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1. The value of resistor R1 is not too criti cal you need to make sure that you get a good logic 1 voltage when the output tran sistor is on and a good logic O when it is off so about 10 kilohms should do A sup ply decoupling capacitor C1 typically 100nF should be placed close to the logic device s There is a potential source of problems with this arrangement Because you are using edge triggered clocking of a logic circuit as a control input rather than as a proper clock signal any glitches or other unwanted transitions on the receiver output can cause the load to switch in sympathy see Fig 3 This would be perceived as unreliable or erratic behaviour e g the on off switch only works some of the time or the load seems to switch on or off on its own accord Fig 4 A switch debouncer which removes unwanted transitions from the signal TO TOGGLE CONTROL Fig 5 Using a minimum pulse width to ignore glitches Everyday Practical Electronics October 2002 Glitch Free In our reader s case there may or may not be problems depending on how clean the output from the receiver is If the switch on the transmitter is not debounced though it is possible that the receiver will faithfully replicate the switch bounce you will have to check this and debounce the switch at the transmitter if necessary The classic switch debounce circuit is shown in Fig 4 Note that in this arrange ment you n
2. Low Voltage Chaser Lights Mains Interface A selection of other Interface circuits The series will be of special interest to teachers responsible for technology education It will also be of great interest to any readers who wish to learn to program PICs with their own simple designs yet do not wish to learn PIC programming to the advanced level that more sophisticated designs require EVERYDAY PRACTICAL SU TUNING FORK AND METRONOME If music be the food of love play on fine but only if its well tuned and on beat This PIC based design can help you ensure that your serenades at least start off with the correct notes even if you do then play them in the wrong order The PIC accurately generates the seven basic tones of an octave any of which can be selected via a switch as can the octave It can output the selected tone to headphones or a speaker at a panel con trolled level It also compares its own tone with the frequency of an acoustically or electrically input note and indicates via an l e d how closely the two signals match Lots of flashing and you re way off no flashing and you re spot on The metronome mode is selected in place of the tuning fork and outputs a click track which can be set for different time signatures and with an accented down beat DON T MISS AN ISSUE PLACE YOUR ORDER NOW Demand is bound to be high NOVEMBER 2002 ISSUE ON S
3. TRAIN SOUNDS 4 selectable sounds whistle blowing level crossing bell clickety clack amp 4 in sequence SG01M 6 95 FACTOR PUBLICATIONS THE EXPERTS IN RARE amp UNUSUAL INFORMATION Full details of all X FACTOR PUBLICATIONS can be found in our catalogue N B Minimum order charge for reports and plans is 5 00 PLUS normal P amp P SUPER EAR LISTENING DEVICE Complete plans to build your own parabolic dish microphone Listen to distant voices and sounds through open windows and even walls Made from readily available parts R002 3 50 LOCKS How they work and how to pick them This fact filled report will teach you more about locks and the art of lock picking than many books we have seen at 4 times the price Packed with information and illustrations R008 3 50 RADIO amp TV JOKER PLANS We show you how to build three different circuits for disrupt ing TV picture and sound plus FM radio May upset your neighbours amp the authorities DISCRETION REQUIRED R017 3 50 INFINITY TRANSMITTER PLANS Complete plans for building the famous Infinity Transmitter Once installed on the target phone device acts like a room bug Just call the target phone amp activate the unit to hear all room sounds Great for home office security R019 3 50 THE ETHER BOX CALL INTERCEPTOR PLANS Grabs telephone calls out of thin air No need to wire in a phone bug Simply place this device near the phone lines to hear the
4. we regret Advertisement Offices EVERYDAY PRACTICAL ELECTRONICS ADVERTISEMENTS VOL 31 No 10 OCTOBER 2002 MILL LODGE MILL LANE THORPE LE SOKEN ESSEX C016 OED Phone Fax 01255 861161 HARD TO FIND We often receive phone calls from potential readers asking where they can get a copy of EPE both from UK customers and those abroad Basically EPE should be available from any newsagent almost anywhere in the world but generally speaking you will need to order a copy in advance either to be delivered to your home by the newspaper boy girl or shop saved for you In the UK most large newsagents will also have copies on their shelves but if they do not please don t be put off by the checkout person telling you it has not arrived is late at the printers or is no longer published Unfortunately it appears that a few staff members in stores will give a fob off reply rather than sort out the problem presumably because they don t have the time to help individ ual customers buying low priced items EPE is distributed in the UK by COMAG who deliver to every UK wholesaler and therefore copies are available to any UK newsagent supermarket garage convenience store etc EPE has not missed an issue or been late publishing in the last 20 years and we don t intend to start now PROBLEM Anyone who visits a large newsagents these days will realise the problem they have in stocking a wide range of magazines there are just so many
5. 18 99 SOLAR MOTORS Tiny motors which run quite happily on voltages from 3V 12V d c Works on our 6V amorphous Gin panels and you can run them from the sun 32mm dia 20mm thick 1 50 each MAMOD STEAM ENGINES and a full range of spare parts Check out www mamodspares co uk SUPER WIDEBAND RADAR DETECTOR Whistler 1630 Detects both radar and laser X K and KA bands speed cameras and all known speed detection systems 360 degree coverage front and rear waveguides 1 1in x 2 7in x 4 6in fits on visor or dash new low price 99 Ref WH1630 Other models available at www radargun co uk BUG DETECTORS A new detector at a sensible price Detects bugs hidden in rooms computers etc between 1 200MHZz adjustable sensitivity 9V PP3 battery required 29 95 Ref BDET2 GIANT WEATHER BALLOONS made by Totex we blew one up to 7ft diameter then it popped due to stones on the ground 13 99 Ref TOTEX BARNET CROSSBOWS We stock the entire range of crossbows check out our web site at www xbows co uk HOT AIR BALLOON KITS Everything you need to build a 1 7m high 4 5m in circum hot air balloon launch over a small burner or heater 12 49 Ref HA1 CROOKES RADIOMETER Fascinating glass bulb contains blades driven around by the sun 9 99 Ref SC120B GIANT TV OR PC VIEWING SCREEN Turn your TV into a super size screen converts small screens into a super size 26in 26 99 Ref SVGA2 RADIOSONDES Made by Valsala unused
6. 4 PHASE SHIFT RING A ring with three equal phase shifters Fig 18b is a neat means of generating a three phase signal But suppose you need some other number of phases Any number over two can be provided with one precau tion The total number of inverters in the ring must be odd If it is even there is over all d c positive feedback and the circuit latches up If you need an even number of phases you have to add one plain inverter with no associated phase shift components to keep the d c feedback negative One potentially useful arrangement is to have four shifts of 45 each This enables outputs to be selected at multiples of 45 notably 90 The necessary fifth inverter can be used as a gain adjustable stage to set the oscillation level The frequency is that at which R and C have equal impedances i e f 1 27CR The loop shift must be 180 For a 3 sec tion phase shift the average per section must be 60 for four sections 45 and so on It is also possible to generate outputs phased 90 apart with a 3 inverter ring Fig 19 Here two pairs of double RC net works each generate a 90 shift The fre quency is about 1 27RC PHASE SHIFTING In theory three or more RC or CR net works can be cascaded to give an overall phase shift of 180 A single inverting ampli fier can then maintain oscillation see Fig 20 These circuits are usually referred to as phase shift oscillators though of course
7. ELECTRONICS SERVICE MANUAL plus a FREE SUPPLEMENT Printed version only Road East Ferndown Dorset BH22 9ND l I enclose payment of 29 95 for one Manual or 49 90 for both Manuals saving 10 by We offer a 30 day MONEY BACK GUARANTEE I ordering both together plus postage if applicable on ESM see the panel above for details l i also require the appropriate ESM Supplements four times a year These are billed i I separately and can be discontinued at any time Please delete if not required POSTAGE CH ARG ES FOR ESM i i MEM CD ROM POST FREE TO ALL COUNTRIES i FUE NAME eiaa ere teres o E E A aE ores wy EE G ee wa ee ar Geer nee Ge a aE a ere oe Ger Note we use the VAT portion of the MEM CD ROM payment l PLEASE PRINT to pay for overseas postage l ADDRESS CRC Price PER ESM PRINTED MANUAL i Postal Region Surface Air l 2 nnu 2u 2 22 2n 2n nnn nunn nnn nnn nunnu nun nnn EnEn EnNEEmmE Mainland UK FREE l I Scottish Highlands l POSTCODE ss esse UK Islands amp Eire 7 each o l Europe EU 23 each j SIGNATURE 2220022466000 24 a a a a a a re aae ea a eTa Europe Non EU 23 each 30 each i ee USA amp Canada 28 each 39 each l _ enclose cheque PO in UK pounds payable to Wimborne Publishing Ltd Far East amp Australasia 35each 43each l _ Please charge my Visa Mastercard Amex Diners Club Switch Switch Issue No Rest of World 28 each 52each I I
8. tray of 25 relays for just 9 95 Ref SPEC1 VENNER TIME CONTROLS Designed to be wired in permanent ly they will switch up to 16A 240V a c motorised with dial and pins New and boxed 15 Ref VTS GYROSCOPES We still sell original 1917 design hours of fun for all the family complete with stand string box and info 6 Ref EP70 INNOVATIONS We also sell a wide range of innovative products for the home these are at www seemans com INVERTERS Convert 12V d c into 240V mains modified sine wave 300 watt 150 watt continuous 59 95 Ref VER3 600 watt model 330 watt continuous 79 95 Ref VER4 10 WATT SILICON SOLAR PANEL 10 year life waterproof 365mm x 365mm x 26mm 14V 10W 1 8kg framed 84 99 Ref PAN STICKY LABELS Small address labels etc are very useful and can be ordered online at www stickon co uk 2 WAY MIRROR KIT Contains enough material to make up to a 500mm x 2200mm mirror excl glass full instructions 19 95 Ref WF001 22 AIR RIFLE Under lever type powerful Chinese training rifle 38 26 Ref A1047 500 pellets 2 68 Ref A1091 22 AIR RIFLE STANDARD TYPE Chinese training rifle on legal limit for air rifles 29 75 Ref A1040 Pellets 2 68 Ref A1091 BULL ELECTRICAL UNIT D HENFIELD BUSINESS PARK HENFIELD SUSSEX BNS5 9SL TERMS CASH PO OR CHEQUE WITH ORDER PLUS 5 50 P amp P UK PLUS VAT 24 HOUR SERVICE 7 50 UK PLUS VAT OVERSEAS ORDERS AT COST PLUS 3 50 AC
