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Everyday Practical Electronics 2009-07 - cycle

1. K8021 Kit 155 37 Sub Woofer Amplifier Bass reflex system with adjustable tube Complete kit exc wood panels to build a 100W compact active sub woofer 25 100Hz K8077 Kit 85 80 Velleman Instruments We also carry the Velleman range of fully assembled test equipment This range of hand held Scopes and PC based measurement equipment uses all the latest techniques to achieve state of the art equipment that would be at home in any industrial applications or in the hands of the enthusiast PcLab bode plotter SB PC Oscilloscope A digital storage oscilloscope uses the power of your PC to visualize electrical signals Its high sensitive display resolu tion down to 0 15mV combined with a high bandwidth and a sampling fre quency of up to 1GHz are giving this unit all the power you need Two channel U PCSU1000 USB PC Scope amp Probes 316 64 2MHz USB PC Function Generator A digital function generator which can be connected with a PC via USB Standard signal waves like sine triangle and rec tangle are available other sine waves can be easily created The signal waves are created in the PC and produced by the function generator via DDS Direct Digital wave Systhesis PCGU 1000 USB Function Generator 118 38 05 op 10 15Vdc supply USB Scope amp Function Generator A complete USB powered lab in a box Feature packed 000 LT software for two channel
2. 7 78 Full specs on our web site 113 67 Handheld Oscilloscope l e40MHz Sampling rate e 12Mhz Analogue bandwidth High resolution LCD with Backlight Data recorder function RS232 PC Link Supplied with Probe Carry case amp Leads ee HPS40 Handheld Scope 257 06 e Other Velleman Instruments APS230 Advanced Personal Scope 385 00 4 HSP10 Handheld Scope 115 14 HSP10SE Handheld Scope inc case 128 22 HPS50 Handheld USB Scope 257 45 PCS500A PC Digital Storage Scope 317 46 PPS10 Personel Poscket Scope 115 13 VPS10 Panel Scope 115 53 4 PCS 10 4 Channel Data Logger 32 68 see our web site for full specifications Tel 0191 2514363 Cullercoats 5 50 50 greater than 1kg or gt 30 Fax 0191 2522296 Tyne amp Wear EE 5550 Postal orders payable to sales esr co uk NE30 4PQ ursa ESR Electronic Components Ltd PIC Programmer a yOver 300 Kits Mini Kits amp Modules check web site tor details Station Road H 9 The UK s number 1 source of VELLEMAN products We are the only current UK supplier able to offer the full range of Velleman Mini Kits Kits Modules amp Test Equipment All the latest products added as released Suitable for a wide range of Microchip PIC mi crocontrollers onboard configurable 40 pin ZIF 4 socket Microcontroller se lection using patch jumper easy to use programming
3. PlICprog2006 software included SUBD connector set included K8076 Kit 24 95 PIC Programmer For Microchip FLASH PIC microcontrollers supports 4 different 300 mil PICs 8p 14p 18p and 28p test buttons and LED indicators Supplied with programming examples amp easy connection to a PC through the serial port Supplied with a PIC16F627 and software to compile and program your source code K8048 Kit 25 38 VM111 Assembled 36 20 USB Interface A interface board with 5 digital input amp 8 digital output chan nels In addition there are two analogue inputs amp two ana logue outputs with 8 bit resolu tion All communication routines are contained in a Dynamic Link Library DLL You may write custom Win dows 98SE 2000 Me XP applications in Delphi Visual Basic C Builder or any other 32 bit Windows applica tion development tool that supports calls to a DLL K8055 Kit 25 65 VM110 Assembled 38 78 USB Interface Board With a toal of 334 input outputs including ana logue digital and 1PWM output Connection to the computer is galvanically op tically isolated so that dam age to the computer is not possible thus providing a high level of secure implementa tion Supplied with test software amp examples K8061 Kit VM140 Assembled Mini PIC Application Module Create your own custom PIC application without the hassle of making the hardware 9 Free programmable I Os Onboard Relay LEDs
4. HOW TO ORDER o ORDER ON LINE www jaycarelectronics co uk PHONE 0800 032 7241 FAX 61 2 8832 3118 o EMAIL techstore jaycarelectronics co uk POST P O Box 107 Rydalmere NSW 2116 Australia e ALL PRICING IN POUNDS STERLING o MINIMUM ORDER ONLY 10 Australian Eastern Standard Time Monday Friday 09 00 to 17 30 GMT 10 hours only Expect 10 14 days for air parcel delivery LUXEON STAR LED DRIVER KIT KC 5389 5 plus postage amp packing Luxeon high power LEDs are some of the brightest LEDs available in the world They offer up to 120 lumens per unit and will last up to 100 000 hours This kit allows you to power the 1W 3W and 5W Luxeon Star LEDs from 12VDC Use super bright and energy efficient LEDs in your car boat or caravan a e Kit supplied with PCB and all electronic components Super Bright 1 Watt LED Star Modules 5 plus postage amp packing These LEDs are just as bright as the leading brand but cost a whole lot less They are increasingly finding their way into general lighting applications and with a service life of 100 000 hours will virtually never need replacing They provide up to 25 lumens per watt and are available in a number of colours Z 0500 Red ZD 0502 Amber ZD 0504 Green ZD 0506 Blue ZD 0508 White ZD 0510 Warm white ag ame 12V LIGHT OPERATED KG 9090 7 28 RELAY KIT plus postage amp packing
5. PROGRAMMING THE PIC CHIP If you re not building the PlCprobe from a kit you must first program the 10F200 or 202 micro with the file PicProbe hex The software files are available for free download via the EPE Library site access via www epemag com Since the micro is a surface mount device programming it presents added complications Itmustbe done in circuit but before the board is fully populated This section explains how to do this You need both a Vpp voltage source of around 13V and a normal 5V supply If you have decided to use the 78L05 regulator then you can derive the 5V supply from that If you have chosen to omit the regulator you will need to apply 5V to pin 5 of the PIC micro and OV to pin 2 The micro must first be soldered in place making sure that the orientation is correct If you are using the regulator solder that in too then solder both the positive and negative supply leads to the board Special pads to access pins 1 3 and 6 of the PIC have been provided on the board specifically for programming These are labelled respectively A B and C on the component overlay The pad labelled GND can be connected to the external programming circuit shown above right You may solder wires to these pads for the programming phase and later when the micro has been successfully programmed remove these wires Back up pads for the links required in normal operation have also been
6. 179 95 Also available 30 in 1 19 95 50 in 1 29 95 75 in 1 39 95 130 in 1 44 95 amp 300 in 1 69 95 see website for details Tools amp Test Equipment We stock an extensive range f soldering tools test equipment power supplies inverters amp much more please visit web site to see our full range of products Two Channel USB Pc epee pce i This digital storage oscillo scope uses the power of your PC to visualize electrical sig nals Its high sensitive display resolution down to 0 15mV combined with a high band i width and a sampling fre quency of up to 1GHz are giving this unit all the power you need Order Code PCSU1000 399 95 Personal Scope 10MS s The Personal Scope is not a graphical multimeter but a com plete portable oscilloscope at the size and the cost of a good mul amp timeter Its high sensitivity down KATTA to 0 1mV div and extended scope functions make this unit ideal for hobby service automo tive and development purposes Becat of its exceptional value for money the Personal Scope is well suited for educational use Order Code HPS10 189 95 169 95 See website for more super deals www quasarelectronics com sec Online Ordering Facilities e Full produc Listing bso amp Photos e Kit Documentation amp Software Poon Everyday Practical Electronics Magazine has been publishing a series of popular kits by the acclaimed Silic
7. Mix articles this device is the more power ful and feature loaded part which we would have preferred to have used but for the fact that it is difficult to solder But then that is why kits like these are of interest they have done all the hard work in providing you with a small PCB fitted with everything you need to develop your own design The kit also comes with a standard PicKit 2 programmer which is the means by which new programmes are down loaded onto the PCB A 1GB MicroSD Media card is sup plied which you can use with the MicroSD card reader fitted to the PCB accessible using the Microchip flash filesystem software Phono leads are provided to connected to a television for video and sound output A cheap games controller modelled on the PS2 controller nicely emphasises the games aspect of the kit A simple RS232 adaptor enables you to connect a serial device or PC to the Everyday Practical Electronics July 2009 board That s a simple yet nice touch as it means you have a lot of connectivity without needing to dig out a soldering iron or visit your local electronics store to purchase exotic connectors A 300mA 9V DC unregulated power supply is also provided fitted with US style mains pins This comes as standard on kits supplied to Europe too so it isn t of much use but these power supplies are very cheap and readily available A close up of the PCB is shown in the photo above
8. Compression HF Drivers Twin amps for main amp HF unit Available in 10 100W 50W W 135 00 12 300W 100W 285 75 pair discounts available Behringer Eurolive 2 way Lightweight Speakers Maiin pdi piel Peak LED amp 2 wa EQ h mii o Compression HF Drivers Available in 12 B212A 450W 125dB 186 30 15 B215A 450W 126dB 215 10 pair discounts available ABS gopro Plastic construction multiple mount points W Band Stereo graphic equalizer 62 90 Band Stereo graphic equalizer A Q3 DEQ1024 Dia 31 band stereo graphic 6 05 DEQ2496 24bit EQ Real Time Analyser 175 10 FBQ2496 19 1U Feedback Distroyer 90 10 DSP110 Shark Feedback Distroyer 51 85 AMP800 Compact Headphone Amplifier 28 02 Media Player _ Dual SD Card player Plays MP3 files stored on standard SD cards upto 4 on CD players Speaker Cabinets Wooden cabs for all round PA use MC 8 MC 10 MC 12 pair discounts available 100V Line Horns Outdoor IP65 rated horn speak b with all the features normally found SDJ 135 00 97dB 8 75W 32 00 98dB 10 125W 40 85 99dB 12 200W 65 85 Moulded Cab with compression HF Driver Top hat amp Hanging mounts K112 100dB 12 300W 137 95 K115 102dB 15 400W 161 60 pair discounts available With integral transformer for 100V use 8 2 5 10 amp 15W Tappings 23 93 10 5 10 15 amp 25W Tappings 32 29 12
9. HOW TO USE OSCILLOSCOPES AND OTHER TEST EQUIPMENT R A Penfold 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 including signal generators logic probes logic pulsers and crystal calibrators Order code BP267 5 49 167 pages 91 pages 104 pages Everyday Practical Electronics July 2009 DIRECT BOOK SERVICE The books listed have been selected by Everyday Practical Electronics editorial staff as being of special interest to everyone involved in electronics and computing They are supplied by mail order direct to your door Full ordering details are given on the last book page FOR A FURTHER SELECTION OF BOOKS AND CDROMS SEE THE SHOP ON OUR UK WEBSITE www epemag co uk All prices include UK postage ELECTRONIC PROJECT BUILDING FOR BEGINNERS R A Penfold This book is for complete beginners to electronic project building It provides a complete introduction to the practical side of this fascinating hobby including the following topics Component identification and buying the right parts resistor colour codes capacitor val
10. Main Board Display Board MAY 09 Infrared Audio Headphone Link Microstepping Unipolar Stepping Motor Driver JUNE 09 Spectacular Bike Wheel POV Display double sided Remote Volume Control amp Preamplifier Module Main Board 714 set 711 set of 3 Display Board Ald Power Supply Board 716 JULY 09 Solar Water Heating System Controller Main Board Display Board PIC Probe double sided Simple Data Logging Weather Station Main Board RS232 Board EPE SOFTWARE All software programs for EPE Projects marked with a star and others previously published can be downloaded free from the Library on our website accessible via our home page at www epemag com PCB MASTERS PCB masters for boards published from the March 06 issue onwards can also be downloaded from our website www epemag com go to the Library section EPE PRINTED CIRCUIT BOARD SERVICE Order Code Project Quantity Price enclose payment of Everyday Practical Electronics Sja E Card No no N ea bie cra Nenia eroi Valid From Expiry Date Card Security No Maestro Issue No cheque PO in sterling only to Signature Note You can also order PCBs by phone Fax or Email or via the Shop on our website on a secure server http www epemag com Everyday Practical Electronics July 2009 CEASSIFIEDFADVERTISEMENTS Everyday Practical Electronics reaches more UK readers than
11. This kit can operate as a twilight on off switch or as a light trigger relay Operated from 12 volts this versatile project triggers a 6 amp relay when the light intensity falls below an adjustable threshold Turn lights on around the house when it goes dark or trigger an alarm when a light is switched on Kit supplied with Kwik Kit PCB relay and all electronic components Recommended plugpack MP 3002 Checkout Jaycar s extensive range For your FREE catalogue log on to www jaycarelectronics co uk catalogue or check out the range at www jaycarelectronics co uk amp lectronics 131 82 65 90 146 87 YE ouia DA 300 2x 150W 2U 19 PA 81 00 DA 500 2x 250W 2U 19 PA 100 00 DA 800 2 x 400W 2U 19 PA 131 00 DA 1000 2 x 500W 2U 19 PA 167 50 Powered Mixer By Behringer 2 x 450W_Amp 8 Mono Channels 2 Stereo Channels 3 Band EQ channel Clip LEDs Effects Processor Dual 7 Band Graphic PMP3000 260 10 Mixing Desk 4 Mono Channels 2 Stereo Channels Effects Processor 2 Aux Sends per channel USB Audio Interface 48V Phantom power XENYX 1204FX Mixer Powered Speakers ti i te a ny 2 40W Studio Monitor 2 way Speakers mile in Pairs Available in Black or White 63 50 per pair 107 10 ni qx Moulded Active PA Speakers Mic or Line level inputs Top hat amp
12. more for overseas Payment in sterling only please Visa Maestro and MasterCard accepted Send fax or phone your card number card expiry date valid from date and card security code the last 3 digits on or just under the signature strip with your name address etc Or order on our secure server via our UK website Overseas customers your credit card will be charged by the card provider in your local currency at the existing exchange rate C Produ har vest g blication ea ryesting Energy sing a Trade Publer orgeno ONES VOL 38 No 7 JULY 2009 amp Recently I ssan e are all g I e use 0 Editor MATT PULZER Consulting Editors DAVID BARRINGTON JOHN BECKER Subscriptions MARILYN GOLDBERG General Manager FAY KEARN Editorial Admin 01202 873872 Advertising and Business Manager STEWART KEARN 01202 873872 On line Editor ALAN WINSTANLEY EPE Online Internet version Editors CLIVE Max MAXFIELD and ALVIN BROWN Publisher MIKE KENWARD READERS TECHNICAL ENQUIRIES Email techdept 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 in
13. BACKUP HEAT Fig 6 Wiring to the main PCB may be there for 20 years so make it very secure Sleeve over the cable with UV resistant conduit or run it well behind the panel so the sun cannot degrade it Wrap the sensor with insulation so the air temperature round it and the first few cm of cable is at roughly the same temperature as the surface to be measured The sensor is more sensitive to its lead temperature than the pack age temperature so the cable must be exposed to the heat too For pipes the sensor can be fixed with a jubilee clip or tiewraps if not too hot to the pipe so glue is not needed but heat transfer compound and insulation as above is recommended Do not over tighten Solartwin panel On the back of a Solartwin panel mark a point half way across the panel and 100mm down from the top edge Cut a 25 x 60mm with 25mm being the vertical dimension plug from the insulation with a craft knife taking care not to score the metal collector plate of the panel under the insulation Prise it out with a blunt knife Push a 5mm drill bit parallel to the plate 25mm in under the foam in one corner of the hole to make a pocket for the sensor and ensure there is flat metal to slide the sensor up against Reinsert the insulation plug after gluing the sensor with the wires run ning along the collector plate face then 28 exiting along the side of the plug Tape over the plug and wires with duct tape so there a
14. CONS for the top sensor supply AEEA wrt 2 HHA TT L E Jo g ap F Connecting to other types of solar system On solar systems with 6V nominal PVs such as the latest Solartwin replace R14 and D14 with links and remove ZD2 With the lower gate drive voltage the FET on resistance will be a little higher but will still be low enough for a typical solar pump On non PV driven systems the posi tive or mains live end of the pump will be driven from a fixed voltage so there will be no light level input to drive the kWh calculation and to adjust the clock so connect a small 12V PV of about one watt to CON2 terminal 1 and 3 and do not connect the pump supply to terminal 3 The PV should be loaded to ensure its voltage output tracks the heat level of the sun as mentioned in Part 1 If the controller is not enough load adda resistor in parallel Remove the LED as it could overload a one watt PV A very small efficient 6V to 20V mains power supply could be used to charge the battery if this small PV has inadequate output and asmaller capacity battery is also then possible Remove R26 or its link and feed this fixed voltage straight into IC4 and IC5 For mains pumps drive a mains capa ble solid state relay from the FETs You can even eliminate the FETs diode OR the two IC2 outputs together and drive the relay from the diodes with the relay cathode to OV but R14 s value may need reducing to allow enough cu
15. If the orange LED stays on permanently in this mode then the probe tip is changing at a rate greater than 50ms In latched mode the orange LED will turn on and stay on with any change on the probe tip This is handy for detect ing very infrequent changes The latch is cleared and the LED turned off when the switch button is pressed The pushbutton switch has three functions 1 changing orange LED mode 2 clearing the latch and 3 ena bling a pull up resistor on the probe tip To change modes you press and hold down switch S1 button for two seconds After two seconds the orange LED will blink to indicate the mode is about to change When the button is released the mode is toggled In latch mode a single press of the button will immediately reset the latch If the button is pressed when power is first applied a pull up resistor on the probe tip is enabled Normally the pull up is disabled which makes the input impedance very high In this configuration the LEDs will flash ran domly until the probe is connected to the target test point This is very useful for tracking down floating circuits on the target under test If this is not an issue then enable the pull up and the tip will go to a soft logic 1 The only way to reset the pull up is to re power the probe Software Internally you don t get much room to play with in this tiny PIC Because the device is so small and the task rela tively simple th
16. K DATA LOGGING WEATHER STATION between the PIC pin 7 and each of the data lines to the three I C devices The PIC actually has a synchronous serial port for I7C bus interfacing but this hasn t been used here because it has more limitations than benefits Instead the I C interface is implemented fully in the firmware of the weather station The asynchronous RS232 serial port on the PIC is connected through a standard MAX23z2 serial interface driver IC2 pro viding suitable voltage levels for serial communication The MAX232 part of the circuit is manually switched on and off by the user using switch S4 when a data dump is needed Getting this part of the circuit to work proved more difficult than it might seem because even when switched off the MAX232 would sometimes stay in a partially run ning state It appeared to be drawing power parasitically through its three I O connections to the PIC Resistors 10kQ between the PIC and each of these I O lines solved that particular problem The RS232 interface is set up for 2 way communication but only transmission from the PIC is built into the firmware since this is all that is needed However the capability is there for the device to receive serial communication for anyone who wanted to extend the capabilities of the design Interfacing the rain sensor is simple The rain gauge is a tipping bucket type and operates by closing a switch mo mentarily each time the bucket empt
17. The normal screen will appear after a few seconds with no button presses cycling around the temperatures After a week the clock will have self adjusted to nearly the right time Always double press the buttons as there are regular short periods when the button detect routine is paused to allow other code to execute so it occasionally misses the first press Pressing the Menu button at any time will bring up the set variables screen again where you can enter your own preferences Each time the unit is reset or powered up again following a flat battery there is the option to revert to the default values but don t take this option as the defaults will already be stored in EEPROM and you may have modified them to your own values The hour needs setting again In the bottom right of the LCD it will display for pump on 0 for pump off and if the system exports heat At night the measurements are slowed down for power saving so dur ing each hour the Aux relay will only change state once and the buzzer sound for a few minutes at most Rewiring D16 anode from IC1 to the 3 6V rail instead would lead to the buzzer being available permanently if you require it Fail safe In the event of a persistent overheat or panel sensor failure an emergency macro comes in and sets the pump running continuously as long as there is some sun with a warning message to warn you to investigate why the event occurred The clock and kWh measur
18. polarity are not applicable to many real world components With the fancier types of LED it is usually necessary to consult the supplier s component catalogue This should provide a connection diagram With LEDs it is usually all right if the suck it and see method is used to find the correct method of connection Getting an LED connected the wrong way around should not result in any damage The reverse breakdown voltage of a LED is usually quite low and will probably be breeched if the component is connected with the Everyday Practical Electronics July 2009 wrong polarity Excess voltages usually zap semiconductors almost instantly but this is an exception and the component should not come to any harm The driver circuit for the LED will ensure that an excessive current cannot flow Of course in some circumstances it could be difficult to correct matters if you do not get it right at the first attempt You certainly need to know the correct method of connection before dealing with a large number of LEDs It is a good idea to check the polarity of LEDs before connecting them into a circuit and virtually every multi range test meter has a facility for checking the polarity of diodes Unfortunately LEDs have relatively high forward threshold voltages and this factor makes it impossible to test them using some meters Where a suitable test meter 1s available it certainly represents the easiest way of checking the pola
19. 00 MHD 55 Mid High range Horn 30W 21 83 DMX Control Desk 16 DMX Channels 8 Built in Programs 16 recordable LCD readout 16 Faders 16 Flash Buttons 19 Rack mountable 5U Smoke machine control Mic for sound activated programs DC 2416 DMX Midi Control Desk LED Lighting 128 00 PAR56 LED Can 5mm LEDs DMX 49 00 PAR56 LED Can 10mm LEDs DMX 46 70 DMX Flood 252 10mm LEDs DMX 87 75 LED Light Effects go online to see video s of these effects REVO II 156 LEDs DMX Moonflower effect 91 00 REVO III 392 LEDs DMX Moonflower effect 126 00 110 00 Quad Gem 224 LEDs DMX 4 lens effect Laser Light Effects HQ Power 40mW Green DMX Laser Effect 175 00 QTX 40mW Green 80mW Red Laser 164 99 Equinox 80mW Red 40mw Green Laser 195 00 Band Lighting fSolutioni Per ee b ri r Popular iColor4 professional 4 channel DMX flood light with colour mixer features Built in programs or full DMX ee i 2 x iColor4 DMX Effects inc lamps 222 50 2 x iColor4 with colour mixer amp foot control 324 99 Moving Heads DOW Lemp Acme Pan amp Tilt 11 Colors 14 Gobo s Stand alone master slave or DMX Built in Programs Sound activated Channels also available with 150W HID lamps 2 x iMove 5S Moving Heads UV Lighting Ultra Violet Lighting effects 400W UV Cannon no lamp 400W UV Lamp for above 2 Fluorescent Fitting amp Tube 4 Fluorescent Fitting amp Tube Rep
20. 10 minutes to make your first digital design It is so powerful that you will never outgrow its capability Software TINA includes the following Virtual Instruments Oscilloscope Function Generator Multimeter Signal Analyser Bode Plotter Network Analyser Spectrum Analyser Logic Analyser Digital Signal Generator XY Recorder Flowcode V3 Hobbyist Student For details on Flowcode see the previous page for simulating digital logic circuits Create ae your own macros highly scalable Create This offer gives you two seperate CD ROMs in DVD style cases the software will need registering FREE with Designsoft TINA and your own circuits components and i c s Matrix Multimedia Flowcode details are given within the packages Easy to use digital interface Animation brings circuits to life Vast library of logic macros and 74 series i c s with data sheets Powerful tool for designing and learning Hobbyist Student 44 inc VAT PROJECT DESIGN WITH CROCODILE TECHNOLOGY Sea Bit ece a oneMS An Interactive Guide to Circuit Design Site Licence 599 plus VAT An interactive CD ROM to guide you through the process of circuit design Choose from an extensive ELECTRON Te range of input process and output modules including CMOS Logic Op Amps PIC PICAXE Remote Control Modules IR and Radio Transistors Thyristors Relays and much more COMPONENTS PHOTOS A high quality Click Data for a complete guide to the pin
21. 14V 68Q 10V TO 16V 1009 Fig 10 5 If using a higher supply voltage insert a resistor in series with the LEDs constant of the circuit That is the responsiveness of the display so it is worthwhile experimenting with their values Since the signal from the micro phone is amplified by IC1 the cir cuit is very sensitive Indeed it will respond to a pin dropping The pins on IC2 are rather short so this IC needs to fit snugly close to the Protobloc Please Take Note Last month in the Lightning Detec tor IC2 should be a 7661 device The circuit is corect Next Month Festive Lights Construction brief e _ The longer lead is the anode the shorter lead is the cathode MIC 1 electret microphone 3 E Solder short lengths of 0 6mm dia insulated wire to the solder pads One pad is connected to its case so make sure this lead is connected to OV To ensure trouble free assembly you should try and follow these basic guidelines Always use single core 0 6mm diameter plastic sleeved wire for wire links not thicker The ends of the wire should be stripped of plastic for about 8mm The use of thicker wire can permanently damage the springy sockets underneath each hole Never use stranded wire it can fray and catch in the sockets or a strand can break off and cause unwanted connections below the surface of the breadboard It is very important to make sure that the bared ends of link
22. 45 each includes postage to anywhere in the world the pillow PIC Micro Probe A hardware tool to help debug your PIC software PIC Video Cleaner Improving video viewing on poorly maintained TVs and VCRs PIC Graphics LCD Scope A PIC and graphics LCD signal monitor for your workshop PIC to Printer Interface How to use dot matrix printers as data loggers with PIC microcontrollers PIC Polywhatsit A novel compendium of musical effects to delight the creative O enclose cheque F O bank draft to the value of musician l O please charge my Visa Mastercard Maestro PIC Magick Musick p y Conjure music from thin air at the mere untouching gesture Of Kete ENOM a fingertip PIC Mini Enigma Card Security Code Share encrypted messages with your friends true The last 3 digits on or just under the signature strip spymaster entertainment Valid From Expiry Date PIC Virus Zapper fee Can disease be cured electronically Investigate this e leave Slee ane controversial subject for yourself PIC Controlled Intruder Alarm SEND TO A sophisticated multi zone intruder detection system that l offers a variety of monitoring facilities Everyday Practical Electronics PIC Big Digit Display Wimborne Publishing Ltd Control the giant ex British Rail platform clock 7 segment Sequoia House 398a Ringwood Road Ferndown digits that are now available on the surplus market Dorset BH22 9AU PIC Freezer Alarm Tel 01202 873872 Fax 01202 874562
23. 5 10 15 20 25 amp BOW Tappinas 34 51 Wireless Radio Mic s UHF radio mic systems with 16 selectable frequencies PLL synthesized diversity system lied with carry case Available as a single hand backlit LCD readout sup S mic or dual hand mic Optional belt pack with head mic MP16UHF Single Hand mic UHF system 120 00 MP216UHF Dual Hand mic UHF system 188 50 Optional belt pack transmitter amp head mic 53 20 Radio Mic Spares Light weight replacement ead worn mics available in Black or skin coloured Fitted with 3 Pole mini XLR y connectors m HSE 150 SK Skin coloured 29 89 HSE 150 SW Black head mic 29 89 HSE 60 SK Skin coloured single ear 71 95 other styles available see web site for details Mic Speaker amp Lighting Stands Table top Mic stand Boom Mic stand chrome Aluminium Speaker Stand 398 611 21 Music Stand with sheet holder 10 50 Heavy duty lighting stand amp T bar 34 80 SGG GU a a Station Road H 9 Cullercoats A gS 5 50 greater than 1kg or gt 30 Tyne amp Wear Cheques Postal orders payable to NE30 4PQ ursa ESR Electronic Components Ltd Replacement Speakers lt 8 Pro music 150W speaker 17 37 200 433 10 Pro music 200W speaker 20 86 200 436 12 Pro music 250W speaker 28 96 200 439 15 Pro music 300W speaker 48 60 00 314 1 Pro series Tweeter 50W 8 70 200 318 1 Pro series Tweeter 50W 11
24. Controller 26 Everyday Practical Electronics July 2009 Constructional Project The main PCB the lightning protection diodes have not been fitted to this board the plugs put the PCBs loosely into the box and then hold the cable up against the plugs to see the alignment and length needed No twist is needed in the cable 110mm is the right length for the specified box but adjust it for your box if different Mount the main PCB on pillars about 3mm long on the base of the box Make sure none of the mounting screws con nect to any PCB track It is best to finally install the PCBs into the enclosure after the testing and calibration explained below has been completed Mount the buzzer in the box us ing double sided adhesive pads The prototype s one was too large to attach to the specified box s sides so it was stuck to the top of the components on the main PCB The relays have separate N O and N C contacts These are connected together by the PCB to make a changeover con tact but you can separate them into two contacts using track cuts if you need to Make sure the cuts are wide enough to withstand the voltage you apply Panel sensor For the panel sensor ICsens1 select wire that is able to withstand the tem perature of your panel Standard PVC cable is unlikely to be suitable You could use a short length of high tem perature wire such as PTFE insulated next to the panel and less expensive cable
25. E a O Project Design Single User same only the licence for use varies i O Project Design Multiple User under 500 students a O Project Design Multiple User over 500 students I I I I I 0 0 I I I I 0 I a POL TVA G ao acy Sasa E ETET EEA Sees we oe Ben ae tee ee aoe eae aeeees ees POMNCSS 2 2524 ee ye ee cee eee ees eee eee E eto e eee eee eaes ee ee POS COU spresti igni TORNO vacate edcaweadeceas t DION Ae sttcpies ee E E teen EEES O enclose cheque PO in sterling payable to WIMBORNE PUBLISHING LTD for O Please charge my Visa Mastercard Maestro t Valid From Card expiry date s Cad NO e rsrsirdsnns inidan ARAARA A Maestro Issue No Card Security Code The last 3 digits on or just under the signature strip hmmemeHeHememeeeemeeeemeHeemeeeeeememeemeeeeenemeeeeeeeeeeeee ee 64 Everyday Practical Electronics July 2009 Email editorial wimborne co uk Matt Pulzer addresses some of the general points readers have raised Have you anything interesting to say Drop us a line All letters quoted here have previously been replied to directly R WORTH 73 will be jf LETTER OF THE MONTH 5 Stripboard CAD Dear EPE You asked for comments on stripboard layout programs following Peter Barrett s letter in the April issue I have been using VeeCad for over a year and produced a number of boards with it in combination
26. Even though the 16F88 has an on board oscillator that could potentially run a real time clock this shuts down when the device sleeps Hence an external crystal oscil lator using a 32 768kHz watch crystal was needed The PIC keeps driving this crystal even when it is sleeping Although these crystals are pretty accurate they aren t perfect and can be out by maybe five seconds a day In the worst case over a year this can add up to an error of half an hour Details on using switch S2 can be found in Part 2 next month A second pushbutton switch S1 is accessible from the front panel This is used to reset the weather station Reset in this case does not mean a hardware reset of the PIC Instead the reset button is used to zero the address pointer for the EEPROM memory The user would normally do a reset after data is dumped so that all the memory in the device becomes available again for logging If a reset is not done via this button the weather station will keep logging from where it last left off This will happen even if the device is powered down or re boots itself due for example to a fault condition There is no way to wipe the EEPROM memory in the weather station This has been done deliberately to enable data to be recovered even if the address counter has become corrupted If a data dump is performed just after a reset the entire contents of the EEPROMs will be dumped all 64kB or 16 384 records four b
27. How to prevent your food from defrosting unexpectedly Email orders epemag wimborne co uk PIC World Clock Graphically displays world map calendar clock and global Payments must be by card or in Sterling cheque or barat bank draft drawn on a UK bank rojects ae A 3 part series using PICAXE devices PIC microcontrollers that Normally posted within seven days of receipt of order do not need specialist knowledge or programming equipment Send a copy of this form or order by letter if you do PIC based Muning Fork and Metronome not wish to cut your issue Thrill everyone by at long last getting your instrument properly tuned Versatile PIC Flasher Order on line from An attractive display to enhance your Christmas decorations www epemag com or your child s ceiling or by Phone Fax Email or Post BECOME A PIC PROJECT BUILDER WITH THE HELP OF EPE Recycle It BY JULIAN EDGAR Making an adjustable loud screamer This month we re re visiting our old friend the 12V phone charger As shown in Dec 08 it s easy to give these chargers an adjustable output voltage However it s also easy to make them perform a completely different function and here we use two to make a loud screamer N ADDITION to a couple of 12V car phone chargers you ll also need a small speaker for this project You can use any salvaged wide range speaker but in keeping with a mobile phone theme we used a boxed speaker from
28. It can even be used in older cars that don t have electronic ignition or used as an interceptor for cars with engine management systems Your spark plugs will thank you RECYCLE IT ANEMOMETER Next month we have a real treat for recycling fans especially those who kept an old video player on the off chance that surely it s too good to bin The connection between measuring wind speed and the technology to play Gone with the Wind you ll have to wait for the next issue AUGUST 09 ISSUE ON SALE 9 JULY ADVERTISERS INDEX BETA LAYOUT CRICKLEWOOD DISPLAY ELECTRONICS ESR ELECTRONIC COMPONENTS JAYCAR ELECTRONICS JPG ELECTRONICS LABCENTER LASER BUSINESS SYSTEMS MAGENTA ELECTRONICS NURVE NETWORKS LLC PEAK ELECTRONIC DESIGN PICO TECHNOLOGY QUASAR ELECTRONICS SHERWOOD ELECTRONICS SOLARTWIN STEWART OF READING ADVERTISEMENT OFFICES Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU PHONE 01202 873872 Fax 01202 874562 EMAIL epeads wimborne co uk For Editorial address and phone numbers see page 7 Published on approximately the second Thursday of each month by Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Printed in England by Acorn Web Offset Ltd Normanton WF6 1TW Distributed by Seymour 86 Newman St London W1T 3EX Subscriptions INLAND 19 95 6 months 37 90 12 months 70 50 2 years OVERSEAS standard air service 23 00 6 months
