket black SK4 6 35mm standard mono jack socket Aluminium chassis with base front panel size 203mm x 63mm x 152mm approx B7G valveholder 2 off battery holder for B5 PPS battery clip 4 off 32mm tube and 0 56mm enamelled cop per wire for L1 L2 see text control knob 4 off five way tagstrip 8 ohm head phones aerial wire M3 spacers multi strand connecting wire solder tags 3 off solder fixings etc well suited for use with valves Coil form ers and ferrite cores would seem to be unobtainable these days The most practi cal solution is to use a simple home made coil of the air cored variety These were often used wi
205. s are complicated and they are physically difficult to wire together The electronic alternative detailed in the cir cuit diagram of Fig l gives much simpler wiring and as it operates at a switched low voltage it gives an easier and more economi cal installation The wiring to the switches can be in low current alarm cable for example and it can be used to operate a wide variety of loads not necessarily mains powered How It Works The circuit works in the following way Logic gate ICla applies an exclusive OR function to switches S1 and S2 two way switching then IC1b applies the same func tion with the output from Cla and the state of switch S3 This gives the effect of an optional inverted signal depending on the condition of S3 All eight possible combina tions are detailed in the truth table shown an analysis of which shows that in effect chang ing any state of any switch toggles the lamp on or off accordingly The RC networks R4 to R6 and C1 to C3 are for improved noise immunity Resistors R1 to R3 provide a load for the switches which promotes reliable operation at low voltage and also assists with noise immunity by lowering the input impedance of the circuit The output buffer transistor TR1 can be any low power n channel MOSFET which switches the relay The remainder of the cir cuit is a low power regulated power supply Note that although signal switching is done at a low voltage if the wiring is run al
206. s catering for 8 pin 18 pin 28 pin and 40 pin PICs see Fig 3 The PICs are notated as IC5 to IC8 and their data input output pins are variously combined onto five bus lines as shown in Fig 1 The bus lines are terminated at pin header strips or terminal pins to which external circuit components can be connected The three larger sockets are intended for use with PIC16x84 and F87x devices although it is likely that some other PIC types can also be programmed via them The 8 pin socket has been included at read er suggestion There are several small PICs that are likely to be suitable for program ming via this socket although none have been tested Consult data sheets for PIC types not specifically mentioned here by name It is recommended that ZIF sockets are installed in any PIC position which is like ly to be regularly used but they are not made in 8 pin size so far as is known 702 13 D6 116 D4 9 e D2 7 DO 5 RW 3 CX 100V Fig 4 The two standard I c d module pinout arrangements L C D CONNECTION An additional pin header strip is con nected to PIC port pins RBO to RB5 which is intended for the plugged connection of an optional alphanumeric liquid crystal display l c d whose typical pinouts are shown in Fig 4 Also connected to this pin header are VR2 the l c d contrast setting preset and the 5V and OV connections as required All connections at this header are the same as s
207. s 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 businesses You also get valuable reproduction and duplication rights so that you can sell the manuals as you like R030 7 50 680 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 office 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 31 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 14 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 15 95 UNIPOLAR STEPP
208. s powered drills up to WEB http www QuasarElectronics com email epesalesQQuasarElectronics com an SURVEILLANCE High performance surveillance bugs Room transmitters supplied with sensitive electret microphone amp battery holder clip All transmit ROOM SURVEILLANCE MTX MINIATURE 3V TRANSMITTER Easy to build amp guar anteed to transmit 300m 3V Long battery life 3 5V operation Only 45x18mm B 3007KT 6 95 AS3007 11 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 7 95 AS3018 12 95 HPTX HIGH POWER TRANSMITTER High performance 2 stage transmitter gives _ a greater stability amp higher qual fef i ity reception 1000m range 6 gx 12V DC operation Size 70x15mm 3032KT 9 95 l AS3032 18 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 8 95 AS3051 14 95 VTX VOICE ACTIVATED TRANSMITTER Operates only when sounds detected Low standby current Variable trigger sen sitivity 500m range Peaking circuit supplied for maximum RF out put On off switch 6V operation Only 63x38mm 3028KT 12 95 AS3028 21 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 two st
209. s started arriving from Argentina then from Brazil a few days later then Mexico and then the USA Mails then arrived from Korea Japan South Africa and eventually mainland Europe Each mail contained the same message and Turnpike made it easy to spot that an unsolicited file was attached Some files were very large several megabytes long which reduced my mailfeed to a crawl at times A quick scan with anti virus software soon revealed the sinister truth and from then on it was a case of circling the wagons I sensed something big was about to break out The trickle of files turned into a minor deluge files of every description arriving from people I d never heard of Spreadsheets images and doc files all tried to wriggle their way onto my hard disk In the early stages I would E mail the senders thanking them very much but alerting them to the presence of their unwanted guest if users were on a fast network they would probably never ever know that the Sircam worm had infested their system In sev eral cases my E mail bounced back their mailbox quota had been exceeded presumably because Sircam had created such a logjam that their network couldn t mail the worm out quickly enough Infra Dig Things took a turn for the worse when I fired up my new infra red phone see last month and a new laptop in order to fetch some E mail You guessed it Sircam was soon trying to wriggle its way through the airwaves via my mobile phone In