9. ALL PRICES INCLUDE UK POST AND PACKING CD ROM prices include VAT and or postage to anywhere in the world ELECTRONIC MUSIC AND MIDI PROJECTS R A Penfold Whether you wish to save money boldly go where no musi cian has gone before rekindle the pioneering spirit or sim ply have fun building some electronic music gadgets the designs featured in this book should suit your needs The projects are all easy to build and some are so simple that even complete beginners at electronic project construction can tackle them with ease Stripboard layouts are provided for every project together with a wiring diagram The mechanical side of construction has largely been left to individual constructors to sort out simply because the vast majority of project builders prefer to do their own thing in this respect None of the designs requires the use of any test equip ment in order to get them set up properly Where any set ting up is required the procedures are very straightforward and they are described in detail Projects covered Simple MIIDI tester Message grabber Byte grabber THRU box MIDI auto switcher Auto manual switcher Manual switcher MIDI patchbay MIDI controlled switcher MIDI lead tester Program change pedal Improved program change pedal Basic mixer Stereo mixer Electronic swell pedal Metronome Analogue echo unit Order code PC116 10 95 124 pages THE INVENTOR OF STEREO THE LIFE AND WORKS OF ALAN DOWE
10. LED FLASHER 2 Similar to above but flash in sequence or randomly Ideal for model railways 3052MKT 5 95 INTRODUCTION TO PIC PROGRAMMING Learn programming from scratch Programming hardware a P16F84 chip and a two part practical hands on tutorial series are provided 3081KT 21 95 SERIAL PIC PROGRAMMER for all 8 18 28 40 pin DIP serial programmed PICs Shareware soft ware supplied limited to programming 256 bytes registration costs 14 95 3096KT 10 95 ATMEL 89Cx051 PROGRAMMER Simple to use yet powerful programmer for the Atmel 89C1051 89C2051 amp 89C4051 uC s Programmer does NOT require special software other than a terminal emulator program built into Windows Can be used with ANY computer operating sys tem 3121KT 24 95 3V 1 5V TO 9V BATTERY CONVERTER Replace expensive 9V batteries with economic 1 5V batter ies IC based circuit steps up 1 or 2 AA batteries to give 9V 18mA 3035KT 5 95 STABILISED POWER SUPPLY 3 30V 2 5A Ideal for hobbyist amp professional laboratory Very reliable amp versatile design at an extremely reason able price Short circuit protection Variable DC voltages 3 30V Rated output 2 5 Amps Large heatsink supplied You just supply a 24VAC 3A transformer PCB 55x112mm Mains operation 1007KT 16 95 ters can be received on an ordinary VHF FM radio between 88 108MHz Available in Kit Form KT or Assembled amp Tested AS TELEPHONE SURVEILLANCE MTTX
11. MINIATURE TELEPHONE TRANSMITTER Attaches anywhere to phone line Transmits only when phone is used Tune in your radio and hear both parties 300m range Uses line as aerial amp power source 20x45mm 3016KT 8 95 AS3016 14 95 TRI TELEPHONE RECORDING INTERFACE Automatically record all conversations Connects between phone line amp tape recorder not supplied Operates recorders with 1 5 12V battery systems Powered from line 50x33mm 3033KT 9 95 AS3033 18 95 TPA TELEPHONE PICK UP AMPLIFIER WIRELESS PHONE BUG Place pick up coil on the phone line or near phone earpiece and hear both sides of the conversation 3055KT 11 95 AS3055 20 95 HIGH POWER TRANSMITTERS 1 WATT FM TRANSMITTER Easy to construct Delivers a crisp clear signal Two stage circuit Kit includes microphone and requires a simple open dipole aerial 8 30VDC PCB 42x45mm 1009KT 12 95 4 WATT FM TRANSMITTER Comprises three RF stages and an audio preamplifier stage Piezoelectric microphone supplied or you can use a separate preampli fier circuit Antenna can be an open dipole or Ground Plane Ideal project for those who wish to get started in the fascinating world of FM broadcasting and want a good basic circuit to experiment with 12 18VDC PCB 44x146mm 1028KT 22 95 AS1028 34 95 15 WATT FM TRANSMITTER PRE ASSEMBLED amp TESTED Four transistor based stages with Philips BLY 88 in final stage 15 Watts RF power on the air 88 108MHz A
12. t half give a kick from their charged EHT capacitors even when the mains is unplugged Take care of electricity at any time folks ENVIRONMENTAL MONITORING Dear EPE I am not an electronic genius but I need one who knows the latest in remote camera and atmosphere surveillance I wonder if someone amongst your staff or readerhip would be familiar with the equipment I need for a research project in downtown Manhattan NYC USA The goal is to capture images and atmospheric data such as tempera ture humidity CO and CO levels over a period of two years that is before during and after the construction of a green roof I am looking for a remote system that could record images and atmospheric data to a desktop computer and then relay these by phone A 24 hour camera will be necessary but we will take say four shots and air samples per day and create a log that can give us valuable information over time The system will be installed on the roof of my building Images need to cover a space of Everyday Practical Electronics October 2002 1 700 square feet Computer server and phone line will sit in the elevator shack on the roof Green roofs is a roof surface where you plant greenery directly on the roof The water proofing and irrigation technologies required are widely used in Germany to improve human lifestyle and the environment We are the first private owners to employ such a system in New York and maybe n
13. 36 95 TELEBOX STL as ST but fitted with integral speaker 39 50 TELEBOX MB Multiband VHF UHF Cable Hyperband tuner 69 95 For overseas PAL versions state 5 5 or 6 mHz sound specification For cable hyperband signal reception Telebox MB should be con nected to a cable type service Shipping on all Telebox s code B State of the art PAL UK spec UHF TV tuner module with composite 1V pp video amp NICAM hi fi stereo sound outputs Micro electronics all on one small PCB only 73 x 160 x 52 mm enable full tuning control via a simple 3 wire link to an IBM pc type computer Supplied complete with simple working program and documentation Requires 12V amp 5V DC to operate BRAND NEW Order as MYO0 Only 39 95 code B See www distel co uk data_my00 htm for picture full details HARD DISK DRIVES 272 14 2 TOSHIBA MK1002MAV 1 1Gb laptop 12 5 mm H New 59 95 22 TOSHIBA MK4313MAT 4 3Gb laptop 8 2 mm H New 105 00 22 TOSHIBAMK6409MAV 6 1Gb laptop 12 7 mm H New 98 00 2 2 TOSHIBA MK1614GAV 18 Gb laptop 12 mm H New 149 95 2 to 3 2 conversion kit for Pc s complete with connectors 15 95 3 COMPAQ 313706 B21 IBM 9 gb ULT SCSI3 New 199 00 312 FUJI FK 309 26 20mb MFM I F RFE 59 95 32 CONNER CP3024 20 mb IDE I F or equiv RFE 59 95 32 CONNER CP3044 40 mb IDE I F or equiv RFE 69 00 3 2 QUANTUM 40S Prodri ve 42mb SCSI I F New RFE 49 00 5 MINISCRIBE 3425 20mb MFM I F or equiv RFE 4
14. 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 Logic Probe testing ELECTRONIC 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 amp multiples electricity electric circuits alternating circuits Passive Components resistors capacitors inductors transformers Semiconductors diodes transistors op amps logic gates Passive Circuits Active Circuits The Parts Gallery will help students to recognise common electronic components and their corresponding symbols in circuit diagrams Included in the Institutional Versions are multiple choice questions exam style questions fault finding virtual laboratories and investigations worksheets Circuit simulation screen ANALOGUE ELECTRONICS Analogue Electronics is a complete learning resource for this most difficult branch of electronics The
15. 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 FOR PICmicro Flowcode is a very high level language programming system for PlCmicro microcontrollers based on flowcharts Flowcode allows you to design and simulate complex robotics and control systems in a matter of minutes Flowcode is a powerful language that uses macros to facilitate the control of complex devices like 7 segment displays motor controllers and c d displays The use of macros allows you to control these electronic devices without getting bogged down in understanding the programming involved Flowcode produces MPASM code which is compatible with virtually all PlCmicro programmers When used in conjunction with the Version 2 development board this provides a seamless solution that allows you to program chips in minutes Requires no programming experience Allows complex PICmicro applications to be designed quickly Uses international standard flow chart symbols ISO5807 Full on screen simulation allows debugging and speeds up the development process Facilitates learning via a full suite of demonstration tutorials Produces ASM code for a range of 8 18 28 and 40 pin devices Institutional versions include virtual systems burglar alarms car parks etc Burglar Alarm Simulation PRICES Prices for each of the CD ROMs above are Orde
16. SELLING WELL BUT STILL AVAILABLE IT IS A DIGITAL MUL TITESTER complete with backrest to stand it and hands free test prod holder This tester measures d c volts up to 1 000 and a c volts up to 750 d c current up to 10A and resist ance up to 2 megs Also tests transistors and diodes and has an internal buzzer for con tinuity tests Comes complete with test prods battery and instructions Price 6 99 Order Ref 7P29 INSULATION TESTER WITH MULTIMETER Internally gener ates voltages which enable you to read insulation directly in megohms The multimeter has four ranges AC DC volts 3 ranges DC milliamps 3 ranges resistance and 5 amp range These instruments are ex British Telecom but in very good con dition tested and guaranteed OK probably cost at least 50 each yours for only 7 50 with leads carrying case 2 extra Order Ref 7 5P4 REPAIRABLE METERS We have some of the above testers but slightly faulty not working on all ranges should be repairable we supply diagram 3 Order Ref 3P176 BT TELEPHONE EXTENSION WIRE This is proper heavy duty cable for running around the skirting board when you want to make a permanent extension Four cores properly colour coded 25m length only 1 Order Ref 1067 HEAVY DUTY POT Rated at 25W this is 20 ohm resistance so it could be just right for speed controlling a d c motor or device or to control the output of a high current Price 1 Order Ref 1 33L1 1mA PANEL MET
17. The output signal from ICla flows via capacitors C3 and C9 to the Talk T pin of input output socket SK3 In addition some of this signal flows through preset potentiometer VR2 The sliding contact selects a fraction of this and passes it via capacitor C4 and resistor R6 to the inverting input pin 6 of IC1b The non inverting input pin 5 biasing arrange ments are the same as for ICla using fixed resistors R7 and R8 in conjunction with capacitor CS A further signal arrives at IC1b invert ing input from the Listen L pin of socket SK3 through capacitor C10 and resistor R9 This has been derived from the talk output of the remote unit Op amp section ICIb may be regarded as a mixer for the local and distant signals and since feedback resistor R10 is equal in value to input resistors R6 and R9 the gain 735 is unity actually 1 The level of the local own voice signal may be adjusted using preset VR2 VOLUME CONTROL The output of IC1b pin 7 is applied via capacitor C6 to the top end of the potential divider comprising fixed resistor R11 con nected in series with panel mounted poten tiometer VR3 A fraction of the signal is obtained from the sliding contact and applied to the input pin 2 of power ampli fier IC2 This device has been designed to allow an 8 ohm loudspeaker to be connected between its outputs pin 5 and pin 8 to develop one watt approximately Here headphones are used and since