29. Number The SIM also stores other carrier specific data such as the SMSC Short Message Service Centre number Service Provider Name SPN Service Dialling Numbers SDN Advice Of Charge parameters and Value Added Service VAS applications as well as the subscriber s own stored contact list as a desk telephone are now quite affordable and are ideal for locations where you need a proper phone without the hassle or cost of a landline An example of these is the Telular Phonecell SX5d stocks of which can be found on UK eBay for 20 or so Be aware that there are several products with similar names you want the UK model that works on the GSM mobile system It accepts most UK SIM cards except those from the 3 network and can be used for phoning and texting wherever a normal mobile handset will operate Another brand to look for is the Nokia Premicell which is a mobile adapter for any standard telephone or switchboard You connect your phone to the black box and then you can use any phone even a black Bakelite one in your car holiday chalet site office caravan or boot sale pitch Some Premicells will work with telephones equipped with rotary dials The price of these versatile units on eBay is generally between 20 and 50 but it is important to know what you are buying check out the model number and type it into Google to find a data sheet Both the Nokia Premicell and the Telular Phonecell use a batt
30. PSU445 Main PCB 55x95mm Kit Order Code 3153KT 24 95 Assembled Order Code AS3153 34 95 Telephone Call Logger Stores over 2 500 x 11 digit DTMF numbers with time and date Records all buttons pressed during a call No need for any con nection to computer during operation but logged data can be downloaded into a PC via a serial port and saved to disk Includes a plastic case 130x100x30mm Supply 9 12V DC Order Code PSU445 Kit Order Code 3164KT 54 95 Assembled Order Code AS3164 69 95 ere are a few of the most recent products dded to our range See website or join our mail Newsletter for all the latest news 4 Channel Serial Port Temperature Monitor amp Controller Relay Board 4 channel computer F serial port temperature monitor and relay con troller with four inputs for Dallas DS18S20 or DS18B20 digital ther mometer sensors 3 95 each Four 5A rated relay channels provide output control Relays are independent of sensor channels allowing flexibility to setup the linkage in any way you choose Commands for reading temperature and relay control sent via the RS232 interface using simple text strings Control using a simple terminal comms program Windows HyperTerminal or our free Windows application software Kit Order Code 3190KT 69 95 Assembled Order Code AS3190 84 95 40 Second Message Recorder Feature packed non volatile 40 second multi message sound
31. R A Penfold This book is primarily aimed at beginners and those of limited experience of electronics Chapter 1 covers the basics of analogue and digital multimeters discussing the relative merits and the limitations of the two types In Chapter 2 various methods of component checking are described including tests for transistors thyristors resistors 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 experience is assumed Using these simple component and circuit testing techniques the reader should be able to confidently tackle servicing of most electronic projects 96 pages Order code BP239 5 49 DIGITAL GATES AND FLIP FLOPS lan R Sinclair This book intended for enthusiasts students and technicians seeks to establish a firm foundation in digital electronics by treating the topics of gates and flip flops thoroughly and from the beginning No background other than a basic knowledge of electronics is assumed and the more theoretical topics are explained from the beginning as also are many working practices The book concludes with an explanation of microprocessor techniques as applied to digital logic 200 pages 9 95 OPERATIONAL AMPLIFIER USER S HANDBOOK R A Penfold The first part of this book covers standard operational amplifer based building blocks integrator precisio
32. SP183 20 x BC547B transistors SP104 15 x 16 pin DIL sockets SP186 8 x 1M horizontal trimpots SP109 15 x BC557B transistors SP189 4 x 5 metres solid core wire SP112 4 x CMOS 4093 SP192 3 x CMOS 4066 SP115 3 x 10mm Red LEDs SP195 3 x 10mm Yellow LEDs SP116 3 x 10mm Green LEDs SP197 6 x 20 pin DIL sockets SP118 2 x CMOS 4047 SP198 5 x 24 pin DIL sockets SP124 20 x Assorted ceramic disc caps SP199 5 x 2 5mm mono jack plugs SP130 100 x Mixed 0 5W C F resistors SP200 5 x 2 5mm mono jack sockets SP131 2 x TLO71 Op Amps SP133 20 x 1N4004 diodes SP134 15 x 1N4007 diodes SP135 5 x Miniature slide switches SP136 3 x BFY50 transistors Catalogue available 1 inc P amp P or FREE with first order P amp P 1 75 per order NO VAT Cheques and Postal Orders to RESISTOR PACKS C Film RP3 5 each value total 3650 25W 3 40 RP7 10 each value total 730 0 25W 4 65 SHERWOOD ELECTRONICS RP10 1000 popular values 0 25W 6 60 RP4 5eachvalue total3050 W 4 20 M PEAH Ors AT a JJ RP8 10 each value total 610 0 5W 6 85 d 5 RP11 1000 popular values 0 5W 8 95 P CRICKLEWOOD g ELECTRONICS Established 1981 Frustrated with your supplier Visit our component packed website for a vast range of parts old and new many unavailable elsewhere www cricklewoodelectronics com 1000 s OF PRICES REDUCED Alternatively phone us on 020 8452 0161 with your requirements Ww Visit our Shop Call or Buy online at www cr
33. a hands free car phone system You can often pick these up at the same time as phone chargers Cost Well at garage car boot sales and the like expect to pay only a few pounds for the lot But what can you do with these bits and pieces One answer is to make avery loud pulsing screamer Components In this system the two phone charg ers perform different functions The first is modified to produce a pulsing output voltage which in turn pow ers the second charger The second charger is modified to produce the audio output tone which is fed to the speaker And the speaker Well it makes the loud noises The modifications to the charger boards are very easy and it takes only CAR PHONE CHARGER 1 PULSING 12V SUPPLY a few minutes to get the screamer up and running In addition to the chargers and the speaker you ll also need a selection of capacitors You ll only end up using two of them but having a range avail able makes it easy to get the sounds you want Building it The first step is to modify one of the chargers to produce the pulsing output Begin by removing the printed circuit board from its cigarette lighter plug enclosure then remove the out put filter capacitor This is the electro lytic capacitor that s usually located near to the output leads a typical value is 680uF Just desolder it and place it in your parts drawer you never know when it might come in handy for some other projec
34. amateur radio or short wave listening station Often the experience which is needed is learned by one s mistakes however this can be expensive To help overcome this guidance is given on many aspects of setting up and running an efficient station It then proceeds to the steps that need to be taken in gaining a full transmitting licence Topics covered include The equipment that is needed Setting up the shack Which aerials to use Methods of construction Preparing for the licence go mrerole m oe010 0 4 45 86 pages 25 SIMPLE INDOOR AND WINDOW AERIALS E M Noll Many people live in flats and apartments or other types of accommodation where outdoor aerials are prohibited or a lack of garden space etc prevents aerials from being erected This does not mean you have to forgo shortwave listening for even a 20 foot length of wire stretched out along the skirting board of a room can produce acceptable results However with some additional effort and experimentation one may well be able to improve performance further This concise book tells the story and shows the reader how to construct and use 25 indoor and window aerials that the author has proven to be sure performers Order code BP136 2 25 AN INTRODUCTION TO RADIO WAVE PROPOGATION J G Lee Radio wave propogation is one of the more important discoveries made in the early 20th century Although technology lagged behind early experimenters pursu
35. and install the PCBs into the case If testing a complete system after connecting it all up bear in mind that every day has different weather and day length so your measurements may vary day to day Also remember that the PV voltage varies depending on whether the pump is on or off The pump may load the voltage down many volts see Table 1 last month For sensor error messages on the LCD a LO indication is a sign of a short circuit sensor or wiring or open circuit on positive supply or an equivalent for on board components An HI indica tion means open circuit earth wiring or maybe a faulty sensor Connecting up Connections to the pump panel and sensors are shown in Fig 6 Any or terminal can usually be used for any sensor but if lightning suppression is fitted on or off board do not connect any sensor other than ICsens1 to CON4 terminal 1 or 2 Unused sensor inputs should be linked to Sensor Ve on the connectors with a 1 to10k resistor For the backup heating you need to work out how to connect it in On many gas heating systems it will need the changeover contacts of RLA con necting in across the HWC thermostat or central heating controller Google for Honeywell X and Y Plan circuits to see how most are wired Beware they are usually at mains potential so observe precautions below about mains If lightning protection is on board only allow the panel sensor and supply to be connected to CON4 use
36. are indeed many circuit configurations Even with the same circuit structure it is possible to find component values to be different for the same stated cut off frequency because other characteristics of the filters are different Furthermore full analysis of filter circuits requires some advanced mathematics so anyone who has not studied mathematics or engineering to university level will probably struggle with the more mathematical treatments of the topic Fortunately you do not have to use advanced maths to design and make use of filter circuits The well known filter configurations have been extensively studied and boiled down to recipes for finding component values Traditionally this was done with the help of books containing tables of values but now as you might expect there are software tools that can do even more of the work for you To make appropriate choices even designing filters from recipes it helps to know the relevant terminology including some terms relating to the mathematics and something about the different filter characteristics and circuits available so that is what we will be looking at now in Circuit Surgery This month we will look at basic terms and filter characteristics and next month we will look at some popular filter circuits However before we start we will take a quick look at the choice of op amps 56 Op amp choices The LM324 mentioned in Paul s post is a low power quad
37. be writing the next DOOM3 graphics system on this platform but rather re creating games from the 1980s arcades Don t be put of by this however Few of us have the skill and knowledge to fully understand today s complex graphics algorithms but with this system it is possible for anyone to fully understand and develop their own games That in itself is quite an achievement and can be enormous fun and very satisfying The style of the book is quite infor mal and often in the first person so it gives the sense that the author is in a one to one conversation with you The book has not been well proofread which can sometimes cause confusion but overall the author s passion for the subject comes across strongly and you cannot help but soak up some of it It s an enjoyable read which is unusual for a user manual DVD The DVD holds all the source code described in the manual including demonstration applications that can be quickly downloaded onto the PCB All the software tools mainly Microchip s MPLAB v8 15 and PIC24 C compiler are supplied Even the full schematics of the board are provided which will make hacking the board or designing your own add on PCBs easy There are several other eBooks in PDF format including Andre La Mothe s The Black Art of Video Game Console Design It s an unusual but very entertaining book with the first 510 of 900 pages covering the develop ment of electronics
38. cap it can save some nasty stabs Also note the S1 access hole in the pen body Constructional easiest to get in SMD and in small quantities But there would be some benefit if one of the two downstream capacitors ie between the regulator output and ground OV could be larger in fact as large as you can get in SMD The second change was in the input circuit The PIC only has six pins two of which are the power supply GP3 pin 6 the probe input can withstand a maximum of 13 5V In the vast ma jority of circumstances this would be more than adequate but once again we ve gilded the lily somewhat by Ts4148 LEDS UNDER SIDE TS4148 adding a pair of diodes D1 D2 across the input one each to the positive sup ply and ground OV along with a series resistor This protects the input from accidental higher voltages and for the price is a worthwhile addition This is very handy in case you touch something at a higher potential than the power supply If you don t need this protection the diodes can simply be omitted The 4 7kQ resistor could be retained or replaced by a wire link if you wish It won t matter either way 2 8 5V OR REG1 78L05 6 15 V ONLY REQUIRED FOR HIGHER VOLTAGE OPERATION SEE TEXT IC1 PIC 1 OF 200 OR PIC 1 OF 202 NOTE ALL DEVICES IN THIS PROJECT ARE SURFACE MOUNT 78 L05 PIC1 OF20X IN GND MMUN2211 PICPROBE gt 9 ow D F
39. devices and conventional compo nents For a detailed explanation we refer readers to pages 16 and 17 of the January 2009 issue The other big difference in this project is the size or lack thereof of the PC board Like the SMDs them selves it is tiny The double sided printed circuit board component layout and full size board are shown in Fig 2 The board is available from the EPE PCB Service code 717 This board does not have plated through holes so you will need to make some links between the two copper layers of the board These are easy to make using short lengths of tinned copper wire This board measures just 106 x 5mm and should be a relatively snug fit in side the pen case Don t push it all the way in to check though you may not be able to get it back out again Fig 2 install the parts on the PC board as shown in this twice size overlay Note that this assembly differs slightly from the accompanying photo which shows the author s prototype ie no regulator or input protection diodes for working at higher voltages MC785L05 TS4148 x2 I U D O JE 100n F L REG1 TW ICE FULLSIZE 0 Lo 2007180 ALL CO MPON ENTS ARE SM D AN D ON COPPER SIDE OF PC BOARD A B C AN D GN D ARE USED FOR IN CIRCUIT PROG RAMMING SO LDER DARNING NEEDLE 35 40mm OV FOR CLARITY OF PC BOARD E AC TUAL SIZE PICPROBE Constructional
40. extra cost Free Phone UK 0800 389 8560 Simply send your layout files and order ONLINE PCB POOL COM sales pcbhb pool com a ae Everyday Practical Electronics July 2009 E 100 solar electric pump saves more energ y Simple installation joins existing pipes VS 5 year system performance warranty j No antifreeze chemicals w Quote ref SS EPE 0609 4 yo ae Fs for your Se Me special i discount fn poke mii One CEN install WON ZAKK One storey phone survey standard installation Price includes 5 VAT anc cie cuni when quoting EPE 0609 DIY kits justi 2299W Full kit excludes delivery Includes 15 VAT and discount when quoting EPE 0609 instant phone quotes brochure 24hr 0845 1300 137 Ww salartwin com higsolartwin canm E Renewable Energy Association Member Association for Environmentally Conscious Building Member ji ELECTRONICS LTD MICROSTEPPER Stepping Motor Driver May 09 EPE 1 2 1 4 1 8 and 1 16 microstep driver for standard 4 phase _ unipolar motors Up to 46V at 3A 4 Adjustable current with efficient PWM control Opto isolated in puts and outputs for computer LPT or logic level control SLA7062M driver chip contains ae all sequencer logic Only needs KIT 920 Step and Direction inputs C1 8 76 Kit includes PTH circuit board Chip and all components Connection details and Slow 1 Speed demo PC software free 4 dow
41. fault finding and repairing valve amplifiers A hands on approach to valve electronics classic and modern with a minimum of theory Planning fault finding and testing are each illustrated by step by step examples A unique hands on guide for anyone working with valve tube in USA audio equipment as an electronics experimenter audiophile or audio engineer Particular attention has been paid to answering questions commonly asked by newcomers to the world of the vacuum tube whether audio enthusiasts tackling their first build or more experienced amplifier designers seeking to learn the ropes of working with valves The practical side of this book is reinforced by numerous clear illustrations throughout Order code NE40 23 99 368 pages AUDIO AMPLIFIER PROJECTS R A Penfold A wide range of useful audio amplifier projects each project features a circuit diagram an explanation of the circuit operation and a stripboard layout diagram All constructional details are provided along with a shopping list of components and none of the designs requires the use of any test equipment in order to set up properly All the projects are designed for straightforward assembly on simple circuit boards Circuits include High impedance mic preamp Low impedance mic preamp Crystal mic preamp Guitar and GP preamplifier Scratch and rumble filter RIAA preamplifier Tape preamplifier Audio limiter Bass and treble tone controls
42. features to a variety of applications while maintaining extremely low power and small size The PIC18F46J50 devices include full speed USB 2 0 for designs requiring connectivity for remote field upgrades or the downloading of data Both MCU families include a unique mTouch sensing peripheral which lowers system cost by enabling capacitive touch user interfaces Additionally a Peripheral Pin Select PPS function gives designers the flexibility to map the desired digital peripherals to I O With all of these features the new MCUs provide the peripheral set of a typical 64 or 80 pin device in only 28 or 44 pins Numerous applications can benefit from the extreme low power and peripheral integration of the PICI18F46J11 and PIC18F46J50 MCUs across consumer industrial automotive and medical markets Designers looking to evaluate the new PICI8F46J11 devices can use the PIC18 Explorer Board part number DM183032 99 99 and Plug In Module part number MA1 80023 25 The PIC18F46J50 MCUs are supported by the new PIC18F46J50 FS USB Demo Board part number MA1 80024 45 which also plugs in to the PIC18 Explorer Board The six PICI8F46J50 USB 8 bit family members are available now for general sampling and volume production The 28 pin package options for the PIC18F24J50 PICI8F25J50 and PIC18F26J50 MCUs are QFN SSOP SOIC and SPDIP The 44 pin package options for the PIC18F44J50 PICI8F45J50 and PIC18F46J50 MCUs are QFN
43. from VCR heads Or perhaps you ve found how the guts of a cassette player can be easily turned into a metal detector Well we made the last one up but you get the idea lf you have some practical ideas write in and tell us board the inductor is placed near to the output and is simply acoil of wire A second bridging link should also be installed across the output diode on each board see Fig 2 The prototype was configured to produce a very loud 200ms burst of 300Hz sound at one second intervals so it was configured more as a growler than a screamer This involved us ing a supply voltage of 12V a 470uF capacitor in the pulsing charger and a 47uF capacitor in the tone charger In addition the inductors and output diodes were bridged on both chargers as described above Housing your screamer Many hands free speakers use boxes that are held together with screws allowing the enclosure to be easily opened If that s the case the two modified chargers can be insulated eg by being wrapped in electrical tape and then placed inside the enclosure one each side of the speaker basket Alternatively the chargers can be housed in a separate case EPE 45 STORE YOUR BACK ISSUES ON CD ROMS ae different drum sounds L TNA Gone OF SHG seven instruments atfone time pala platefhand plateland footlacty US SONY ira and volume 7 Tj SAGHEIN Using PIC OGM gantin oro
44. from the ground up all the way back to semiconductor theory Like the XGS user manual it is written in a very open relaxed style and the passion of the author comes across quite strongly A passion that is rather infectious Software Although much of the low level software provided has been written in assembly language all of the demon stration code and tutorials assume use of the C programming language There are no tutorials on the C language they had to stop somewhere so if you are not comfortable with programming in C then you should consider getting a few books on the subject first Nurve are working on a BASIC com piler for the XGS but to obtain the best results from this tiny system we would advise that C with a little assembly is the best route to take The software is presented in simple logical blocks within the user manual which makes it very easy to cut and paste into your own applications NTSC verses PAL Having been developed in the US it should come as no surprise to learn that all the example programs have been written to comply with the 41 NTSC video standard For those of us in countries that use PAL or SE CAM the video will still sync on our televisions but the display will be in monochrome Nurve haven t at present any plans to produce PAL video drivers but are expecting that someone in the XGS community will develop a suitable driver and make it available publicly The
45. getting bogged down in understanding the programming Flowcode produces MPASM code which is compatible with virtually all PICmicro programmers When used in conjunction with the Version 3 development board this provides a seamless solution that allows you to program chips in minutes Requires no programming experience Allows complex PlCmicro applications to be designed quickly Uses international standard flow chart symbols Full on screen simulation allows debugging and speeds up the development process e Facilitates learning via a full suite of demonstration tutorials Produces ASM code for a range of 18 28 and 40 pin devices New features in Version 3 include 16 bit arithmetic strings and string manipulation improved graphical user interface and printing support for 18 series devices pulse width modulation 12C new ADC component etc The Hobbyist Student version is limited to 4K of code 8K on 18F devices MODDYVISt StUGent teva 6 ie tec coerce ncae ceere caeaeecucrs 44 inc VAT Instltutional Schools HE FE Industry 99 plus VAT Institutional Professional 10 user Network Licence 300 plus VAT SILC CONGR eit eae tire ee E ns saeco ee ree arene 599 plus VAT Flowcode 10 user Network Licence 350 plus VAT Flowcode 50 user Network Licence 699 plus VAT UK and EU customers add VAT at 15 to plus VAT prices 63 Everyday Practical Electronics July 2009 SPECIA
46. hardware is fully capable of sup porting PAL it s just waiting for someone with an XGS system and a PAL television to do the work Colour video can be generated however over the VGA connector VGA is thankfully a global stan dard and the video driver for it has been provided Although limited to 64 colours two bits per red green and blue channel it is still quite an accomplishment for colour to be generated by a simple PIC processor and the results look great Sound The sound output is limited as it relies on simply toggling a single I O pin to generate audio frequencies The results are how ever quite good and perfectly suit able for use with simple games Various techniques for generating audio are covered in the user guide with enough information for users to be able to experiment with better techniques Pricing The XGS PIC 16 bit discussed in this article can be ordered online from the Nurve Networks website at www xgamestation com Orders are shipped only from the USA at pres ent Pricing is 159 plus 45 USD shipping costs to the UK Conclusion For anyone interested in experi menting with video generation but who does not want to start tinkering with hardware yet this is an ideal system The wealth of information provided is more than sufficient to educate you in video game develop ment and even if you get bored with video the PCB is an ideal general purpose PIC24 development pla
47. impedance matching and effects of different filter tyoes Advanced Theory which covers the use of filter tables mathematics behind filter design and an explanation of the design of active filters Passive Filter Design which includes an expert system and filter synthesis tool for the design of low pass high pass band pass and band stop Bessel Butterworth and Chebyshev ladder filters Active Filter Design which includes an expert system and filter synthesis tool for the design of low pass high pass band pass and band stop Bessel Butterworth and Chebyshev op amp filters ROBOTICS amp MECHATRONICS Case study of the Milford Instruments Spider Robotics and Mechatronics is designed to enable hobbyists students with little previous experience of electronics to design and build electromechanical systems The CD ROM deals with all aspects of robotics from the control systems used the transducers available motors actuators and the circuits to drive them Case study material including the NASA Mars Rover the Milford Spider and the Furby is used to show how practical robotic systems are designed The result is a highly stimulating resource that will make learning and building robotics and mechatronic systems easier The Institutional versions have additional worksheets and multiple choice questions Interactive Virtual Laboratories Little previous knowledge required Mathematics is kept to a minimum and all ca
48. indicate the three or four digit serial number that follows the prefix No multipliers are used with this system which works on the simple basis of one band per digit of the serial number The band that indicates the cathode end of the component is supposed to be much wider than any of the others However in practice the polarity is often something less than obvious and careful scrutiny of the bands might be needed in order to determine which lead is which The other alternative method of polarity marking is mainly used for rectifiers and it has the body of the component tapered slightly at the cathode k end This thinning of the component corresponds quite well with the arrowhead part of the circuit symbol Rectifiers are mostly much larger than ordinary diodes and have thick leadout wires that can safely accommodate high currents Most of the unusual encapsulations that were used in the past have now become obsolete The few remaining high power rectifiers that have exotic encapsulations usually have the polarity clearly marked with say a diode circuit symbol Light work of It The light emitting diode LED is probably the type of diode that has provided Everyday Practical Electronics July 2009 the most problems over the years together with a great deal of correspondence from readers of this magazine An LED is a true diode and unlike a simple filament bulb it will only light up if it is connected to the power s
49. inductor capeacmtor arestoj Aulo frequency selection Meqgures mam pompanent value and other parameters too such as the OC resistance of inductors automatically rie Sp URWE Sea taller eramene pha Automatically test ond identity your network cables with the tarot Pook Aas T Suppled with al thes 0 inc WAT al iy 65 NATI rf e EE niman nnn a a SOLATRON 1250 Frequency Flesponse Anatyser 10 uHZ to 20MHZ AGILENT E44028 Spectrum Angee 1DOHS 3 GAZ with Pee TON Tracking Genarmtes IDA Narrow Fies ASH OFE UK MARCONI 2022E Synithesived AM FM Sial Genara IOKHZ 1 01GHZ wpeci Ofer Used Equipment Most Manuals Supplied Please check availability before ordering or calling Prices plus carriage and VAT Marana mie reese and ESA Capecdence from tuF to 22 000ur ESR fram 0 01 ohnnate 20 cle Battery included Gold plated croc clips Network Cable Anaya Special Offer AND Reduced VAT Atlas DCA Reduced VAT r dgfption in main offer aa ee P 5 now oo f peores ST Peak Electronic Denn Ltd West Road House West Road Buxton Derbyshire SK17 6HF tel01298 70012 www peakelec co uk sales peakelec co uk ISSN 0262 3617 PROJECTS THEORY NEWS COMMENT e POPULAR FEATURES o VOL 38 No 7 July 2009 Wimborne Publishing Ltd 2009 Copyright in all drawings photographs and articles published in EVERYDAY PRACTICAL ELECTRONICS is
50. is that printed battery technology can enable By 2015 NanoMarkets sales of products that utilise printed batteries will total 1 5 billion in revenues with the value of the batteries themselves amounting to more than 200 million While this should be seen as encouraging NanoMarkets believes that more printed battery firms will have to follow the lead of Power Paper and look to develop applications for their batteries rather than just produce the batteries themselves since remaining as a battery supplier will likely spell the demise of many firms This strategy will offer potentially bigger markets for printed batteries manufacturers to tap into but it also means a potentially significant shift in the focus of the business models and the need for additional finance The new NanoMarkets report analyses and quantifies the opportunities for printed batteries for the period 2009 to 2016 The report contains detailed eight year forecasts of both printed batteries and the products that are powered by them It also contains assessments and projections of the technologies emerging in this area both the battery chemistries and the printing technology and profiles of the leading companies in this space including Btu Spark Enfucell Planar Energy Devices Power ID Power Paper Prelonic Technologies Rocket Electric VARTA and VTT Applications covered include RFID and smart packaging electric shelf labels smart cards sensors cosmetic and pharmaceutica
51. just resistors and capacitors RC circuits cannot be used to make high performance filters due to their soft response and the high attenuation of the signal they cause Very good filters with sharp cut offs can be made using RLC circuits but inductors LOW PASS FREQUENCY BAND PASS FREQUENCY are often bulky and expensive are limited by the non ideal characteristics such as series resistance and are susceptible to magnetic pickup of interference Using the properties of negative feedback circuits using just resistors and capacitors together with op amps can provide the same response as an RLC circuit without the aforementioned problems Filters can be classified according to the pass band low pass filters let low frequencies through high pass filters let high frequencies through Band pass filters let a specific range of frequencies through Bandstop filters reject a specific range of frequencies A notch filter is a bandstop filter with a very narrow stop band which can be useful for rejecting a specific unwanted frequency The graphs in Fig 1 illustrate ideal filter responses For an ideal filter the transition from pass band to stop band occurs at a single frequency Ideal filters are sometimes called brick wall filters due to the vertical shape of the response curve For real filters the transition from pass band to stop band occurs over a range of frequencies see Fig 2 thus we need to defi
52. layouts of i c s transistors etc Click More Information for detailed background information with many animated diagrams Nearly all the circuits can be instantly simulated in Crocodile Technology not included on selection of over the CD ROM and you can customise the designs as required 200 j i 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 Get TINA Flowcode for a total of just 50 including VAT and postage WHAT S INCLUDED Light Modules Temperature Modules Sound Modules Moisture Modules Switch Modules Astables including 555 Remote Control IR amp Radio Transistor Amplifiers Thyristor Relay Op Amp Modules Logic Modules 555 Timer PIC PICAXE Output Devices Transistor Drivers Relay Motor Direction amp Speed Control 7 Segment Displays Data sections with pinouts etc Example Projects Full Search Facility Further Background Information and Animated Diagrams Runs in Microsoft Internet Explorer All circuits can be viewed but can only be simulated if your computer has Crocodile Technoloy version 410 or later A free trial version of Crocodile Technology can be downloaded from www crocodile clips com Animated diagrams run wi
53. of the sensors is built into the software Place all sensors closely together in a warm place at 50 70 C Then using the menu adjust the vari able Temp_scaler by deducting adding about 1 for each degree hot cold they indicate until all sensors read the same This takes care of any differential errors and should bring the absolute level which is less critical to within 1 C If you have an accurate thermometer you can also set the absolute to read correctly with respect to this known standard Better than 1 C is achievable but it only displays to the nearest degree Check them at room temperature although accuracy is not needed there Check again at near 0 C if you are using any freeze prevention functions eg on the auxiliary sensor A small change in the software calculation could be attempted if you can t get it to calibrate correctly at both 0 C and 60 C ie build a temperature offset into the software to complement the slope change already there by adjusting Temp_scaler But 30 the sensors should calibrate accurately enough without resorting to that Or you can select one sensor that does cor rectly calibrate as it is likely you only need one to go down to 0 C Check the panel sensor at 110 C 120 C too if you use an evacuated tube panel With a known fixed voltage on the PV supply check the displayed PV voltage Adjust PV_scaler in direct proportion to any error For time calibration three settable v
54. or set up charges and full design rule checks included on all orders For more information visit www pcb pool com Free phone UK 0800 389 8560 Email sales pcb pool com Everyday Practical Electronics July 2009 NanoMarkets report highlights printed batteries NanoMarkets a leading industry analyst in Virginia USA has announced the release of Printed Battery Markets 2009 and Beyond The report contains the latest analysis and market projections from NanoMarkets ongoing research of the thin batteries market NanoMarkets has reached a stage where printed batteries are now a viable technology Thanks to advances in materials and manufacturing there are products on the market that utilize them However the conventional wisdom a few years back was that RFID was going to be the killer application for printed battery technology That has not happened because of printed RFID s slower than anticipated market acceptance While printed RFID will still be an important application for printed batteries the real story today is powered smart cards which are an increasingly important technology for the credit card industry and consumers Smart cards is an area where printing is already used as the manufacturing process Being able to integrate the power source in the production of smart cards is extremely attractive for manufacturers Meanwhile the story of printed batteries has shifted from being about their own opportunity to what it
55. order 20 Everyday Practical Electronics July 2009 The new PicoScope 4000 Series high resolution oscilloscopes PicoScope 4000 Series 4424 High Resolution Oscilloscopes have true 12 bit resolution Inputs with The PicoStepe 4274 amd a vertical accuracy of 1 This latest generation of PicoScopes features a deep memory of 32 M samples When combined with rapid trigser mode this can capture up to 1000 trigger events at a rate of thousands ol wavelorms per second PC based capture view and use the acquired waveform on your PC right where you need It Software updates free software updates for the life of the Product USB powered and connnected perfect for use in the feld or thie Wb Programmable supplied with drivers and example code TL bits oe or TE bite with naaie ehani AU Mz for oscliiscope and epectrum modes 37 M ramplis thared between acove charmed BO PS s matin PicoScnpe 4074 channels Piecing THe A ciane USR 2 0 Rieg edga falling edec cee with hynieresis muls width runy pilas dros out windowed www picotech com scope511 01480 396395 SHERWOOD ELECTRONICS Buy 10 x 1 Special Packs and choose another one FREE 15 x 5mm Red LEDs SP137 4 x W005 1 5A bridge rectifiers 12 x 5mm Green LEDs SP138 20 x 2 2 63V radial elect caps 12 x 5mm Yellow LEDs SP142 2 x CMOS 4017 25 x 5mm 1 part LED clips SP143 5 Pairs min crocodile clips 15 x 3mm Red LEDs Red amp Black 12 x 3mm Green