210. s well as anti static precautions SETTING UP Assuming the circuit is being solar powered once the power supply capaci tor Cl has been fully charged in the sun via the solar cell see Part 1 adjust the regulator s preset trimmer VR until 3 6V is measured across electrolytic capacitor C2 solder pins are provided on both sides of C2 while the Gate Sentinel is sounding This it will do as long as your gate is open Remember that capacitor C2 causes a delay to any adjustments that are made to the voltage Current consumption is virtually nil on standby and about 60uA when the buzzer is sounding TAKE FLIGHT GATE SENTINEL Resistors e Se R5 R8 AM7 2 off R6 iR 29 S OP R7 1M All 0 25W 5 carbon film TALK page Capacitor 1p min radial elect 10V 47n polyester film 33p ceramic plate Semiconductors D3 1N4148 signal diode IC1 MC14093BCP quad 2 input NAND Schmitt trigger Miscellaneous WD1 low profile wire ended piezo sounder S1 normally closed reed proximity switch with bar magnet see text Printed circuit board Uniboard avail able from the EPE PCB Service code 305 multistrand connecting wire link wires solder pins solder etc Note Component designations run on from the Solar Powered Power Supply and Voltage Regulator described in the July 01 issue Approx Cost Guidance Only dislike a rasping sound around 200Hz and will for a whi
211. sary to experiment a little to find the correct method of connection One side of a variable capacitor connects inter nally to the chassis so getting the connec tions around the wrong way will place a short circuit across coil L2 and prevent the circuit from working Getting all the wiring installed is not too difficult As with any hard wiring strong joints are more or less guaranteed if the tags and ends of the leadout wires are solder tinned prior to making a connection Pin 4 of valve V1 is used as a convenient anchor point for one lead of capacitor C1 Do not use pin 5 as this does have an inter nal connection to the valve There are three connections between the OV batteries and these must all be insulat ed with tape or sleeving to make sure that they cannot accidentally come into electri cal contact with each other or other parts of the circuit The batteries can be fixed to the right hand side panel of the chassis using adhesive pads The unused leads of T1 and L4 should be cut short and any exposed wire must be insulated to ensure that no unwanted connections occur HEADPHONES Low impedance mono headphones can be used with a standard jack socket used for SK4 Stereo headphones will also work but only one phone will be driven For operation with stereo headphones it is 718 TO V1 PING TOL2 5 TOL1 1 BANDSPREAD Fig 5 Wiring to variable capacitors VC1 and VC2 solid dielectric type preferab
212. se reliable working speed varies with line quality existing V90 modems waste up to a minute each time a connec tion is made by handshaking with line test signals If the phone line has a call waiting service which sends bleep tones down the line to warn that someone is trying to make a voice call while the line is engaged existing modems often mis take call waiting for a disconnect tone and hang up on the Internet without giv ing the surfer any choices A V92 modem solves both these prob lems with non volatile memory which builds a library of previous settings When the modem dials an Internet serv ice with matching software they quickly recognise a known situation and skip the rest of the handshake The V92 modem also recognises a call waiting tone for what it is puts the Internet connection on hold and then uses the stored settings to reconnect quickly when the speech caller hangs up Connexant the spin off from modem chip maker Rockwell which has driven V92 expects ISPs to offer the services by the end of this year Some modems already promise V92 in the small print Clearer publicity might spoil V90 sales ELECTROMAIL CEASES MAIL ORDER Electromail a division of RS Components have confirmed that they have ceased to provide a mail order serv ice However it is still possible to purchase RS goods on credit card only either via the web site http rswww com or via tele phone to 01536 444079 695 M
213. se them and the data they can supply This new series is being produced by a team of writers co ordinated by Alan Winstanley and drawing from the vast range of knowledge of the electronics department at Hull University Some months have been spent planning the content and working on demonstra tion projects for readers to build and test The course will employ a Pico Technology PC based oscilloscope to provide PC displays of the various parameters to be measured The scope will be available to readers at a Special Offer price SUBJECTS The course is planned to cover the following areas Temperature Light and Colour Sound and Ultrasonics Time Humidity Gases Smoke and pH Electric and Magnetic Fields Radiation Movement Acceleration Strain and Vibration Optical Digital Presence Distance and Position Weather It will look at a range of circuit topics from Basic Principles through Op Amps Instrumentation Amplifiers Filters Comparators ADC Data Logging etc Each part will have associated labs and projects The new series will assume some basic knowledge of electronics so if you want to start right at the very beginning with a series that requires no previous knowledge you will need to look at the previous Teach In which is available on CD ROM Teach In 2000 see page 73 for details FREE PIC INGS Thanks to John Becker we are now on version three of his highly acclaimed PIC Toolkit see page 700 we know readers will find th