18. The soft ware has been written to eliminate switch bounce problems The circuit is designed to operate from a 3V d c supply and no voltage regulation is required It must not be run at a voltage greater than 6V d c The PIC consumes very little current and since only one matrixed l e d is on at any one time the current consumption of the whole unit is only about 10mA Consequently the circuit can be powered by two series connected AA cells 1 5V each It can also be operated on a 2 5V supply so that rechargeable NiCad cells with their lower terminal voltage 1 2V could also be used The PIC can be run from a voltage as low as 2V although the l e d s will be far less bright RANDOMISING The game requires that random numbers are generated to determine the raider s next move This is achieved by using a register which counts continuously while the pro gram is running The counter is read when ever one of the cursor positioning switches is pressed Since this will occur at various time intervals depending on the player and 756 OF OFOFOPOPOCHOFOFOROROROFOFOFO O O O O O O X Ww V U r S R Q P 0 N M L K J H G F E D C B A board and Fig 5 above the option al switch board see text efo ogo Ole ofo ofo ofo gt pofo ofo pofo ojo ofo ofo ofo ofo ofo the fact that the count rate is very fast the actual count reached will to all intents be indeterm
19. This works in the same way as the code for the Visual BASIC version described in a pre vious Interface article The routine used for MSComm 1 reads single characters from the port converts each one to its ASCII value and then writes that value to Labell In the original program an If Then End If structure was used to check that the right OnComm event had occurred If the right event had occurred i e a new byte of Bae SRA re I OL 2 m Cai m l data had been received the port was read the conversion was made and data was written to the label With VBA the If Then End If struc ture is not quite the same and the origi nal routine just causes an error message when used with VBA In this case the rou tine can be reduced to a single line of code with no End If statement required at the end of the routine In fact it must be omitted or an error message will be produced The routine for the EXIT button simply closes communications with the serial port and closes the program The VBA version of the program works as well as the original Visual BASIC version and it can be seen working within VBA in Fig 3 Output The second VBA listing is for a simple serial transmission program The form is equipped with START and EXIT buttons as in the serial port reading program It also has a label but this time it is used to show the value generated by a scrollbar Fig 3 The serial reader program operating withi
20. This is actually not the first time a compa ny has tried to use a projected image for user control NCR of Dayton Ohio has previous ly suggested a projection system that saves drivers the effort of getting out of their cars or leaving the window open for too long when using a drive in bank Currently the driver needs to push a cash card into the machine and then enter a PIN and instruction codes A few years ago NCR proposed GB 2 350 457 a projector which is slung high on the forecourt to beam an image of the ATM key board down onto the windscreen The driver points at the key numbers and these move ments are tracked by an optical or infra red sensor mounted alongside the camera The sensed numbers are projected onto the wind screen with an OK button to point at The driver then only has to open the window or door quickly to grab the dispensed cash The same system could be used to order goods or food said NCR But there is no sign yet of a drive in service which works this way TRIP RECORDER THE LATEST Global Positioning System GPS and Automated Vehicle Location AVL technolo gies have been incorporat ed into a Trip Recorder manufactured by Directions Ltd The recorder is supplied with four different versions of mapping software Using its GPS module it saves its position at regular inter vals The position reports which include time data speed latitude and longi tude give you a comprehensive schedule o
21. Zero Power memory which greatly simplifies desgn For an excellent DIY practical article see the May issue of Everyday Practical Electronics magazine Ideal School College con struction project Supplied in good RFE condition complete with data sheet Less than 30 Only 29 95 or 4 99 00 of makers price Order RW44 Order PH26 THE AMAZING TELEBOX TV SOUND amp VIDEO TUNER CABLE COMPATIBLE _ a oS 2 Convers your colour monitor into a QUALITY COLOUR TV The TELEBOX is an attractive fully cased mains powered unit containing all electronics ready to plug into a host of video monitors or AV equipment which are fitted with a composite video or SCART input The composite video output will also plug directly into most video recorders allowing reception of TV channels not normally receivable on most television receivers TELE BOX MB Push button controls on the front panel allow reception of 8 fully tuneable off air UHF colour television channels TELEBOX MB covers virtu ally all television frequencies VHF and UHF including the HYPERBAND as used by most cable TV operators Ideal for desktop computer video sys tems amp PIP picture in picture setups For complete compatibility even for monitors without sound an integral 4 watt audio amplifier and low level Hi Fi audio output are provided as standard Brand new fully guaranteed TELEBOX ST for composite video input type monitors
22. bears comparison with some of the best For example the EE Buccaneer not now available was described at the time as outperforming almost any other design of its type the EPE Bounty by compari son exceeds its performance by around 40 per cent The following is the Bounty s response to a 25mm one inch diameter brass coin at varying distances with good tuning 160mm A singing tone 200mm A clear tone 240mm A barely discernible signal The EPE Bounty will detect a pin at 35mm and large non ferrous objects at half a metre s distance and more Note however that these measurements apply in air and not in the ground where depth of penetration will depend largely on the min eralisation present Contrasted with this it is far more reluc tant to pick up tin foil A tin foil disc of the same size as the brass coin is detected at only half the distance in air This rejection of tin foil is due in part to the metal detec tor s low frequency which avoids what is called skin effect Besides this if the two coils are positioned as described ferrous metals are to a very large extent rejected to such an extent in fact that a 25mm diameter brass coin looks the same to the detector as a lump of iron weighing twenty times as much Bounty s power consumption is conve niently low it draws around 10mA which means that it may potentially be powered off a small PP3 9V battery As it is it is p
23. board via the TB1 connector Referring to Fig 1 resistor R2 and diode D2 permit the correct use of the PIC s MCLR pin 1 both during and after programming The completed unit needs to be connect ed to a suitable serial port on the PC The cable should have a 9 pin male connector on one end for the unit and a suitable con nector for the PC s serial port on the other Fig 3a shows a cable schematic for a com puter having a 9 pin serial port connector For this cable the cable selector links on the p c b should be straight as in Fig 3b see earlier INSTALLING PC SOFTWARE The PC software has been written in Visual Basic 6 VB6 and should run on any recent Microsoft operating system including Windows 95 98 ME NT 4 0 2000 and XP The installation set consists of four files Setup exe which is the installation pro gram Setup lst which provides setup con trol parameters to the Setup exe plus ICTest1 cab and ICTest2 cab which con tain the actual Digital I C Tester program VB6 runtime files and i c model definition type number files Create a temporary new folder having any name of your choice e g C ICTester and copy the files into it Then run the Setup exe either by entering C ICTester Setup exe in the Windows run dialogue window or by double clicking on Setup exe in the File Explorer Once the setup has begun most users should be able to accept the default settings offered During the installation p
24. connector female p c b mounting SK3 24 pin universal ZIF socket see text TBI 4 way terminal pin strip turned pin socket strip 2 x 12 way see text TB2 TB3 Printed circuit board available from the EPE PCB Service code 371 p c b supports 4 off 40 pin d i l socket 16 pin d i l socket 4 off heatsink 21 C W for IC1 and mounting hardware solid insulat ed wire for jumper links solder etc Approx Cost Guidance Only 25 excl connectors 719 720 DIGITAL I C TESTER CIRCUIT BOARD SEE TEXT D1 La fe e e e fe e fe ae 4 3 214 C6 TE 6 05in 153 7mm d a E IC2 TP9 TP10 Sesceses gee Cd TP7 TP8 4 025in 102 2mm Fig 2 Printed circuit board component layout and full size copper foil master track pattern Everyday Practical Electronics October 2002 required These combinations cater for the majority of 14 16 and 20 pin packages Provision has been made on the p c b to accommodate an 8 way d i l switch bank for S1 if required instead of the 4 way using the unused holes seen below S1 on the p c b in Fig 2 The additional four ways can be hard wired to any combina tions wanted The p c b tracks located below the switch should make the setting up of these combinations easy CONSTRUCTION The Digital I C Tester is constructed on a single sided p c b whose component lay out and tracking details are shown
25. conversations taking place R025 3 00 CASH CREATOR BUSINESS REPORTS Need ideas for making some cash Well this could be just what you need You get 40 reports approx 800 pages on floppy disk that give you information on setting up different businesses You also get valuable reproduction and duplication rights so that you can sell the manuals as you like R030 7 50 700 PC CONTROLLED RELAY BOARD Convert any 286 upward PC into a dedicated auto matic controller to independently turn on off up to eight lights motors amp other devices around the home office laboratory or factory Each relay output is capable of switching 250VAC 4A A suite of DOS and Windows control programs are provided to gether with all components except box and PC cable 12VDC PCB 70x200mm 3074KT 31 95 2 CHANNEL UHF RELAY SWITCH Contains the same transmitter receiver pair as 30A15 below plus the components and PCB to control two 240VAC 10A relays also supplied Ultra bright LEDs used to indicate relay status 3082KT 27 95 TRANSMITTER RECEIVER PAIR 2 button keyfob style 300 375MHz Tx with 30m range Receiver encoder module with matched decoder IC Components must be built into a circuit like kit 3082 above 30A15 14 95 PIC 16C71 FOUR SERVO MOTOR DRIVER Simultaneously control up to 4 servo motors Software amp all components except servos control pots supplied 5VDC PCB 50x70mm 3102KT 15 95 UNIPOLAR STEPPER MOTOR DRIVER for
26. phase shifting is involved in all the oscilla tors we have just been discussing Phase shift oscillators may look neat but they have two major disadvantages which stem from the fact that the second RC section loads the first the third loads the second and so on This greatly increases the attenuation at f For a network with three cascaded RC or CR Magtrix Connectors and Electronics Send for leaflet Today Tel 01254 830761 Fax 01254 830408 Email sales magtrix co uk Website www magtrix co uk sections all with equal R and C the gain needed to sus tain oscillation is nearly 30 For a four section network it is nearly 20 A single inverter may not pro vide enough gain The second snag is a that it is no longer possible to pick off fo 0 39 CR outputs evenly spaced out in phase Also the voltage diminishes at each successive section A third problem is that the gain is not readily adjustable If however one inverter provides more than enough gain a reduc tion can be made by shunting off some of the current into a sec ond inverter Fig 21 which presents a load of RI and can be used as an output buffer This trick can be used with other oscilla tors For a three section RC network f 0 39 RC For a four section RC network f 0 19 RC Attenuation can be reduced by taper ing the networks Successive resistances are multiplied by a factor N and successive capacitances divided