56. oscilloscope spectrum analyser recorder function generator and PCSGU250 USB Scope amp Function gen r incandescent lamps Wide e of effects Hi power OSFETs 3A per channel K8088 RGB LED Controller Kit 15 15 VM146 Assembled version 22 52 VM151 Assembled version with remote control 29 53 Pocket Audio Generator Microprocessor Technology Digital waveform audio generator 50Hz 100Hz 1kHz 10kHz amp 20kHz K8065 Kit VM156 Assembled High Power LED Driver Power up to four 1W or two 3W high power LEDs not incl Delivers accurate constant current required by most high power LEDs built in rectifier for easy connection to AC source compact size short circuit protected no heatsink re a quired K8071 Kit 5 86 VM143 1W for IW LEDs 10 52 VM143 3W for 3W LEDs 11 07 3 30V 3A Power Supply Suitable as a power supply for all common Velleman kits using a stabilised DC voltage between 3 and 30V 3A max Of course this power supply unit can also be used for other purposes By replacing the trimmer by a potentiometer it may even be used as an adjustable power supply unit Supplied with heat sink K7203 Kit 1A Power Supply Low cost universal symmetric power supply just add a suitable transformer and a heatsink trimmers can be replaced by po tentiometers to allow continuous ad justment of output LED output indicators K8042 Kit 13 41 20 00 25 10
57. port and any standard terminal comms program 4 LED s display the status ZIF sockets not included Supply 16Vdc Kit Order Code 3123KT 24 95 Assembled Order Code AS3123 34 95 Introduction to PIC Programming Go from complete beginner to burning a PIC and writing code in no time Includes 49 page step by step PDF Tutorial Manual Program ming Hardware with LED test section Win 3 11 xXP Programming Software Program Read Verify amp Erase and 1rewritable PIC16F84A that you can use with different code 4 detailed examples pro vided for you to learn from PC parallel port Kit Order Code 3081KT 16 95 Assembled Order Code AS3081 24 95 871 Credit Card Sales PIC Programmer Board Low cost PIC programmer board supporting a wide range of Microchip PIC microcontrollers Requires PC serial port Windows interface aan Kit Order Code VK8076KT 21 95 PIC Programmer amp Experimenter Board The PIC Programmer amp Experimenter Board with test buttons and LED indi cators to carry out educa tional experiments such as the supplied programming examples In cludes a 16F627 Flash Microcontroller that can be reprogrammed up to 1000 times for experimenting at will Software to compile and program your source code is included Kit Order Code VK8048KT 22 95 Assembled Order Code VVM111 39 95 Controllers amp re data acquisition and control units we have S
58. processor which will save you the cost of a regulator although as you will soon see we have a trick up our sleave to avoid using two regulators While the physical interface is a standard not all keyboards implement identical data 60 F T rm Keyboard Interfacing protocol features If your requirements are for a simple keyboard input device then that is not a problem If you would like to configure the keyboard or perhaps access special keys then each keyboard type will require different codes to be sent or received It s easy enough to work out you can use the source code provided with this article to examine the codes sent when keys are pressed and released but it does mean that one solution does not fit all For the basic keys however a common standard exists and is supported by the code which accompanies this article Physical Interface The physical interface is shown in Fig 1 with the associated signal names Note that this is the socket end as found on PCs The clock and data signals are bi directional and to achieve this they are both implemented within the keyboard or whatever device you are connecting as an open collector That means that the logic levels on these pins can be either OV or high impedance pull up resistors fitted between your processor and the connector ensure that when the lines are in a high impedance state the voltage rises to SV When you are reading the keyboard this means t
59. provided on the PC board The type of programmer we recommend is the COM84 style programmer whose schematic appears above A computer s serial port will be required and the software to use is WinPic available free to download from www hamradioindia org circuits winpic php We are assuming you re building the PICprobe from a kit ie the micro is already programmed If you are not you will need to programme the IC as described above You need to decide if you want to use your logic probe for low voltage work only as in the original design or for general purpose higher voltage work If it is for low voltage work only ie 5V or less you can leave out the voltage regulator and place 14 We used the WinPic version compiled on 9 December 2005 but other versions should be similar After soldering the wires totheA BandC pads you should breadboard this circuit The two BC546 NPN transistors are used to switch on and off the higher programming voltage which for normal programming should be between 12 5V and 13 5V RS 232 at pin 6 Adjust your input T Vpp voltage level to within this range There will be a small voltage drop across the 10kQ resistor in series between Vpp and the collector of the BC546 pin 6 When the Txline pin 3 ofthe serial port is low the voltage at pin 6 ofthe PIC10F20x should be around OV When it is high it should be between 12 5V and 13 5V The WinPIC software will automatic
60. re verse direction The range of control is from fully OFF to fully ON in both directions The direction and speed are controlled using a single potentiometer Screw terminal block for connections Kit Order Code 3166v2KT 22 95 Assembled Order Code AS3166v2 32 95 AC Motor Speed Controller 700W Reliable and simple to install project that allows you to adjust the speed of jam an electric drill or 230V AC 4 single phase induction motor rated up to 700 Watts Simply turn the potentiometer to adjust the motors RPM PCB 48x65mm Not suit able for use with brushless AC motors Kit Order Code 1074KT 14 95 Assembled Order Code AS1074 23 95 See www quasarelectronics com for lots more motor controllers QUASAR electronics The Electronic Kit Specialists Since 1993 Electronic Project r Great introduction to the world of electron ics Ideal gift for budding electronics expert 500 in 1 Electronic Project Lab Top of the range Com plete self contained elec tronics course Takes you from beginner to A Level standard and beyond Contains all the hardware and manuals to assemble 500 projects You get 3 comprehensive course books total 368 pages Hardware Entry Course Hardware Advanced Course and a microprocessor based Software Program ming Course Each book has individual circuit explanations schematic and connection dia grams Suitable for age 12 Order Code EPL500
61. so in decibels this is 10log 0 5 dB which is 3dB The vertical axis on filter frequency response graphs eg Fig 2 which shows filter gain or attenuation is usually scaled in decibels which as we have just seen is a logarithmic scale For a gain A the value in decibels is 20log A dB Note the factor of 20 which is used here for signal voltage or current rather than the factor of 10 which is used for expressing signal power in decibels The horizontal frequency axis of the graph is also usually logarithmic eg the scale is marked 1Hz 10Hz 100Hz 1kHz etc at even intervals These times ten steps are referred to as decades If the gain or attenuation in the pass band does not vary much with frequency it is described as flat In some filters the pass band gain has distinctive ripples as frequency varies the depth of these ripples is usually measured in decibels The stop band may also have ripples Filter slope and phase lift The slope of the frequency response in the transition region and possibly the stop band indicates how quickly the filter s gain drops as the frequency moves away from the cut off The slope is measured in dB per octave or dB per decade this value is called the fall off or roll off The fall off may be different near GAIN dB PASS BAND GRADIENT IN dB OCTAVE TRANSITION REGION CUT OFF FREQUENCY Fig 2 Frequency domain response Everyday Practical Electronics July 2009 and f
62. switches S1 to S3 previously existed as part of the garage alarm system I have and any of these switches when opened will also initiate the alarm trigger delay circuit The operation of this is straightforward in that if switches S1 to S4 remain open for more than six seconds then capacitor C1 will charge via potentiometer VR1 un til the voltage on the non inverting pin of the LM358 op amp is greater than the 9V level on the inverting pin as set by resistors RI and R2 When this happens the op amp Fig 2 Trigger delay circuit diagram for the Heating Oil Storage Tank Burglar Alarm output swings hard positive which switches on transistor TR1 thus energising the small 12V PCB relay Diode D1 protects TRI from reverse voltages back EMF The voltage free contact associated with the PCB relay is then used via connector CNI to latch on the Panic Input audio alarm which is a part of the original garage burglar alarm system George Caldwell Drumahoe Londonderry INGEN U T Y _ Wis your forum where you UNLIMITED BE INTERACTIVE can offer other readers the benefit of your Ingenuity Share those ideas earn some cash and possibly a prize Why not take a look at our website www epemag com AUY AALS AAL a ROLL Please reserve deliver a copy of Everyday Practical Electronics for me each month e Title First Name Address Postcode s Surname Tel Everyday Practical Electronics is publi
63. switches and four for the corners of the LCD cutout Place the bare PCB onto the underside of the box lid with Everyday Practical Electronics July 2009 ctional IC4eke are epee J2 el fee Ld amp i oy hae O al la 1 D E cg C dp l JP1 jm gt ig h E O Fig 4 Main double sided PCB for the Solar Water Heating System Controller 2 85in 72 4mm PCB BOTTOM Everyday Practical Electronics July 2009 23 Constructional Project A suggested front panel label is shown in the title picture Use the main PCB as a guide to drill four holes in the bottom of the box One hole is not in the PCB corner as this provides better insulation between that screw and the relay contacts Drill holes in the back of the box for hidden wires or sides at the two ends for the sensor and other external cables Add enlarge holes to let the buzzer sound out LCD PCB Solder all components into the LCD PCB leaving the LCD till last Make sure no component touches any metallic parts on the back of the LCD CONS is optional as you can solder the ribbon cable straight to the PCB If CON9 is fitted solder R38 on the track side of the PCB as well as the reset switch and VR1 if you want to operate them by opening the box rather than having holes drilled into the front panel Track sided mounting is recommended as they are rarely needed in normal use Resistor R47 also goes on the track side Capacitor C10 may n
64. that the col ours are correct red towards the probe orange in the middle and green towards the switch If your LEDs light it s a pretty good bet that you haven t made any mistakes or shorted out any SMD pins Next remove power wait a few min utes and then solder the PIC IC1 to the board taking care with its orientation That done apply power again the LEDs should be flashing in an apparent random fashion but only one should be lit when you touch the probe tip to the positive supply and then to OV which of course equates to a logic high and logic low 1 pno q jamming srame mate aoten Assembly is now complete all you have to dois drill a 2mm hole in the pen case as shown in the photo to access pushbutton switch S1 then slide the completed PC board into the case until the switch is right under the hole EPE Where Do You Get It www jaycare lectronics co uk pionner gut usingjthe fone Pemo TOL ii ramme On sale in WHSmiths or available direct from us Price 9 50 including UK p amp p 01202 8738 72 www epemag com Everyday Practical Electronics July 2009 15 Constructional Project E VE presented the Remote Con trol amp Pre amplifier Module as a stand alone project because we believe that many constructors will want to build it into an existing case It is designed to fit flush behind a front panel hence the LEDs and the rotary encoder are located al
65. the internal wiring Short form kit contains PCB sensor and all specified components You ll need to add your own 240V GPO switched IEC socket and case UNIVERSAL DRILL MOTOR SPEED CONTROLLER KIT KC 5477 19 00 plus postage amp packing Apart from power tools it s often handy to be able to control the speed of other 240V motors Suitable for brush motors up to 10A the circuit is a revised version of our popular 5A speed controller Complete kit includes screen printed case PCB and all specified components You ll need a garden variety IEC lead as well 433MHZ REMOTE SWITCH KIT KC 5473 13 25 plus postage amp packing Suitable for remote contro of practically anything up to a range of 200m The receiver has momentary or toggle output and the momentary period can be adjusted Up to five receivers can be used in the same vicinity Short form kit contains two PCBs and all specified components e Extra transmitter kit KC 5474 POST amp PACKING CHARGES Order Value Cost 10 49 99 5 50 99 99 10 100 199 99 20 200 499 99 30 500 40 Note Products are despatched from Australia so local customs duty amp taxes may apply OJ Prices valid until 30 6 09 Max weight 12lb 5kg Heavier parcels POA Minimum order 10 ars a NS Aa NY as i E oe ALAN CDI IGNITION MODULE REPLACEMENT KIT KC 5466 50 plu
66. the manner described ports RA1 and RA2 will be driving most of the time I suggest that a couple of 150Q resistor be placed in the leads from ports RA1 and RA2 to limit the current This results in only two more resistors and it will save blowing the output drivers of the PIC Colin Wilson by email You are correct the maximum current sourced by an output pin should be 20mA and the LEDs are not current limited by a resistor Looking at the specifications of current versus output at 20mA a high output is typically 3 25V and low output is 0 7V when running from a SV supply So the available voltage for the LED when driven by a high output for the anode and a low output for the cathode is 3 25V 0 7V or 2 55V We measured a red green LED at 20mA and found that the forward voltage for the green LED was 2 25V and 2 2V for the red So the current is therefore more likely to be about 22mA instead of 20mA The PIC will probably survive this extra current However as you say 15092 limiting resistors at pin I and pin 18 would be better 65 Surfing The Internet t Wor Alan Winstanley It s the Wolf man oogle is among the world s most prominent brands and it must be serious if the verb to google can be conjugated from the eponymous search engine s name A number of challenges to Google s dominance have appeared in recent years At one time a direct rival Yahoo could actually charge businesses for t
67. we ve reserved buttons 1 6 and the optional Channel front panel switch for a possible future multi channel upgrade This would al low up to five simpler slave modules to be daisy chained off CON8 all under your command via remote control Pressing any of these buttons causes C1 meaning Channel 1 to appear on the display but has no other func tion at present Fig 15 top right That s it your new Remote Volume Control is ready for use Sit back and enjoy the music EPE Reproduced by arrangement with SILICON CHIP magazine 2009 www siliconchip com au TL 500 Multi Logging System b jsi hjj Metts EE u m iota 9 au n aio Multi Logging System which can be used inside and outside every location where a registration of environmental conditions is needed Also suitable for industrial use The System contains a software application a Windows USB receiver and separately available wireless sensors for temperature humidity and CO2 measurement The new temperature data of all sensors every 45 seconds is pas sed on wirelessly USB to the PC for further processing A visuali sation program is at your disposal EPE BINDERS KEEP YOUR MAGAZINES SAFE RING US NOWI Including Messenger Soft ware to send temperature mes sages by email With Email to SMS service these messages can also be received by SMS UK Distributors www rapidonline co
68. we reckon it could be at least twice as long without causing any problems Avoid routing the cable close to the analogue section of the control module Earthing So far you should have just two wires connected to the chassis earth point the mains earth wire from the IEC socket and a second wire to the E input at CONS of the power supply Now run an additional mains rated green yellow earth wire from the pad just to the left of If your infrared receiver module has a metal shield like this one then be sure to insulate it from the front panel as described in the text 17 Constructional MUTE INDICATOR C CHANNEL SELECT MODE CHANNEL NUMBER Fig 15 the 2 digit readout displays volume and balance on a 0 85 scale and flashes an indicator when muted Note that the channel select mode is for a possible future upgrade and can be ignored at present the rotary encoder to the chassis earth point This solidly earths the body ofthe encoder to protect the microcontroller from static discharge To earth the audio ground run an other wire from the chassis earth point to the free pad situated between CON5 and CON6 on the control module again using mains rated green yel low wire Both earth wires should fit into a single spade crimp terminal to mate with the free end of the chassis mounted lug see Fig 14 This earthing method will reduce the chances of creating an audible earth loop in your
69. wires and component leads are straight before inserting them into the breadboard Kinks in the wire will catch in the springy clip below the socket and damage it if you have to tug to release the wire from the holes Everyday Practical Electronics July 2009 Make sure that the arrangement of components and wire links is tidy with components snugly fitting close to the surface of the Protobloc This usually means providing more link wires than is perhaps necessary so as to avoid having wires going every which way across the board Never connect the battery leads to the top and bottom rails of the breadboard until you have carefully checked that all the component connections correspond to those on the circuit diagram Some components such as switches and relays do not have appropriate wire leads for insertion into the Protobloc If you have access to a soldering iron solder short lengths of single core 0 6mm diameter plastic sleeved wire to the terminals of these components S51 EALING with components that Dow have two leadout wires should be very easy since there is not a great deal that you can get wrong It is simply a matter of fitting the component into position trimming the wires to length and soldering it to the circuit board In many cases it really is that simple and nothing more is involved when dealing with twin lead components such as resistors and small inductors With some other types however ther
70. with initially Circuit Maker a program which I purchased some years ago but which is unfortunately now no longer supported and more recently the free TinyCad which is currently being invigorated by anew group of developers My experience with VeeCad has been very good It does exactly what it says on the box and first time working layouts are the norm provided a schematic is drawn first and its netlist imported This of course also improves Mac OSX and Linux interfacing Dear EPE Thank you for your interest in Mac and Linux platforms Our products are entirely designed and manufactured in the UK Although we are a small company we are expanding and currently export to customers in 39 countries Please see the following two links the first for Mac customers and the second for Linux customers The Linux datasheet is useful because it describes the low level access to the port and the simple command structure to command the relay DIO cards Note that with both Linux and Mac platform the FTDI virtual COM port drivers are already installed as part of the OS build you don t need to download any drivers unlike Windows there are both 32 and 64 bit drivers depending on which processor type the PC has The Mac application was developed by a customer in Australia as a home automation project It is an open source app so customers can download the code and use it as a basic building block for their own req
71. 1 5V supply voltage which is provided by transistor TR1 resistor R1 and potentiometer VR1 used as a variable resistor Adjust ment of VR1 alters the supply voltage and determines the sensitivity of the circuit Capacitor C2 couples the signal from the radio frequency amplifier and detector stage to the second building block a low power au dio amplifier based on IC2 which powers a small loudspeaker LS1 Potentiometer VR2 acts as a volume control Fig 10 1 Complete circuit diagram for the breadboard AM Radio 48 Everyday Practical Electronics July 2009 GND IN OUT Vcc With the flat face facing you the pin functions are shown above VC1 variable capacitor In this circuit the two terminals may be connected either way round Usually sold as a transis tor radio tuning capacitor TR1 type BC108 NPN Seen from below the emitter lead is next to the small metal tag Clock wise from the emitter are the base and B collector leads oS TO18 IC2 type LM386 audio amp Viewed from the top an indented dot and a half moon shape at one end indicate pin one The pins are num bered anti clock wise ending at pin 8 opposite pin 1 The miniature tuning capacitor and ferrite aerial wired to the terminal block TB1 Everyday Practical Electronics July 2009 Components needed AM Radio Integrated circuit IC 1 type TA7642 AM radio IC Integrated circuit
72. 1 steel strip 70 x 25 x 3mm for rain sensor mounting bracket 1 20 x 8mm galvanised steel bolt plus nut and washers to suit for rain sensor mounting bracket 1 length of stainless or galvanised steel wire 50mm long 1 2mm diameter Assorted pop rivets 1 AA battery clip for three AA batteries 1 1m length single core shielded audio cable 1 1m length 4 core alarm cable 1 3 x 2mm disc shaped rare earth magnet or two 3 x 1mm magnets 1 DB9 female socket in line solder type 1 5 pin panel mounting DIN socket and line plug to match plus mounting screws for socket 1 right angle PC mount momentary close pushbutton switch mini tactile S1 1 PC mount momentary close pushbutton switch mini tactile S2 1 glass encapsulated magnetic reed switch S3 1 SPST slide switch and mounting screws S4 21 PC solder pins 1 18 pin IC socket 1 16 pin IC socket 2 8 pin IC sockets 1 32 768kHz watch crystal X1 Semiconductors Reproduced by arrangement with SILICON CHIP magazine 2009 www siliconchip com au 1 PIC16F88 microcontroller IC1 programmed with weather station hex 1 MAX232 serial RS232 interface driver IC2 2 24C256 or 24LC256 serial EEPROMs IC3 IC4 1 DS1621 temperature sensor IC5 1 5mm super bright red LED Capacitors 2 33pF ceramic C1 C2 code 33 or 33p 1 100nF ceramic C3 code 104 or 100n 5 1uF tantalum bead or sub min elect C4 C8 Resistors 0 5W 5 3 390Q colour code orange white bro
73. 44 00 12 months 83 00 2 years Express airmail 32 00 6 months 62 00 12 months 119 00 2 years Payments payable to Everyday Practical Electronics Subs Dept Wimborne Publishing Ltd Email sups epemag wimborne co uk EVERYDAY PRACTICAL ELECTRONICS is sold subject to the following conditions namely that it shall not without the written consent of the Publishers first having been given be lent resold hired out or otherwise disposed of by way of Trade at more than the recommended selling price shown on the cover and that it shall not be lent resold hired out or otherwise disposed of in a mutilated condition or in any unauthorised cover by way of Trade or affixed to or as part of any publication or advertising literary or pictorial matter whatsoever im plifier im DC sup yn board with ideal for iker system or fer guitar amp heatre systems etc short circuit protected ca ior 14 18 ik for above 11 18 90 Assembled with heatsink 38 54 O 120VA Toroidal Transformer 14 25 io Amplifier Stereo 2 x 50Wrms ora Mono 100Wrms ampli fier Three input sensitivity settings Overload amp short cir cuit protection protection against incorrect power supply polarity Speaker transient suppression K4004 Kit 54 88 High End Control Amplifier 4 Input inc RIAA input Headphone output Audio Grade OpAmps Capacitor less Coupling Including Solid Aluminium Housing
74. 68 03 496 gquasarelectronics com E ics com Fax 07092 E mail oe Web www i SE VISA O Electron SOLO QUASAR electronics Get disc In PIC amp ATMEL Pr grammers e have a wide range of low cost PIC k ATMEL Programmers Complete range and ocumentation available from our web site Programmer Accessories 0 pin Wide ZIF socket 7IF40W 14 95 8Vdc Powersupply PSU010 18 9 eads Parallel LDC136 3 95 Serial LDC441 3 95 USB LDC644 2 95 NEW USB amp Serial Port PIC Programmer USB Serial connection Header cable for ICSP MTE Free Windows XP soft ware See website for PICs supported ZIF Socket and USB lead extra 18Vdc Kit Order Code 3149KT 39 95 Assembled Order Code AS3149 49 95 NEW USB All Flash PIC drd ts USB PIC programmer for all Flash devices No external power supply making it truly portable Supplied with box and Windows XP Software ZIF Socket and USB lead not incl Assembled Order Code AS3128 44 95 Assembled with ZIF socket Order Code AS3128ZIF 59 95 PICALL ISP PIC Programmer Will program virtually all 8 to 40 pin serial mode AND parallel mode PIC15C family PIC microcontrol lers Free Windows soft ware Blank chip auto detect for super fast bulk programming Optional ZIF socket Assembled Order Code AS3117 24 95 Assembled with ZIF socket Order Code AS3117ZIF 39 95 ATMEL 89xxxx Programmer ai Uses serial
75. 75 ISSN 0956 974X Russian Cold War Spy Sets And Encoders A Window To The World Restorati Rebuilding A Post war Aerodyne 301 e Noe aki Eddyston Component Lore Switches Pop ie CT378 mi e ome e gi pe W2 gece 19 j www radiobygones co uk www radi iobygones com ig Player a sons qhe aX O nicatio ot ot grom precul Telec x A pado y S esc a radiowy oo ARTICLES on restoration and repair history circuit techniques personalities reminiscences and just plain nostalgia you ll find them all Plus features on museums and private collections and a full colour photo feature in every issue IT S MOSTLY about valves of course but solid state whether of the coherer and spark gap variety or early transistors also has a place FROM THE DAYS of Maxwell Hertz Lodge and Marconi to what was the state of the art just a few short years ago There is also a selection of free readers For Sale and Wanted advertisements in every issue Radio Bygones covers it all THE MAGAZINE is published six times a year and is only available by postal subscription it is not available at newsagents TO TAKE OUT a subscription or to request a sample copy please complete the form below and return it to RADIO BYGONES Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 Web site www radiobygones com SS ga Radio A SAMPLE C
76. 8 Monopoly Money Universal High Energy LED Lighting System JULY 08 PIC MIDI Sound Wave Generator Galactic Voice Coolmaster AUGUST 08 Four Channel A V Selector DC Relay Switch For High Current Loads Versatile Temperature Switch Mains Monitor Monitor Interface SEPTEVIBRR 08 Magnetic Cartridge Preamplifier Super Speedo Corrector Ultrasonic Eavesdropper S Video To Composite Video Converter double sided OCTOBRR 08 Inteligent Car Air Conditioner Controller Cordless Power Tool Charger Controller 20W Class A Amplifier Module Left Channel Right Channel PSU NOV MBER 08 x 50MHz Frequency Meter Mk 2 Version 1 581 6 66 Version 2 582 6 66 Version 3 583 6 66 Variable Turbo Boost Control 690 Fuel Cut Defeater 691 oe 6 34 DECHVIBRR 08 Christmas Star 692 6 97 20W Class A Amplifier Speaker Protector amp Muting 693 6 66 Radar Speed Gun Head 694 Display 695 f Set 14 95 JANUARY 09 20W Class A Amplifier Preamplifier and Remote Volume Control 7 93 1000 1 UHF Prescaler double sided 12 05 FEBRUARY 09 1 3V To 22V Regulated Power Supply Control Board Display Board LED Tachometer 70 PRO ECTTITLE MARCH 09 Tank Water Level Indicator x Digital Stereo VU Peak Meter Main Board Switch Board APRIL 09 Versatile 4 Input Mixer Oscar Noughts amp Crosses Machine x GPS Based Frequency Reference
77. EEPROM memory The firmware can easily be modified for reading at more frequent intervals With a six minute logging frequency it has over two months capacity At the other extreme with hourly recording it will store almost two years of data The data is accessed through an on board RS232 inter face enabling easy downloading straight to a laptop or desktop computer If like me you don t own a laptop there is a simple solution The controller is cheap and easy enough to build that you can make two and simply swap one out and take it home to dump the data at your leisure In fact the most time consuming part about the project isn t the electronics it s the hardware Building the rain sensor will probably take the most time and effort But if you don t have the time or inclination at modest cost you can even solve that little problem too While unsuccessfully looking for a suitable com mercial weather station I found a good quality rain sensor for 90 US that will interface with the weather station More on this next month Circuit description and operation The Data Logging Weather Station circuit diagram is shown in Fig 1 As mentioned the circuit is based around a microcontroller IC1 Since low power consumption and 34 simplicity were paramount a PIC16F88 nanowatt micro controller was chosen This has pretty much all the peripheral interfaces needed already integrated in
78. IC2 type LM386 low power audio amplifier Transistor TR1 type BC108 or similar in a TO18 style package Ferrite rod coil aerial L1 30 turns 0 2mm enamalled copper wire ferrite rod 50mm x10mm dia or medium wave ferrite aerial Variable tuning capacitor VC1 value between about 100pF and 500pF when adjusted to its maximum value Usually sold as miniature transistor radio tuning capacitor Loudspeaker LS1 miniature 8Q or 16Q impedence Capacitors C1 to C6 values 10nF polyester C1 10uF 16V radial elect C2 C4 100nF polyester C3 100uF 16V radial elect C5 C6 Potentiometers VR1 VR2 values 100k VR1 and 10kQ VR2 miniature preset types Resistors R1 to R3 values 47kQ R1 R3 1kQ R2 All 0 25W carbon film Switch S1 On Off single pole single throw SPST Battery B1 9V plus connecting leads Protobloc wire links and a two way screw terminal block TB1 Breadboard The Protobloc component layout for the AM Radio circuit is shown in Fig 10 2 To make the coil L1 you will need to wind about 30 turns of enamelled copper wire onto the fer rite rod The tuned circuit L1 and VC1 should be connected up using a two way section of terminal block as shown and the two common 0 6mm leads plugged into to the breadboard Notes e To set up the circuit turn VR2 to maximum volume which in this breadboard layout is fully anticlock wise Then adjust VR1 until the radio just stops o
79. L PACKAGE OFFER DIGITAL WORKS TINA Pro V7 Basic Flowcode V3 Hobbyist Student TINA Analogue Digital Symbolic RF MCU and Mixed Mode Circuit Simulation Testing and PCB Design TINA Design Suite is a powerful yet affordable software package for analysing designing and real time testing analogue digital MCU and mixed electronic circuits and their PCB layouts You can also analyse RF communication optoelectronic circuits test and debug microcontroller applications Enter any circuit up to 100 nodes within minutes with TINAS easy to use schematic editor Enhance your schematics by adding text and graphics Choose components from the large library containing more than 10 000 manufacturer models Analyse your circuit through more than 20 different analysis modes or with 10 high tech virtual Counter project instruments Present your results in TINA s sophisticated diagram windows on virtual instruments or in the live interactive mode where you can even edit your circuit during operation Digital Works Version 3 0 is a graphical design tool that enables you to construct Customise presentations using TINA s advanced drawing tools to control text fonts axes line width colour and layout You can create digital logic circuits and analyze their and print documents directly inside TINA or cut and paste your results into your favourite word procesing or DTP package behaviour It is so simple to use that it will take you less than
80. LEDs SP144 5 Pairs min crocodile clips 10 x 3mm Yellow LEDs assorted colours 25 x 3mm 1 part LED clips SP146 10 x 2N3704 transistors SP10 100 x 1N4148 diodes SP147 5 x Stripboard 9 strips x SP11 30 x 1N4001 diodes 25 holes SP12 30 x 1N4002 diodes SP151 4 x 8mm Red LEDs SP18 20 x BC182B transistors SP152 4 x 8mm Green LEDs SP20 20 x BC184B transistors SP153 4 x 8mm Yellow LEDs SP23 20 x BC549B transistors SP154 15 x BC548B transistors SP24 4 x CMOS 4001 SP156 3 x Stripboard 14 strips x SP25 4 x 555 timers 27 holes SP26 4 x 741 Op Amps SP160 10 x 2N3904 transistors SP28 4x CMOS 4011 SP161 10 x 2N3906 transistors SP29 4 x CMOS 4013 SP164 2 x C106D thyristors SP33 4 x CMOS 4081 SP165 2 x LF351 Op Amps SP34 20 x 1N914 diodes SP166 20 x 1N4003 diodes SP36 25 x 10 25V radial elect caps SP167 5 x BC107 transistors SP37 12 x 100 35V radial elect caps SP168 5 x BC108 transistors SP38 15 x 47 25V radial elect caps SP172 4 x Standard slide switches SP39 10 x 470 16V radial elect caps SP173 10 x 220 25V radial elect caps SP40 15 x BC237 transistors SP174 20 x 22 25V radial elect caps SP41 20 x Mixed transistors SP175 20 x 1 68V radial elect caps SP42 200 x Mixed 0 25W C F resistors SP177 10 x 1A 20mm quick blow fuses SP47 5 x Min PB switches SP178 10 x 2A 20mm quick blow fuses SP49 4 x 5 metres stranded core wire SP181 5 x Phono plugs asstd colours SP102 20 x 8 pin DIL sockets SP182 20 x 4 7 63V radial elect caps SP103 15 x 14 pin DIL sockets
81. Loudness filter Loudness control Simple graphic equaliser Basic audio mixer Small 300mW audio power amp 6 watt audio power amp 20 32 watt power amp and power supply Dynamic noise limiter A must for audio enthusiasts with more sense than money TETAI 1005 5 45 VALVE AMPLIFIERS Second Edition Morgan Jones This book allows those with a limited knowledge of the field to understand both the theory and practice of valve audio amplifier design such that they can analyse and modify circuits and build or restore an amplifier Design principles and construction techniques are provided so readers can devise and build from scratch designs that actually work The second edition of this popular book builds on its main strength exploring and illustrating theory with practical applications Numerous new sections include output transformer problems heater regulators phase splitter analysis and component technology In addition to the numerous amplifier and preamplifier circuits three major new designs are included a low noise single ended LP stage and a pair of high voltage amplifiers for driving electrostatic transducers directly one for headphones one for loudspeakers 116 pages 288 pages Order code NE33 34 99 69 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 Double si
82. OPY of Radio Bygones 23 79 Bygones Add 75p for overseas airmail postage SUBSCRIPTIONS post paid 1YEAR 2YEAR UNITED KINGDOM ae aa 2229225 e082 es 902 29s ees soaceasscocoussses ces ss REST OF EUROPE AIRMAIL 25 50 49 00 Please print clearly and check that you have the number correct REST OF THE WORLD AIRMAIL eres 30 00 58 00 The card IS valid from ee eT To Exp date oe me ee oe oe ee O Yes would like a sample copy for 3 75 Maestro Issue No Sanna es Deu A free issue is available for download from www radiobygones com z a My namels eee a a a a stan ear cunem O Yes would like to take out a subscription for l l Mya ele oho esr a LI One year 6 issues O Two years 12 issues EIIENclosera chica Eanikcre a ae a payable to Wimborne Publishing Ltd Post Code Zipin sheen Nel ee eee eae ore LI Please debit my Visa Mastercard Maestro card SIMIC Cees ey eee ee E Se eee re ee If you do not wish to cut your issue send a letter or a copy of this form Everyday Practical Electronics July 2009 C Bus Shop C Bus Wireless Laser Business Systems Ltd Tel 44 0 20 8441 0788 Stewart Kearn on 01202 873872 or email stewart kearn wimborne co uk D ORIGINAL p a Beta LAYOUT Specialising in Prototype PCBs Free Laser Stencil E NEW with all Prototype PCB orders WEN 1 WD prototype service NEN Chemical Tin Finish no
83. Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 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 posted within seven days of receipt of order Everyday Practical Electronics July 2009 Breadboarding by Dr Malcolm Plant a A beginner s guide to simple solder free circuit prototyping Part 10 AM Radio and Sound Sensor Project 17 AM Radio LTHOUGH radios are common enough and cheap why not make your own from a few readily available components For example the design shown in Fig 10 1 is uncomplicated thanks to the two integrated circuits IC1 and IC2 and it will receive radio stations transmit ting amplitude modulated AM radio frequencies delivering your selection to a small loudspeaker S1 O Circuit details The central component for the first building block is integrated circuit IC1 a radio on a chip Essentially its purpose is to amplify the small volt age generated across the tuned circuit comprising the LC combination that is variable tuning capacitor VC1 in parallel with inductor L1 When the radio is tuned in to a station by adjusting VC1 a small alter nating voltage is generated across the tuned circuit This is processed by the rest of the circuit to extract the informa tion carried by this carrier wave IC1 requires a