214. sed on its own the physical demonstration provided by the PlCtutor 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 PlCtutor 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 SS This highly acclaimed CD ROM by John Becker together with the PlCtutor COMPONENTS experimental and development board will teach you how to use PIC microcontrollers PHOTOS i with special emphasis on the PIC16x84 devices The board will also act as a 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
215. should blow quickly enough to pre vent destruction of the Zener This is not guaranteed to be effective but to provide the best chance of success a fast blow fuse should be used for FS3 Also the value of the fuse should be only a little greater than the maximum load on the output Great care should be taken over all aspects of construction to prevent faults occurring in the first place Ble Bz Bit Bi Bz POLE CAM Aa l GREEN LED Sib CH OFF POLE CAM Because of their rapid on off action switching regulators tend to generate radio frequency interference r f 1 which can flow into power supply lines or be radi ated from the connecting wires This can cause noises from the loudspeakers of radio equipment connected to the same supply or in the vicinity of the circuit This is not a problem here because the mains supply is disconnected when the regulator is operating Also interference cannot be radiated because the circuit is enclosed in an earthed metal box CONSTRUCTION Construction is based on a single sided printed circuit board p c b The topside component layout and full size underside copper foil track master are shown in Fig 2 Dan TES a2 tlla Yous 1 A Dii e Sov Fig 2 Printed circuit board component layout and full size copper foil master track pattern for the Camcorder Power Supply Everyday Practical Electronics October 2001 691 This board is available from the EPE PC
216. side of the heater cathode connects direct to the OV rail However the other connection to the heater cathode is taken about 1 5 volts positive by the LT battery B5 so there is actually a small reverse bias on the control grid Valve V1 provides radio frequency r f amplification with r f choke L3 acting as the anode load Some of the output signal at the anode is fed back to the aerial coil via trimmer capacitor VC3 and coupling winding L1 There is an inversion of the signal through V1 but the phasing of L1 is such that positive feedback regeneration is applied If too much feedback is applied the cir cuit will oscillate and proper reception will In practice there is less than perfect lin earity through a valve or any other ampli fying device and one set of half cycles receives more amplification than the other set This gives a very inefficient form of rectification but does provide some audio output from an a m amplitude modula tion broadcast signal Negative feedback is often used to reduce distortion and the positive feed back utilized here has the opposite effect As the amount of regeneration is increased the gain of the circuit is boost ed but the increase is much larger on the set of half cycles that originally received only slightly higher gain Advancing the Regeneration control VR1 therefore pro duces a much higher output level with both the gain and detection efficiency being boosted Another a
217. sor on a single chip including all the sensing and drive circuitry This can give significant cost advantages over existing sensors Not only this but the sensors show significant performance advantages over other types These manifest themselves in terms of much lower power consumption and a higher frequency response extending up to figures of a few hundreds of Hertz rather than a few tens of Hertz when compared to other convective sensors The basic device consists of a suspended polysilicon micro heater see Fig 1 When a current is passed through this heated ele ment the thermal difference between the element and the surrounding gas generates a convective flow of gas When the device experiences some accel eration the change in the convection flow of the gas causes a temperature difference between the sides of the heated element Temperature sensors placed on either side of the heater element then detect a temperature 706 difference The acceleration is proportional to that applied to the device The temperature sensors can be either thermocouples or thermistors Both types are equally compatible with CMOS fabri cation technology and the interfacing requirements for both types can be accom modated equally as well However there are a few differences in the actual con struction of the devices THERMOCOUPLES CONNECTIONS TO COLD JUNCTIONS GLASS AREA POLYSILICON HEATER Fig 1 Thermocouple based acce