27. punched for standard cage nuts A mains dis tribution panel internally mounted to the bottom rear provides 8 x IEC 3 pin Euro sockets and 1 x 13 amp 3 pin switched utility socket Overall ventila tion is provided by fully louvered back door and double skinned top section with top and side louvres The top panel may be removed for fitting of integral fans to the sub plate etc Other features include fitted castors and floor levelers prepunched utility panel at lower rear for cable connector access etc Supplied in excellent slightly used condition with keys Colour Royal blue some grey available CALL Can be supplied in many other configurations 33U 42U 47U Order as BC44 Order as DT20 Order as RV36 External dimensionsiExternal dimensions External dimensions mm 1625H x 635D xImm 2019H x 635D xImm 2019H x 635D x 603 W 64 H x 25 1603 W 79 5 H x 25 1603 W 88 H x 25 D x 23 W D x 23 W D x 23 W Only Only Only 245 345 410 COLOUR CCD CAMERAS DCE Undoubtedly a miracle of modern technology amp AS our special buying power A quality product fea turing a fully cased COLOUR CCD camera at a give away price Unit features full autolight sensing use in low light amp high light applications A 10 mm fixed focus wide angle lens gives excellent focus and resolution from close up to long range The composite video output will
28. while the other nibble defines the column Thus the location at column 1 row 1 is represented by the hexadecimal hex number OOh The raider s initial position is set at 23h as it will be in the third row down in the fourth column while the posi tions of the merchant ships are stored as numbers Olh 14h 26h 30h and 43h The cursor position is defined in the same way starting at 40h ROW COLUMN w i olo Of 0 0 o o 2 own o 0 1 Of 0 0 1 1 ets won o 0 o 1 1 4 1 1 928i Fig 2 Arrangement of the program registers which hold the ship positions and their status At least five cursor moves are required to reach the raider s initial position giving the enemy ship a chance to get away at the beginning of the game The position of the enemy ship is stored in a register called ENMY and the cursor position in one called AIM The status of the merchant ships i e sunk or afloat is stored in register MRCH as five bits These are set binary 00011111 at the start of the game and individually reset to zero as each ship is sunk These bits control the display so that a 0 in a particular position in this register prevents the L e d for that ship from turning on so that only the positions of the remaining merchant ships will be indicated When all five ships have been sunk the game is lost and from the relative position of the cursor and the last ship sunk the player will know how close he came to catchi
29. 19R19 THREE BOOKS The Mullard Uniles Handbook Practical Electronic Projects and Short Wave Receivers for Beginners Order Ref 400 SMITHS COOKER CLOCK Their Ref OCU9900 1 in its own metal case but without a face plate still in maker s packing Order Ref 2 17L7 SUPERIOR FERRITE ROD AERIAL This is an extra special Yzin diameter rod so the long and medium wave coils are extra robust Order Ref D203 DOLLS HOUSE SWITCH A very neat white body with red control tag Pack of 2 Order Ref 57 MAINS RELAY Plugs into octal base double pole changeover contacts which look OK for up to 10A Order Ref 7TOP 14 THERMAL DELAY SWITCH Length of delay depends upon the voltage applied to its heater coil which caus es the 10A contacts to open This again plugs into octal base Order Ref 7TOP15 TINY MAINS MOTOR This is only 2in square the shaded pole type with good length of in spindle Order Ref 7 1R7 COMPUTER DUST COVER Made for Altai these dust covers are a special opaque plastic measuring 22in long 14in wide and Gin deep nicely boxed Order Ref D204 PROJECT BOX Conventional plastic construction colour is beige and size approximately 250mm x 130mm x 50mm deep Divides into 2 halves held together by screws Ventilators in the top and bottom corners but these are quite a decoration and give the box a pleasing look Order Ref D201 LIMITED SPACE LIGHT SWITCH It is only about 2in x din brown Bakelite but rated a
30. Becker this article documents the process of run ning John s EPE Toolkit TK3 Oct Nov 01 PIC programming application under Windows XP and Windows 2000 2K Windows NT 2K and XP are often crit icised for not allowing applications direct access to the I O functionality This is due to them running the processor in Protected Mode unlike Windows 95 98 and ME which do not and for which TK3 was written It is worth noting that the process described here should hold true for any soft ware application that requires access to the computer s input output I O architecture XP BASICS With Windows XP to enable easier usability and command access to directo ries within the operating system s architec ture the first step is to obtain the Open Command Window Here functionality lay Campie fe DE Men Pie e en E um gt aas TE LOT Sa 1 The af ete i Fi Compete 2 ies seen ter Li di Sims En LF a ee E Se cas ar pen Eire sac t Leg aed anaty eid bn Pip eid tor County op pie ad Mal My Dore Pt ilin ee ta Chie Saati Fraertes Fig 1 Windows XP Open Command Window Here function ality screen 758 ae Local T A r es ewe CT Er j rooms gJ Shared Sener Hi This allows the user to utilise Windows Explorer to locate directories on the com puter and then open a command window similar to the old DOS prompt at a cho sen location see Fig 1 This func
31. C B WITH COMPONENT LAYOUT AND EXTRAS e L C D BREADBOARD AND PIC CHIP INCLUDED e ALL TOP QUALITY COMPONENTS AND SOFTWARE SUPPLIED KIT 880 34 99 with 16F84 39 99 with 16F877 PIC TOOLKIT V2 SUPER UPGRADE FROM V1 e 18 28 AND 40 PIN CHIPS READ WRITE ASSEMBLE amp DISASSEMBLE PICS SIMPLE POWER SUPPLY OPTIONS 5V 20V ALL SWITCHING UNDER SOFTWARE CONTROL MAGENTA DESIGNED PCB HAS TERMINAL PINS AND OSCILLATOR CONNECTIONS FOR ALL CHIPS e INCLUDES SOFTWARE AND PIC CHIP 29 99 with 16F877 KIT 878 22 99 with 16F84 EPE PIC Tutorial At last A Real Practical Hands On Series e Learn Programming from scratch using PIC16F84 e Start by lighting l e d s and do 30 tutorials to Sound Generation Data Display and a Securit System e PIC TUTOR Board with Switches I e d s and on board programmer PIC TUTOR BOARD KIT Includes PIC16F84 Chip TOP Quality PCB printed with Component Layout and all components not ZIF Socket or Displays Included with the Magenta Kit is a disk with Test and Demonstration routines KIT 870 27 95 Built amp Tested 42 95 Optional Power Supply 3 99 ZIF Socket 9 99 LCD Display 7 99 LED Display Reprints Mar Apr May 98 3 00 set 3 SUPER PIC PROGRAMMER e READS PROGRAMS AND VERIFIES e WINDOWS SOFTWARE e PIC16C6X 7X AND 8X e USES ANY PC PARALLEL PORT e USES STANDARD MICROCHIP HEX FILES e OPTIONAL DISASSEMBLER SOFTWARE EXTRA e
32. C8 E Comms Error von a Test Everyday Practical Electronics October 2002 are used by C2 s internal circuitry to con vert the supplied voltage from 5V to 12V Connection to the PC is via a 9 pin female D type connector SK2 To test the functionality of a digital logic i c a known set of logic levels must be presented on each pin and the resulting responses received back from the i c then analysed VO PINS The PICI6F877 has a total of 33 I O input output pins Of these 24 are used to connect the PIC to the i c under test Each of the 24 I O pins is connected to a pin on the i c test socket SK3 via a 100Q2 resistor within resistor modules RMI to RM3 These resistors act as current lim iters to protect the PIC and the device under test The danger is that an output of the test 1 c could become connected to a PIC I O pin also designated as an output Each pin on the i c test socket is biassed to the 5V test power rail via a 4k7Q resis tor within resistor modules RM4 to RM6 This is to force unused pins on the test socket to a known logic level and also enables open collector TTL 1 c s that have their outputs either floating or pulled to ground to be tested During the test cycle the PIC sends a low logic level to the base of transistor 717 Q TP1 OSC1 CLKIN O PSP7 RD7 PSP6 RD6 PSP5 RD5 PSP4 RD4 RX DT RC7 TX CK RC6 SDO RC5 NC SDI SD
33. PIC Big Digit Display e Simple Audio Circuits 1 Freezer Alarm Washing Ready Indicator FEATURES e Teach In 2002 Part 7 Ingenuity Unlimited Practically Speaking e New Technology Update e Circuit Surgery e Net Work The Internet Page HESE BACK ISSUES JUNE 02 PROJECTS Biopic Heartbeat Monitor Frequency Standard Generator Simple Audio Circuits 2 e World Lamp FEATURES e Teach In 2002 Part 8 Interface New Technology Update e Circuit Surgery Ingenuity Unlimited Net Work The Internet Page JULY 02 PROJECTS e EPE StyloPIC e Infra Red Autoswitch Simple Audio Circuits 3 e Rotary Combination Lock FEATURES e Teach In 2002 Part 9 Practically Speaking Using The PIC s PCLATH Command Ingenuity Unlimited Circuit Surgery New Technology Update Net Work The Internet Page PROJECTS e PIC World Clock Pickpocket Alarm e Big Ears Buggy Simple Audio Circuits 4 FEATURES Teach In 2002 Part 10 Using Square Roots with PICs Ingenuity Unlimited e Evolutionary Electronics Interface Circuit Surgery Net Work The Internet Page SEPT 02 PROJECTS e Freebird Glider Control e Portable Telephone Tester e EPE Morse Code Reader Vinyl to CD Preamplifier FEATURES e Circuit Surgery New Technology Update Practically Speaking Net Work e Flowcode for PlCmicro Logic Gate Inverter Oscillators e Net Work The Internet Pa
34. S1 This switch allows a GND OV connection to be made to pin 12 of the test socket and a 5V connection to be made to pins 19 20 and 22 as Everyday Practical Electronics October 2002 IC2 MAX232 C2 C2 OV PATCH PIN 1122 O SERIAL CABLE LINKS SEE TEXT SK2 TP7 TP8 T1 IN T1 OUT e T2 IN T2 OUT ee TP9 TP10 R1 OUT R1 IN O oO R2 OUT R2 IN COMPONENTS Resistors See R1 R6 R7 4702 3 off S O D R2 1k TALK R3 4k7 page R4 R5 2k2 2 off RM1 to RM3 1002 8 x individual resistors d i l module 3 off RM4 to RM6 4k7 8 x commoned resistors s i l module 3 off All 0 25W 5 carbon film or better except RM1 to RM6 Capacitors C1 C4 220u radial elect 25V 2 off C2 C3 C11 100n ceramic disc 5mm pitch 3 off C5 to C8 1u radial elect 50V 4 off 10p ceramic disc 5mm pitch 2 off C12 10u radial elect 16V C9 C10 Semiconductors REC1 bridge rectifier 50V 1A D1 D3 green l e d 3mm 2 off D2 1N4148 signal diode D4 red l e d 3mm TR1 BC213 pnp transistor or similar IC1 7805 5V 1A voltage regulator IC2 MAX232 RS232 line driver IC3 PIC16F877 20P microcontroller preprogrammed see text Miscellaneous X1 20MHz crystal S1 4 way S p s t d i l switch p c b mounting see text Everyday Practical Electronics October 2002 O0O000000 0 1 Gr E D SK1 power connector see text SK2 9 way D type sub min