84. THE NOWUK MAGAZINE FOR ELECTRONICS TECHNOLOGY COMPUTER a st JSF E C TRONIC 5 Me WTS rt GOT BR EAD B 0 R DING PROVE cs 8 75 US 10 a CAN gt Copyright 2009 Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU UK and TechBites 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 TechBites 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 TechBites Interactive Inc and Wimborne Publishing Ltd have used their best efforts in preparing these materials and works However TechBites 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 tts publishers and agents disclaim any responsibility for
85. There are two DB9 connectors for controllers allowing for two player games if you purchase a second controller phono connectors for video and sound output and a VGA connector for connecting to a standard LCD or CRT monitor A 6 pin PS 2 keyboard connector is also provided While most keyboards are now fitted with USB interfaces it is still possible to purchase PS 2 style keyboards and at a very low cost The PS 2 interface is a very easy to use pro tocol and suitable software is provided A MicroSD Media card socket offers the ability to access Gigabytes of cheap flash storage Finally a 22 way 0 1 inch header provides a very easy to access expansion port bringing plenty of use ful I O signals to the outside world Everyday Practical Electronics July 2009 This PCB makes for an ideal general purpose development platform not just for video games User guide It s nice in this digital age to get a printed manual This one is a high quality 300 page spiral bound book that covers the technology and techniques for generating video on a microcon troller how to use the various interfaces on the PCB and software tool installa tion and use It also delves into some more advanced game specific tech niques such as tiling which enables you to generate complex scenery with limited memory resources Bear in mind that the term complex is relative this is a very simple video system You re not going to
86. al fault finding are described although of course there is no such thing as a digital fault all faults are by nature analogue This book is written entirely for a fault finder using only the basic fault finding equipment a digital multimeter and an oscilloscope The treatment is non mathematical apart from Ohm s law and all jargon is strictly avoided Order code NE22 33 99 308 pages 274 pages BOOK ORDERING DETAILS All prices include UK postage For postage to Europe air and the rest of the world surface please add 2 per book For the rest of the world airmail add 3 per book CD ROM prices include VAT and or postage to anywhere in the world Send a PO cheque international money order sterling only made payable to Direct Book Service or card details Visa Mastercard or Maestro to DIRECT BOOK SERVICE WIMBORNE PUBLISHING LIMITED SEQUOIA HOUSE 398a RINGWOOD ROAD FERNDOWN DORSET BH22 9AU 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 wimborne co uk Order from our online shop at www epemag com BOOK ORDER FORM Full NAME Fac sect civesitisaorhcreseirtlecan aeosartdald acuidlestouuau
87. allow about 30 seconds for the 1000uF filter capacitors to discharge You can then insert IC1 and IC2 in their sockets making sure that the notched pin 1 ends line up with notches in the sockets Before moving on you must now program the microcontroller IC2 if JP3 POSITION INTERFACE ON CON8 1 2 ISP DEFAULT 1 2 SPI FUTURE MULTI CHANNEL UPGRADE Table 2 jumper JP3 should be installed in the 1 2 position it s blank see the Microcontroller Programming panel Initial setup Once construction and testing are complete a simple set up procedure must be followed to prepare the mod ule for use Before beginning make sure that you ve set up your remote control as per the information pre sented last month in the Universal Infrared Remote Controls panel First check that the power is switched off then install jumper shunts on JP1 and JP2 see Table 1 and JP3 pins 1 2 Table 2 A jumper must also be installed on CONS pins 1 3 see Fig 7 last month and photos at all times except when the microcontroller is being programmed Note that if this jumper is missing at power up the display will flash an error code of 90 Now apply power while observing the Ack LED It should flash five times to indicate that the unit is in set up mode The 7 segment display should be blank except for the the mute indicator continuously flashing Next point your remote at the on board infrare
88. ally when testing always power the system using the voltage that will be used in the final applica tion This is because the pitch and pulsing frequency will vary with sup ply voltage Note that depending on the value of the capacitors used the circuit will work down to about 4V Making it louder If you want to increase the loudness of the output solder a bridging wire across the inductor on each circuit OUTPUT RI 5609 Fig 2 here is a typical circuit for a 12V phone charger The primary modification is to alter the value of the timing capacitor to dramatically lower the frequency at which the charger is operating Shorting the output inductor and output diode increases the output level Everyday Practical Electronics July 2009 Recycle It frr Whenever you throw away an old TV or VCR or washing machine or dishwasher or printer do you always think that surely there must be some good salvageable components inside Well this column is for you And it s also for people without a lot of dough Each month we ll use bits and pieces sourced from discards sometimes in mini projects and other times as an ideas smorgasbord And you can contribute as well If you have a use for specific parts which can easily be salvaged from goods commonly being thrown away we d love to hear from you Perhaps you use the pressure switch from a washing machine to control a pump Or maybe you salvage the high quality bearings
89. ally switch this voltage on or off as required To access the serial port we used a serial cable with an IDC 10 pin header attached as in the photograph below Once you are satisfied that the circuit is working correctly you may connect the serial cable to your computer s COM1 port Now you should run the WinPic programmer You must first select the COM84 programmer for the serial port 5V Vpp 5V 10F20x PIC 10F20x COM84 COMPATIBLE PROGRAMMER V APPROX 13V t PIC TO BE PROGRAMMED ON PICPROBE PC BOARD a a in the Interface tab While you are there check that the interface is working correctly by clicking on the Initialise button If everything is working correctly you should getthe message Interface tested Ok If not double check your wiring Now goto Device gt Select and select the PIC10F20x as your device You should now be able to erase program and read the micro To load the firmware go to File gt Load and select the PicProbe hex file Then choose Device gt Program to program the micro If this worked go to Verify to check that the firmware has been programmed correctly a link between its input and output positions The first step in the assembly is to carefully solder the SMD devices to the PC board but don t install the PIC just yet To install these parts you will need a soldering iron with a fine pointed tip and a magnifying lamp A pair of sel
90. amp Buzz er PIC16F630 inc VM142 Assembled 66 48 83 15 26 00 USB DMX Interface Control DMX fixtures using a PC and USB interface test software and DMX Light Player software is included a DLL is provided to write your own software Stand alone test func tion that outputs all 512 channels at a time with adjustable levels Supplied with case lead amp CDROM K8062 Kit 55 55 VM116 Assembled 69 64 Record Playback Kit 10 to 35 second record time High Quality Audio Amplifier amp Speaker Included _ Separate Line output External Trigger Speed Control 4 5Vdc Supply 14A Standby Prices Exclude Vat 15 UK Carriage 2 50 less than 1kg PLEASE ADD CARRIAGE amp VAT TO ALL ORDERS LEAP INTO THE FUTURE Powerful EDA Software at Affordable Prices PROTEUS DESIGN SUITE Features Easy to use standard Windows interface Automatic component placement Publication quality schematics and gateswap optimization Fully configurable bill of materials Highly configurable design rules Large component libraries for both Interactive design rule checking simulation and PCB layout Polygonal and split power planes Mixed mode SPICE circuit simulation World class shape based autorouter Co simulation of PIC AVR 8051 and Automatic mitre unmitre commands ARM7 microcontroller firmware Industry standard CADCAM amp ODB
91. and TQFP For more information visit Www microchip com XLP Everyday Practical Electronics July 2009 MIAC with free graphical programming software Matrix Multimedia tell us they have recently launched a flexible controller for the hobbyist and industrial markets the MIAC is a rugged PIC microcontroller designed to allow those with no programming experience to develop highly functional control systems The free software supplied with MIAC allows users to design a program using standard flow chart icons simulate the program on screen and then download the program to the MIAC using a standard USB lead The MIAC unit itself is packed with features including eight analogue or digital inputs four 10A relays four motor outputs keypad LCD display and a CAN bus interface which enables networks of MIACs to be developed The unit is powered by an advanced 18 series PIC and is also compatible with all third party PIC compilers The MIAC and Flowcode 3 graphical programming software is priced at just 120 ex VAT 135 US 180 making MIAC one of the best value for money controllers on the market say Matrix Matrix Multimedia is a leading producer of development tools for the electronics industry The company s products include Flowcode E blocks ECIO Locktronics and MIAC Over the last 16 years Matrix has developed a broad portfolio of development software and hardware allowing engineers hobbyists and students
92. and handling price 2 00 VAT 2 35 for a sample or 44 00 VAT 51 70 for a box of 44 866 battery pack originally intended to be used with an orbitel mobile telephone it contains 10 1 6Ah sub C batteries 42 x 22 dia the size usually used in cordless screwdrivers etc the pack is new and unused and can be broken open quite jf easily 7 46 VAT 8 77 asto Please add 1 66 VAT 1 95 postage amp packing per order JPG Electronics Shaws Row Old Road Chesterfield S40 2RB Tel 01246 211202 Fax 01246 550959 www JPGElectronics com Mastercard Visa Switch Callers welcome 9 30 a m to 5 30 p m Monday to Saturday NEXT MONTH KEYLESS ENTRY SYSTEM Ideal for doors in cars homes and industry this is a keyless entry system with a difference Its super secure because it features a rolling code forget about someone reading and using your infra red signal to break in With this system every time you use it the code changes making hi tec intruders lives a well deserved misery FAST NiMH BATTERY CHARGER This is a truly versatile charger it can charge up to 15 identical NiMH or NiCad cells and you can build it to suit any size cells or cell capacity Users set the charge rate to fast or trickle and of course it has built in safeguards including temperature sensing PROGRAMMABLE IGNITION PART 1 Want to program the ignition timing on your car Now you can with this completely new design
93. and the LED on the main board There is one PC board link sort of anyway The in line The DS1621 temperature sensor chip is soldered to the end of a four wire lead as shown on the left and in the photo below If using telephone or alarm cable it makes sense to use red for ve black for ve and the blue and white wires for data Vec IC5 37 38 Constructional Parts list Data Logging Weather Station its a a a m J availabe from the EPE PCB Service 1 130 x 68 x 43mm plastic utility box UB3 1 500mm length of 100mm diameter PVC sewer pipe 150mm length for rain sensor and 200mm length to house the controller 3 PVC end caps to fit 100mm sewer pipe 1 180 x 360mm piece of 0 4mm galvanised steel sheet for primary funnel 1 260 x 15mm piece of 0 4mm galvanised steel sheet for secondary funnel bracket 1 80 x 125mm piece of 0 6 to 0 8mm thick aluminium sheet for tipping bucket 1 100 x 50mm piece of 0 6 to 0 8mm thick aluminium sheet for secondary funnel 1 95 x 25mm piece of 0 6 to 0 8mm thick aluminium sheet for tipping bucket bracket 2 M4 x 20mm machine screws and nuts corrosion resistant 4 M4 x 12mm M4 machine screws corrosion resistant plus 1 nut 1 small piece of fine wire gauze for primary funnel also used on discharge holes below the tipping bucket 2 100 x 8mm galvanised steel bolts plus nuts and washers for each to make mounting brackets for rain sensor and controller housing
94. andard dual in line DIL package but IC2 has a single row of pins spaced by 0 1 inch 2 54 mm and its package is not surprisingly called a single in line SIL package This second IC is designed to provide an indication on five LEDs of the strength S1 OME integrated circuits offer flexibility in A circuit design For example the 555 timer can be operated as a monostable or an astable depending on the configuration of external resistors and capacitors thereby lending itself to a number of applications Similarly the 741 and other varieties of operational amplifier op amp can be used for switch ing or audio amplifier applications and much more The flexibility and cheapness of these two ICs makes them Components needed Sound Sensor Integrated circuit 1C1 type LM386 low power audio amplifier Integrated circuit IC2 type LB1413N LED level meter in a 9 pin SIL package Electret microphone insert MIC1 sub or ultra miniature omni directional Light emitting diodes LED1 to LED5 two green two red and one blue suggest 3mm dia types Capacitors C1 to C5 values 100nF polyester C1 C3 10uF 16V axial elect C2 22uF 16V axial elect C4 100uF 16V radial elect C5 Potentiometer VR1 value 10k miniature preset type Resistors R1 R2 values 2 7KQ R1 and 4 7kQ R2 Both 0 25W 5 carbon film Switch S1 On Off single pole single throw SPST Battery B1 9V plus connecting leads Protobloc and w
95. annel reaches the maximum volume setting ie 85 further com mands to increase the volume are ignored When one channel reaches the minimum volume position 0 further commands will continue to decrease the volume in the other channel until both are at minimum if they are not identical Increasing the volume from 19 Constructional Project DOUBLE ENDED QUICK Saale s CASE BASE i M4 x 10mm SCREW NUTS AND STAR WASHER Fig 16 the mains earth lead must be securely attached to the base of the metal chassis Here s how to assemble a suitable earthing point for attaching two spade lugs The two nuts lock the assembly in place this minimum position restores the original balance seperation Muting Muting is achieved by hitting the Mute or 12 buttons depending on your model ofremote Hitting the mute button a second time immediately restores the original volume level and simultaneously increases it by one step Note that pressing Vol Down while muted does decrease the volume level shown on the display but it doesn t turn the muting off This allows you to wind down the volume to a respectable level first perhaps when you ve been caught out with the wick wound up far too high Muting is indicated by the flashing of the second inverted deci mal point Fig 15 top left which will continue to flash even during display blanking when enabled Multi channel upgrade Finally
96. ant Any write to the timer will clear it and start timing again so you can t use any read modify write instruction This was a trap I fell into I have run the timer at 50ms per overflow counts from 0x3d to 0 in 50ms then is reloaded with 0x3d If you check and branch when the timer is zero you can have a routine which is executed at a regular period for timing tasks The program begins by setting the oscillator configuration port pin con figuration inputs or outputs starting the timer and resetting the LEDs As the processor has no interrupts the only way to monitor the probe tip is to poll it This is done in the main loop and the smaller the main loop or the quicker it executes the smaller the pulse transi tion that can be detected This is one limitation of the design but in practice it doesn t appear to be a problem The main loop moves the state of the probe input to the red green output checks the status of the mode change flag and looks for the timer to reach zero On the button Every 50ms the time function is called The job of the time function is to check that the button S1 has been held down for two seconds and to up date the orange LED in either pulse or latch modes First we will look at the button down timer To do this we have a variable called CNTO which is preloaded with 40 Every time the time function is called we decrement CNTO if the but ton is pressed If it is not pressed we r
97. any other UK monthly hobby electronics magazine our sales figures prove it We have been the leading monthly magazine in this market for the last If you want your advertisements to be seen by the largest readership at the most economical price our classified page offers excellent value The rate for semi display space is 10 VAT per centimetre high with a minimum height of 25cm All semi display adverts have a width of 5 5cm The prepaid rate for classified adverts is 40p VAT per word minimum 12 words All cheques postal orders etc to be made payable to Everyday Practical Electronics VAT must be added Advertisements together with remittance should be sent to Everyday Practical Electronics Advertisements Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Phone 01202 873872 Fax 01202 874562 Email epeads wimborne co uk For rates and information twenty three years BTEC ELECTRONICS TECHNICIAN TRAINING NATIONAL ELECTRONICS VCE ADVANCED ICT HNC AND HND ELECTRONICS FOUNDATION DEGREES NVQ ENGINEERING AND IT DESIGN AND TECHNOLOGY LONDON ELECTRONICS COLLEGE 20 PENYWERN ROAD EARLS COURT LONDON SW5 9SU TEL 020 7373 8721 www lec org uk TELEPHONE RECORDING ADAPTER Records from phone line to dictaphone Send all payments to GS Electronics 387 Meadgate avenue Chelmsford Essex CM2 7NN Total 24 24p inc P P BOWOOD ELECTRONICS LTD Suppliers of Electronic Components Place a secure order o
98. ar from the cut off thus we can describe both initial fall off and ultimate fall off Note that an octave is a range of frequencies in which the higher frequency is twice the lower the same term is used in music As already mentioned a decade is a range in which the upper value is ten times the lower The variation of phase shift with frequency is also an important characteristic of filters Phase shift relates to the time delay of signals passing through the filter If the delay is different at different frequencies the signal will be distorted Constant delay corresponds with a linear increase of phase shift with frequency The terms constant delay or linear phase are used to refer to filters that are ideal or have very good performance in this respect Mathematics The full mathematical treatment of filters uses what are known as complex numbers to represent both signals and circuit characteristics Unlike ordinary numbers which have just one value complex numbers have two values referred to as the real and imaginary parts This two dimensional quality essentially enables complex numbers to fully represent both the frequency and phase attributes of a signal or circuit something which a single value for say a voltage or frequency cannot do When analysing filters using complex numbers we find critical complex number frequencies at which the response of the filter is zero or infinity These points are called zeros and pol
99. ard code into the video library to create an RS232 terminal reminiscent of the classic VT100 mainframe computer interfaces A potentially useful device in its own right but once more just a step in the direction of a more interesting device but more on that next month Competition It would be interesting to see what applications people can dream up for the video hardware and software we have developed over the last few months and we would love to see them To provide a bit of encouragement we are offering a Nurve Networks XGS PIC 16 development system reviewed elsewhere in this issue for the most interesting design submitted by the end of October We ll announce the winner and publish the design in PIC n Mix later in the year Send your submissions or indeed any other comments to mike hibbett gmail com Our thanks to Nurve Networks for making an XGS available 61 EPE S PLEASED TO BE ABLE TO OFFER YOU THESE ELECTRONICS CD ROMS ELECTRONICS PROJECTS eS Electronic Projects is split into two main sections Building Electronic Projects Logic Probe testing 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
100. ariables can be increased decreased to slow speed up the clocks You need a PV connected to do this check Check the time on the maintenance display after a period of slightly under one day and adjust Time_interrupt by adding two for each three minutes fast each day Check it before midnight as it auto corrects then and so it will upset your calibration measurement Once that is correct to within 1 to 2 minutes per day although five min is acceptable in most situations check the Mins int internal delay based minute counter just before the 59 mins point and check that the normal time read ing is also at the same minutes Add subtract about 21msec to Timing de lay_fine for each minute fast slow Mins int is per hour Timing delay_coarse will not need changing unless Timing _ delay_fine goes over 250 or under 0 Over the course of a year check the displayed adjusted time against real time and note down the error every couple of months Work out the aver age error and change Minute_offset and or DST to suit at the end of the year Any erratic timing is a sign the Dawn_light_level threshold is incorrect or that you are getting a lot of spurious light on the PV at night Day to day running When the unit is first powered up following PIC programming use the op tion on the LCD to revert to the default values after which a time setting screen appears Use the up down buttons to set the displayed hour of the day to the nearest hour
101. cable so it can be placed in a housing or other suitable location where the temperature is to be measured There are a few possible cable choices including a length of 4 core alarm cable telephone cable or Ethernet LAN cable A length of about a metre was used for the prototype and this worked well Constructors could probably extend this length but no testing has been done on longer lengths The cable only needs to handle a digital signal at about 60kHz so it shouldn t be too demanding Mias We re getting a bit ahead of ourselves mechanical details will be presented next month but this shot shows how the control box is hung inside a PVC pipe with the hanger bracket riveted to the PVC pipe cap lid Everyday Practical Electronics July 2009 Constructional Fig 3 it s up to you which software you use for data logging there s a mountain of it out there a lot of it freeware This screen grab shows the Eltima RS232 software which the author uses More on this next month The wires on one end of the cable are simply soldered directly to the appropriate pins on the DS1621 Follow the wiring diagram and the photograph which shows the underside of the DS1621 All DS1621 pins except pins 4 and 5 are trimmed before soldering so that they can be bent flat onto the back of the device without touching one another Bending them back like this gives a more compact final result After soldering coa
102. ckO2 Iv BootleckO1 T Lock T Lock T 385156 F WDTON FF SPIEN CKOPTT EESAVE T BoOTSZz1 BOOTSZ0T BOOTRST lw BODLEVELI BODEN I SUTI SUTO CKSEL3 T CKSEL2 CKSEL1 CKSELO pii LRG Sel terme mear Refer to device datasheet please Cancel HE y Hinpidramme Lil Clear All ji Set All Wat Tike Bead Fig 18 the parallel port programmer uses PonyProg which has an entirely different fuse configuration menu Again copy this example and hit the Write button microcontroller yourself A 10 way header CON8 has been included onthe PC board for connection to an in system type programmer Tempo rarily remove the jumper between pins 1 and 3 of CON8 to allow connection ofthe programming cable Also make sure that there s a jumper between pins 1 and 2 of JP3 Once you have a suitable program mer together with the necessary cables and Windows software to drive it all you need to complete the job is a copy of the microcontroller program for the Remote Volume Control amp front panel Balance button and use the rotary encoder Each press or click adjusts the level by 0 5dB regardless of the state of JP2 However holding down the remote s button for more than one second will case a temporary shift to 1 5dB adjustment steps When in balance adjustment mode the left inverted decimal point flashes see Fig 15 Two dashes on the LED displays indicate that the balance is centred Hittin
103. d without exception Low voltage wiring As afirst step disconnect the mains cable to prevent mishaps while work ing under the hood You can then complete the assembly by running all the low voltage wiring If a separate transformer has been used its two secondary 15V AC windings must be terminated at the transformer input CON1 of the power supply board Twist the wires together and keep them as short as possible to reduce radiated noise Next connect the 15V 15V and GND outputs at CON2 and 5V at CON3 on the power supply to the matching inputs at CON1 and CON2 of the Remote Volume Control amp Preamp Module Note that the GND output at CON3 on the power supply is not used Use only heavy duty hook up wire for the job Take great care to ensure that you have all of the connections correct a mistake here may damage the control module We suggest four different cable colours to reduce the chances of a mistake If you want to control left right bal ance from the front panel then you ll also need to install a pushbutton switch This will enable you to use the rotary encoder for both volume and balance adjustments The terminals of the switch are simply wired between the BALANCE and GND inputs at CONS Having said that balance ad justment is a rare requirement after initial setup which would be done via remote control so most construc tors will not need this switch The module also provides a s
104. d receiver IC3 and press the numbers 1 or 2 twice It s significant which of these numbers is chosen A 1 enables display blank ing meaning that the display will go blank eight seconds after each volume or balance adjustment Conversely 2 disables this feature causing the display to be always on On the second press the Ack LED should flash five times again indicating that the code was received and the cho sen equipment address TV SAT AUX etc successfully saved You should now power down the unit and remove the set up jumper JP1 only This procedure can be repeated in the future should you wish to change the equipment address or display blanking option In use As mentioned previously volume span is effectively 127dB 95 5dB to 31 5dB As the PGA2310 supports 0 5dB gain steps there are 255 steps from minimum to maximum volume To fit this on a 2 digit readout and make it more intelligible the level is scaled down to a 0 to 85 range by dividing it by three The result is accurate to 1 5dB so you ll need to adjust the volume balance by three points before you see a change in the readout Note that 64 corresponds to OdB unity gain Everyday Practical Electronics July 2009 Advameg LEE Lats Moon T Beene e Wa pegam iach natant Pape bii Af SP triable ROOTRST M EERME d Rar Een TF Wu aie moe TE Ste Ub AAS v4 Crap Eran Fig 17 h
105. ded boards are NOT plated through hole and will require vias and some components soldering to both sides 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 Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 Email orders epemag wimborne co uk On line Shop www epemag com 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 photocopies of articles are available if required see the Back Issues page for details WE DO NOT SUPPLY KITS OR COMPONENTS FOR OUR PROJECTS Please check price and availability in the latest issue A large number of older boards are listed on and can be ordered from our website Boards can only be supplied on a payment with order basis PRO ECTTITLE APRIL 08 Studio Series Remote Control Module MIDI Activity Detector PIC In Circuit Programming Add On x PC Controlled Burglar Alarm Main Board Display Board MAY 08 PC Controlled Burglar Alarm Keypad Electric Mobility Buggy Monitor Mini Theremin JUNE 0
106. ding at their own pace The book can be used at a variety of levels Contents Introduction to the PIC microcontroller Programming the 16F84 microcontroller Introductory projects Headers porting code which micro Using inputs Keypad scanning Program examples The 16C54 microcontroller Alphanumeric displays Analogue to digital conversion Radio transmitters and_ receivers EEPROM data memory Interrupts The 12 series 8 pin microcontroller The 16F87X microcontroller The 16F62X microcontroller Projects Instruction set files and registers Appendices Index Order code NE39 19 99 PRACTICAL ELECTRONIC FAULT FINDING AND TROUBLESHOOTING Robin Pain To be a real fault finder you must be able to get a feel for what is going on in the circuit you are examining In this book Robin Pain explains the basic techniques needed to be a fault finder Simple circuit examples are used to illustrate principles and concepts fundamental to the process of fault finding This is not a book of theory it is a book of practical tips hints and rules of thumb all of which will equip the reader to tackle any job You may be an engineer or technician in search of information and guidance a college student a hobbyist building a project from a magazine or simply a keen self taught amateur who is interested in electronic fault finding but finds books on the subject too mathematical or specialised The fundamental principles of analogue and digit
107. discouraging electricity use during peak periods but could also lead to many families facing higher fuel bills Benefits include knowing exactly how much power appliances consume for instance televisions left on standby With luck USB data ports will be incorporated in these meters leaving plenty of opportunity for EPE contributors and other clever designers to provide add on devices for interpreting the data in innovative ways and using it control other devices 100 Uses for a dead cat Well not quite but what about other uses for a spare SIM card Unlike certain smart cards used in ticketing and payphone applications it appears that SIM cards cannot be reprogrammed which makes them pretty useless for data storage or other projects On the other hand they are ideal for use in static mobile telephones Once an expensive luxury mobile phones having the same form factor WHAT EXACTLY IS A SIM A Subscriber Identity Module SIM is the element that authenticates and identifies mobile subscribers on the network they are using A memory chip stores this information and other data on a removable SIM card that can be transferred from one telephone computer dongle or other telephony device and inserted in another Data stored on SIM cards can include Integrated Circuit Card ID ICCID International Mobile Subscriber Identity IMSI Authentication Key Ki Local Area Identity LAI and Operator Specific Emergency
108. e and cathode and these have the abbreviated forms of a and k respectively The circuit diagrams in EPE include the a and k markings but they will not necessarily be included in circuit diagrams published elsewhere A is often used in place of the cathode marking possibly accompanied by a instead of the anode marking None of these additional legends are actually required since the polarity is indicated by the diode symbol itself However these extra markings should be helpful to those of limited experience with circuit diagrams and circuit symbols Banded together A band marked around the body of the component near the cathode k lead is by far the most common method of indicating the polarity on a diode It can be helpful to remember that this band corresponds to the bar at the cathode end of the diode s circuit symbol There are two common exceptions to this method of marking the polarity of a diode One method tends to cause a certain amount of confusion by retaining the usual band and augmenting it with additional bands The type number of a diode as with most semiconductors is normally marked on the body in minute lettering A different approach is adopted with multi band diodes which use a system of colour coding based on the system used for resistors As far as I am aware this system is only used for diodes that have a IN prefix Three or four bands are used to
109. e is one slight complication which is that the components must be fitted the right way round In most cases there will not be any dire consequences if a mistake is made and one of these components is fitted the wrong way round but the finished project is unlikely to work properly until the error is corrected In a minority of cases and particularly where rectifiers are concerned there 1s a real possibility of components being damaged and possibly in a spectacular fashion It is sometimes acceptable to use a suck it and see approach with trial and error being used to find the correct method of connection but in general this method is not a good idea It is better not to connect any component unless you are sure of the correct method and to rigidly adhere to this approach until you have the ability to sort out the risky situations from those that pose no threat of damaging anything One way traffic Most semiconductor components have more than two leadout wires or pins and the only common exception is the diode The diode is the simplest form of semiconductor and it is a sort of electronic valve It allows an electric current to flow in one direction but blocks any significant flow in the other direction Connecting a diode with the wrong polarity allows a current flow in the wrong direction while blocking any flow of current in the right direction This more or less guarantees that the circuit will not work properly a
110. e software was written in PIC assembler using the PIC IDE 7 5 tool kit which is available free from www microchip com The IDE gives you an editor and assembler and is quite easy to learn As this micro has no interrupts and very little resources it doesn t take long to master but as I found out there are a few traps for the unwary The first thing to master is the internal oscillator and its calibration if required When the device is manufactured it has a MOVLW instruction loaded into the last byte of the memory On power reset the micro starts at the last address and executes the MOVLW instruction This loads a calibration value into the W register and is factory set The program counter then rolls around to 0 and starts executing the user s code The problem comes when you erase the device and lose the MOVLW instruc tion If you want a 4MHz calibrated Everyday Practical Electronics July 2009 oscillator then you need to read the last byte and write it down then manually put it back in All this seemed unneces sary as I wanted it to run as fast as possi ble As the first instruction I loaded W with 0x7E which makes the oscillator run at its fastest speed Internal timer The next item to master is the in ternal timer This is a bit tricky as the micro has no interrupts to trigger asynchronous events The timer is free running and you can only read the timer register and compare it with a const
111. e that EPE is not offering official endorsement of their products Views expressed in Readout are always solely those of the author and are printed because of their topical or general interest value or as in this case in response to specific requests for information Oscar LEDs Dear EPE I was delighted with the simplicity of Brian Healy s Oscar project in the April issue However on closer inspection I notice that there are no current limiting resistors for the LEDs Was this deliberate or an oversight With a supply voltage of approximately 5 5V the LEDs will pass a lot more current than the recommended 20mA I think that Peter s comment Also in general the software prefers all through hole components to surface mount ones and if your project has a lot of ICs then you are going to be placing a lot of X s which is the software mark for cutting a track is unfair to VeeCad It is the stripboard that imposes these limitations not the program One final point I have found that Roger Lascelles the VeeCad developer is always open to suggestions for improvements and offers help on the VeeCad forum I must point out that other than being a very satisfied user I have no connections with VeeCad or Roger Lascelles Dave Sims by email there s no satisfied Thank you David recommendation like a customer or so that the ports of the PIC can safely supply Even when the ports are multiplexed in