218. splay modules I enclose cheque P O bank draft to the value of Please charge my Visa Mastercard Amex Diners Club Switch PhyzzyB COMPUTERS BONUS ARTICLE 1 Signed and Unsigned CIPIT nane EE e E E e a a ee E Binary Numbers By Clive Max Maxfield and Alvin Brown PhyzzyB COMPUTERS BONUS ARTICLE 2 Creating an Event Card No a n an aa 3 85 3 3 3 3 83 3 3 8H 8 83 3 3 B HW 3 HN HN B3 B3 HN N B B BN HN BN 3 3 3 N HN uu I Counter By Clive Max Maxfield and Alvin Brown Expiry Date sk RR des Switch Issue No INTERGRAPH COMPUTER SYSTEMS 3D GRAPHICS A chapter from Intergraph s book that explains computer graphics technology in an interesting and understandable way with full colour graphics EXTRA ARTICLE ON VOL 1 amp 2 THE LIFE amp WORKS OF KONRAD ZUSE a brilliant pioneer in the evolution of computers A bonus article on his life and work written by his eldest son including many previously unpublished photographs NOTE This mini CD ROM is suitable for use on any PC with a CD Send a copy of this form or order by letter if you do not wish to ROM drive It requires Adobe Acrobat Reader available free from cut your issue the Internet www adobe com acrobat 4 SEND TO Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 87
219. t levels such as occur at night and during overcast weather Under such conditions the supply to the transformer is automatically reduced to 160V The lamps receive only 16V but they are still bright enough for signalling under low light conditions and the low voltage prolongs their life OPTIMISING The software has three optimisation pro cedures The first is the Split Optimiser which analyses the current red and green timings It determines whether the change times should be advanced retarded or remain the same It increments or decre ments the timings by one to four seconds at each analysis 711 The Offset Optimiser delays or advances Aha kakak the whole red green timing in units of four seconds during each cycle so as to opti mise traffic flow Finally the Cycle Time Organiser oper ates once every five minutes or every two and a half minutes when necessary It identifies the most critical road junction in a region and attempts to adjust the cycle time of the lights to reduce congestion Cycle time can be increased or decreased by amounts of four eight or 16 seconds By this combination of relatively small changes in the timings SCOOT is able to respond rapidly to the current demands of traffic BENEFITS The benefits of using a computer con trolled system based on electronic sensors have been demonstrated by surveys in sev eral urban areas including Worcester Southampton Glasgow and Coventry SCOOT sys
220. t sources setting every output low In most applications this is no better than allowing the shift register to drive the outputs since the data on the outputs will still be invalid For most purposes it is best to tie the Blanking input to ground so that the outputs always operate normally Internal latches and the Strobe input are then used to ensure that the data on the outputs of the shift register is not trans ferred to the output pins until fully valid data is available This is achieved by hav ing the Strobe input held low until a full set of 32 bits has been clocked into the chip A pulse is then applied to the Strobe input to transfer the new data to the out put pins and latch it there Any changes on the outputs of the shift register then have no effect on the output pins until another set of data has been clocked in and another strobe pulse is generated Versatile Output The circuit diagram for the 32 bit out put port appears in Fig 3 The accompa nying software uses the 32 outputs as four 8 bit output ports but they can be used as two 16 bit ports a single 32 bit type 32 single bit outputs or any other set up that requires no more than 32 out put lines In order to keep the software straight forward the Data input is driven from DO of the printer port while the Strobe and Clock inputs are respectively driven by the printer port s Strobe and ALF handshake outputs This conveniently places the data a
221. t the kerbside They are then obliged to cross into the other traffic lane in order to pass the obstruction While doing this they might well pass over an inductive sensor which would then indicate a vehicle apparently travelling in the oppo site direction SCOOT software is able to DO1217 DEREHAM LKMAN 0 X41160 LITLPORT HIGHGT X41160 LITLPORT HIGHGT D01217 DEREHAM LKMAN O D04317 BSHPBG BSHPGT S D04317 BSHPBG BSHPGT S 205329 SVD Chartwell Z05329 SVD Chartwell D04317 BSHPBG BSHPGT LOPE 0511 0511 OPE OPE OPE Bus arrival Congestion formed TX fault TX replies restored Congestion cleared Congestion cleared Congestion formed Bus departed OPE Congestion cleared Fig 2 The traffic log records all events on the system immediately they occur of lights at all road junctions This infor mation is also presented for all the junctions in an area in tabular form The computer also displays a running log of events on the system Fig 2 shows a typical abstract from this and illustrates the kinds of event reported just after 9 32 one Friday morning in September A few minutes after the last entry in the figure the log reported the failure of a Wait lamp at the junction of High Street and Baker Street in Gorleston The mainte nance contractor was automatically alerted to the failure The log went on to show that the lamp was replaced nine minutes and 33 seconds later The data is used only for monitoring a
222. tandard building blocks circuits provided Where 160 pages 744 applicable advice on how to alter the circuit parameters is provided The circuits covered are mainly concerned with signal generation power supplies and digital electronics The topics covered in this book include 555 oscillators sinewave oscillators function generators CMOS oscilla tors voltage controlled oscillators radio frequency oscillators 555 monostables CMOS monostables TTL monostables precision long timers power supply and regulator circuits negative supply generators and voltage boosters digital dividers decoders etc counters and dis play drivers D A and A D converters opto isolators flip flops noise generators tone decoders etc Over 170 circuits are provided which it is hoped will be useful to all those involved in circuit design and applica tion be they professionals students or hobbyists Order code BP322 5 45 192 pages Project Building amp Testing ELECTRONIC PROJECTS FOR EXPERIMENTERS R A Penfold Many electronic hobbyists who have been pursuing their hobby for a number of years seem to suffer from the dreaded seen it all before syndrome This book is fairly and squarely aimed at sufferers of this complaint plus any other electronics enthusiasts who yearn to try some thing a bit different No doubt many of the projects fea tured here have practical applications but they are all worth a try for their inte