35. SE nu HA TT PIC Training amp Development System The best place to start learning about microcontrollers is the PIC16F84 This is easy to understand and very popular with construction projects Then continue on using the more sophisticated PIC16F877 family The heart of our system is a real book which lies open on your desk while you use your computer to type in the programme and control the hardware Start with four very simple programmes Run the simulator to see how they work Test them with real hardware Follow on with a little theory Our complete PIC training and development system consists of our universal mid range PIC programmer a 306 page book covering the PIC16F84 a 262 page book introducing the PIC16F877 family and a suite of programmes to run on a PC The module is an advanced design using a 28 pin PIC16F872 to handle the timing programming and voltage switching requirements The module has two ZIF sockets and an 8 pin socket which between them allow most mid range 8 18 28 and 40 pin PICs to be programmed The plugboard is wired with a 5 volt supply The software is an integrated system comprising a text editor assembler disassembler simulator and programming software The programming is performed at normal 5 volts and then verified with plus and minus 10 applied to ensure that the device is programmed with a good margin and not poised on the edge of failure Requires two PP3 batteries which are not suppli
36. Step is useful if for example you want to probe around the i c under test AWVUTSROPONM wo 000000000000 ABCDE FGHIJKL Lx O Photo 6 Pin connections dialogue screen Everyday Practical Electronics October 2002 with an oscilloscope or logic probe Every time a pattern is sent to the test i c the PC software will display a message box asking you to press the lt CR gt lt ENTER gt key before it moves onto the next step The Test Statistics panel shows how many test cycles have been made 0 to 999 the current sequence or pattern num ber being executed as specified in the device profile file and how many test cycles the device has passed or failed TEST PROCEDURE When ready click the Start button Because this is the first time you have test ed an i c with this power pin configuration a dialogue box is displayed see Photo 6 The picture shows how to correctly apply power to the i c under test Also it shows you how the 1 c should be inserted in the socket Notice that in this case no power patch wires are required as this i c package is supported by the on board d i l switches So set d 1 1 switches S1 3 and S1 4 to the ON position as indicated Press OK to start the test All being well after a couple of seconds you should have a display similar to that in Photo 7 Select Window from the top menu and then Tile Vertically to get the software to arrange everything neat
37. The next group allows the information display colours to be changed Clicking any of the coloured panels brings up the colour picker dialogue The Paths groups allows the default location of the Data Models i c types storage path to be specified Clicking the ellipsis button on the right the one with allows you to explore the avail able disk drives and folders and locate the location of the data model files The settings groups allow some display options and the DIP switch type and usage to be specified The Show Tool Bar and Show Status Bar options allow the Tool and Status bars to be shown or hidden which is useful if screen real estate is scarce In some cases the software attempts to gain the user s attention by flashing mes sages on the screen The option Allow Flashing Text controls whether these mes sages flash or are static The option Always Warn About Test IC Power Pin Configuration controls how the software warns the operator about the power pin configuration of the i c under test If On the software always issues a warning If Off the software only issues a warning when either the first 1 c of the session is to be tested or a new i c type has been select ed that has a different power configuration from the previous type tested The DIP Type options control the look of the graphic used for showing the d i l switch settings Select the type that best matches your d i l switch type The switch ban
38. WITH DEMO PROGRAM SOFTWARE DISK PCB INSTRUCTIONS AND 16 CHARAC TER 2 LINE LCD DISPLAY Now features full 4 channel chaser software on DISK and pre programmed PIC16F84 chip Easily re programmed for your own applica tions Software source code is fully commented so that it can be followed easily LOTS OF OTHER APPLICATIONS PIC Real Time In Circuit Emulator Icebreaker uses PIC16F877 in circuit debugger Links to Standard PC Serial Port lead supplied Windows 95 Software included Works with MPASM and MPLAB Microchip software 16 x 2L C D Breadboard Relay I O devices and patch leads supplied As featured in March 00 EPE Ideal for beginners AND advanced users Programs can be written assembled downloaded into the microcontroller and run at full speed up to 20MHz or one step at a time Full emulation means that all I O ports respond exactly and immediately reading and driving external hardware Features include Reset Halt on external pulse Set Breakpoint Examine and Change registers EEPROM and program memory Load program Single Step with display of Status W register Program counter and user selected Watch Window registers KIT 900 34 99 POWER SUPPLY 3 99 STEPPING MOTOR 5 99 Fax 01283 546932 Tel 01283 565435 Everyday Practical Electronics October 2002 EPE PIC TOOLKIT 3 e THE LATEST TOOLKIT BOARD 8 18 28 AND 40 PIN CHIPS e MAGENTA DESIGNED P
39. Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 Web sites www radiobygones co uk www radiobygones com 745 INTER CE Robert Penfold Adding MSCOMM Active X control to your PC TE two previous Interface articles were devoted to the use of the MSCOMM ActiveX control to permit serial communi cations with Visual BASIC programs The advantage of this method is that it will work with any 32 bit Windows operating system including Windows XP without the need for any third party add ons The main drawbacks are that this con trol is not included with anything less than the Visual BASIC Professional Edition and it is something less than straightforward in use MSCOMM and VBA Software topics usually pro duce a certain amount of feed back from readers and the pieces on MSCOMM are cer tainly no exceptions A few readers pointed out that this control is included with Microsoft Word and Excel as part of VBA Visual BASIC for Applications On checking two PCs that had Microsoft Office installed but had never been loaded with Visual BASIC Profes sional one had MSCOMM and the other did not VBA is not only included with Microsoft applications it is also provided with some soft ware from Corel Autodesk etc However VBA is not always installed when the Typical option is chosen dur ing installation It is sometimes necessary to return to t
40. _ Twin TDA2003 Boards can only be supplied on a payment with order basis World Lamp JUNE 02 RE ee Input Impedance Preamplifiers Single Trans Canute Tide Predictor JUNE 00 Low Noise Preamplifier Dual Trans PIC Gen Frequency Generator Counter JULY 00 268 5 07 Tone Control Q Meter 269 4 36 Bandpass Filter EPE Moodloop AUG 00 271 5 47 Frequency Standard Generator Receiver Quiz Game Indicator 272 4 52 Digital Handy Amp 273 4 52 X Biopic Heartbeat Monitor Active Ferrite Loop Aerial SEPT 00 274 4 67 Simple Audio Circuits 3 JULY 02 Remote Control IR Decoder Software only Dual Output Power Supply x PIC Dual Channel Virtual Scope OCT 00 5 15 Crossover Audio Filter Handclap Switch NOV 00 270 3 96 Infra Red Autoswitch X PIC Pulsometer Software only XEPE StyloPIC l Twinkling Star DEC 00 Rotary Combination Lock Main Board g Interface Board Festive Fader i Mot rists BuzzBox x Using the PIC s PCLATH Command Software onl P ICtogram Big Ears Buggy AUG 02 amp PIC Monitored Dual PSU 1 PSU amp PIC World Clock Monitor Unit Simple Audio Circuits 4 Static Field Detector Multi project PCB Freq ae Two Way Intercom JAN 01 Resonance Detector UFO Detector and Event Recorder Vinyl To CD Preamplifier SEPT 02 366 Magnetic Anomaly Detector x Freebird Glider Control 367 Event Recorder Morse Code Reader 368 Audio Alarm Headset Communicator
41. afo YO OOOO OO0O000000 00 070 O O O O O OO000000f000000 O O O O O O 0_0_Q O O O OOOO COMPONENTS Resistors R1 R2 2k2 2 off See R3to R9 47Q 7 off S OD R10 to R17 10k 8 off TALK R18 4k7 All 0 25W 5 carbon film page Capacitor C1 22p ceramic disc Semiconductors TR1 to TR5 BC558 pnp transistor or similar IC1 PIC16C54 microcontroller preprogrammed see text SE1110 5 x 7 matrixed l e d display row anode see text Miscellaneous S1 to S5 min push to make switch p c b or panel mounting see text 5 off S6 min s p s t toggle switch Stripboard 24 holes x 24 strips strip board 17 holes x 15 strips optional see text plastic case to suit see text battery holder connector for 2 x AA bat teries connecting wire solder etc 15 excluding battery Approx Cost Guidance Only counter RND and the program then pro ceeds as appropriate to the decoded value to move the enemy one square down right left or up or to exit the routine without change Adding or subtracting 10h or Olh from the current contents of the ENMY register does this and a software check is also made to ensure that the ship does not move out of the displayed area Everyday Practical Electronics October 2002 Thus if the enemy is at position 16h and Olh move right is added the result will be position 17h which is off the screen This is detected and Olh is subtra
42. any 5 6 8 lead motor Fast slow amp single step rates Direction control amp on off switch Wave 2 phase amp half wave step modes 4 LED indicators PCB 50x65mm 3109KT 14 95 PC CONTROLLED STEPPER MOTOR DRIVER Control two unipolar stepper motors 3A max each via PC printer port Wave 2 phase amp half wave step modes Software accepts 4 digital inputs from exter nal switches amp will single step motors PCB fits in D shell case provided 3113KT 17 95 12 BIT PC DATA ACQUISITION CONTROL UNIT Similar to kit 3093 above but uses a 12 bit Analogue to Digital Converter ADC with internal analogue multiplexor Reads 8 single ended channels or 4 dif ferential inputs or a mixture of both Analogue inputs read 0 4V Four TTL CMOS compatible digital input outputs ADC conversion time lt 10uS Software C QB amp Win extended D shell case amp all compo nents except sensors amp cable provided 3118KT 52 95 LIQUID LEVEL SENSOR RAIN ALARM Will indi cate fluid levels or simply the presence of fluid Relay output to control a pump to add remove water when it reaches a certain level 1080KT 5 95 AM RADIO KIT 1 Tuned Radio Frequency front end single chip AM radio IC amp 2 stages of audio amplification All components inc speaker provid ed PCB 32x102mm 3063KT 10 95 DRILL SPEED CONTROLLER Adjust the speed of your electric drill according to the job at hand Suitable for 240V AC mains powered drills up
43. been tested and some experimentation may be needed to obtain correct operation 139 STORE YOUR BACK ISSUES ON MINI CD ROMS A great way to buy EPE Back Issues our mini CD ROMs contain back issues from our EPE Online website plus bonus articles all the relevant PIC software and web links Note no free gifts are included All this for just 12 45 each including postage and packing VOL 1 CONTENTS BACK ISSUES November 1998 to June 1999 all the projects features news Us etc from all eight issues Note No advertise ments are included PIC PROJECT CODES All the available codes for the PIC based projects published in these issues VOL 2 CONTENTS BACK ISSUES July 1999 to December 1999 all the projects features news lUs etc from all six issues Note No advertisements are included PIC PROJECT CODES All the available codes for the PIC based projects published in these issues VOL 3 CONTENTS BACK ISSUES January 2000 to June 2000 all the projects features news Us etc from all six issues PIC PROJECT CODES All the available codes for the PIC based projects published in these issues VOL 4 CONTENTS BACK ISSUES July 2000 to Dec 2000 all the projects features news lUs etc from all six issues PROJECT CODES All the available codes for the programmable projects in these issues VOL 5 CONTENTS BACK ISSUES January 2001 to June 2001 all the projects features news