112. econd switch input at CONS labelled CHAN NEL This is intended for a possible future multi channel upgrade and should not be connected as it cur Everyday Practical Electronics July 2009 Constructional Project ENCODER EARTH AUDIO EARTH EN NAG OTE CONTROL LUL g TOM owe u j H m MODULE 240VAC INPUT DOUBLE ENDED NEUTRAL BLUE LIVE BROWN USE ONLY MAINS RATED CABLE FOR ALL MAINS WIRING AND INSULATE ALL CONNECTIONS BALANCE SELECT OPTIONAL Fig 14 follow this basic diagram when hooking up your module Use heavy duty hook up wire for all of the low voltage power supply connections For the mains side use only mains rated cable and be sure to keep it well away from the low voltage side A few strategically placed cable ties will keep everything in position even if a wire should happen to come adrift rently has no function Use good quality shielded audio cable for all the audio connections Terminate one end of the cables in RCA phono plugs for connection to the control module s inputs and outputs Depending on your requirements you may wish to fit chassis mount RCA phono sockets at the other end and mount these on the rear of your case Finally you ll need to make up the cable for the main board to display board connection This is simply a length of 20 way IDC ribbon cable terminated with 20 way plugs at each end see photos We used a 12cm length for the prototype but
113. ed this newly discovered phenomenon eagerly for in understanding the physics of propagation they were discovering more about our Universe and its workings Radio wave propagation has its origins in the world of solar physics The Sun s radiation provides the mechanism for the formation of the ionosphere How the ionosphere is formed and how it provides long distance communication is carefully explained Non ionospheric propagation including moonbounce or satellite communications is covered as well This book has been written with the average electronic hobbyist in mind Technical language and mathematics have been kept to a minimum in order to present a broad yet clear picture of the subject The radio amateur as well as the short wave listener will find explanations of the propogation phenomena which both experience in their pursuit of communications enjoyment Order code BP293 4 45 50 pages 116 pages 67 THEORY AND REFERENCE BEBOP TO THE BOOLEAN BOOGIE Second Edition Clive call me Max Maxfield This book gives the big picture of digital electronics This in depth highly readable 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
114. ed up to more than the bottom sensor or about 65 C depending on which mode the software is in the LED should light indicting that IC2 can turn the pump on Be careful if you use a soldering iron to apply heat as it s easy to overheat the sensors Check the pump LED goes off when the panel sensor is cooled again It should also go off if the sen sor is 65 C to 80 C but the PV supply is reduced below about 6V indicting that the PIC is correctly responding to low light levels But note that it may also go off anyway if the supply is below about 4V as IC2 may not cor rectly function at such low voltages and does not need to Check that the LCD indicates the correct PV voltage remembering that it displays in deci volts ie volts divided by ten Note that it may take the software up to 60 seconds to cycle round to the correct point to activate these on off transitions so conduct the tests slowly Optional current reduction For the lowest possible supply cur rent at the expense of the LCD contrast getting too low as the battery voltage charge reduces increase the value of R47 to the highest possible value that gives a readable display at a low bat tery state such at 3 3V Replace the resistor or solder resistors in parallel to it on the PCB track side to bring it s value to a suitable value in the range 470Q to 4 7Qk Everyday Practical Electronics July 2009 Constructional Go back to the assembly stage
115. ee e e555 occe sees soe ones see eee eo so ee eo oh eee ee l Post Code Toore e ee T o VOL 17 VOL 18 BACK ISSUES January 2004 to June 2004 BACK ISSUES January 2007 to June 2007 BACK ISSUES July 2007 to December 2007 Price 16 45 each 29 95 for Five Year CD ROM LJ enclose cheque P O bank draft to the value of L please charge my Visa Mastercard Maestro includes VOL 19 BACK ISSUES January 2008 to June 2008 Ca ar 0 eee Sy es eg eo ey a aa VOL 20 BACK ISSUES July 2008 to December 2008 J es Card Secur Ity Code 24 22 225e5 The last 3 digits on or just under the signature strip l NEW FIVE YEAR CD ROM Jan 2003 to Valid From o o anaa Expiry Date 0 0 Dec 2007 Maestro Issue No NOTE These CD ROMs are suitable for use on any PC witha CD ROM drive They require Adobe Acrobat Reader available free from the Internet www adobe com acrobat WHAT IS INCLUDED All volumes include the EPE Online editorial content of every listed issue plus links to all the available PIC Project Codes for the PIC projects published in those issues Please note that we are unable to answer technical queries or provide data on articles that are more than five years old Please also ensure that all components l are still available before commencing construction of a project from a back issue SEND TO Everyday Practical Electronics Wimborne Publishing Ltd
116. ee website for full details 12Vdc PSU for all units Order Code PSU445 8 95 Here are just a few of the am w and USB Experiment Interface Board 5 digital input chan nels and 8 digital out put channels plus two analogue inputs and iz two analogue outputs iii with 8 bit resolution Kit Order Code VK8055KT 20 95 Assembled Order Code VVM110 39 95 Rolling Code 4 Channel UHF Remote State of the Art High security 4 channels Momentary or latching relay output Range up to 40m Up to 15 Tx s can be learnt by one Rx kit in cludes one Tx but more avail able separately 4 indicator LED s Rx PCB 77x85mm 12Vdc 6mA standby Two amp Ten Channel versions also available Kit Order Code 3180KT 44 95 Assembled Order Code AS3180 54 95 Computer Temperature Data Logger Serial port 4 channel tem perature logger C or F Continuously logs up to 4 separate sensors located 200m from board Wide range ot tree software applications for stor ing using data PCB just 45x45mm Powered by PC Includes one DS1820 sensor Kit Order Code 3145KT 17 95 Assembled Order Code AS3145 24 95 Additional DS1820 Sensors 3 95 each a items are available in kit form KT sus or re assembled and ready for use AS prefix 177 4 Ch DTMF Telephone Relay Switcher Call your phone num ber using a DTMF phone from anywhere in the world and re motely turn on off any i of t
117. eed bending over a little to clear the box lid so leave its leads long Use short wire offcuts to link the LCD to the PCB Check carefully for any solder bridg es on both PCBs as the track spacing is small in places Connect pin 1 of the ribbon to pin 1 of both PCBs sockets and arrange for the cable to neatly exit the connector from the correct side of the plug Insert the plugs into the PCBs before assembling 4 35in 110 5mm Fig 5 LCD PCB for the Solar Water Heating System Controller Components R38 R47 S5 and VR1 can be fitted to the back side see text the tracks facing you the four switches centralised left to right and the PCB centralised vertically Part drill into the lid through these 12 holes After assembling the PCB check that your hardware matches these holes adjust their positions if needed and increase their sizes to suit The reset switch and VR1 positions are not marked so add your own holes if you need them using a small hole for access with a fine tool The LCD spacers should be of such a length that they allow the switch buttons to protrude through the box lid when the LCD is up against the lid 3 to 4mm spacers for the display connection to PCB suited the proto type made from a 10mm pillar cut in half and filed down and using 2 5mm diameter screws 10mm spacers filed down to 9mm with 3mm screws were used for fitting the PCB to the box lid The LCD PCB for the Solar Water Heating System
118. ement will stop and only areset will restore normal operation Please don t get the impression from this that controller failure is likely it s just the author s professional caution that has led him to build in some fail safe features as unlike for most EPE projects this one has to run reliably for 10 to 20 years of continuous use The prototype has not failed in over a year of running so we hope you will have many years of energy efficient and flawless running out of this controller Disclaimer The controller has been designed to work with Solartwin systems amongst others but the design is not endorsed by Solartwin so they may not honour their warrantee on their components if they can show that the use of this con troller affected the system s reliability It seems extremely unlikely that there will be any such effect on the compo nents as no extra voltages are being ap plied to the pump than normal Indeed the use here of lightning protection could improve reliability Panel reliabil ity could however be slightly degraded if your connections are not well made as this could stop the pump running and overheat the panel more often than normal EPE Everyday Practical Electronics July 2009 e eee l P vY pr It s cheap and simpleto build operates completely unc ctional ittended and will juntforyears on alset ot AA Aiaia Ti If you need to record weather data at a remote
119. ere s how to set the fuse bits in AVR Prog as used with the AVR ISP Serial Programmer Once you ve set all ofthe options exactly as shown click on the Write button F YOU RE BUILDING this project from a kit then the microcontroller IC1 will have been programmed and you can ignore the following information Alternatively if you ve sourced all the components sepa rately then you ll need to program the values below this attenuate the input signal whereas those above it amplify To increase or decrease the volume hit the Vol Up or Vol Down buttons on your remote or turn the rotary encoder With jumper JP2 installed each press or click of the encoder moves the volume by just 0 5dB Ifthe remote s button is held down so that it automatically repeats the adjustment steps jump to 1 5dB after one second Some audio systems may not require the fine 0 5dB adjustment steps To increase the steps to 1 5dB for every but ton press or click remove jumper JP2 In this case holding down the remote s buttons makes no difference to the step size which always remain at 1 5dB On balance To adjust the balance between the left and right channels use the Ch Up and Ch Down buttons on your remote in stead Alternatively press the optional Everyday Practical Electronics July 2009 Constructional Project Configuration and Security bits fT Bootheckt2 I Boothockt1 T Bootlo
120. ery recharged by a mains power pack Each model has a built in antenna and can be connected to a variety of external aerials Note that if you buy a dedicated SIM card for your Premicell or Phonecell it is important to make at least one call with it every six months Inactive cards tend to be disregarded by the networks and you might lose any call credit Everyday Practical Electronics July 2009 EPE PIC RESOURCES V2 CD ROM ORDER FORM Please send me quantity EPE PIC RESOURCES V2 CD ROM i E Price 14 45 each includes postage to anywherein the world 7 Namie eee e tree eee tcen eee ree eecereea era roeeeser yarn esete 7 Address a E eere eer ee 7 a Pe ee a cop todo todonocdo ete dated teeta de tenet ted eteedte retetetete ete tote tate etetedetete tated teteteyetetetetetetetatetetetetetete te tetetelstetetetetetets a E eae Post Code ware ten Om O enclose cheque P O bank draft to the value of O please charge my Visa Mastercard Maestro CNO L rae tee eee eee ee er eee ee eae Card Security Code The last 3 digits on or just under the signature strip WUC EO Miler ee eee nee Expiry Date e Maestro Issue No 200 e00 Visa k SEND TO Everyday Practical Electronics Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 Email orders epemag wimborne co uk Payments
121. ery type is higher or IC4 and IC5 may be overstressed 18mA suits the specified 150mAh battery as not all the current goes to the battery once JP2 is on Disconnect the supplies and JP2 between each of the steps below particularly when connections are made Check the battery voltage is at IC1 socket pin 20 with JP2 on Connect the LCD PCB and check the battery voltage is on one of IC1 socket pins 25 28 when an appropriate button is pressed Insert the ICs Programme the PIC at Everyday Practical Electronics July 2009 this stage if not already done using CON1 Reconnect the supplies and the LCD should display text if not adjust VR1 till it is readable Press reset if needed to start the processor although it should start correctly upon inserting JP2 If you can t get the contrast high enough try changing D10 and D11 to Schottky types such as 1N5817 to reduce the 2V rail to about 2 5V Check for 2 5V at IC1 pin 5 and that the voltage across R1 is 20 50mV or 10 30mV with the LCD off after midnight This current is quite sensitive to battery voltage Higher voltages across R1 than this means you have a fault Connect at least a panel and bottom sensor to CON4 6 with resistors to Sensor Ve for unused sensors It is easiest to test with loose sensors on short wires rather than ones installed on the panel and HWC The LCD should then display temperatures with LO for any unused sensors Ifthe panel sensor is heat
122. eryday Practical Electronics July 2009 Of course a 4 x AA flat battery holder could also be used with either a dummy cell or shorting wire replacing one of the four cell positions If you use this method don t forget which cell you ve replaced or you could end up putting one into the shorted position One end of the utility box has a socket for connecting the temperature and rain sensors The temperature sensor IC5 requires four connections Vcc ground data and clock while the rain sensor has a two wire connection ground and signal A five pin DIN audio connector was chosen for the task with the ground connection shared between the temperature and rain sensors A range of other socket types would be suitable including separate sockets for the temperature and rain sensor if this is desirable The main consideration should be ensuring a reliable connection Inside the box there are two PC boards on which all components are mounted except the slide switch S4 for dumping data and the rain and temperature sensors The PC boards slide into the mounting slots provided in the utility box with the component side of both facing towards the socket that connects the temperature and rain sensors Solder pins have been included on the PC boards for the interconnections that are needed Those pins on the main controller PIC board that are needed for connection to the MAX232 board should be mounted on the copper side of the board s
123. es respectively If it seems a bit strange to get infinite output response from a filter remember this occurs with complex numbers not with the ordinary values We can translate the complex frequencies of the poles and zeros to the real frequencies shown on the frequency response graphs such as in Fig 2 We then find that at the pole and zero frequencies the response graphs change slope For a simple case these frequencies correspond exactly to the cut off frequencies 3dB point or break frequencies at which the response turns up or down Poles cause the gain of the filter to decrease with increasing frequency with the eventual rate of decrease being 6dB octave or 20dB decade Zeros cause the gain of the filter to increase with increasing frequency with the rate of increase being 6dB octave or 20dB decade at sufficient distance from the zero Poles make phase shift more positive by 90 per pole and zeros make phase shift more negative by 90 per pole OUTPUT VOLTAGE OVERSHOOT STOP BAND oO 10 TO 90 V FREQUENCY LOG SCALE GAIN dB 6dB PER OCTAVE SLOPE 12dB PER OCTAVE SLOPE PHASE SHIFT DEG LOG FREQUENCY f Fig 3 Frequency domain response showing poles and phase The effect of poles is illustrated in Fig 3 which shows a low pass response with two break frequencies determined by the presence of poles The order of a filter equals the number of poles or zeros whichever i
124. eset CNTO back to 40 The only way CNTO can make it to 0 is if we have 40 consecutive calls to time with the button pressed 40 x 05 2 seconds When CNTO reaches 0 we set a flag BDOWN to signal to the main loop that the mode change func tion needs executing Everyday Practical Electronics July 2009 Constructional The orange LED is handled with dif ferent pieces of code depending on the mode set The flag LATCH determines the mode Every time the red green LED chang es state we set a flag CHANGE This flag is read by the time routine In pulse stretch mode the orange LED is turned on when CHANGE is set and then CHANGE is cleared If CHANGE is not set the orange LED is turned off This means that the mini mum time that the orange LED is on will be 50ms which is more than enough for your eye to see Latch mode is similar in that when CHANGE is set the orange LED is turned on but is not cleared until the button is pressed This is detected using the BPRESS flag Mode changing uses a separate function labelled cngmode When this function is called it will blink the orange LED using simple delay loops until the button is released When the button is released the LATCH flag is inverted and the routine exits back to the main loop Construction If this is your first SMD surface mount device project you will find there is a rather radical difference be tween handling fitting and soldering these
125. extito nothing MUNN iii Everyday Practical Electronics July 2009 TENO UK MAGAZINEFOR ELECTRONICS TECHNOLOGYIS COMPUTERIPROIECTS i SUBSCRIPTIONS Subscriptions for delivery direct to any address in the UK 6 months 19 95 12 months 37 90 two years 70 50 Overseas 6 months 23 00 standard air service or 32 00 express airmail 12 months 44 00 standard air service or 62 00 express airmail 24 months 83 00 standard air service or 119 00 express airmail Online subscriptions for downloading the magazine via the Internet 18 99US approx 13 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 Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 Email subs epemag wimborne co uk Also via the Web at www epemag com Subscriptions start with the next available issue We accept MasterCard Maestro 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 PVC printed with the magazine logo in gold on the spine Price 7 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
126. f closing tweezers can be used to hold each device in position as it is soldered Once these SMD parts are in sol der on the probe tip the switch and the external connection wires As mentioned earlier the tip is a sewing needle These are often nickel plated which makes soldering a bit difficult Test it first if it is difficult or impos sible to get solder to take you may need to file off a small section of the nickel plating The size of the probe is up to you and the type of work you ll be doing We d be inclined to use a small darn ing needle as these tend to have less Everyday Practical Electronics July 2009 of a point so you won t get stabbed but are still fine enough for the vast majority of work The needle we used was about 35mm long and so far hasn t been missed from the sewing box Don t forget that the power wires polarised figure 8 cable need to pass through the pen top cap so it is wise to do this now rather than later You ll need to drill a hole in the end of the cap to accommodate the wires The last component to be fitted should be the PIC chip as this allows you to check the LED operation before solder ing the PIC IC1 in position To do this connect power and in turn short the cathode K of each LED to ground OV Teme rue iesi ANTRO e Each should light in turn you won t do any harm to transistor Q1 doing this As you do this also check
127. fix Motor Speed Controllers Here are just a few of our controller and driver modules for AC DC Unipolar Bipolar stepper motors and servo motors See website for full details DC Motor Speed Controller 100V 7 5A Control the speed of almost any common DC motor rated up to 100V 7 5A Pulse width modulation output for maximum motor torque at all soeeds Supply 5 15Vdc Box supplied Dimensions mm 60Wx100Lx60H Kit Order Code 3067KT 17 95 Assembled Order Code AS3067 24 95 Computer Controlled Standalone umpa lar Stepper Motor Driver i Drives any 5 35Vdc 5 6 or 8 lead unipolar stepper motor rated up to 6 Amps Provides speed and direc tion control Operates in stand alone or PC controlled mode for CNC use Connect up to six 3179 driver boards to a single parallel port Board supply 9Vdc PCB 80x50mm Kit Order Code 3179KT 15 95 Assembled Order Code AS3179 22 95 Computer Controlled Bi Polar akid Motor Driver Drive any 5 50Vdc 5 Amp bi polar stepper motor using fe externally supplied 5V lev els for STEP and DIREC TION control Opto isolated inputs make it ideal for CNC applications using a PC running suitable software Board supply 8 30Vdc PCB 75x85mm Kit Order Code 3158KT 23 95 Assembled Order Code AS3158 33 95 Bidirectional DC Motor Speed Controller Control the speed of most common DC motors rated up to 32Vdc 10A in both the forward and
128. for the rest of the run but ensure for joint reliability that the join is in a protected area and not outside your Everyday Practical Electronics July 2009 house This joint is a good place to put the lightning protection board Use screened twin core cable such as microphone cable The datasheet for the MCP9700A recommends a 20 1j1F ceramic de coupling capacitor across the and leads or 1pF ifin a high interference environment Such interference is unlikely but as it s difficult to get to the sensors to modify them later especially on the panel we recom mend that a 1uF capacitor is fitted to at least ICsens1 Leaded capacitors are easier to work with and give stronger solder joints but high temperature ones are expensive so for ICsens1 at least use surface mount ones of 1205 size 3mm long or larger and able to withstand 125 C Solder the capacitor half way up the untrimmed sensor leads with the leads on the ends rather than underneath the capacitor so the overall sleeving holds the joints together Preheat the capacitor slowly to 100 C before sol dering to reduce the chance of cracking it Make sure the joints are solid See the sensor photograph which shows a sensor with two separate single core PTFE cables Slide three pieces of heatshrink tub ing over the three wires of the cable with the central one longer This is slipped right under the capacitor to prevent shorts between the capacitor and t
129. fully protected and reproduction or imitations in whole or in part are expressly forbidden Our August 2009 issue will be published on Thursday 9 July 2009 see page 72 for details Everyday Practical Electronics July 2009 www epemag com Projects and Circuits PICPROBE from an original by Ross Purdy A PIC based logic probe that fits inside a ballpoint pen case REMOTE VOLUME CONTROL amp PREAMPLIFIER MODULE PART 2 by Peter Smith Part 2 completes the construction and provides the set up procedure SOLAR WATER HEATING SYSTEM CONTROLLER PART 2 by Edward Chase Assembly testing and calibration of this zero carbon system SIMPLE DATA LOGGING WEATHER STATION PART 1 by Glenn Pure Records rainfall and temperature and operates completely unattended BREADBOARDING PROJECTS by Dr Malcolm Plant Part 10 AM Radio Sound Sensor INGENUITY UNLIMITED Oil storage tank burglar alarm TECHNO TALK by Mark Nelson Not just for cellphones XGS VIDEO GAMES DEVELOPMENT SYSTEM by Mike Hibbett A review of Nurve Network s PIC based system RECYCLE IT by Julian Edgar Making an adjustable loud screamer PRACTICALLY SPEAKING by Robert Penfold Component polarities CIRCUIT SURGERY by lan Bell Filter circuits Part 1 PIC N MIX by Mike Hibbett Keyboard Interfacing NET WORK by Alan Winstanley It s the Wolf man Regulars and Services EDITORIAL NEWS Barry Fox highlights technology s leading edge Plus everyday news fr
130. g the Ch Down button moves the sound stage left On the first two presses a single dash is shown in the left digit position indicating the di rection of movement Likewise one or two presses of the Ch Up button from the centred position results in a single dash in the right digit position Subsequent presses display a num ber indicating the relative attenuation level of the opposing channel For example if the current volume level Preamplitier Module This can be downloaded from our website in a file named DAVOL ZIP This archive contains the file DAVOL HEX which needs to be programmed into the micro s program FLASH memory Just follow the instructions provided with the programmer and software to complete the task Finally the various fuse bits in the Almega8515 must be cor rectly programmed as depicted in Figs 17 and 18 If you miss this step your module may behave erratically is set to 50 and the balance is favour ing the left side and reads 5 the actual levels are left 50 right 45 After four seconds of inactivity the unit automatically reverts to volume adjust ment mode To bypass the four second delay and immediately exit balance mode use the volume up down buttons on your remote or press the Balance button again Both channels are simultaneously adjusted when the volume is in creased or decreased maintaining the balance separation Note that when either ch
131. gether with simulations of the circuits in the Teach In series plus Flowcode a limited version a high level programming system for PIC microcontrollers based on flowcharts The Teach In series covers everything from Electric Current through to Microprocessors and Microcontrollers and each part includes demonstration circuits to build on breadboards or to simulate on your PC In addition to the Teach In series the book includes 15 CMOS based simple projects from the Back To Basics series by Bart Trepak these are Fridge Freezer Alarm Water Level Detector Burglar Alarm Scarecrow Digital Lock Doorchime Electronic Dice Kitchen Timer Room Thermometer Daily Reminder Whistle Switch Parking Radar Telephone Switch Noughts and Crosses Enigma and a Weather Vane There is also a MW LW Radio project in the Teach In series 152 pages CD ROM Order code ETI 8 50 THE AMATEUR SCIENTIST 3 0 CD ROM hi The complete collection of The Amateur xy Scientist articles from Scientific American magazine Over 1 000 classic science projects from a renowned source of winning projects All projects are rated for cost difficulty and possible hazards Plus over 1 000 pages of helpful science techniques that never appeared in Scientific American Exciting science projects in Astronomy Earth Science Biology Physics Chemistry Weather and much more The most complete resource ever assembled for hobbyists and professionals looking for n
132. hat your processor pins must be inputs When writing to the keyboard care must be taken to not set a pin to output high do it at the wrong time and your keyboard may try to drive the line low We don t address writing to the keyboard in this article relying instead on the default configuration of the keyboard on power up The circuit fully supports bi directional communications however should you wish to write the software yourself The data signal is a synchronous bit stream with the timing aligned to a clock signal generated at the same time as shown in Fig 2 A device will typically operate with a clock rate of about 10kHz but you cannot rely on this for performing your own timing your software must read the level of a data bit as the clock signal is moving from high to low This can be achieved by implementing a tight loop polling the level of the clock bit or through an interrupt Both are perfectly acceptable but as we intend to use the code developed in this article in a video project interrupts will give us better flexibility and so we are taking the interrupt route Data Bits The keyboard protocol consists of between one and three bytes of data First bit received E a 1 Mike Hibbett f i rr 1 Data 2 Not Implemented 3 Ground 4 5V 5 Clock 6 Not Implemented Fig 1 PS 2 socket transmitted in quick succession Each byte is sent as 11 bits one start bit eight da
133. he privilege of appearing in the Yahoo Directory Runners up in the race are MSN with Ask coming a distant fourth Microsoft now offers Live Search at www live com and Ask recently resurrected its English butler Jeeves in its commercials at ask com Other search engines or directories for you to try include Dogpile www dogpile com the Open Directory Project www dmoz org and the venerable AltaVista www altavista com which is now owned by Yahoo Ask com absorbed the interesting Teoma search engine technology first mentioned in Net Work in July 2004 AltaVista is notable for its easily accessible Babelfish language translator tool Apart from some relatively unobtrusive advertisements Google s natural results are the battleground where online businesses fight for first prize In their quest for more clicks and greater profits owners of websites can pay good money to ensure their website can leapfrog over their competitors to be No 1 Google has an immense built in artificial intelligence that strives to deliver accurate results It knows that if it responded with inaccurate recommendations then its usefulness would be devalued along with its advertising revenue Therefore Google dislikes being fooled by search engine optimisers and it penalises an inaccurate website by dropping them altogether One trend is emerging as the Internet becomes choked with ever more online resources poking a search phrase int
134. he 4 relays as de sired User settable Security Password Anti Tamper Rings to Answer Auto Hang up and Lockout Includes plastic case 130 x 110 x 30mm Power 12Vdc Kit Order Code 3140KT 54 95 Assembled Order Code AS3140 69 95 8 Ch Serial Port Isolated I O Relay Module Computer controlled 8 channel relay board 5A mains rated relay outputs and 4 opto isolated digital inputs for monitoring switch states etc Useful in a variety of control and sensing applications Programmed via serial port use our new Windows interface termi nal emulator or batch files Serial cable can be up to 35m long Includes plastic case 130x100x30mm Power 12Vdc 500mA Kit Order Code 3108KT 54 95 Assembled Order Code AS3108 64 95 Infrared RC 12 Channel Relay Board F Control 12 onboard relays with 6 included infrared remote con trol unit Toggle or momentary 15m range 112 x 122mm Supply 12Vdc 0 5A Kit Order Code 3142KT 47 95 Assembled Order Code AS3142 59 95 Audio DTMF Decoder and Display Detect DTMF tones from tape recorders receivers two way radios etc using the built in mic or direct from the phone line Char 4 acters are displayed on a 16 character display as they are received and up to 32 numbers can be displayed by scroll ing the display All data written to the LCD is also sent to a serial output for connection to a computer Supply 9 12V DC Order Code
135. he centre wire Add one larger longer piece of sleeving that goes over everything Solder the three wires of the cable to the sensor with the screen to the sensor pin 3 slide the heatshrink up in place with the larger one firmly to the base of the sensor package and shrink all four pieces Check you can place the side sensor face onto a flat surface without the sleeving preventing it Then dip the whole sensor into a pot of thin varnish to cover all the heatshrink Wipe any excess off the flat faces of the sensor as these need to be kept flat and leave to dry When dry repeat for a second coat Other sensors For the other sensors use the same approach however you can use 0 1uF leaded capacitors here so two of the sleeves can slide up over the capacitor wires There is no need to varnish these unless mounted in a damp place re membering that condensation may make even a normally warm place damp if it goes cold sometimes A more waterproof design would be needed if you are go ing to immerse a sensor in liquid eg by epoxying the whole sensor with sleeving into a metal tube with closed ends For ICsens1 glue one of the flat faces to the surface to be measured with epoxy glue Make the faces as close as possible and securely fix the cable to something so it cannot put any strain on the sensor even in high winds It Connecting the supression capacitor across the sensor leads PA Constructional Project SENSORS
136. he plugs and wires Gluing the sensors on is not essential here as there are no high winds to contend with as long as the wiring is securely held The best positions for the sensors are Top at the transition between the domed top of the HWC and the cylin drical sides Middle half way up or at a level that will give you enough hot water when the backup heating that uses this sensor operates Not lower than the lowest pipe on the backup heating coil Bottom 25mm above the level of the cold inlet pipe but not vertically above it Any pipes and bosses in the HWC walls can cause local vertically rising or falling water currents at a different temperature to the normal temperature at that HWC level So mount any sen sors at least 100mm sideways away from such points Testing With the LCD PCB disconnected and leaving out the ICs from their sockets and the removable jumpers connect a current limited supply of 15V to 18V to the PV input of CON2 Check that the battery charges up and that there is 10V on IC2 socket pin 6 The voltage drop across resistor R26 should be around 180mV which represents 18mA charge current to the battery Check it under a range of supply voltages and battery charge states to ensure IC4 and IC5 are cor rectly keeping the current constant Adjust R9 and R10 equally to get the desired current for the battery you are using don t go below 10Q Do not exceed 18mA even if C 10 for your batt
137. ial electrolytic capacitor bottom has an indentation around the body at the positive end PCM electrolytic capacitors have a similar indentation but it is of no importance Both types are marked with and or signs as well 55 Reader Circuits mney United reglar round up of readers own circuits wn A PICO PC BASED OSCILLOSCOPE WORTH 799 100Mrz Analogue Bandwidth Dual Channel Storage Oscilloscope Spectrum Analyser e Frequency Meter Multimeter f USB Interface ff you have a novel circult Idea which would be of Use to other readers then a Pico Flechnology PC based oscilloscope could be yours f After every 20 published 1U circuits Pico Technology will be awarding a PicoScope 3206 digital storage oscilloscope for the best IU submission In addition a PicoScope 2105 Handheld scope worth 199 will be presented to the runner up Heating Oil Storage Tank Burglar Alarm Avoiding a drain on resources his project was driven by the need to provide some form of alarm to combat SECURITY LAMP OIL TANK the attempted burglary or inappropriate WITH MOVEMENT g ne SENSOR 230V 50Hz interference with the heating oil within my black plastic storage tank located at the rear of my back garden With the ever increasing cost of heating oil it has become quiet common for thieves to furtively remove the contents of home heating oil storage tanks These thieves gain access
138. ices division of mobile operator Orange a leader in this field claims that from vehicle tracking to stock control machine to machine solutions give you visibility into whats happening as it happens without having to be there in person By enabling remote equipment such as cameras copiers containers and even payment machines to interact with your information systems you have the vital real time data you need to make quick decisions and manage your internal processes more efficiently Keeping track Already Vodafone SIM cards are used in TomTom satnav systems to enable users to receive location specific traffic updates and other local information SIM cards installed in vending machines already provide suppliers with live data on stock and cash levels The catering industry relies on SIM cards attached to refrigerators and freezers to monitor the safe keeping of the contents while office equipment and industrial machinery use SIM cards to report faults and enable engineers to carry out remote diagnosis SIM cards are also installed in some car park advance information signs and security systems CCTV and burglar alarms Cash machines and retail point of sale equipment use SIM cards as do real time outpatient healthcare monitoring systems SIM cards enhance driver safety and vehicle security for road haulage companies and 22 enable large fleet operators to keep track of their vehicles and drivers Consumers like yo
139. icklewoodelectronics com 02018452 O16 IERE nans Not Just For Cellphones e ime ana Tecnnolalk Mark Nelson SIM cards which give mobile phones their memory and unique identity or anonymity if you prefer have other uses too This month Mark Nelson explains how they could be the vital enabler for a new range of M2M communications devices for our homes and workplaces IM cards are such an essential element of mobile messaging that it might appear perverse that they could have a role to play in static non mobile communication Nevertheless they are forecast to take on a major role in the fascinating new world of machine to machine communication M2M for short So what is M2M all about and what will it mean to electronicists like you and me S Massive markets Simply stated M2M enables machinery to talk to computers by exploiting four entirely separate developments Mobile data networks are now more robust the SIM card data modules are cheaper and more mature business benefits are more clearly understood and competition means that equipment suppliers and network service operators are determined to extract and offer the maximum value possible Rob Conway chairman of the GSM Association enthuses that there is a commercial opportunity to embed SIM cards into 750 million new devices between now and 2014 But what exactly are the benefits Are they mission critical or merely nice to have The Business Serv