223. ted and it will help you understand how a computer can be used as a creative music tool It covers soundcards sequencers hard disk digital audio recording and editing plug ins printing scores with notation software using your PC as a synthesiser getting music onto and off the Internet using Windows sample PC music set ups FAQs a glossary advice on hardware and software and a list of industry contacts 116 pages Order code PC117 11 95 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 4 49 96 pages 743 Circuits Data and Design PRACTICAL ELECTRONIC FILTERS Owen Bishop This book deals with the subject in a non mathematical way It reviews the main types of filter explaining in sim ple terms how each type works and how it is used The book also presents a dozen filter based projects with applications in and around the home or in the constructor s workshop These include a number of audio projects such as a rythm sequencer and a multi voiced electronic organ Concluding the book is a practical step by step guide to designing simple filters for a wide range of purposes with circuit diagrams and worked examples 88 pages Order code BP299 5 49 ELECTRONIC HOBBYISTS DATA BOOK R A Penfold This book shou
224. tems have always improved journey times when compared with fixed time systems On average it has been esti mated that using SCOOT reduces traffic delays by 20 per cent The contents of this kerbside traffic control box are described in the text It takes months of work to collect the data and produce the plan for a fixed time system The SCOOT system continuously updates itself to take account of present READ MORE ABOUT IT BRC HES CIIGDEGSOUUEGRHO GONI ONG Owen Bishop continues the theme of electronic control in his book ACKNOWLEDGEMENT Understand Electronic Control Systems ISBN 0 7506 4601 2 which is Thanks are due to Peter Lock of the available through our Direct Book Service Order code NE35 price 17 99 NCCUTCC for demonstrating and explain including UK p amp p See page 744 for ordering details ing the system to the author C MOS B W Camera 15mm 15mm 29 00 C MOS Colour Camera 15mm 15mm 65 00 PCB B W Camera 32mm 32mm 24 00 PCB Colour Camera w Audio 32mm 32mm 65 00 23cm 1 3GHz Video Audio Transmitter 35 00 13cm 2 4GHz Video Audio Transmitter 35 00 1 2 Watt 2 4GHz Video Audio Transmitter 120 00 4 TFT Boxed Colour Monitor w Audio 110 00 Video to VGA Converter 65 00 VGA to Video Converter 90 00 External USB Video Capture Box 55 00 All prices exclude VAT Many more products on our website WWW BITZTECHNOLOGY COM Tel 01753 522 902 Fax 01753 571 657 712 Everyday Practical Electronics
225. th valve receivers and give surprisingly good results The coil used in this set is wound on a 32mm diameter plastic former about 65mm long The former is actually cut from a 32mm Trap Inlet Height Adjuster which should be available from Everyday Practical Electronics October 2001 TO VC1 TO VC1 TO VC3 TO VC1 VC2 L2 L1 14 TURNS 9 TURNS 11mm METAL CHASSIS Fig 3 Details of the home made tuning coil The plastic coil former measures 32mm diameter by about 65mm length Strips of tape can be used to stop the windings unravelling see photograph right the plumbing department of your local DIY superstore However any rigid plastic tube of about the right size will suffice Details of the coil are provided in Fig 3 Both windings are made using 24s w g 0 56mm enamelled copper wire The windings will tend to unwind and spring apart and the simplest method of resisting this is to drill holes of about 1mm in diam eter to take the leads from the coil This provides a simple but effective means of holding the ends of each winding in place Tuned winding L2 starts about 10mm or so from one end of the former Start by threading the free end of the wire through the appropriate hole 5 in the former to leave a lead about 250mm in length Then wind two turns around the former and produce a small loop 4 in the wire This will act as a con nection point for the tapping on coil L2 To complete the winding
226. the Data input is set at the correct logic level for the first bit of data which in this example is logic 1 A pulse is then supplied to the Clock input and it is on the low to high transition that the data is clocked into the first cell of the shift register This process is repeated until all 32 bits have been clocked into the chip For the sake of simplicity in the example of Fig 2 there are only four bits of data with the first two at logic 1 and the second two at logic 0 Data Strobe Fig 2 Simplified timing diagram for the UCN5818AF All Change As each bit of data is clocked into the chip the data already in the shift register is moved one place further along The first bit of data therefore appears on out put 1 pin 38 initially but has worked its way along the line to output 32 pin 3 by the time the thirty second bit has been clocked in o DO 2 O Strobe 1 To Printer O ALF 14 Port O Gnd Fig 3 The complete circuit diagram for the 32 bit Output Port The only external component is capacitor C1 Everyday Practical Electronics October 2001 The data in the shift register is not valid until the final bit in a set of 32 has been clocked into the chip and it must not be placed on the output pins until then One solution is to hold the Blanking input at pin 19 high while data is being fed into the chip This switches on the cur rent sink at each output and switches off the curren