44. by switching it off briefly NOT SUCH EASY PICKINGS Although all the cards appear to be stacked in favour of the PIC the raider is just as much in the dark about the position of the merchant ships as the player is about the position of the enemy The PIC has no strategy other than to randomly move about the sea looking for ships even to the extent of crossing and re crossing the same squares If a ship is encountered then it will be sunk but as in war that is a matter of luck Since the PIC has no memory of previous games or indeed even of its last move there is no point in making the positions of the merchant ships variable or changing COLUMN X5 COLUMN x6 Fig 1 How the ships are positioned The enemy battleship at the centre of the display is unseen The circle represents your battleship and is a moveable flashing l e d Everyday Practical Electronics October 2002 3V S6 O SEE TEXT VE MCLR ao RA4 IC1 PIC16F84 Fig 3 Complete circuit diagram for the PIC Pocket Battleships game their position between or during games These are therefore fixed by the program as is the raider s initial position The sea is divided into squares each indicated by an l e d with the columns numbered 0 to 6 while the rows are numbered as 0 to 4 as shown in Fig 1 Each position is defined by one byte shown in Fig 2 where the most significant nibble highest four bits defines the row
45. by N As N is made very large the 3 section attenuation factor falls towards eight and the 4 section towards four Making N 10 achieves most of the improvement and even N 2 is worthwhile The RC network discriminates against harmonics and even if the input to a multi section network is a square wave the output is a fairly pure sine wave However it occurs at a high impedance point and can only be used if picked off by a very high impedance buffer This adds its own quota of distortion FORMIDABLE Phase shift oscillators are fascinating circuits which over their long history fo 0 13 CR b Everyday Practical Electronics October 2002 Radio bygones The leading magazine for vintage radio enthusiasts 11 Fig 20 Phase shift oscillators a Three section RC b Four section RC they go well back into the valve era have elicited from circuit analysts some formidable feats of mathematics But if you need a low distortion oscillator you will be well advised to leave them alone and stick to Wien or dual integrator circuits Whilst we have concentrated on the use of basic CMOS inverter gates the princi ples can equally well be applied through the use of dual input inverting gates such as NAND and NOR Fig 21 Gain adjustment circuit R1 acts as a load on A1 The magazine is published six times a year and is available by postal subscription It is not available at newsagents RADIO BYGONES
46. case of sudden loud clicks and other nois es Satisfy yourself on this point before putting it on Connect the battery and note that the On l e d operates If acoustic feedback is evi dent which should not occur when the headphones are worn adjust Volume con trol VR3 Listen to the headphones and speak into the microphone If you can hear your voice clearly the circuit is working If it is obvi ous that the microphone gain is too small quiet sound even with VRI VR2 VR3 set to maximum reduce the value of resistor R2 to 560 ohms after switching off and removing the i c s Repeat all this with the other circuit boards then observing the anti static pre cautions mentioned earlier remove the 1 c s from their sockets and replace them in their anti static packaging De solder the jack sockets potentiometer and positive battery connector lead Connect a piece of strand ed wire to the 6V p c b point instead O g 28 Ae a Ry C3 a ci later Completed prototype circuit board Everyday Practical Electronics October 2002 157 MASTER BOX The sloping front aluminium instrument case used for the prototype Master unit gives a professional appearance see photographs There is an advantage in using a box that is of part plastic construc tion This is because a case made entirely of metal will need additional insulation on the Phones output socket Find the best positions for the switches panel potent
47. fidently tackle servicing of most electronic projects Order code BP239 4 49 DIGITAL GATES AND FLIP FLOPS lan R Sinclair This book intended for enthusiasts students and techni cians seeks to establish a firm foundation in digital elec tronics by treating the topics of gates and flip flops thor oughly and from the beginning Topics such as Boolean algebra and Karnaugh map ping are explained demonstrated and used extensively and more attention is paid to the subject of synchronous counters than to the simple but less important ripple counters No background other than a basic knowledge of elec tronics is assumed and the more theoretical topics are explained from the beginning as also are many working practices The book concludes with an explanation of microprocessor techniques as applied to digital logic Order code PC106 9 95 96 pages 200 pages Music Audio and Video QUICK GUIDE TO ANALOGUE SYNTHESIS lan Waugh Even though music production has moved into the digi tal domain modern synthesisers invariably use ana logue synthesis techniques The reason is simple analogue synthesis is flexible and versatile and it s rel atively easy for us to understand The basics are the same for all analogue synths and you ll quickly be able to adapt the principles to any instrument to edit exist ing sounds and create exciting new ones This book describes How analogue synthesis works The essen tial module
48. has completed right click on the new shortcut and select Properties Then click on Change Icon click OK to accept the message stating that the cur rent target contains no icon information and in the Change Icon window click the browse button Now browse to the installa tion directory and select the tk3prog exe file as the icon source then select the only graphic offered within that file and click OK You should now have a correct looking icon on your Desktop that will successful ly run TK3 LC 759 FREE Electronics Hobbyist Compendium book with Teach In 2000 CD ROM t Teach in EPE TEACH IN 2000 CD ROM The whole of the 12 part Teach In 2000 series by John Becker published in EPE Nov 99 to Oct 2000 is now available on CD ROM Plus the Teach In 2000 interac tive software covering all aspects of the series and Alan Winstanley s Basic Soldering Guide including illustrations and Desoldering Teach In 2000 covers all the basic principles of elec tronics from Ohm s Law to Displays including Op Amps Logic Gates etc Each part has its own section on the inter active software where you can also change component values in the various on screen demonstration circuits The series gives a hands on approach to electronics with numerous breadboard circuits to try out plus a sim ple computer interface which allows a PC to be used as a basic oscilloscope ONLY 12 45 including VAT and p amp p Order code Teach I
49. huge range of topics from valve and tube technology and the application of cathode ray tubes to radar to digital tape systems and optical recording techniques Since Foundations of Wireless was first published over 60 years ago it has helped many thousands of readers to become familiar with the principles of radio and electronics The original author Sowerby was succeeded by Scroggie in the 1940s whose name became synonymous with this classic primer for practitioners and students alike Stan Amos one of the fathers of modern electronics and the author of many well known books in the area took over the revision of this book in the 1980s and it is he with his son who have produced this latest version 400 pages Order code NE27 21 99 GETTING THE MOST FROM YOUR MULTIMETER R A Penfold This book is primarily aimed at beginners and those of limited experience of electronics Chapter 1 covers the basics of 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 resis tors capacitors and diodes Circuit testing is covered in Chapter 3 with subjects such as voltage current and continuity checks being discussed In the main little or no previous knowledge or experi ence is assumed Using these simple component and cir cuit testing techniques the reader should be able to con
50. i e location 40h one of the ships there would be sunk In this way some of the player s ships could be sunk before they even left port In this version the port l e d could remain illuminated to inform the player that new ships were still available ENEMY HOME PORT The idea of a home port could also be easily extended to a base for the enemy location 06h for example Here if the enemy returned to port the player would loose the game so that as well as trying to protect his ships the player would be forced to patrol near the enemy base to prevent the raider from returning home This option could appear only after all of the merchant ships had been sunk and here the movement options of the raider could be limited to move up move right or stay still so that it would naturally tend to head for its base at the top right hand corner of the display when no more merchant ships remain afloat Modifications to the software to develop other scenarios to make the game harder would form an excellent basis for a science project to give budding programmers an Opportunity to exercise their programming skills 157 Special Feature USING TKS WINDOWS AND 2000 MARK JONES Li F TEJ EPE ME amp Ph EL PIGNAN HIHE PONLE In answer to readers queries how to get EPE Toolkit TK3 operating under these other systems OLLOWING a number of posts on the EPE Chat Zone and some further correspondence with John
51. load a profile file that relates to the specified type This file contains details about the number of pins on the i c which pins are inputs and outputs have no internal connection and which are its power pins The profile also contains detailed instruc tions on how to test the i c From the pro gram s main menu select File and then Load IC Profile After a few moments a list of the available profiles should be displayed in the right hand panel see Photo 3 If the panel is empty then you will need to tell the software where the Datasheets folder is located The default is c Program Files ICTester DataSheets The left hand panel allows you to browse your computer s drives and folders until you locate the Datasheets folder u j cs Photo 3 Selection screen for i c types Scroll down the list of available profiles and select 7400 You can double click to load or click once and then click the Load button The Profile Directory window should now disappear and you will see just the main application window On the status bar at the bottom though you should now see some additional information such as that in Photo 4 7400 Coe 1 615200 Eau Photo 4 Status bar TESTING OPTIONS To start the testing process select IC Test from the top menu and then select Test Specified IC window similar to that in Photo 5 will be displayed Quad input HAND Hodal Lam e ic x _ aan Stun l