140. ies The PIC detects this through an interrupt and increments an internal rain counter by one Everyday Practical Electronics July 2009 X1 32 768kHz U I Fig 1 there are just five ICs and a handful of other components in the Weather Station circuit The rain sensor input S3 on the PIC RBO pin 6 is nor mally held high by a 220kQ resistor when the switch is not closed A high value resistor was used because there is a small risk that the tipping bucket could stick in the centre The control box from the rear showing the battery pack three AA cells and the five pin DIN connector along with the hanger bracket at the top 35 Constructional Fig 2 two PC boards are used 1 a main board containing the PIC16F88 IC1 and the two 24C256 serial EEPROMs IC3 and IC4 and 2 an RS232 interface board which holds the MAX232 IC2 The DS1621 is not mounted on a PC board but is housed inside the temperature measurement container position and keep the switch closed Ifthis occurs the battery would quickly drain if a smaller say 10kQ pull up resistor had been used instead There are two extra features included in the circuit One is a small pushbutton switch S2 on the PC board that is only accessible when the case is open This is used to calibrate the clock in the controller You may wonder why this is needed To achieve low power consumption the PIC spends most of its time sleep ing
141. ig 1 the circuit can be built in two versions the one shown here suitable for general purpose work or without REG1 suitable only for low voltage work Note points marked A B C and GND on the circuit are pads on the circuit board for programming the PIC in situ 1 Constructional Project The SMD LEDs are really bright especially in normal lighting This photo clearly shows them glowing even though they have been swamped by the very bright photo flash we used for the photo with SILICON CHIP magazine 2009 www siliconchip com au Circuit details Surface mount LEDs so tiny that they are almost impossible to find if you drop them on a carpeted floor trust us are directly driven from 1 double sided PC board code 717 available from the EPE PCB Service size 106mm x 5mm see text 1 clear plastic ballpoint pen case with top and cap 1 35 to 40mm long darning needle 1 500mm length thin figure 8 cable red and black 1 small red alligator clip 1 small black alligator clip 1 ultra miniature SMD momen tary action pushbutton switch Semiconductors 1 PIC10F200 or PIC10F202 SMD 8 bit FLASH micro controller programmed with PicProbe hex IC 1 1 MMUN2211 SMD NPN resistor equipped transistor Q1 1 red SMD LED LED1 1 green SMD LED LED2 1 orange SMD LED LEDS 2 184148 SMD diodes D1 D2 1 5V SMD positive regulator see text REG1 Capacitors 3 100nF SMD Resist
142. ional Versions are multiple choice questions exam style questions fault finding virtual laboratories and investigations worksheets ANALOGUE ELECTRONICS Se a output stage 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 circuits 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 sections Phase Shifting Networks 4 sections Active Filters 6 sections Oscillators 6 sections from Positive Feedback to Crystal Oscillators Systems 12 sections from Audio Pre Amplifiers to 8 Bit ADC plus a gallery showing representative p c b photos acca teyy ELECTRONICS V2 0 bo omom a eS ee eS a a pe ee e e ee a Virtual laboratory Traffic Lights Digital Electronics builds on the knowledge of logic gates covered in Electronic Circuits amp Components above and takes users through the subject of digital electronics up to the operation and architecture of microprocessors The virtual laboratorie
143. ire links Hot point If you are expecting to light the five LEDs continuously for a prolonged of a varying signal it is an LED meter doing much the same thing as a VU meter in a hifi system RED Fig 10 3 Complete circuit diagram for the Sound Sensor 50 Everyday Practical Electronics July2009 oo0o O oo0oo0o0o 0 O O0000 ANOMOTO OM OO DD je jel jel jel O O OO00000 O lej ej ej le O O OO0000 0 0 2 000004 0000000000 O w 0 000000 i O 0 440 o o gt N F m N VR1 R 2 a 00000 opmodo 00000 0b808 0 0000 BATTERY UU UU Ds Fig 10 4 Assembly for the Sound Sensor on Protobloc length of time do not exceed the 9V supply voltage most of the power is Notes e C4 and R2 determine the Breadboarding Component Info 43 2 1 IC2 type LB1413N LED level meter Reading from the chamfered end the pins are numbered 1 to 9 OO IC1 type LM386 audio amplifier Viewed from the top an indented dot and a half moon shape at one end indicate pin one The pins are num bered anti clock wise ending at pin 8 opposite pin 1 OO lo NNN ooo LED1 to LED 5 3mm green 2 red 2 and blue 1 light emitting diodes time consumed within IC2 It is recom mended that when using a higher power supply voltage that you insert a resistor in series with the LEDs to restrain the power consumed within the IC package see Fig 10 5 6 5V TO 12V 470 8V TO
144. it s used And there s much MUCH more The author s tongue in cheek humour makes it a delight to read but this is a REAL technical book extremely detailed and accurate Contents Fundamental concepts Analog versus digital Conductors and insulators Voltage current resistance capacitance and inductance Semiconductors Primitive logic functions Binary arithmetic Boolean algebra Karnaugh maps State diagrams tables and machines Analog to digital and digital to analog Integrated circuits ICs Memory ICs Programmable ICs Application specific integrated circuits ASICs Circuit boards PWBs and DWBs Hybrids Multichip modules MCMs Alternative and future technologies 470 pages Order code BEB1 BEBOP BYTES BACK and the Beboputer Computer Simulator CD ROM Clive Max Maxfield and Alvin Brown This follow on to Bebop to the Boolean Boogie is a multimedia extravaganza of information about how computers work It picks up where Bebop left off guiding you through the fascinating world VAU mse of computer design and you ll have a few chuckles if not belly laughs along the way In addition to over 200 megabytes of mega cool multimedia the CD ROM contains a virtual microcomputer simulating the motherboard and standard computer peripherals in an extremely realistic manner In addition to a wealth of technical information myriad nuggets of trivia and hundreds of carefully drawn illustrations
145. itestwanustacnss Address 2 0 2 cccccecceccecceceeeeececceeaeceeceececauceeceeaeeaeeas Post code ANON E a vanicenessosceuee O enclose cheque PO payable to DIRECT BOOK SERVICE for O Please charge my card Card Number Valid From Date EE Telephone NO sscsasisnissvascensccetectcsvesionns Card expiry date Maestro Issue No the last three digits on or just below the signature strip Please continue on separate sheet of paper if necessary Everyday Practical Electronics July 2009 A BEGINNERS GUIDE TO CMOS DIGITAL ICs R A Penfold Getting started with logic circuits can be difficult since many of the fundamental concepts of digital design tend to seem rather abstract and remote from obviously useful applications This book covers the basic theory of digital electronics and the use of CMOS integrated circuits but does not lose sight of the fact that digital electronics has numerous real world applications The topics covered in this book include the basic concepts of logic circuits the functions of gates inverters and other logic building blocks CMOS logic i c characteristics and their advantages in practical circuit design oscillators and monostables timers flip flops binary dividers and binary counters decade counters and display drivers Order code BP333 5 45 119 pages AUDIO AMPS BUILDING VALVE AMPLIFIERS Morgan Jones The practical guide to building modifying
146. l patches smart bandages sensors and others Details of the report are available at www nanomarkets net Lin VaT Wan a4 Surface mount device project A PIG based logic probe that fits inside a ballpoint pen case HIS PROJECT CAME ABOUT through the recent trend in electronics towards lower op erating voltages If you look around at the latest chips being offered from semiconductor manufacturers you will see that most are designed to operate on 3 3V or less Having produced a few designs with 3 3V components recently I discovered that my old favourite test tool the logic probe wouldn t operate below 5V I looked around my usual electronic suppliers but couldn t find anything that would work on less than 5V So I decided to design and build one myself The first requirement was to make it work over as wide an operating voltage as possible so that it could be used on the old legacy 5V systems and down to some of the latest proces sors at 2 8V The second requirement was low cost 10 I took a look inside the existing probes I had only to find them full of analogue components some of which were now obsolete Micro size The quickest and easiest approach seemed to be to build something around a small microcontroller so I went on the hunt for anything that was small cheap and worked on a wide supply voltage I ended up at the Microchip website looking at our old friend
147. lacement Lamps We carry one of the widest range of pae mm lamps for Disco Band amp Theatre lighting all from Leading brands See our web site for full details Prices Exclude Vat 15 UK Carriage 2 50 less than 1kg PLEASE ADD CARRIAGE amp VAT TO ALL ORDERS Editorial Offices EVERYDAY PRACTICAL ELECTRONICS EDITORIAL Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Phone 01202 873872 Fax 01202 874562 Email enquiries epemag wimborne co uk Web Site www epemag com See notes on Readers Technical Enquiries below we regret technical enquiries cannot be answered over the telephone Advertisement Offices Everyday Practical Electronics Advertisements Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Phone 01202 873872 Fax 01202 874562 Email stewart kearn wimborne co uk a AVAI LapiLiry WS a Copies of EPE are available on subscription anywhere in the world see opposite and from all UK newsagents distributed by SEYMOUR EPE can also be purchased from retail magazine outlets around the world An Internet online version can be purchased and downloaded for just 18 99US approx 13 per year available from www epemag com Savejonjenergysbills Solar zerojcanbon enenoyi REMOTEVOLUME CONTROLI amp PREAMPLIFIER MODULEIrart ia E2009 395 Ama RECYCIEI ee J Alhuman powered LEDItorch forjn
148. lculations are explained Clear circuit simulations 62 Everyday Practical Electronics July 2009 PiCmicro TUTORIALS AND PROGRAMMING VERSION 3 PiCmicro MCU development board Suitable for use with the three software packages listed below This flexible development board allows students to learn both how to program PlCmicro microcontrollers as well as program a range of 8 18 28 and 40 pin devices from the 12 16 and 18 series PlCmicro ranges For experienced programmers all programming software is included in the PPP utility that comes with the development board For those who want to learn choose one or all of the packages below to use with the Development Board Makes it easier to develop PlCmicro projects Supports low cost Flash programmable PlCmicro devices Fully featured integrated displays 16 individual l e d s quad 7 segment display and alphanumeric I c d display Supports PlCmicro microcontrollers with A D converters Fully protected expansion bus for project work USB programmable Can be powered by USB no power supply required ASSEMBLY FOR PiCmicro V3 Formerly PiCtutor Assembly for PlCmicro microcontrollers V3 0 previously known as PlCtutor by John Becker contains a complete course in programming the PIC16F84 PlCmicro microcontroller from Arizona Microchip It starts with fundamental concepts and extends up to complex programs including watchdog timers interrupts and s
149. leep modes The CD makes use of the latest simulation techniques which provide a superb tool for learning the Virtual PICmicro micro controller this is a simulation tool that allows users to write and execute MPASM assembler code for the PIC16F84 microcontroller on screen Using this you can actually see what happens inside the PlCmicro MCU as each instruction is executed which enhances understanding Comprehensive instruction through 45 tutorial sections Includes Vlab a Virtual PlCmicro microcontroller a fully functioning simulator Tests exercises and projects covering a wide range of PlCmicro MCU applications Includes MPLAB assembler Visual representation of a PlCmicro showing architecture and functions Expert system for code entry helps first time users Shows data flow and fetch execute cycle and has challenges washing machine lift crossroads etc Imports MPASM files PRICES Prices for each of the CD ROMs above are Order form on next page HARDWARE a x a VAT and postage supplied with USB cable and programming software 40 OFF Buy the Development Board together with any Hobbyist Student or Institutional versions of the software CD ROMs listed below and take 40 off the total including VAT price SOFTWARE FOR 16 Series PICmicro Version 4 The C for PlCmicro microcontrollers CD ROM is designed for students and professionals who need to learn ho
150. ley Dearing says We are now back to doing what we do best Sony s launch event was not a good sign though To put some buzz into the worldwide unveiling Sony hired a disused Jubilee Line tube train station deep under London s Charing Cross A tube train was shunted in and X Series Walkmen installed for the press and public to try One of the big selling points of Sony s new iPod busting Walkman is Wi Fi connectivity for easy YouTube streaming Podcast direct downloading and Internet browsing The player also receives FM radio Unfortunately Sony forgot that there is no Wi Fi or FM radio cover in an underground tube tunnel So the demonstrators had to keep explaining why the new Walkman s special features would not work PICS WITH THE WORLD S LOWEST SLEEP CURRENT Microchip has announced the world s lowest power sleep current for 8 bit microcontrollers MCUs The PICI8F46J11 and PIC18F46J50 MCUs feature Microchip s new nanoWatt XLP eXtreme Low Power Technology which enables typical sleep currents of less than 20nA The new nanoWatt XLP technology gives designers the flexibility to customise their applications for the lowest power consumption through multiple internal wake up sources such as real time clock and calendar alarm brown out resets interrupts and watch dog timers all while maintaining I O states The general purpose PICI18F46J11 MCUs enable designers to easily and inexpensively add new
151. location there are very nice professional logging weather stations out there that do the lot with solar panels for power and the ability to record rainfall temperature humidity barometric pressure wind speed and direction and sunlight hours While it would be nice to have all that capability I had a need that was a lot simpler Like many people I only wanted to record rainfall and temperature More importantly I couldn t justify the cost of the professional systems which typically run to four figures There are plenty of hobbyist weather stations out there too and at much better prices They appear very capable but none can log data unattended for an extended period well I did find one but even it was hundreds of pounds A bit of research convinced me that it wouldn t be too hard to build my own including a suitable rain sensor So that s just what I did a Logging tation ac Gienn Bats Constructional Project N THE ELECTRONICS SIDE I decided a low power microcontroller was the way to go With the right de vice and a bit of care in design current consumption has been kept down to an average of around 10UA meaning a set of three AA batteries should last for years virtually their shelf life in fact In terms of logging capability with half hourly read ings it is capable of storing just under a year s worth of rainfall and temperature records utilising the 64 kilobytes of on board
152. ly at the expense of quality no doubt and also allowed for a market to appear in alternative input devices such as bar code scanners and magnetic card swipe readers So although this article is predominately about keyboards exactly the same code and hardware can be used to interface to a number of other exotic devices based on the PS 2 interface While the PS 2 keyboard is beginning to go out of fashion now it is still possible to purchase them new in retail stores at very low cost And of course there is always eBay Interfacing to a USB keyboard is significantly more complicated so let s hope those older standard devices stay around for a while The physical interface has now settled on a small six pin connector only four pins of which are used Fig l Two for communication and two for power Keyboards operate at 5V and would not be expected to draw more than 275mA so you have to account for this potential current consumption in your hardware design making sure you have the headroom in your 5V power supply In some cases your keyboard may draw more power than your own circuit As the keyboard runs at 5V it therefore outputs a data signal to your processor with a SV swing This should not cause any problems when interfacing to a 3V processor so long as the processor can tolerate 5V on its inputs Many do such as the PIC24 device that we will be using in this article You are free of course to use a 5V
153. m www audon co uk 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 PVC 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 7 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 At least 50 sensors can be connected More information AREXX Engineering The Netherlands T 31 38 4542028 F 31 38 4524482 WOLU S a www arexx com Everyday Practical Electronics Wimborne Publishing Ltd Sequoia House 398a Ringwood Road Ferndown Dorset BH22 9AU Tel 01202 873872 Fax 01202 874562 E mail editorial epemag wimborne co uk Web site http www epemag com We also accept card payments Mastercard Visa or Maestro Send your card number and card valid from and expiry date plus Maestro Issue No and the security code on the back of the card with your
154. mplete Sofheane Deeb repeat Eit eBook on Designing the KGS Consola Parnilas i r Compatible Fui swe bie G S Micro Edition Unit The Fun A ay io loam Emisoedtioed Svan _ se j am iii in q 7 i m mi N 1 WWW XAGAMESTATION COM hi HURAE JNE Everyday Practical Electronics July 2009 EPE PIC PROJECTS VOLUME 1 d vat E MINI CD ROM A plethora of 20 hand PiCked PIC Projects from selected past issues of EPE Together with the PIC programming software for each project plus bonus articles The projects are PIC Based Ultrasonic Tape Measure You ve got it taped if you PIC this ultrasonic distance NOTE The PDF files on this CD ROM are measuring calculator suitable to use on any PC with a CD ROM EPE Mind PICkI drive They require Adobe Acrobat Reader in er included on the CD ROM Want seven ways to relax Try our PIC controlled mind machine PIC MIDI Sustain Pedal y Comm J10 M e E Add sustain and glissando to your MIDI line up with this inexpensive PIC controlled effects unit CD ROM ORDER FORM PIC based MIDI Handbells Ring out thy bells with merry tolling plus a MIDI PIC up of course Please send me quantity EPE Mood PiCker EPE PIC PROJECTS VOL 1 CD ROM Oh for a good night s sleep Insomniacs rejoice your wakeful nights could soon be over with this mini micro under Price 14
155. must be by card or in Sterling cheque or bank draft drawn on a UK bank Normally posted within seven days of receipt of order Send a copy of this form or order by letter if you do e not wish to cut your issue A See eee ee ee eee eee eee eee ee eee eee eee ee BECOME A PIC WIZARD WITH THE HELP OF EPE Everyday Practical Electronics July 2009 23 Constructional Project Olar Water Hea Controller Part2 By EDWARD CHASE MA Cantah CEng MIMechE ti ng System Save on energy bills with no CO2 solar energy ast month we covered the design j of this project and this month we cover assembly testing and calibration Assembly PCB layouts are shown in Fig 4 and 5 Ready made unpopulated PCBs are available from the EPE PCB Service Insert the IC sockets first and then all other components leaving the largest ones like C6 and relays till last Capaci tor C6 should be bent over and laid flat against the PCB to save board height For CON2 4 5 6 7 and 8 lock the adjacent parts together before inserting them Insert two wire links J1 and J2 in the main and one J3 in the LCD PGB plus any others needed to replace optional components Leave the battery till last and do not insert JP2 Beware as soon as the battery is soldered in there is the pos sibility of damaging high currents from 24 it if soldering is performed near it or if the PCB is laid on any metal surface even
156. n our website or call our sales line All major credit cards accepted Web www bowood electronics co uk Unit 10 Boythorpe Business Park Dock Walk Chesterfield Derbyshire S40 2QR Sales 01246 200222 Send 60p stamp for catalogue on display and classified advertising please contact our Advertisement Manager Stewart Kearn as above The British Amateur Electronics Club Archive Website Archiving extracts for 140 Newsletters from 1966 2002 Currently have interesting and useful selected articles from 19 Newsletters Also a section about built electronics projects with schematics and photos Plus useful info downloads and links NO ADVERTS Website Address http baec tripod com PIC Prototyping Kits PCB s and components for 18 28 amp 40 pin PIC s Also DTMF and CTCSS kits Worldwide delivery at low cost www cstech co uk spinvent co uk adewent with the Procell ler mcroacontrolier and Spin programang language froo Para las THS SPACE COULDBEYOURS FOR UST 50 Contact Stewart on 01202 873872 Stewart kearn winborne co uk INCLUDING P amp P FROM OUR DIRECT BOOK SERVICE SUS SUNONMGS UEC a ee TOOLS pius FREEIGD ROM Everyday Practical Electronics July 2009 Miscellaneous VALVES AND ALLIED COMPONENTS IN STOCK Phone for free list Valves books and magazines wanted Geoff Davies Radio tel 01788 574774 1 0 2 5 30 0 RPM MAINS MOTORS 240V 4W Body 50mm diameter
157. n rectifier function generator amplifiers etc and considers the ways in which modern devices can be used to give superior performance in each one The second part describes a number of practical circuits that exploit modern operational amplifiers such as high slew rate ultra low noise and low input offset devices The projects include Low noise tape preamplifier low noise RIAA preamplifier audio power amplifiers d c power controllers opto isolator audio link audio millivolt meter temperature monitor low distortion audio signalgenerator simple video fader and many more 120 pages Order code BP335 5 45 PRACTICAL ELECTRONICS HANDBOOK Fifth Edition lan Sinclair Provides a practical and comprehensive collection of circuits rules of thumb and design data for professional engineers students and enthusaists and therefore enough background to allow the understanding and development of a range of basic circuits Contents Passive components Active discrete components Circuits Linear I C s Energy conversion components Digital 1 C s Microprocessors and microprocessor systems Transferring digital data Digital analogue conversions Computer aids in electronics Hardware components and practical work Micro controllers and PLCs Digital broadcasting Electronic security 440 pages Order code NE21 24 99 MUSIC AUDIO AND VIDEO QUICK GUIDE TO DIGITAL AUDIO RECORDING lan Waugh Covers e What computer system y
158. n swine flu statistics the number of transistors in a Pentium processor railway passenger totals for 2008 and many more I was constantly greeted with the Short Circuit No 5 response WolframAlpha isn t sure what to do with your input We have heard of Google beating search engines before the last one being Cuil www cuil com which has disappeared off the radar of regular web users Cuil launches a small thumbnail image alongside search results ees attempting to guess what the ee most appropriate image will be The meaningless one alongside EPE mag s entry resembles an explosion in a psychedelic knitting yarn factory WolframAlpha much but for everyday users that multi coloured Google logo will remain a feature of our Internet search experience for some time into the future Don t forget to check over the EPE website at www epemag com You can email me at alan epemag demon co uk promises Everyday Practical Electronics July 2009 Electronics Teach In FREE CD ROM Mike Tooley A broad based introduction to electronics find out how circuits work and what goes on inside them Plus 15 easy to build projects The 152 page A4 book comes with a free CD ROM containing the whole Teach In 2006 series originally published in EPE in PDF form interactive quizzes to test your knowledge TINA circuit simulation software a limited version plus a specially written TINA Tutorial to
159. n switch a number of different output devices and can be powered by a battery or mains plugpack SMS CONTROLLER MODULE KIT 17 00 Control appliances or receive alert notification from anywhere By sending plain text messages this kit will allow you to control up to eight devices At the same time it can also monitor four digital inputs It works with old Nokia handsets such as the 5110 6110 3210 and 3310 which can be bought inexpensively Kit supplied with PCB pre programmed microcontroller and all electronics components with manual Requires a Nokia data cable which can be readily found in mobile phone accessory stores JYCAr 11 75 This simple circuit illuminates a string of LEDs to quickly indicate the water level in a rainwater tank The input signal is provided by ten sensors located in the water tank and connected to the indicator unit via light duty figure 8 cable Kit supplied with PCB with overlay machined case with screenprinted lid and all electronic components e Requires 8mm OD PVC hose pipe length required depending on depth of tank e Requires 12 18V AC or DC plugpack 6 00 Many modern cars feature a time delay on the interior light allowing driver amp passengers CC time to buckle up amp get organised Aiea before the light dims amp finally goes out This kit enables your car to have the same handy feature with a soft fade out afte
160. nd in some circumstances can have disastrous consequences Diodes designed for use at high currents in power supply circuits are usually called rectifiers and getting one or more of these fitted the wrong way around is almost certain to result in some damage and could even be dangerous Despite their simplicity diodes can be problematic when building electronic projects In fact some types of diode are notorious in this respect with even experienced constructors finding that the polarity markings of a diode are sometimes less than clear In some cases 32 Catia jk Giarchi Amda bal Catona kj Practically Speaking Robert Penfold looks at the Techniques of Actually Doing it 1 cliche h Fig 1 The diode circuit symbol left together various methods of identifying the anode and cathode leads of the actual components All these methods are very loosely based on the circuit symbol the markings give the impression that they have been deliberately designed to be confusing and in a few instances the polarity markings are totally absent In general normal diodes cause relatively few problems They are usually in the form of small tubular components in glass or plastic encapsulations that look a bit like miniature resistors The circuit symbol for a diode together with various physical representations for this type of component are shown in Fig 1 The two terminals of a diode are called the anod
161. ne specifically what we mean by cut off frequency The cut off is often defined to be the point where the filter s gain is 3dB with respect to the pass band gain The stop band HIGH PASS FREQUENCY GAN BAND STOP FREQUENCY ALL PASS FREQUENCY FREQUENCY FREQUENCY Fig 1 Ideal filter responses Everyday Practical Electronics July 2009 may also be specifically defined in terms of reduction in gain although there is not a standard gain reduction for stop band as there is with the 3dB point for cut off The range of frequencies between the pass and stop bands is the transition region or skirt Filter cut off The reason for choosing 3dB to define filter cut off is that it represents the point at which half power is delivered to the load compared to the nominal full power output in the main part of the pass band The definition of the decibel is based on the logarithm of the power ratio of two signals Pl and P2 such that the power ratio in decibels is given by 10log P2 P1 dB If we are expressing power gain eg of an amplifier then P1 would be the input power and P2 the output power For measuring a power quantity relative to a reference Pl would be the reference level and P2 the value we are measuring So for filters P1 the reference point would be the nominal pass band full power output and P2 would be the output at the frequency of interest For half power output we have P2 P1 0 5
162. ng needle seemed to fit the bill quite nicely here I also wanted to have a pulse stretching or latching function to view and change very quick pulse transitions soa switch would be required to change modes and clear the pulse latch when required Modifying the design You can see from the circuit diagram Fig 1 that there isn t much to the PICprobe design However it does have some differences to the author s original circuit and project Since there would be a lot of hobby ists who might want to use the probe for testing devices with higher voltages provision for an optional 5V voltage regulator has been added to the PC board design This involved including the pads and tracks fora5V SMD surface mount regulator 78L05 REG1 Due to the mi niscule power drawn by the circuit the regulator should be quite happy working up to its maximum input voltage of 30V If you only want low voltage opera tion the regulator can be left out and a link added to connect the DC in and DC out pads where the regulator would be The regulator input and output fil ter capacitors can remain they won t do any harm and may even do a bit of good in decoupling a supply We ve specified 100nF capacitors because we have found these are the Everyday Practical Electronics July 2009 This photo shows the first prototype without the extra components added for higher voltage operation or input protection Don t forget to keep the pen
163. ng of your application to set up the two I O pins and the interrupt After that just make a call to PIC24ps2keyGetKey which will return the value of any key pressed in ASCII The function PIC24ps2keyGetByte can also be used if you want to see the raw bytes coming back from your keyboard or whatever device you plug in This can be used to help you develop special interface software for other more exotic devices At the beginning of the header file is a statement that you may not be familiar with enum This is aC language feature that allows you to define a set of named constants a little like a short cut to creating a list of define values Each named constant takes a value one higher than the constant to its left in the list Enums can be used in more complicated ways than simply as a short cut to creating constants but that s a more complicated topic for a later date The reason for creating these values is to enable the PIC24ps2keyGetKey routine to return values for keys other than the normal alphanumerics such as function or arrow keys The enum lists in hopefully an obvious manner names for keys that you may well want to use A typical use would be like this key PIC24ps2keyGetKey if key gt F1 handle function keys switch Key case F 1 break case F2 break else display key pressed putch key Unfortunately there isn t a simple relationship between keys on a ke
164. nload from website iZOW Stereo Amp Low distortion 11W channel _ Stereo 20W Mono True rms Real Power High Slew Rate bandwidth amp low noise Ideal MP3 booster _ Short Circuit amp Overtemp Protect ed STA7360 chip Needs 8 to 18V supply EPE Project May2005 0 P amp P per order or 7 99 for next accepted Mail Order Only Staffs DE14 2ST 3 546932 magenta2000 co uk 59 Our periodic column for PIC programming enlightenment e are taking a break this month from video generation to take a look at interfacing to a full sized computer keyboard using the PS 2 interface There is a point to this detour as our video articles have developed over the last few months we have aimed towards building an RS232 video terminal device and that will need a keyboard We won t go into the details of that project right now but knowing this helps explain the sudden change of direction and interfacing to a PS 2 keyboard is quite an interesting subject anyway so it s worth taking a look PS 2 History The PS 2 keyboard specification appeared in 1984 with the release of the IBM PC AT It s only in the last five years that USB keyboards have started to replace PS 2 as the dominant interface therefore PS 2 interfaces have been the defacto standard for almost 20 years quite an achievement As you might imagine having a standard in place for such a long time has helped to drive the costs down considerab
165. o Google and ploughing through an onerous list of recommendations starts to leave users feeling rather short changed if not exasperated It s like asking a librarian to locate the best book on a topic and he or she throws a pile of index cards at us so we have to start searching for ourselves If we don t like what we read the librarian suggests we read the next card in the pile With the road to search heaven littered with the remains of Teoma AltaVista Yahoo The Open Directory and more periodically a search engine comes along that promises to change everything for the better Instead of typing keywords or phrases into Google and being hit with a blizzard of web links what if a search device actually answers your question for you 5 This has partially been the approach of Ask com type in a z question in plain English and you get a list of web links Plenty of data but no information In an attempt to offer a straight answer to our search queries the latest Google beating search engine 66 WolframAlpha could signal a new way of finding answers on the web to launch is WolframAlpha www wolframalpha com This new arrival has at least one thing in common with Google its founder is a mathematical genius It describes itself as a computational search engine and its declared aim is to provide definitive answers to factual queries Founded by London born Stephen Wolfram www stephen
166. o that they point towards that board enabling easier connection Six connections are needed between the two boards including V and ground The overlay of both boards In the prototype the on off switch on the battery pack was shorted see enlargement because the switch was on the wrong side of the pack You could use a 4 x AA pack with one cell shorted out Everyday Practical Electronics July 2009 Here are the two PC boards shown slightly over size for clarity They match the diagrams shown left Note that there are also connections underneath the boards the underside of the main PC board is shown below Constructional Project Fig 2 makes it clear where the interconnections should occur SW to SW P9 to P9 and so on There are two sets of positive and negative connection points on each board One of the sets on the MAX232 board which should face out from the copper side is for connection to the battery pack while the second set connects power to the PIC board The second set of power connection pins on the PIC board is for the temperature and rain sensor socket The MAX232 board also has two pins marked to switch on the overlay which need to be run to dump switch S4 Assembly is straightforward As usual watch for correct orientation of polarised components besides the ICs the only ones are the five electrolytic capacitors on the MAX232 board
167. om the world of electronics ELECTRONICS TEACH IN 2 New book with Free CD ROM Using PIC Microcontrollers PIC RESOURCES CD ROM EPE PIC Tutorial V2 plus PIC Toolkit Mk3 and a selection of PlC related articles SUBSCRIBE TO EPE and save money PIC PROJECTS CD ROM A plethora of handPiCed projects BACK ISSUES Did you miss these CD ROMS FOR ELECTRONICS A wide range of CD ROMs for hobbyists students and engineers READOUT Matt Pulzer addresses general points arising DIRECT BOOK SERVICE A wide range of technical books available by mail order plus more CD ROMs EPE PCB SERVICE ADVERTISERS INDEX Readers Services Editorial and Advertisement Departments INCORPORATING ELECTRONICS TODAY INTERNATIONAL 10 16 24 32 48 54 22 40 Ad 52 56 60 15 23 31 AS AG 62 65 67 70 72 All prices INCLUDE 17 5 VAT Postage amp Packing Options Up to 2Kg gross weight UK Standard 3 7 Day Delivery 3 95 UK Mainland Next Day Delivery 8 95 Europe EU 6 95 Rest of World 9 95 up to 0 5Kg lOrder online for reduced price UK Postage We accept all major credit debit cards Make cheques PO s payable to Quasar Electronics Please visit our online shop now for full details of over 500 electronic kits projects modules and publications Discounts for bulk quantities Quasar Eled tronics Limited PO Box P Bishops Stortford mat CM23 4WP United Kingdo Tel 08717 177 1