227. the parallel printer port on e Software for simulating digital logic circuits i e Create your own macros highly scalable deed Pe eo Hood WINANGUN Create your own circuits components and i c s c Ee y Mcd ic Although the course focuses on the use of e Easy to use digital interface the PlCmicro series of microcontrollers e Animation brings circuits to life this product will provide a relevant Counter project e Vast library of logic macros and 74 series i c s with data sheets background in C programming for any e Powerful tool for designing and learning microcontroller PRICES Hobbyist Student 45 inc VAT Institutional Schools HE FE Industry 99 plus VAT Prices for each of the CD ROMs above are 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 ELECTRONIC 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 u
228. to divO Division by zero movlw 16 16 bit division movwf bitcnt clrf remdrH Clear remainder clrf remdrL dvloop clre Set quotient bit to 0 rlf dividL Shift left dividend and quotient rlf dividH Msb into carry rlf remdrL and then into partial remainder rlf remdrH movfw divisH Compare partial remainder and divisor subwf remdrH w skpz goto testgt Not equal so test if remdrH is greater movfw divisL High bytes are equal compare low bytes subwf remdrL w testgt skpc Carry set if remdr divis goto remrlt movfw divisL Subtract divisor from partial remainder subwf remdrL skpc Test for borrow decf remdrH Subtract borrow movfw divisH subwf remdrH bsfdividL O Set quotient bit to 1 Quotient replaces dividend which is lost remrlt decfsz bitcnt goto dvloop clr Clear error flag z divO return Return with z set if error end Peter Hemsley via the Net Thank you Peter that s great This code has been added to our PIC Tricks folder which is available on EPE Disk 4 and from our FTP site see EPE PCB Service page for details Readers we now have several hints and code routines of use to PIC programmers in our PIC Tricks folder If you have any short hints or bits of code you think might be useful to add as well send it to me for possible inclusion Everyday Practical Electronics October 2001 PLCs AND SCHOOLS Regarding your July 01 Editorial I rather got the impression that Editor
229. to zero Preset VR2 is adjusted so that the output voltage is at the required value If it rises the voltage at the wiper will exceed the ref erence value and the oscillator on times will be reduced in relation to the off peri ods If the output voltage falls the on times will be increased The regulator has Everyday Practical Electronics October 2001 in built short circuit protection and it will turn down when approximately 2 5A is exceeded Resistor R14 and capacitor C5 connect ed in series to pin 3 frequency compensa tion determine the regulation loop gain characteristics The values specified are those recommended by the manufacturer Capacitor C6 connected to pin 6 soft start prevents a current surge when the regulator is switched on FINAL PROTECTION Optional last ditch protection is pro vided by Zener diode D11 which is con nected across the output after fuse FS3 This provides protection in the event of some catastrophic circuit failure resulting in a sudden rise in output voltage sia GCHIOFF POLE The Zener breakdown voltage is selected to be about 25 per cent higher than the output voltage so that it does not normally conduct If the voltage tries to rise for some reason the Zener diode clamps this at its breakdown voltage and a large current can flow through it The current would be much greater than could be handled continuously but the fuse
230. try out plus a simple computer interface which allows a PC to be used as a basic oscilloscope ONLY 1 2 45 including VAT and p amp p We accept Visa Mastercard Amex Diners Club and Switch cards 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 TEACH IN 2000 CD ROM ORDER FORM Please send me quantity TEACH IN 2000 CD ROM Price 12 45 approx 20 each includes postage to anywhere in the world Post Code C enclose cheque P O bank draft to the value of Please charge my card Card Bus anda urbe uS Gai PEE PNE E PEE LEE EE Expiry Date Switch Issue No Note Minimum order for cards 5 SEND TO Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail orders 9 epemag wimborne co uk Online store www epemag wimborne co uk shopdoor htm Payments must be by card or in Sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order SAVE UP TO 68p AN ISSUE DON T MISS THE WINDOW OF OPPORTUNITY MAKE SURE OF YOUR COPY NOW FREE 16 Page Supplement PIC TOOLKIT TK3 FOR WINDOWS Plus TEACH IN 2002 Part 1 Annual subscription rates 6 Months UK 15 Overseas 18 standard air service 27 express airmail 1 Year UK 28 50
231. ts is now low Now imagine then that the other touchswitch S2 IC1d is touched Follow the same logic sequence and you will see that the bistable latch changes state since IClc and ICld essentially invert one another when one output is high the other is low and vice versa This switches one l e d flasher on while it switches the other off IN SEQUENCE It is interesting to note that we have here arguably a one bit computer It has a Keyboard two touchswitches a memory to memorise your last key press logic i c s may serve as a form of memory and a display the different coloured l e d s At any rate this is the only project in this Uniboard series which uses sequential logic instead of combinational logic Combinational logic merely reacts to the present state of the inputs or the combina tion of highs and lows which are present at the inputs Sequential logic on the other hand is influenced by a previous state of the inputs Also it is interesting to note just what it is that constitutes memory In digital electronics it is feedback which is used to store events In this case the outputs of COMPONENTS REGISTER Resistors R5 R8 33M metal See film 2 off D R6 R9 10k carbon S film 2 off R7 eae TALK page film R10 39 carbon film R11 R12 22M metal film 2 off All 0 25W 5 or better Capacitor C3 C4 47n polyester film 2 off Semiconduct