52. metal fittings or fastenings on the search head Before bolting the shaft to the control box feed the audio cable through it then bolt it to the side of the control box Bolt the shorter length of p v c conduit to the other side of the control box and push the 90 degree angle bend onto its bottom end Attach the audio cables from the search coils to the p c b as shown see Fig 3 with the screen of both audio cables again going to OV Finally insert IC1 and C2 in the d i l sockets ICI is static sensitive discharge your body to earth before handling TH SETTING THE COILS The one downside to any I B metal detector design is its need for two coils which must be very carefully and rigidly positioned in relation to one another The present design does make some room for error though not much Nonetheless the method of setting the two search coils is simple enough if one works patiently and carefully A completed p c b is required before we can pot the coils The coils should be potted with clear polyester resin on a hard non metallic base do not buy polyester resin filler Any base will do on condition that it is rigid The author used a piece of white masonite see Fig 3 and glued a border of 5mm wood dowelling around the perimeter to hold the resin The potted coil was left raw beneath the masonite protected by the resin Begin by placing the coils directly on top of one another ensuring th
53. not insert IC2 and IC3 or connect the tester to the PC until preliminary checks have been completed If the board is to be used as is i e with out a case attaching small stick on rubber feet to each corner is a wise precaution If the intention is to house it in a suitable case a 24 pin wire wrap type socket can be used for SK3 as this will provide ade quate clearance between the components on the p c b and the case lid The ZIF sock et can then be plugged into the wire wrap socket A similar arrangement can be used for mounting d 1 1 switch S1 No provision for a power socket was made on the p c b due to the different types of power connectors currently in use Instead two terminal pins can be fitted and then an appropriate power socket for the chosen power supply soldered directly to these as in the prototype Note that there are three holes located around IC1 that are not used These points enable power to be tapped off for use with other circuits if desired There are four terminal pins TP3 to TP6 located to the left of IC3 Ignore pins TP3 and TPS The TP4 TP6 pair control the RS232 interface rate With the default PIC firmware and 20MHz crystal connect ing TP4 to TP6 selects an interface speed of 57 6K baud Without this link 19 2K baud is used A plug in jumper link was used on the prototype FIRST TESTS Once construction is completed re check that all components have been oriented correctly an
54. of a random crackling sound No further amplification is required and since capacitor C6 blocks r FINE TUNE TUNE Everyday Practical Electronics October 2002 216 CF401008 d c virtually any kind of earpiece sounder or loudspeaker may be used to make the signal heard SEARCH COILS The winding of the two search coils is relatively easy and is not critical a little give and take is permissible Both the coils are identical The full coil winding and construction details are shown in Fig 3 Use 33s w g about 0 26mm enamelled copper wire winding 100 turns on a 150mm dia former see Fig 3 You may create the former with a sheet of stiff card board with twelve pins stuck through it at a suitable angle the heads facing slightly outwards The coil should be wound clockwise around the pins then temporar ily held together with stubs of insulating tape passed underneath and pressed together over the top The coil may be jumble wound Once this has been done the pins are removed and a second coil is wound in exactly the same way In each case mark the beginning and end wires Label one coil Tx transmitter the other Rx receiv er Each coil is then tightly bound by winding insulating tape around its entire circumference FARADAY SHIELD Next each coil needs a Faraday shield This minimises ground and capacitive IC1d HOF40 1058 a 10 Si WO PEIZO SOUNDER 709 effects electros
55. of robotics from the control systems used the transducers available motors actuators and the circuits to drive them Full 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 calculations are explained Clear circuit simulations PRICES Hobbyist Student ss 45 inc VAT _ _ Institutional Schools HE FE Industry 99 plus VAT Prices for each of the CD ROMs above are Institutional 10 user Network Licence 199 plus VAT Order form on third page She Licence as 499 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices PlCmicro TUTORIALS AND PROGRAMMING VERSION 2 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 PICmicro microcontrollers as well as program a range of 8 18 28 and 40 pin devices For experienced programmers all programming software is included in the PPP utility that comes with the development board For those who want to lear
56. of them At the present time there are over 3 000 different newsstand magazines being published in the UK and virtually no single store can display them all simply because they do not have the space Also around 80 of the revenue that retailers receive from sales comes from around 30 of the different magazines so in financial terms it s only really worth stocking around 1 000 different magazines the top 1 000 in terms of revenue EPE presently ranks at number 919 in revenue terms and outsells our nearest competitor by around 80 on the UK newsstands Of course even 1 000 different magazines take up a large display area and most stores cannot hope to carry so many different titles For instance our sister magazine Radio Bygones see the Supplement in this issue cannot get into the retail supply chain and is only available on subscrip tion so it is not even counted as one of the 3 000 magazines SOLUTION If you cannot get hold of a regular copy of EPE then there are a couple of solutions the cheap est is to download issues from our EPE Online web site which has now been operating for four years Go to www epemag com pay by credit card 9 99 US for 12 issues around 7 and down load the magazine within a few minutes The other solution is to pay for a subscription By ordering 12 issues in advance you will save 49p an issue the equivalent of two free issues every year and if you order for two or three years you can save
57. oscillates at an audio frequency determined by resistor R1 and capacitor Cl while resistor R2 limits Fig 2 EPE Bounty Treasure Hunter circuit diagram HOF A01 ee 4100 TURNS Bos 9 EMAk WIAE ON 150mm DA FORMER TX SEARCH HEAD the peak current passing through the trans mitter coil to 12mA ON THE LEVEL The front end of the receiver section is a simple yet sensitive preamplifier based on IC2a which boosts the signal from the coil Rx Its gain about 165 is set to a level where signal amplitude shows good varia tion at the presence of metal It also pro vides sufficient gain for the following Stages Wired as a comparator or rather a level detector IC2b detects the peaks of the amplified receiver waveform These peaks however are sharp and small like the proverbial tip of the iceberg and this could severely stunt the sensitivity of the circuit It is at this point that a simple yet vital enhancement is introduced Resistor R9 is added to provide hysteresis through posi tive feedback thereby returning the signal to a square wave and effectively tripling the sensitivity of the detector The output of IC2b at pin 7 is fed via capacitor C5 to peak detector IClc Since ICIc is a Schmitt inverter only pulses of a certain amplitude break through to output pin 6 With correct adjustment of the Tune and Fine Tune controls VR2 and VR3 there is a point at which the signal just breaks through in the form
58. phase 1 8 deg step 200 step Body 56mm x 36mm 14 99 each Ref STEP6 pack of 4 for 49 95 BASIC GUIDE TO LOCKPICKING New publication gives you an insight 6 Ref LPK NEW HIGH POWER MINI BUG With a range of up to 800 metres and 3 days use from a PP3 this is our top selling bug Less than 1in square and a 10m voice pick up range 28 Ref LOT102 IR LAMP KIT Suitable for CCTV cameras enables the camera to be used in total darkness 6 Ref EF138 INFRA RED POWERBEAM Handheld battery powered lamp 4in reflector gives out powerful pure infra red light Perfect for CCTV use nightsights etc 29 Ref PB1 YOUR HOME COULD BE SELF SUFFICIENT IN ELECTRICITY Comprehensive plans with loads of info on designing systems panels control electronics etc 7 Ref PV1 200 WATT INVERTERS plugs straight into your car cigarette lighter socket and is fitted with a 13A socket so you can run your mains operated devices from your car battery 49 95 Ref SS66 THE TRUTH MACHINE Tells if someone is lying by micro tremors in their voice battery operated works in general conversation and on the phone and TV as well 42 49 Ref TDS INFRA RED FILM 6in square piece of flexible infra red film that will only allow IR light through Perfect for converting ordinary torches lights headlights etc to infra red output using only stan dard light bulbs Easily cut to shape 6in square 15 Ref IRF2 or a 12in square for 29 95 Ref IRF2A
59. 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 Amex Diners Club or Switch to DIRECT BOOK SERVICE WIMBORNE PUBLISHING LTD 408 WIMBORNE ROAD EAST FERNDOWN DORSET BH22 9ND Books are normally sent within seven days of receipt of order but please allow 28 days for delivery more for overseas orders Please check price and availability see latest issue of Everyday Practical Electronics before ordering from old lists For a further selection of books see the next two issues of EPE Tel 01202 873872 Fax 01202 874562 Email dbs epemag wimborne co uk Order from our online shop at www epemag wimborne co uk shopdoor htm BOOK ORDER FORM Full NAME cosdccdscscwiiccdasavsnccesdssancsedeateedeatyeveseseeacnends Address aoe catiece tired accncdunesckuncusineaeusdaesenccducdevaveusexenedecs Post code 8 10 gt Se reer PSE en Se a Spent e ears es ren Telephone NO _ enclose cheque PO payable to DIRECT BOOK SERVICE for _ Please charge my card Card Number Please continue on separate sheet of paper if necessary If you do not wish to cut your magazine send a letter or copy of this form Everyday Practical Electronics October 2002 PROJECT TITLE Order Code Forever Flasher JAN ety 330 Time Delay Touch Switch 331 amp PIC Magick Musick 332 Vers
60. printed circuit boards are fabricated and what the innards of memory ICs look like You ll also gain a working knowledge of Boolean Algebra and Karnaugh Maps and understand what Reed Muller logic is and how it s used And there s much MUCH more including a recipe for a truly great seafood gumbol Hundreds of carefully drawn illustrations clearly show the important points of each topic The authors tongue in cheek British humor makes it a delight to read but this is a REAL technical book extremely detailed and accurate A great reference for your own shelf and also an ideal gift for a friend or family member who wants to understand what it is you do all day RATE ROLEN ROQC E 470 pgs large format Rol R H 26 95 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 fascinat ing world of computer design and you ll have a few chuckles if not belly laughs along the way In addition to over 200 megabytes of mega cool multimedia the CD ROM contains a virtual microcomput er simulating the motherboard and standard computer peripherals in an extremely realistic manner In addition to a wealth of technical information myriad nuggets of triv ia and hundreds of careful