168. omponents Writing letters leaflets invitations etc and other word processing jobs Keeping track of your finances using a spreadsheet Recording details of holidays and other ideas using a database Using the Internet to find useful information and email to keep in touch with family and friends Making back up copies of your work and checking for viruses How to use Windows XP to help people with impaired vision hearing or mobility Provides the basic knowledge so you can gain enough confidence to join the local computer class Order code BP601 8 99 THE INTERNET FOR THE OLDER GENERATION Jim Gatenby Especially written for the over 50s Uses only clear and easy to understand language Larger type size for easy reading Provides basic knowledge to give you confidence to join the local computer class This book explains how to use your PC on the Internet and covers amongst other things Choosing and setting up your computer for the Internet Getting connected to the Internet Sending and receiving emails photographs etc so that you can keep in touch with family and friends all over the world Searching for and saving information on any subject On line shopping and home banking Setting up your own simple web site Order code BP600 8 99 308 pages 228 pages RADIO SETTING UP AN AMATEUR RADIO STATION I D Poole The aim of this book is to give guidance on the decisions which have to be made when setting up any
169. on Chip Magazine Australia These projects are bullet proof and already tested down under All Jaycar kits are supplied with specified board components quality fibreglass tinned PCBs and have clear English instructions Watch this space for future featured kits SMART CARD READER PROGRAMMER KIT June 09 16 00 Program both the microcontroller and EEPROM in the popular gold silver and emerald wafer cards Card used needs to conform to ISO 7816 Standards Powered by 9 12 VDC wall adaptor or a 9V battery Instructions outline software requirements that are freely available on the internet Kit Supplied with PCB wafer card socket and all electronic components e PCB measures 141 x 101mm 13 50 Be the envy of everyone at the next Interplanetary Conference with this galactic voice simulator kit Effect and depth controls allow you to vary the effect to simulate everything from the metallically endowed C 3PO0 to the hysterical ranting of Daleks hell bent on exterminating anything not nailed down The kit includes PCB with overlay enclosure speaker and all components 6 00 Most audiophiles know that loudspeaker enclosures have a Taine frequency rolloff which is inherent in their design Crude bass boost devices that are available simply boost the level of bass anywhere up to 18dB to offer better bass response This isn t the best way to do it The Bass Extender kit boosts the level of the bass to co
170. on one to try it out Nurve Networks founded by An dre LaMothe has been designing and selling a variety of video and FPGA development systems since 2001 Video game development is something of a passion for Andre as he has written several popular books on the subject and his enthusiasm comes across in the documentation supplied with the kit The XGS is a new product from Nurve released at the end of last year and is a clear evolution from previous product offerings There is a huge amount of information supplied in the form of a 300 page printed manual several electronic books and over one hundred relevant datasheets and application notes Unlike other microprocessor development boards that you can purchase Nurve Net works has invested a lot of effort in providing very detailed information and tutorials that will help you learn how to design and write your own video applications and hardware not just tinker with someone elses Contents So what s supplied in the kit The photo above right shows the main contents excluding the DVD The heart of the system is a small double sided PCB measuring 80mm x 80mm fitted with a PIC24HJ256x206 Micro 40 Development System chip processor Those of you who have been following the recent PIC n Mix series of articles will recognise this processor as one of the same fam ily it s a 16 bit processor that can run at up to 80MHz Unlike the part used in the PIC n
171. ong the front edge of the board However all of these devices can be mounted inde pendently on a panel and hard wired back to the PC board via short flying leads if desired Note that if the infrared receiver includes an external metal shield see photo then steps must be taken to ensure that it is insulated from any metal chassis or front panel We sug gest a short strip of insulation tape on the inside of the front panel with a hole cut out to match the hole in the panel Do not rely on the paintwork to provide insulation 16 UAIS SOCONG Aricle Completes tha CONSMMEWON ANG PFOMICAS the setum Mrocoddre The display board should be mount ed to the right side or above the main board ie away from the audio section on standoffs behind an appropriate cutout Additional header sockets or cutdown 40 pin IC sockets can be stacked vertically to increase the display height for a flush fit Both the red and blue displays look great with tinted filters As mentioned last month three different power supply configurations are possible You could also power the unit from an existing regulated DC source if available The minimum requirements are 15V at 20mA and 5V at 120mA Note that the two analogue and digital supplies must share a com mon ground This means that if they re located on physically separate PC boards their grounds must be cabled separately to the single GND input at CON1 Mains wiring As
172. operational amplifier from National Semiconductor www national com The LM324 series are op amps designed for single power supply operation and which have true differential inputs that remain in the linear mode with an input common mode voltage down to OV DC These op amps are mainly aimed at DC applications where large common mode input ranges may be problematic This would include transducer amplifiers and DC gain blocks but of course they can be used in all conventional op amp applications including filters If you are aiming for a filter circuit with very high audio performance then it would probably be better to use an op amp specifically designed for this purpose One example is the LME49740 quad high performance high fidelity audio op amp again from National Semiconductor However unlike the LM324 the LME49740 requires split positive and negative power supplies LME49740 is aimed at AC applications and is comfortable with capacitively coupled outputs For the LM324 the datasheet states that a resistor should be used from the output of the amplifier to ground to prevent crossover distortion This is due to the need to provide sufficient bias current for its class A output stage Filter types Filters constructed from just resistors GAIN capacitors and inductors are called passive filters whereas filters that employ active devices such as transistors or op amps are called active filters Circuits using
173. ors all 6035MD 110kQ 1 4 7kQ 3 1800 12 Reproduced by arrangement the PIC s GP2 red LED and GP1 or ange LED outputs The green LED is driven by the inverse of GP2 using transistor Q1 Even though Q1 is shown on the circuit as a standard NPN type it s a bit more complicated than that It is actually a resistor equipped transistor which has two internal resistors a series resistor to its base B and a pull down resistor to its emitter E These RET de vices are great for use as digital inverters GPO is normally held high by a 10kQ resistor connected to the positive sup ply It s also connected to a pushbutton switch S1 which grounds the input when pressed Which PIC The circuit Fig 1 shows a PIC10F200 as the microcontroller but you can also use a PIC10F202 The program was originally written for the 200 which has 256 bytes of program 16 bytes of RAM and one 8 bit timer Note that neither the PIC10F204 nor PIC10F206 will work in this circuit you must use the 200 or the 202 Operation The probe has three LEDs and a push button switch S1 The red LED is turned on for a logic 1 at the probe tip while the green LED turns on for a logic 0 The orange LED works in one of two modes pulse stretch or latched In pulse stretch mode the orange LED will pulse for 50ms every time there is a change on the probe input This makes very small pulses at the probe tip viewable
174. ou need e Sound and digital audio essentials e What to look for in a sound card e What effects to use e The art of mixing e How to burn your music to CD e How to post your songs on the Web All modern music recordings use digital audio technology Now everyone with a compouter can produce CD quality recordings and this book shows you how Written in a clear and straightforward style it explains what digital audio recording is how to use it the equipment you need what sort of software is available and how to achieve professional results Computer based recording is the future of music and this book shows how you can join the revolution now Order code PC121 7 95 QUICK GUIDE TO MP3 AND DIGITAL MUSIC 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 need 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 MP8s 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 format
175. ource with the correct polarity Unfortunately there is no truly standardised method of indicating the polarity of a LED By far the most common method of indicating the polarity of a LED is to have the cathode leadout wire a few millimetres shorter than the anode lead Fig 2 It is likely that the vast majority of LEDs conform to this method but a minority of these components either do things the other way around or have two leadout wires of equal length Fortunately there is usually an additional means of indicating the polarity which is to have the cathode side of the body flattened slightly It is not possible to guarantee that there are no exceptions to this rule and with LEDs there always seems to be some components that flout the conventions However I have never encountered any LEDs that have the flattening next to the anode leadout wire On the other hand I have used numerous LEDs that have no flattening of the case and a few that also have two leadout wires of equal length It would clearly be helpful to have a sure fire method of determining the polarity of a LED without resorting to some form of electronic testing Although a variety of methods have been suggested over the years none of them have proved to be totally reliable There is an additional problem these days which is simply that modern LEDs are available in a wide range shapes and sizes As a result of this the normal methods of determining LED
176. output a Integrates with MP LAB and AVR Studio Integrated 3D Viewer with 3DS and DXF export labcente r V wwilabcenter com Visit our website or phone 01756 753440 Electronics Labcenter Electronics Ltd 53 55 Main Street Grassington North Yorks BD23 5AA Registered in England 4692454 Tel 44 0 1756 753440 Email info labcenter com for more details
177. ovel solutions to research problems Includes extensive Science Software Library with even more science tools Suitable for Mac Windows Linux or UNIX 32MB RAM minimum Netscape 4 0 or higher or Internet Explorer 4 0 or higher Over 1 000 projects CD ROM Order code ASICD ROM 19 95 PROJECT CONSTRUCTION IC 555 PROJECTS E A Parr Every so often a device appears that is so useful that one wonders how life went on before without it The 555 timer is such a device Included in this book are over 70 circuit diagrams and descriptions covering basic and general circuits motor car and model railway circuits alarms and noise makers as well as a section on 556 558 and 559 timers Note No construction details are given A reference book of invaluable use to all those who have any interest in electronics be they professional engineers or designers students or hobbyists Order code BP44 5 49 POWER SUPPLY PROJECTS R A Penfold This book offers a number of power supply designs including simple unstabilised types and variable voltage stabilised designs the latter being primarily intended for use as bench power supplies for the electronics workshop The designs provided are all low voltage types for semiconductor circuits The information in this book should also help the reader to design his own power supplies Includes cassette PSU Ni Cad charger voltage step up circuit and a simple inverter Order code BP76 5 49
178. overs the PIC16F627 and PIC16F73 and the popular PIC16F84 and PIC16F877 models The CDROM includes program source files HEX code data sheets of devices sensors and schematics of the circuits used in the book 358 pages Order code NE44 21 99 HOW ELECTRONIC THINGS WORK AND WHAT TO DO WHEN THEY DON T Robert Goodman You never again have to be flummoxed flustered or taken for a ride by a piece of electronics equipment With this fully illustrated simple to use guide you will get a grasp on the workings of the electronic world that surrounds you and even learn to make your own repairs You don t need any technical experience This book gives you Clear explanations of how things work written in everyday language Easy to follow illustrated instructions on using test equipment to diagnose problems Guidelines to help you decide for or against professional repair Tips on protecting your expensive equipment from lightning and other electrical damage lubrication and maintenance suggestions Covers colour TVs VCRs radios PCs CD players printers telephones monitors camcorders satellite dishes and much more 394 pages Order code MGH3 21 99 PIC IN PRACTICE 2nd Edition David W Smith A graded course based around the practical use of the PIC microcontroller through project work Principles are introduced gradually through hands on experience enabling hobbyists and students to develop their understan
179. pacitors and certain other high value types such as the tantalum variety Lower value types can be fitted either way around and generally have quite high maximum Fig 3 above The LED will light up when connected as in a but not when it is connected with the polarity shown in b The circuit will work with any battery voltage from 3V to 12V Fig 2 left The cathode lead of an LED is usually a few millimetres shorter than the anode lead This method is not totally reliable though operating voltages Polarised capacitors tend to have quite low maximum operating voltages so it is important to obtain components having an adequate rating in this respect and to fit them the right way round Getting it wrong in either case can result in a spectacular failure often with the component bursting its casing Determining the polarity of electrolytic capacitors is usually very straightforward because the components are marked with and or signs Additionally axial lead types usually have a small indentation running around the end of the body Fig 4 Many printed circuit mounting PCM electrolytic capacitors have a similar indentation but this is of no practical significance Tantalum capacitors used to have a method of colour coding to indicate the value and polarity but this system is now obsolete The value is simply written on the body together with a sign to indicate the polarity Fig 4 An ax
180. plete with explanations of how the circuit works shopping lists of components advice on construction and guidance 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 pushbutton fader computer control interface 12 volt mains power supply 1085 5 45 109 pages ALL PRICES INCLUDE 124 pages UK POST amp PACKING Everyday Practical Electronics July 2009 FAULT FINDING CIRCUITS AND DESIGN PIC BASIC PROJECTS 30 PROJECTS USING PICBASIC AND PICBASIC PRO BOOK Dogan Ibrahim CD ROM J Covering the PICBASIC and PICBASIC PRO compliers this thoroughly revised edition previously entitled PICBASIC Programming and Projects provides an easy to use toolkit for developing applications with PICBASIC Numerous simple projects give clear and concrete examples of how PICBASIC can be used to develop electronics applications while larger and more advanced projects describe program operation in detail and give useful insights into developing more involved microcontroller applications Packed with simple and advanced projects which show how to programme a variety of interesting electronic applications using PICBASIC C
181. r a set time has elapsed amp much simpler universal wiring than previous models we have had e Kit supplied with PCB with overlay amp all electronic components e Suitable for circuits switching ground or 12V or 24VDC car amp truck with negative chassis 29 00 If you re into any kind of racing like cars bikes boats or even the horses this kit is for you The electronics are 4 mounted in the supplied Jiffy box a and the radar gun assembly can be Mm made simply with two coffee tins _ fitted end to end The circuit needs i 2 VDC at only 130mA so you can use a small SLA or rechargeable battery pack Kit includes PCB and all specified components This upgraded version is now even more stable and accurate than the popular original e Secure on line ordering e ALL prices in Pounds Sterling e Minimum order ONLY 10 ORDER YOUF FREE CATALOGUE TODAY KC 5476 plus postage amp packing Want to convert an old chest freezer into an energy efficient fridge or beer keg fridge Or convert a spare standard fridge into a wine cooler These are just two of the jobs this low cost and easy to build electronic thermostat kit will do It can also be used to control 12V fridges or freezers as well as heaters in hatcheries and fish tanks It controls the fridge freezer or heater directly via their power cables so there s no need to modify
182. re no gaps showing Panels by other than Solartwin may need similar treatment but many have pockets built in to easily mount a sensor If you can t get to the panel rear then you may need to attach the sensor to the hot outlet pipe as close as possible to the panel but add a resistor of about 150Q across the ve and pump pins on CON2 so that a trickle of water flows all the time there is a good PV voltage even if the FETs have not demanded the pump to be fully on Test it on a medium sunny day to ensure that the pump never quite stops as long as there is enough sun to heat the panel to more than say 40 C adjust the resistor accordingly This ensures that hot water in the panel reaches the sensor so it can read its temperature correctly The downside is that permanently sending current to the pump considerably less ens charging current under low light conditions Modifying the software to pulse the pump on regularly and briefly to move some panel water to the senor position would be better Hot water cyinder Assuming the HWC has the usual sprayed on polyurethane foam insula tion the HWC sensors can be installed by cutting out 25x60mm plugs of foam from this insulation Push a 5mm drill bit under the foam as before Squeeze some heat transfer compound into the pocket and onto the sensor face and push the sensor into the pocket with the flat side against the cylinder Reinsert the foam plugs and securely duct tape over t
183. recorder module us ing a high quality Winbond sound recorder IC Stand alone operation using just six onboard but tons or use onboard SPI interface Record using built in microphone or external line in 8 24 Vdc operation Just change one re sistor for different recording duration sound quality sampling frequency 4 12 kHz Kit Order Code 3188KT 28 95 Assembled Order Code AS3188 36 95 120 second version also available Bipolar Stepper Motor Chopper Driver Get better performance from your stepper motors with this dual full bridge motor driver based on SGS Thompson chips L297 amp L298 Motor current for each phase set using on board potentiometer Rated to han dle motor winding currents up to 2 Amps per phase Operates on 9 36Vdc supply voltage Provides all basic motor controls including full or half stepping of bipolar steppers and direc tion control Allows multiple driver synchroni sation Perfect for desktop CNC applications Kit Order Code 3187KT 39 95 Assembled Order Code AS3187 49 95 Video Signal Cleaner Digitally cleans the video signal and removes un wanted distortion in video signal In addition it stabilises picture quality and luminance fluctuations You will also benefit from improved picture quality on LCD monitors or projectors Kit Order Code K8036KT 32 95 Assembled Order Code VM106 49 95 ost items are available in kit form KT suffix r assembled and ready for use AS pre
184. ren Went Basie Gommone RIUS wok Dee rae Wy J fran 1 Mes Sh nO G Tnk LEDICONTTO 19 PEECH S INANG PICI pecs eechitoly ouri i Be eave es ne ST ontrollers piCMIcCroc Using P VOL 1 BACK ISSUES January 1999 to June 1999 Plus some bonus material from Nov and Dec 1998 VOL 2 BACK ISSUES July 1999 to December 1999 VOL 3 BACK ISSUES January 2000 to June 2000 VOL 4 BACK ISSUES July 2000 to December 2000 VOL 5 BACK ISSUES January 2001 to June 2001 VOL 6 BACK ISSUES July 2001 to December 2001 VOL 7 BACK ISSUES January 2002 to June 2002 g VOL 8 BACK ISSUES July 2002 to December 2002 VOL 9 BACK ISSUES January 2003 to June 2003 VOL 10 BACK ISSUES July 2003 to December 2003 A great way to buy EPE Back Issues our CD ROMs contain back issues from our EPE Online website plus bonus articles all the relevant PIC software links and web links Note no free gifts are included Order on line from www epemag com or by phone fax email or post BACK ISSUES CD ROM ORDER FORM Please send me the following Back Issue CD ROMs Volume NUMbDGrs 0 2 eee VOL 11 l l VOL 13 BACK ISSUES January 2005 to June 2005 Name iieliiots lt eeda a l VOL 14 BACK ISSUES July 2005 to December 2005 Addross asasinate dae a a l l l VOL 15 BACK ISSUES January 2006 to June 2006 er ee oe eee I l l VOL 16 BACK ISSUES ce July 2006 to December 2006 e
185. rity of LEDs when some doubt exists A simple test circuit can be improvised if a suitable test meter is not available and the simple arrangement of Fig 3 will suffice There are other types of diode such as the Zener and variable capacitance varicap varieties Zener diodes are used in simple voltage stabiliser circuits and at one time they featured in many projects These days they are relatively rare with plenty of low cost integrated circuits offering better ways of obtaining a regulated supply Variable capacitance diodes are mainly used in radio equipment and are little used in general electronics Anyway both types of diode are normally housed in the same encapsulations as other small diodes and have their polarity indicated using the standard methods Diac There is actually another two lead semiconductor component and this is the diac The main use of diacs is in mains power controllers where they are used to trigger a switching device called a triac Diacs are sometimes included in the same section as diodes in component catalogues but they are not diodes A diac provides essentially the same characteristics with a supply of either polarity which is essential since these components are mainly used in AC circuits A diac can therefore be connected either way round High capacity Apart from diodes the only other common two lead components that must be fitted with the right polarity are electrolytic ca
186. rocessor setup from last few month s video article primarily because in a later article we wil be integrating the two together The Last bit received Fig 2 Data format Everyday Practical Electronics July 2009 keyboard interface is actually nothing more than a connector and two pullup resistors You may have noticed that we have changed our power source from the typical 9V DC unregulated input to a 5V regulated one This is because 5V power supplies have become very cheap recently with the proliferation of PDAs and large mobile phones It s also because our microcontroller designs are now moving towards 3 3V or mixed 3 3V and 5V circuits Converting from 9V to 12V down to 3 3V with a standard linear regulator such as the LM7805 or LM317 is going to waste a lot of energy all as heat requiring unattractive heatsinking By using a 5V to 3 3V linear regulator the energy loss is significantly less and a typical circuit can be powered without the need for a bulky heatsink It will save money too The LD1086V33 3 3V linear regulator used in this month s circuit is just one example of such devices suitable for use in this configuration converting 5V to 3 3V It s a simple device to use and requires fewer components than the LM317 We were so impressed with this device that we have decided to standardise on it for use in future PIC n Mix projects You may of course continue to use whatever 3 3V power generation circui
187. rrent into the relay and ZD2 may need uprating On more complicated solar systems the Aux sensor and relay could be used to control secondary pumps or 6 Main PCB mounted in the case 29 Constructional Project motorised valves With a little ingenu ity almost any sort of solar system can be accommodated Electrical safety For installations connected to mains or subject to lightning risk it is pos sible under fault conditions although unlikely that exposed metal parts or parts with thin insulation like sensor leads could acquire a dangerous volt age Thus it is essential to properly earth the OV rail in this controller for those installations Connect a mains earth solidly with thick wire to all the PV and Sensor ve terminals of CON 2 4 5 and 6 so that all sensors and the PV panel are earthed where they connect to the con troller PCB Also ensure every screw through the box has plenty of insula tion between it and tracks Use plastic screws and washers if needed and do not use a metal box Mains wiring must be separated from other wires Do not connect the FETs to more than about 100V even if you substitute higher voltage ones off board Calibration The controller should work ad equately well on a Solartwin system without any calibration However with other systems it is best to do some calibration and even on Solartwin ones improved performance may be obtained with calibration Calibration
188. rtain 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 A roundup of the latest Everyday News from the world of electronics Sony s X series Walkman Barry Fox reports on Sony s new launch T IS now thirty years since Sony put the word Walkman into dictionaries round the world Although Sony s analogue cassette players were hugely successful the Company made a hash of the digital transition Mini Disc never took off and Sony s Digital Walkmen were very user unfriendly largely because Sony insisted on using its proprietary compression system ATRAC with very unpopular software SonicStage and Digital Rights Management MagicGate OpenMG In 2001 Apple grabbed the opportunity to launch the user friendly iPod and Sony has been playing catch up ever since The new X Series Walkman is Sony s best yet largely because ATRAC SonicStage and MagicGate OpenMG have been ditched In a further admission of defeat at the hands of Apple free PC software lets the user drag and drop music and movies by USB link direct to the Walkman from iTunes provided the content is DRM free Product Manager Wes
189. s Order code PC119 7 45 208 pages 60 pages 68 ELECTRONIC PROJECTS FOR VIDEO ENTHUSIASTS R A Penfold This book provides a number of practical designs for video accessories that will help you get the best results from your camcorder and VCR All the projects use inexpensive components that are readily available and they are easy to construct Full construction details are provided including stripboard layouts and wiring diagrams Where appropriate simple setting up procedures are described in detail no test equipment is needed The projects covered in this book include Four channel audio mixer Four channel stereo mixer Dynamic noise limiter DNL Automatic audio fader Video faders Video wipers Video crispener Mains power supply unit Order code BP356 5 45 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 constructed and most are suitable for the newcomer to project construction as they are assembled on stripboard There 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 soundtracks and a basic computer control interface Also there s a useful selection on basic video production techniques to get you started Com
190. s greater The order also relates to the ultimate fall off Ist order 6dB octave 20dB decade 2nd order 12dB octave 40dB decade 3rd order 18dB octave 60dB decade and so on The time domain response of a filter can be characterised by applying a step input signal The following characteristics may be identified see Fig 4 Rise time time to get from 10 to 90 of final value Overshoot percentage of maximum value over final value Ringing decaying oscillations as output settles to final value Settling time time to get within a certain small percentage of final value Filter design is a compromise between requirements such as pass band flatness sharpness of cut off delay flatness phase linearity rise time overshoot etc There are standard filter types which provide particularly good characteristics in specific areas Examples include the Butterworth filter which has as flat pass band the Chebyshev filter which has sharp cut off and the Bessel filter which has a flat delay response We will look at this in more detail next month as well as describing some op amp based filter circuits RINGING SETTLING TIME FOR EXAMPLE TO WITHIN 45 Vo Fig 4 Time domain response 37 58 R li The leading magazine a for vintage radio Bygones enthusiasts April May 2008 e Issue No 112 2008 arch 1 ebro Y ue No 11 Sune Jy ly 20 N _ ey ssue N 0 ig O l AS 3
191. s 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 systems and their arithmetic logic units Sections on Boolean Logic and Venn diagrams displays and chip types have been expanded in Version 2 and new sections include shift registers digital fault finding programmable logic controllers and microcontrollers and microprocessors The Institutional versions now also include several types of assessment for supervisors including worksheets multiple choice tests fault finding exercises and examination questions ANALOGUE FILTERS Filter synthesis Analogue 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
192. s postage amp packing Many modern motor bikes use a Capacitor Discharge Ignition CDI to improve performance and enhance reliability However if the CDI ignition module fails a replacement can be very expensive This kit will replace many failed factory units and is suitable for engines that provide a positive capacitor voltage and have a separate trigger coll Supplied with solder masked PCB a and overlay am case and components some mounting hardware required MICROMITTER STEREO FM TRANSMITTER KIT KC 5341 0 plus postage amp ee This is the third baht of this kit and is far more stable and compact than the original You can connect your CD or MP3 player to the Micromitter and listen to your music all over the house through any FM radio Using a surface mount BH1417F processor this model is crystal locked to a preselected frequency to eliminate frequency drift Supplied with revised PCB with solder mask and overlay case silk Screened lid and all electronic components CLOCK WATCHERS CLOCK KIT WITH BLUE LEDS KC 5416 55 00 plus postage amp packing This fascinating unit consists of an AVR driven clock circuit and produces a dazzling display with 60 blue LEDs around the perimeter It looks amazing and can be seen in action on our website Kit supplied with double sided silk screened plated through hole PCB and all board components as well as the special clock housing
193. s relay with voltage free contacts which in my case is then used in a conven tional loop type alarm system as utilised on the windows and doors in my garage If the oil tank can be approached from a number of directions then it is a simple matter of installing a number of the spotlamps and connecting the auxiliary outputs in an OR format The ambient light adjustment is set such that the lamp will be triggered at any time of the day or night and the lamp on duration timer is set for about three seconds If the tank is close to bushes which the wind can move or if cats dogs birds cross the lamp sensor beam path then the alarm will be triggered falsely For this reason I have incorporated an additional timer circuit which is set for about six seconds This means that even if the lamp is falsely initiated by the wind or an animal then it must stay in this condition for at least six seconds before the main alarm is initiated This arrangement has virtually eliminated nuisance alarms The sys tem has been working without functional problems for over a year and can be applied to many other security requirements around the home Delay circuit details The overall electrical connection diagram is shown in Fig 1 When the security lamp sensor is activated the master lamp switches on and the mains auxiliary output energises the relay which opens switch S4 and initiates the alarm trigger delay circuit Fig 2 Magnetic
194. scillating This is the posi tion of maximum sensitivity VR2 can then be adjusted to provide a suitable volume e Tuning is done with the variable capacitor VC1 Note that the receiver is directional so the coil should be rotated for best reception of a particu lar station You might like to experiment with winding fewer turns of wire when making L1 so as to receive short wave transmissions OO00000 O O e s WES p je ej ej ej O O FERRITE ROD 50mm x 10mm dia UNDERSIDE oh 7 4 VIEW GND IN OUT Fig 10 2 Assembly and wiring for the AM Radio on Protobloc 49 Breadboarding Project 18 Sound Sensor popular with hobbyists A dedicated cause Other ICs such as the LM386 audio amplifier have a more specific use Among the many ICs that are designed for specialist applications is the LB1413N which features in this project The designated purpose of this IC IC2 in Fig 10 3 is to provide a visual indication of the strength of a DC or AC input signal on a row of five LEDs In this case it is the strength of an input signal from a microphone it works as a sound level meter or a volume unit VU meter This means that for this application IC2 is used in the AC mode whereas for the Moisture Meter Mk2 project May 09 IC2 was used in the DC mode The full circuit diagram for the Sound Sensor shown in Fig 10 3 uses two ICs IC1 is an audio amplifier type LM386 in a st
195. sensor circuits through to power amplifiers A shareware version of Matrix s 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 Power Amplifier Sound Activated Switch Reaction Tester Full parts lists schematics and p c b layouts are included on the CD ROM ELECTRONIC CIRCUITS amp COMPONENTS V2 0 Circuit simulation screen Electronics Circuits amp 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 and 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 Included in the Institut
196. shed on the second Thursday of each month and distributed S O R by SEYMOUR Make sure of your copy each month cut out or photocopy this form fill it in and hand it to your newsagent Everyday Practical Electronics July 2009 s o e CIRCUIT SURGERY REGULAR GLINIC BY IAN BELL Filters circuits Part 1 Frequent EPE forum contributer Paul Goodson posted the following plea for help with filters on the EPE Chatzone www chatzones co uk I am trying to make some band pass filters in the audio frequency range 20Hz to 20kHz I would prefer to use the single supply op amp LM324 if possible There is so much dissimilar information out there it s driving me mad There doesn t seem to be any consistency in the way the op amp is configured or any values associated with the components Also the equations are a little above me at the moment Probably as there never seems to be any working example shown with the component values as above I was just hoping to find some better information with a working schematic that I could build and use as a push start Filters are circuits that pass signals at certain frequencies in the pass band while rejecting signals at other frequencies in the stop band A frequency that divides the pass band from the stop band is a cut off frequency It is perhaps not surprising that Paul has found it difficult to find his way through the available information on filters because there
197. system but suc cess is not guaranteed For example if your power amplifier also earths the audio signal an earth loop will exist once the two are hooked together This may or may not be a problem If you notice more hum in your audio system after connecting the preamp then try disconnecting the earth wire to the control module Never ever disconnect the mains earth from the chassis Testing Before applying power for the first time bear in mind that the mains input SETUP NORMAL 0 5dB STEPS 1 5dB STEPS Table 1 jumpers must be installed on both JP1 and JP2 during initial set up 18 end of the power supply circuit board is live Accidentally placing a finger under the board or contacting the mains input terminal block CON4 screws might well prove fatal Therefore it is important that the power supply board is securely mounted in a chassis not floating around on your bench Assuming the board is correctly installed apply power and use your multimeter to measure the three rails at the supply outputs CON2 and CONS If all is well the 15V 15V and 5V rails should all be within 5 of the rated values Now measure between pins 10 and 12 and then pins 10 and 13 of IC1 s socket on the control module You should get readings just below the 15V levels measured earlier Finally check between pins 5 and 4 again the reading should be just below the earlier 5V measurement Now switch off and