232. ttery life this should be regarded as a peak figure A better practi cal limit is 1 5A The author s camcorder never requires more than 900mA and it seems unlikely that any amateur equip ment would need 1 5A If the power in watts is stated in the user s manual divide this by the nominal battery voltage to arrive at the average cur rent Another method would be to work from the battery s stated amp hour Ah capacity dividing this by the known oper ating time in hours Multiply the average current by 1 5 to give a safety margin and to take account of instantaneous demands It is not advisable to measure the current directly unless you are certain of being able to maintain the correct polarity and avoid short circuiting the battery BATTERY CHOICE Lead acid batteries have been chosen for this circuit because they provide a high capacity for a relatively small cost Two 6V batteries are used rather than a single 12V one because these may be charged simulta neously from a 12V car supply A single 12V battery would not be satisfactory because when the battery was well charged there would be no voltage differ ence to drive the current through The specified batteries have a capacity of 7Ah but others could be used with a pro portional change in operating and charging time However do not use a capacity less than 4Ah Note that a pair of 7Ah units provides the equivalent of about 10Ah for a 6V camcorder because the circuit
233. u to plug 2 telephones into the one socket for all normal BT plugs Price 1 50 Order Ref 1 5P50 D C MOTOR WITH GEARBOX Size 60mm long 30mm diameter Very powerful operates off any volt age between 6V and 24V 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 MOST USEFUL POWER SUPPLY Rated at 9V 14A this plugs into a 13A socket is really nicely boxed 2 Order Ref 2P733 MOTOR SPEED CONTROLLER These are suitable for D C motors for voltages up to 12V and any power up to 1 6h 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 BT TELEPHONE EXTENSION WIRE This is proper heavy duty cable for running around the skirting board when you want to make a permanent exten sion 4 cores properly colour coded 25m length Only 1 Order Ref 1067 LARGE TYPE MICROSWITCH with 2in lever changeover contacts rated at 15A at 250V 2 for 1 Order Ref 1 2R7 BALANCE ASSEMBLY KITS Japanese made when assembled ideal for chemical experiments complete with tweezers and 6 weights 0 5 to 5 grams Price 2 Order Ref
234. uits generally involved in sensing and measuring including amplifiers filters comparators and analogue to digital converters ADCs as well as specific circuits for various sensor applications C A P A C IT A N C E M ETE R We aim to give Teach In 2002 a broad appeal so that every reader will gain something from the series in one way or Although some modern multimeters have capacitance another We know that the theory will be highly relevant to measuring capability this is often limited to a maximum of schools and university students around 10 microfarads and is often inaccurate at both ends of Each part includes practical Lab Work based on the sensors the scale circuits and concepts discussed within it The experiments can The circuit described next month allows all types of capacitor be monitored by a multimeter or more fully demonstrated via including non polarised electrolytic and tantalum to be the recommended Picoscope ADC40 PC based oscilloscope measured accurately and over a wide range It measures which will be offered to readers at a special price These labs capacitance from a few picofarads to 10 000 microfarads in help reinforce practical principles that you can then three sub scales 10nF 10uF and 10 00QuF and is accurate incorporate into your own future project designs across the whole range PLUS ALL THE REGULAR FEATURES DON T MISS AN ISSUE PLACE YOUR ORDER NOW Demand is bound to be high NOV
235. unning in the back ground see Part 1 of the series This was achieved by using a normally closed mag netic switch to trigger gate IC1a as well as inverter IC1b LIGHT WORK Piezo disc sounder WD1 may be replaced with an l e d if desired or a l e d may be used together with WDI The l e d is wired between ICI pin 10 and the positive supply line with its anode a the longest lead being taken to positive Everyday Practical Electronics October 2001 Use a ballast resistor in series with the le d use the current limiting formula R V V see Part 2 Aug 01 A white l e d requires no ballast resistor since the effective current flow is limited by the regulator Only an extreme brightness l e d preferably with a narrow viewing angle should be used CONSTRUCTION The Gate Sentinel is built up on the Uniboard p c b as shown in the topside component layout details of Fig 2 together with the copper foil master This board minus components is available from the EPE PCB Service code 305 The Solar Powered Power Supply and Voltage Regulator July 01 components are included in this diagram Commence construction by soldering the link wires and the resistors in posi tion continuing with the diode and the capacitors The cathode k of diode D3 is banded and should be inserted as indicat ed in Fig 2 Finally insert ICI in its d 1 l socket being careful to observe the correct orientation a
236. wen Bishop 710 SCOOT systems speed the flow of road traffic and pedestrians NET WORK THE INTERNET PAGE surfed by Alan Winstanley 726 Sircam and other worms and viruses INTERFACE by Robert Penfold 738 Single chip 32 bit output port Regulars and Services EDITORIAL 687 NEWS Barry Fox highlights technology s leading edge 695 Plus everyday news from the world of electronics BACK ISSUES Did you miss these Many now on CD ROM 707 READOUT John Becker addresses general points arising 721 ELECTRONICS VIDEOS Our range of educational videos 724 SHOPTALK with David Barrington 727 The essential guide to component buying for EPE projects CD ROMS FOR ELECTRONICS 728 A wide range of CD ROMs for hobbyists students and engineers ELECTRONICS MANUALS 740 Essential reference works for hobbyists students and service engineers DIRECT BOOK SERVICE 742 A wide range of technical books available by mail order Wimborne Publishing Ltd 2001 Copyright in all drawings photographs and articles published in PRINTED CIRCUIT BOARD AND SOFTWARE SERVICE 745 EVERYDAY PRACTICAL ELECTRONICS is fully PCBs for EPE projects Plus EPE software protected and reproduction or imitations in whole or in part are expressly forbidden ADVERTISERS INDEX 748 Our November 2001 issue will be published on x P Thursday 11 October 2001 See page 679 for details Readers Services e Editorial and Advertisement Departments 687 Everyday Practical Electronics October
237. will not find anything unusual in the listing in fact it is based on a standard algorithm optimised for the PIC instruction set Note the lines that show how to compare two 16 bit numbers using the limited instructions of the PIC However it is worth noting that a bug exists in Microchip s standard division routine It s the carry or borrow out from double precision addition or subtraction that I found is not guar anteed to be correct for all possible input values The double precision addition and subtraction codes are standard ones published in various Microchip documents and must have been used an unimaginable number of times by PIC pro grammers around the world The good news is that my division routine is OK because a borrow out from the double precision subtraction is guaranteed not to occur Divide 16 bit dividend dividL H by 16 bit divisor divisL H Result quotient in dividL H and remdrL H processor 16f84 include p16f84 inc radix dec Ram equates dividL equ OxC Dividend and quotient quotL equ dividL dividH equ OxD quotH equ dividH remdrL equ OxE Remainder remdrH equ OxF divisL equ 0x10 Divisor divisH equ Ox11 bitent equ 0x12 Bit count divd equ 5432 Test code for MPLAB simulator divs equ 22 org 0 test movlw low divd movwf dividL movlw high divd movwf dividH movlw low divs movwf divisL movlw high divs movwf divisH call divide return divide movfw divisL iorwf divisH w skpnz go
238. with numerous breadboard circuits to try out plus a sim ple computer interface which allows a PC to be used as a basic oscilloscope ONLY 12 45 including VAT and p amp p Robotics INTRODUCING ROBOTICS WITH LEGO MINDSTORMS Robert Penfold Shows the reader how to build a variety of increasingly sophis ticated computer controlled robots using the brilliant Lego Mindstorms Robotic Invention System RIS Initially covers fundamental building techniques and mechanics needed to construct strong and efficient robots using the various click together components supplied in the basic RIS kit Then explains in simple terms how the brain of the robot may be programmed on screen using a PC and zapped to the robot over an infra red link Also shows how a more sophisticated Windows programming language such as Visual BASIC may be used to control the robots Details building and programming instructions provided including numerous step by step photographs 288 pages large format ela 14 99 MORE ADVANCED ROBOTICS WITH LEGO MINDSTORMS Robert Penfold Covers the Vision Command System Shows the reader how to extend the capabilities of the brilliant Lego Mindstorms Robotic Invention System RIS by using Lego s own accessories and some sim ple home constructed units You will be able to build robots that can provide you with waiter service when you clap your hands perform tricks see and avoid objects by using
239. y added if preferred A chassis measuring approximately 203mm x 63mm x 152mm will comfort ably accommodate everything What is intended to be the base plate is used here as the front panel The general layout of the receiver can be seen from the photographs and the exact positioning of the main components is not critical Switch S1 potentiometer VRI and phone jack socket SK4 are effectively used to bolt the front panel to the chassis Tuning capacitor VC1 and bandspread capacitor VC2 are mounted on the front panel above the chassis Some variable capacitors have ordinary 10mm mounting bushes but most types use two or three mounting bolts If mounting bolts are used it is essential that they do not pene trate more than about three or four mil limetres into the capacitor With greater penetration there is a real risk that the bolts will foul the plates and ruin the component Front panel is held in position by the mounting Everyday Practical Electronics October 2001 bolts of the switch potentiometer and headphones socket The valveholders require main mounting holes about 16mm in diameter The holders themselves can be used as templates when marking the positions of the smaller mounting holes These take either metric M3 or 6BA mounting bolts Solder tags are mounted on three of these bolts on the underside of the chassis to provide chassis connection points Hard wired construction is used through out and this

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