198. t The next step is to replace the timing capacitor It s dead easy to find it s the smallest disc shaped capacitor on the printed circuit board and typically has a value of 100nF Carefully desolder SPEAKER CAR PHONE CHARGER 2 Fig 1 the pulsing screamer uses two slightly modified 12V phone chargers and a speaker The first charger pulses the second charger which in turn produces the audio frequency that s reproduced by the speaker 44 this capacitor and temporarily replace it with a 100uF electrolytic capacitor this can be tacked to the copper track side of the board Note that electrolytic capacitors are polarised so be sure to connect the negative lead of this capacitor to the ground V track of the circuit board You might have to do some track trac ing to make sure you get this right A sound charger The next step is to modify the other charger so that it will produce the sound ie an audio tone As before start by removing the output filter capacitor and placing it in your parts drawer That done remove the timing capacitor and temporarily replace it with a capacitor of around 1uF Next connect the outputs of the pulsing charger to the power supply inputs of the tone charger making sure that the polarity of the connec tions are correct see Fig 2 You can then connect the speaker to the tone charger s output terminals Testing and Tuning Now for the smoke
199. t A 6 Port A 7 Port A O Port A 1 Four I O pins on the PIC are not used at all including an analogue input for the A D converter Hence there is scope to expand the capability of the weather station for those who may need additional sensing The above table summarises the I O pin usage on the PIC Putting the controller together The project is assembled in a small plastic utility box second smallest size is used Looking first at the externally visible parts the front panel of the box has holes for the LED and the Reset switch plus a larger cutout for the DB9 female serial port connector There is also a single pole single throw slide switch S2 used for powering up the MAX232 when preparing for a data dump The battery holder 3 x AA is stuck to the back of the box with double sided tape and the wires from this run through two small holes in the box The only battery holder I could find for three AA cells was one with a plastic cover and an on off switch Unfortunately the case opens on the opposite side to the switch Hence the switch is inaccessible when the case is stuck to the utility box and in fact the switch actuator had to be cut flush with the surface of the battery case to enable mounting Since the switch is now inaccessible to minimise the risk of failure I broke open the battery case behind the switch and soldered a link across the terminals to bypass it so the switch is effectively permanently on Ev
200. t the DS1621 and the end ofthe cable in two part epoxy Try to keep the amount of epoxy to a minimum the more there is the more bulk that has to heat up or cool down each time the temperature changes thereby reducing responsiveness Protecting the DS1621 like this should be fine for most uses But be warned experience has shown that it won t tolerate extended immersion or prolonged exposure to wet or damp environments If high water resistance is needed pot the DS1621 in silicone sealant again minimising the amount used then use a Short length of adhesive lined heatshrink tubing over this After heating the heatshrink and while the adhesive is still melted pinch the open end closed until the adhe sive re hardens use gloves or you could burn yourself It s a good idea to apply white paint to the coated sensor to reflect any radiant heat that may reach it If you don t do this you may measure heat from sources other than the surrounding air The temperature sensor is accurate to 0 5 Celsius and is not adjustable NEXT MONTH Full construction details for the rain gauge and temperature measurement housing 39 by Mike Hibbett Reviewing Nurve Networks XGS PIC Based Video Games HE XGS is a system designed to enable hobbyist programmers to develop their own video games and applications on a small printed circuit board You may have seen adverts for it in this magazine this month we got our hands
201. t you choose but keep in mind that the LM317 would not be able to convert 5V down to 3 3V it requires a higher input voltage In Fig 4 is shown the pin layout of the LD1086V33 regulator It comes in a standard package similar to the LM7805 which will be familiar to many can supply up to 1 5A requires just two capacitors and is relatively inexpensive It s not the only 3 3V regulator and possibly not the best but it is a good work horse regulator We now have a stock of them in the PIC n Mix lab The other new component this month is the PS 2 keyboard socket Ours was salvaged from an old PC motherboard using a large soldering iron and a big blob of solder A heat gun would have been better The sockets are described as 6 pin mini DIN female sockets and are available through the usual electronic component suppliers Software The full software for the interface is contained within pic24ps2key c pic24ps2key keymap h and pic24ps2key h The latter header file provides the list of functions that may be used by your own software to access the keyboard interface Using the software is very straightforward a typical initialisation routine called Fig 4 Low drop out LDO regulator Everyday Practical Electronics July 2009 PROGRAMMING HEADER 5V Vin Vout 3 3V 1 5V 3 TO KEYBOARD CONNECTOR 5V ae er DATA CLOCK GND Fig 3 Circuit diagram PIC24ps2keyInit should be called at the beginni
202. ta bits a parity bit and a stop bit The parity bit is present to allow you to perform some basic error detection we ignore this and simply decode each byte within the 11 bit sequence It s possible for the processor to pause the keyboard from sending data by driving the clock line low When the keyboard detects this it will buffer any data until the clock line is released How many keyboard events actually get buffered is keyboard specific so you should take care if you choose to use this feature In this article we don t try and instead buffer the received data within our keyboard interrupt routine Because the number of data bits used in each transfer is not a convenient multiple of eight we cannot rely on the SPI or USART hardware module within the PIC processor to handle the incoming data we will have to use a simple interrupt on the clock pin We read a data bit on the falling edge of each clock pulse a technique which is quite simple to implement with an interrupt but a certain amount of care will be needed when integrating the software with your own application later on We do of course have in mind the video generating application which has some very tight timing requirements Integrating a keyboard interrupt while time critical video interrupts are occurring will present a particularly interesting challenge Keyboard Interface Our circuit for this month is shown in Fig 3 It s based largely on the p
203. ternational reply coupons We are not able to answer technical queries on the phone PROJECTS AND CIRCUITS 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 A number of projects and circuits published in EPE employ voltages that can be lethal You should not build test modify or renovate any item of mains powered equipment unless you fully understand the safety aspects involved and you use an RCD adaptor COMPONENT SUPPLIES We do not supply electronic components or kits for building the projects featured these can be supplied by advertisers 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 magazine and its publishers cannot give any undertakings in respect of statements or claims made by advertisers whether these advertisements are printed as part of the magazine or in inserts The Publishers regret that under no circumstances 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 ce
204. test connect 12V power to the pulsing charger and listen It s likely that the sound will not be quite as you want it it may be too low in pitch and pulsing too slowly for example or vice versa That s easily fixed To speed up the pulsing decrease the value of the timing capacitor in the pulsing charger Simi larly to increase the pitch frequency of the sound decrease the value of the capacitor in the tone charger By making some simple capacitor changes it s possible to have anything from a deep slowly pulsing foghorn to an ultra piercing frantically pulsing screamer and everything in between When you re happy with the sound solder the selected capacitors in place Everyday Practical Electronics July 2009 Reproduced by arrangement with SILICON CHIP at ae magazine 2009 www siliconchip com au The pulsing screamer is easily made from two modified car phone chargers and a speaker In this case we used a brand new speaker from a hands free kit which we picked up at a garage sale but any wide range speaker is suitable Now run the system fora while you might want to wrap the speaker in a pillow and check the temperature of the two ICs They are likely to be warm but they shouldn t be too hot to touch If they are install a 59 5W resistor in series with the 12V supply to the system This will drop the audio output but the ICs will run cooler Incident
205. tform Some may be wondering why this is better than simply purchasing a Nintendo DS lite and a homebrew card you can develop far more complex video games on that And the cost would be slightly less too W aR FS ts j Get your magazine instantly anywhere in the world buy and download EPE from the web TAKE A LOOK A FREE ISSUE IS AVAILABLE A one year subscription 12 issues costs just 18 99 US Back issues are also available 42 You would be right if all you want to do is write video games But that is not the purpose of this kit it s about learning and being able to write games from the ground up where it s just you and the hardware There is a certain satisfaction when watching a bitmap animation wandering across a scene that ev ery pixel has been generated under your control every signal change on that video cable occurred through the compulsion of your software In delivering that buzz and satisfaction the XGS is unique If this has raised your interest in the generation of video by a simple processor then take a look at our PIC n Mix column in previous is sues where we covered the subject There is also an opportunity in this month s PIC n Mix to win the XGS system reviewed in this article although it will require getting out your soldering iron EPE XGAME STATION E E PA T T El l GTE ARO BOEG TERENA Chh WOOER GAME Eons Great tonHobbyists AND Students Co
206. the CD ROM contains a set of lab experiments for the virtual microcomputer that let you recreate the experiences of early computer pioneers If you re the slightest bit interested in the inner workings of computers then don t dare to miss this 35 99 Over 800 pages in Adobe Acrobat format INTERFACING P MICROCONTRC i Martin Bates An essential guide to PIC interfacing techniques using circuit simulation to aid learning Explore in detail microcontroller interfacing techniques using the popular PIC 16F877 Work through step by step examples interactively using circuit simulation software supplied as assembly source code Interfacing PIC Microcontrollers provides a thorough introduction to interfacing techniques for students hobbyists and engineers looking to take their knowledge of PIC application development to the next level Each chapter ends with suggestions for further applications based on the examples given and numerous line drawings illustrate application of the hardware Step by step examples in assembly language are used to illustrate a comprehensive set of interfaces and these can be run interactively on circuit simulation software used to aid understanding without the need to build real hardware A companion website includes all examples in the text which cam be downloaded together with a free version of Proteus s ISIS Lite 298 pages Order code NE48 24 99 GETTING THE MOST FROM YOUR MULTIMETER
207. the PIC One of the microcontrollers in their ever expanding family is the 10F20x series which is available in DIP 8 SO 8 or SOT 23 6 packages The SOT 23 6 was my choice because these are tiny and easy to put inside some type of pen as a housing from an original by Ross Purdy The next mission was to find a hous ing for the design Many years ago I built a logic pulser into a white board marker pen from a magazine article So I decided to check out the local stationery shop for ideas If I could find say a pen moulded in clear plastic then I wouldn t need to drill holes to view the LEDs This would not only make it easier to build but it would look pretty cool as well I found a 10 pack of ballpoint pens that looked about right and cost only 1 00 making for a very cheap case including an end cap to protect the needle probe The pens were a bit on the small size allowing for a PC board only about 5mm wide and 100mm long but it was the height that I was more concerned with I cut out a dummy piece of circuit board glued a few bits on and found that the micro and LEDs would fit eas ily down the barrel of the pen With the micro and housing sorted out at Everyday Practical Electronics July 2009 tention was now concentrated on the functionality required First and foremost was a good sharp tip that you can use to probe the tiny pitch devices that are becoming in creasingly common A sewi
208. the safe and proper functioning of reader constructed projects based on or from information published in these materials and works In no event shall TechBites 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 MARCONI IFR 2030 Signal Generator 10KH2 1 35GH2 Depending on options HP 8591E Sparin Araby ies SKH2Z 1 8GH2 with Tracking Generator Mo moukdengs nmg harietie 17A King Street Mortimer Near Reading RG 3AS Telephone 0118 933 1111 Fax 0118 933 2375 Sam 5pm Monday Friday Be HP8SS1A Spectrum Anatyser IMH 1 36H 75ohm with Tracking Ganaraior Specia Ofter Price HPS5904 Spectra Anaea 1OKHZ 1 7OGHE 75 ohm special Ofer Price CHECK OUT OUR WEBSITE 1 000 s of items currently in stock Extra Special Oscilloscope offer still on Atlas Star Pack Atlas DCA and Atlas LCR in Premium Carry Case Special Offer AND Reduced WATI Atlas DCA Model DCAS55 Semiconductor Analyser Identifies type and pinout Connect any wey round Measures gain junchon charactenstics and more Mow with premium strong probes Atlas LCR Model LCR40 Passive Component Analyser Automatic o nponent identficaton
209. thout Crocodile Technology Single User 39 00 inc VAT well as worldwide web pages subject to Multiple Educational Users under 500 students 59 00 plus VAT Over 500 students 79 00 plus VAT restrictions see licence for full details UK and EU customers add VAT at 15 to plus VAT prices Now contains Irfan View image software for Windows with quick start notes included Minimum system requirements for these CD ROMs Pentium PC CD ROM drive 32MB RAM 10MB hard disk Price 19 95 inc VAT space Windows 95 98 NT 2000 ME XP mouse sound card web browser Please send me CD ROM ORDER FORM a 5 O Electronic Projects O Electronic Circuits amp Components V2 0 ORDERING ALL PRICES INCLUDE UK O Analogue Electronics Version required POSTAGE O Digital Electronics V2 0 O Hobbyist Student O Analogue Filters O Institutional Student Single User Standard Version price O Electronics CAD Pack O Institutional Professional 10 user includes postage to most countries in the world EU residents outside the UK add 5 for airmail postage per order O Robotics amp Mechatronics O Site licence O Assembly for PICmicro V3 O C for 16 Series PICmicro V4 O Flowcode V3 for PlCmicro O Digital Works 3 0 O PiCmicro Development Board V3 hardware I I I I I 0 fl I I I 0 0 i I I I O TINA Pro V7 Basic Flowcode V3 Hobbyist Student I O Electronic Components Photos Version 1 1 E E E
210. to learn about design and build electronic systems For more information contact Matrix Multimedia The Factory Emscote street South Halifax HX1 3AN Tel 44 0 1422 343924 Web www matrixmultimedia com HAPPY BIRTHDAY PCB POOL PCB Pool the UK s leading prototype PCB supplier is celebrating its I5th birthday To mark this milestone they have introduced some new features A one day service send them your files before 8 30am and your boards will be ready for dispatch at 5 00pm A chemical tin finish guarantees ultra flat SMD pads at no extra cost Free laser cut SMD stencils with all prototype PCB orders Order your PCB online and receive a laser stencil to match your PCB design free of Charge Simply follow this link and select Yes I want one www pcb pool com ppuk order_productconfiguration html PCB Pool is a leading online PCB manufacturer specialising in fast turn around prototype quantities and pre production batches Being the pioneer of online PCB ordering and developing the original PCB Pool concept has raised the company s reputation as being the industry s leading PCB prototype manufacturer Offering instant online quotations customers receive professionally manufactured prototypes at discounted prices live online order tracking and live online customer support PCB Pool combines high quality products with first class customer care With no minimum quantity requirement no tooling
211. to the device including an on board oscillator a serial interface driver and A D converters While the A D converter was used in an earlier version of the design for temperature sensing it s not actually needed in the final design because analogue temperature sensing was abandoned Instead sensing is done by a Dallas DS1621 digital sensor IC5 This greatly simplified the circuit which previously required an accurate voltage reference for the A D converter and a circuit to switch this on and off Better still the DS1621 is an IC bus device like the two 24C256 serial EEPROMs IC3 and IC4 which further simplified design and software development The DS1621 has a low power standby mode when not in use further helping to save power Lines of communication These devices require two lines for communication a clock line and a data line The data line is normally held high by a 10kQ pull up resistor An active device pulls the data line low when it needs to during transmission Hence if two devices attempt to transmit at the same time the worst that can happen is that they can pull the shared data line low This is unlikely to present any risk of damage but could lead to unpredictable power consumption in some cases Therefore three 390Q resistors were included in series Everyday Practical Electronics July 2009 RAIN SENSOR S3 CLOCK CORRECT Constructional Project o DUMP S4 IC PIC16F88 RA 1k A Ga LED1
212. to the tank and dismantle the outlet pipework in order to drain the oil into drums or in some cases they pump the oil into a road tanker posing as a legitimate heating oil supply contractor There have also been cases where the thieves crudely punch drill a hole in the plastic stor age tank in order to drain the heating oil A general security problem with home oil tanks is that fitting padlocks on the filler cap is not practical on the plastic type tanks and even if it was this will not prevent disman tling of the outlet pipe work or punching drilling through the tank wall to enable il legal draining Desi DELAY CIRCUIT esign concept What is needed is a type of alarm which reacts when the burglar comes within the Fig 1 General electri proximity of the tank and is initiated after cal block diagram for the 419 SUPPLY a few seconds This basic requirement is Heating Oil Storage Tank TINE E e ONT OCEANE met by the sensing spotlight which many Burglar Alarm people employ to illuminate their front door 54 Everyday Practical Electronics July 2009 or drive when a person approaches These units can be obtained from any of the big DIY stores and come with adjustable ambient light and lamp on duration features Also there is a common type which is fitted with a switched mains supply which is intended to feed an auxiliary spotlight when the master lamp is triggered This switched supply can be used to energise a main
213. u and me will increasingly encounter SIM card enabled devices Visa has announced that it will make 2012 the first cashless Olympics with plans to install thousands of electronic readers at venues These will likely use SIM cards for data transfer as will the ticket barriers that London Underground will upgrade to M2M in time for the games Travellers with O2 mobile phones will be able to pay their fare and pass through these barriers simply by swiping their handset past a contactless receptor Smart meters By far the largest SIM card application planned so far however is the smart meters that will be installed in every British household under the 2008 Energy Act By the end of 2020 some 26 million households and 19 million business sites will have their gas and electricity meters modified or replaced to communicate directly with their energy suppliers removing the need for meter readings and estimated bills Smart meters will provide entirely accurate bills the government explains and a clear in home display will provide domestic customers with information that could help them use less energy promoting greater energy efficiency Research indicates that peak time demand for power falls by five per cent when customers are able to monitor live how much their energy use is costing them Smart meters would enable power com panies to offer separate peak time and off peak tariffs which might reduce energy consumption by
214. ue markings etc advice on buying the right tools for the job soldering making easy work of the hard wiring construction methods including stripboard custom printed circuit boards plain matrix boards surface mount boards and wire wrapping finishing off and adding panel labels getting problem projects to work including simple methods of fault finding In fact everything you need to know in order to get started in this absorbing and creative hobby Temporarily out of print TEST EQUIPMENT CONSTRUCTION R A Penfold This book describes in detail how to construct some simple and inexpensive but extremely useful pieces of test equipment Stripboard layouts are provided for all designs together with wiring diagrams where appropriate plus notes on construction and use The following designs are included AF Generator Capacitance Meter Test Bench Amplifier AF Frequency Meter Audio Mullivoltmeter Analogue Probe High Resistance Voltmeter CMOS Probe Transistor Tester TTL Probe The designs are suitable for both newcomers and more experienced hobbyists Order code BP248 4 49 104 pages COMPUTING FOR THE OLDER GENERATION Jim Gatenby Especially written for the over 50s using plain English and avoiding technical jargon Large clear type for easy reading Among the many practical and useful ideas for using your PC that are covered in this book are Choosing setting up and understanding your computer and its main c
215. uirements Also Indigo customers have used our products in conjunction with their home automation systems www easydaq biz Downloads Downloads Mac htm Everyday Practical Electronics July 2009 project documentation as the schematic and layout are tied together in a similar manner to a schematic PCB layout combination Another advantage is that a one to one printout of the layout can be stuck to the stripboard and there you have a pseudo silk screen to work to again reducing the likelihood of errors Like all CAD programs there is a degree of learning to do before things become second nature but if the guidelines and tutorials on the Help pages are followed then VeeCad is soon mastered Again as with just about every PCB layout program I have used the interface with the Schematic Editor has to be understood and configured so that they work together I think the rules that VeeCad requires are simple to implement and quite logical The reasoning behind them is discussed at http veecad com resource parts cadsanity html The following link will jump you to the Linux datasheet www easydaq biz Datasheet 20Contact 20Details indexEeePCInfoRequest htm Chris Harden Product Design amp Tech Support www easydaq biz Thank you Chris readers will note that this letter is a response to last month s Editorial where I asked for advice on interfacing non Windows computers It is no slight to Easydag or Chris to not
216. unteract the natural rolloff of the enclosure producing rich natural bass It gives an extra octave of response and is sure to please even the most avid sound enthusiasts e Kit supplied with PCB and all electronic components VOLTAGE MONITOR KIT 6 75 This versatile kit will allow you to monitor the battery voltage the airflow meter or oxygen sensor in your car The kit features a 10 LED bar graph that lights the LEDS in response to the measured voltage preset 9 16V 0 5V or O 1V ranges complete with a fast response time high input impedance and auto dimming for night time driving Kit includes PCB with overlay LED bar graph and all electronic components e 12VDC Jaycar Electronics a 28 75 This is an improved version of our popular guitar mixer kit and has a number of enhancements that make it even more versatile The input p550999 sensitivity of each of the four channels is adjustable from a few millivolts to over 1 volt so you plug in a range of input signals from a microphone to a line level signal from a CD player etc A headphone amplifier circuit is also included for monitoring purposes A three stage EQ is also included making this a very versatile mixer that will operate from 12 volts Kit includes case PCB with overlay and all electronic components a FLE TEn K 4 6 00 Uses a handful of components to accurately time intervals from a few seconds to a whole gf day It ca
217. usual all 230V AC wiring must be carried out in a safe and professional manner which means that we assume that you already have the relevant ex pertise or can obtain assistance from someone who has Most importantly the assembly must be housed in an earthed metal enclosure The mains earth must be properly connected to this chassis This can be achieved via a double ended 6 3mm spade lug fastened securely to the base with an M4 x 10mm screw shakeproof washer and two nuts see Fig 16 A basic wiring layout is shown in Fig 14 The mains section of the wiring will obviously need to be amended if the module is to coexist with a power amplifier which will at least share the mains input socket and power switch Note that if using a separate chassis mounted transformer alternative ar rangements must be made for mains Everyday Practical Electronics July 2009 fusing This is best achieved by using an IEC socket with an integral fuse Once all the mains wiring has been completed go back and double check that each connection is secure and well insulated If necessary use heat shrink tubing to completely cover any exposed terminations That done use your multimeter to check continuity between the earth pin of the mains plug and any convenient point on the chassis that is devoid of paint This check must be repeated later when the case is assembled At that time use your meter to check that all panels of the case are earthe
218. w to program embedded microcontrollers in C The CD contains a course as well as all the software tools needed to create Hex code for a wide range of PlCmicro devices including a full C compiler for a wide range of PlCmicro devices Although the course focuses on the use of the PlCmicro microcontrollers this CD ROM will provide a good grounding in C programming for any microcontroller Complete course in C as well as C programming for PlCmicro microcontrollers Highly interactive course Virtual C PlCmicro improves understanding Includes a C compiler for a wide range of PlCmicro devices Includes full Integrated Development Environment Includes MPLAB software Compatible with most PlCmicro programmers Includes a compiler for all the PlICmicro devices S d ener 1 Fa Fa o Af GR sa oes pe E Ida aj Minimum system requirements for these items Pentium PC running Windows 98 NT 2000 ME XP CD ROM drive 64MB RAM 10MB hard disk space Flowcode will run on XP or later operating systems FLOWCODE FOR PiCmicro V3 Flowcode is a very high level language programming system for PlCmicro microcontrollers based on flowcharts Flowcode allows you to design and simulate complex systems in a matter of minutes A Powerful language that uses macros to facilitate the control of devices like 7 segment displays motor controllers and I c d s The use of macros allows you to control these devices without
219. with JP2 removed The main board is double sided but the holes are not plated through on the EPE version so ensure that you solder the leads of components to the top and bottom tracks where applicable Leave a small gap under the component if there is a track on the top connected to it This enables you to feed solder up against the leads The 28 pin IC socket is harder to solder for this reason so buy the turned pin type that has a plastic body that does not sit flush with the PCB If you are not sure about the joint or track quality test it with an ohmmeter between the top and bottom tracks and component pin In particular check that the long OV track is continuous not over etched as any break in this will make later fault finding difficult Space is provided on the PCB for the seven lightning protection di odes but better protection will be obtained if these are all soldered to a small piece of stripboard several metres away from the controller in series between PV ICsens1 and the controller Use soldered joints and short connections on this board for minimum impedance not screwed terminals and generous spacing Solder a short lead though the main PCB to connect the top and bottom tracks if D9 is not fitted there Drilling guide You will find 16 pilot holes not con nected to pads provided on the LCD PCB Four are for LCD mounting only The remaining 12 are for guiding box drilling four for PCB mounting four for
220. wn gold 5 1 1kQ colour code brown black red gold 5 7 10kQ colour code brown black orange gold 5 1 220kQ colour code red red yellow gold 5 Optional parts 1 steel star picket 1 2m long or orange white black black brown 1 or brown black black brown brown 1 or brown black black red brown 1 or red red black orange brown 1 Aluminium and galvanised or Colorbond steel sheet to make a louvred housing for temperature sensor 1 galvanised steel bolt 100 x 8mm and two nuts and washers to suit for mounting the louvred housing 1 DB9 serial communication cable for computer connection See part Il of this project next month for more details on materials for the separate temperature housing Everyday Practical Electronics July 2009 DB9 socket solders directly on to the MAX232 board with the edge of the board pushed between the two rows of pins on the socket Pads are provided on the solder side of this board for pins 1 5 of the socket Pins 6 7 and 8 which sit on the component side also need to be connected A single pad and hole in the PC board is provided for this just near pin 6 of the DB9Y A wire link should be soldered into this pad and on the component side bent and soldered to pins 6 7 and 8 see photo Don t connect pin 9 of the socket Wiring the DS1621 temperature sensor The DS1621 temperature sensor IC5 comes in an 8 pin DIP package For use with this project it is mounted on the end of a
221. wolfram com WolframAlpha utilises Wolfram s Mathematica modelling and visualisation software www wolfram com behind the scenes Mathematica lets you manipulate molecules or visualise a virtual volcano compute and document any technical concept or distil virtually any type of technical data into a human digestible form Mathematica Home Edition is 230 00 inc VAT 300 and in essence it combines the powers of a super spreadsheet a 3D modelling package a documenting mapping programming and algebraic engine with almost any other technically based algorithm function you could need Need more input WolframAlpha is a brave attempt to compute answers in response to calculations or queries It is as if Google Calculator meets Robot No 5 from the movie Short Circuit It has passed its first test already after widespread media coverage in the UK the site stood up on day one with no particular sign of falling over which is more than other ambitious projects eg the British Census website can boast Much is promised by WolframAlpha but the computational engine is careful not to raise our hopes too high at this embryonic stage of its development Perhaps expectations are presently unrealistically high as it probably signals the way ahead rather than being a milestone in itself So far I have yet to witness any real everyday benefit from the new engine after bashing in a variety of factual questions including enquiries o
222. x 25mm with lugs Shaft 7mm diameter 9 85 includ ing postage C Brittain 12 Marina Drive Wolverton MK12 5DW 07986 824998 KITS TOOLS COMPONENTS S A E Catalogue SIR KIT ELECTRONICS 52 Severn Road Clacton CO15 3RB www geocities com sirkituk 71 Europe s Largest Surplus Store 20 000 000 items on line NOW New items added dail Established for over 25 years UK company Display Electronics prides itself on offering a massive range of electronic and associated electro mechanical equipment and parts to the Hobbyist Educational and Industrial user Many current and obsolete hard to get parts are available from our vast stocks which include e 6 000 000 Semiconductors 5 000 Power Supplies 25 000 Electric Motors e 10 000 Connectors 100 000 Relays amp Contactors 2000 Rack Cabinets amp Accessories 4000 Items of Test Equipment 5000 Hard Disk Drives Display Electronics Telephone 29 35 Osborne Road 44 020 8653 3333 Thornton Heath Surrey UK CR7 8PD Fax 44 020 8653 8888 Rechargeable Batteries With Solder Tags NIMH NICAD AA 2000mAh C PP3 150mAh Instrument case with edge connector and screw terminals Size 112mm x 52mm x 105mm tall This box consists of a cream base with a PCB slot a cover plate to pro tect your circuit a black lid with a 12 way edge connector and 12 screw terminals built in 8mm pitch and 2 screws to hold the lid on The cream bases have minor marks from dust
223. yboard and the values that are transmitted over the interface In fact it s quite a confusing jumble To simplify the translation between the two a lookup table is implemented within the software This is held in a separate header file pic24ps2key keymap h The bulk of the interface software is within a very short interrupt routine at the end of the main source file Its job is straightforward shifting in data bits from the interface stripping out a byte after every 11 bits and storing the byte in a small buffer The buffer held in the variable keyBuffer reduces the burden on your main software to respond to incoming data quickly If your application is busy doing something such as a lengthy calculation the interrupt routine will buffer up to 16 data bytes for you It s not a requirement that the keyboard library provides a buffer but it does make sense in many applications and 16 bytes of data is tiny in comparison with the amount of RAM available to us Adding this code to your own project is simple Include the names of the three files in your project workspace and then include the line include pic24ps2key h within your C source files that need to use the functions An example project and test program are included with the main files available for download from the EPE website The program outputs keypresses from a keyboard over the serial pin TXD at 9600 baud Next month we look at integrating this keybo
224. ytes per record Normally only the records up to the last one recorded will be transmitted through the serial port during a data dump The way the data is recorded also enables breaks in the recording to be detected if a full data dump needs to be done but more on that later The weather station is very reliable and I ve never had a need to do a full data dump except for testing but the feature is there just in case Finally there is an LED on the front panel to indicate status This flashes very briefly every four seconds during normal operation It comes on permanently during a data dump and it quickly flashes three times when a reset is performed by the user A high intensity LED is used to improve visibility since it is only on for about three milliseconds each flash again this was done to help keep power consumption down 36 Allocated to Reset switch input unallocated analogue input or digital 1 0 LED output unallocated digital I O Rain sensor switch input I C bus data line SDA RS232 port receive input I C bus clock output SCL Clock calibration switch input RS232 port transmit output Clock crystal Clock crystal unallocated digital I O unallocated digital I O Data dump request input RS232 communication ready input Pin I O port bit Port A 2 Port A 3 Port A 4 Port A 5 Port B O Port B 1 Port B 2 Port B 3 Port B 4 Port B 5 Port B 6 Port B 7 Por

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