61. screen being set for multiple function pins Sequence 4 Read We now read back the logic levels from the i c being tested We expect pins 1 2 4 5 9 10 12 and 13 to be low since we have set them low in the previous instruction However we must now indicate which logic levels are expected on each output pin According to the truth table we looked at for a NAND gate earlier all gates should return a high logic level We now contin ue sending logic levels to the i c being tested and then reading back the actual logic levels from it There is no need to send a Config com mand in the above sequence since the PC software sends the required configuration based on the profile information you spec ified on the first screen during the profile creation MULTIPLEXED PINS Some i c s however have pins that can be either an input or an output depending on the logic level of some other pins and the 74245 is an example of this see Photo 11 At Sequence 7 a Config command has been inserted This enables the tester to be reconfigured and specify which pins are inputs or outputs Testing resumes from Sequence 8 Select the Reset command and click Add Instruction A new line will be added to the display Do the same for VE On Next insert a Send command This is the binary pattern we want to present to the 1 c under test Logic levels are changed by clicking the cell on the new line that you want to change Normally afte
62. seconds to 10 minutes 15m detection range mains operated waterproof 5 99 Ref PIR1PACK or a pack of 5 for 22 95 Ref PIR5PACK or 10 for 39 95 Ref PIR10PACK 12V 12Ah SEALED LEAD ACID BATTERIES 100mm x 150mm x 95mm 4kg 15 each Ref SSLB SEALED LEAD ACID CHARGER AND FLOAT CHARGER Complete unit will charge 12V lead acids and maintain them with an automatic trickle charge Charger on its own is 15 Ref LAC or charger and a 12V 12Ah battery all fully cased is 25 Ref ACB AERIAL PHOTOGRAPHY KIT This rocket comes with a built in camera It flies up to 500 feet 150m turns over and takes an aerial photograph of the ground below The rocket then returns with its film via its parachute Takes 110 film Supplied with everything including a launch pad and 3 motors no film 29 98 Ref Astro BUILD YOUR OWN WINDFARM FROM SCRAP New publication gives step by step guide to building wind generators and propel lors Armed with this publication and a good local scrapyard could make you self sufficient in electricity 12 Ref LOT81 MAGNETIC CREDIT CARD READERS 9 95 Cased with fly leads designed to read standard credit cards Complete with con trol electronics p c b and manual covering everything you could want to know about what s hidden in that magnetic strip on your card Just 9 95 Ref BAR31 77 KILO LIFT MAGNET These Samarium magnets measure 57mm x 20mm and have a threaded hole 5 16th UNF in the cen tre and a magnetic s
63. solder in all the link wires noting that some go under the L e d matrix position Then insert and solder the components in any preferred order A socket must be used for the PIC Although the transistors are specified as BCSS8 types virtually any small signal pnp type will be suitable Care should be taken if other types are used however as their pinouts may vary The l e d matrix type used in the proto type measures 39mm x 23mm although 17mm and 50mm wide types could be used provided that they are specified as row anode In the prototype the display was mount ed on the board by means of two 7 pin sockets obtained by cutting a standard 14 pin d i l i c socket in half It is positioned with its identity writing side to the right as viewed in Fig 4 The prototype was not built into a box and the switches were mounted on a sepa rate piece of stripboard whose assembly details are shown in Fig 5 However the circuit could be fitted into a small handheld case which also has a battery compartment Holes should be drilled for the switches They should be standard push to make Sem SES EE Everyday Practical Electronics October 2002 types and connected to the board by flying leads When the circuit is complete and fully checked for errors and bad soldering the preprogrammed PIC can be fitted into its socket Ensure that this is fitted the correct way around See this month s Shoptalk page for details o
64. some areas figures of 750 are shown I have great news my thermometer now has a reading of pre cisely four What s more the thermometer s column of mercury is halfway up the scale Does that mean we are halfway there I guess not I calculate that at the current rate we can look forward to ADSL being installed in approximately four years time assuming that we are lucky enough to have a trigger level of 200 assigned to our exchange It is worth remembering that whilst BT has done an excellent job of displaying all the related information on their web site it just goes to prove how everyone including BT is becoming ever more dependent on the Internet to share complex information with the rest of us The lack of broadband continues to strangle the development of communications and services across the United Kingdom Next month it s back to the subject of spam mail once again For the last four weeks I have been using a paid for spam filtering ser vice which claims to screen your email and filter out any known spam and virus infected mails How well has the service done in the past month Is it worth the money Ill reveal the net results in next month s Net Work You can email me at alan epemag demon co uk iT mee Se Oe eS nes tee res EC oe ContentSaver Professional is a versatile tool for storing and annotating are 753 Constructional Project PIC POCKET BATTLESHIPS BART TREPAK Become a S
65. stability A slider switch S1 prevents accidental switching as the unit is transported If you wish add a socket for headphones in parallel with or in place of the piezo sounder WD1 Make sure that the battery is secure and will not move about in the case In the case of extremely noisy environments an l e d may be used besides the piezo sounder This is wired from ICIc pin 6 via a lk series resistor to OV The finished prototype p c b D1 has been moved in the final version Everyday Practical Electronics October 2002 COMPONENTS Resistors 47k 2 off 120k 150k 100k 22k All carbon film 0 25W 5 Potentiometers VR1 1k cermet preset VR2 100k carbon track metal can plastic shaft VR3 10k carbon track metal can plastic shaft VR4 100k cermet preset Capacitors C1 C2 1n metallised polyester film 2 off C3 4u7 16V radial electrolytic C4 1001 16V radial electrolytic C5 C6 220u 16V radial electrolytic 2 off C7 1000p 16V electrolytic Semiconductors IC1 HCF40106BEY hex Schmitt inverter see text IC2 TLO72 dual j f e t op amp Miscellaneous WD1 piezo sounder S1 on off slider switch SK1 3 5mm mono jack socket optional see text B1 12V battery 8 x AA Battery holder 8 x AA PP3 battery clip for battery holder 100m 33s w g approx 0 26mm enamelled copper wire print ed circuit board available from the EPE PCB Service order code 370 ABS case with external d
66. that are unusual in the C Tester with the possible exception of the MAX232 RS 232 line driver If your favourite stockist doesn t have it we know that ESR do their advert is on page 706 It is also stocked by Maplin code number FD92A they describe it as an RS 232 Transmitter Receiver same thing as an RS 232 line driver Tel 0870 264 6000 Web www maplin co uk It s worth shopping around for the ZIF socket as these can vary considerably in price between sources quality wise of course you get what you pay for See later for details of obtaining the software Pre programmed PICs are obtain able from EPE advertisers Magenta Electronics amp 01283 565435 web www magenta2000 co uk price 10 each overseas add 1 p amp p Headset Communicator It s the TDA7052 that your local stockist may not have for the Headset Communicator even though he is likely to have all the other components which are common place Again we know that Maplin see above stock it code UK79L ignore the 1W power amp module that they also call the TDA7052 Regarding the connectors yes they can seem a bit expensive but quality is well worth paying for in this context and XLRs are the preferred connectors used by professionals in the audio world Try ESR for these their Everyday Practical Electronics October 2002 advertisement is on page 706 they also stock the TDA7052 i c If funds permit buying ready made XLR con nection lead
67. that is any metal part of the case If as in the prototype unit the socket is mounted on a plastic part there will be no problem If the socket must be mounted on metal the best approach would be to use a fully insulated jack socket Unfortunately most types make automatic connection of the sleeve to the case STE Metra T ONM MOET EW SMA TOMES OF THE If necessary you will need to make an insulating sleeve or a shouldered plastic bush and use plastic washers to isolate it from the metalwork Use a multitester to check that the sleeve does not make electri cal contact with earth before proceeding Take care to wire up the Listen Talk selector and the Talk to All switches correctly The pole lettering and contact tag numbering see inset dia is as shown on most switches of this type If using XLR connectors pin 1 should be connected to Earth OV along with the solder tag which connects to the metal body In the prototype pin 2 and pin 3 are used for the Talk and Listen connections respectively All the wires connected to these sockets will need strain relief In the prototype this was done by means of a cable tie passed through slots in the bottom of the case This will help in preventing the wires from breaking free in service MICROPHONE WIRING The microphone input socket may be mounted on a metal part because its sleeve PLUGS AT SLAVE UNITS GY BATTERY ALR CONNECTOR MASTER END SOCKET REAR VIE
68. the unseen enemy ship can also move one square in the horizontal or vertical direction so that its current posi tion changes and remains unknown Note 754 that if the cursor is placed on the position occupied by one of the merchant ships the Le d will not flash When the player thinks the enemy is at the position of the cursor the fire button may be pressed to try to sink the enemy If the enemy ship is not in this position the cursor will continue to flash and the game will continue If the enemy is at this posi tion then there are two possible outcomes of this engagement either the player s bat tleship or that of the enemy will be sunk and this is determined randomly If the enemy is sunk the player wins the game indicated by the cursor ceasing to flash but if his own ship is sunk then a new one will appear at the start position with the enemy remaining at the position where the ship was sunk If the enemy warship moves into a posi tion occupied by a merchant ship then that COLUMN XO 8 COLUMN X1 COLUMN XZ COLUMN X3 COLUMN X4 ship will be sunk immediately 1 e the Le d will go out and the current position of the raider will be revealed Of course as soon as the player attempts to move the cursor to this new position the enemy may also move If the merchant ship that is sunk is the last one the game is lost and the cursor returns to its start position To re start the game the unit must be reset
69. to the talk of the other and also making the common earth connection two way communication would be estab lished Of course additional switching is Everyday Practical Electronics October 2002 Rear panel shows the three XLR type sockets for connecting up the Slave units Completed Slave unit with belt clip attached to the lid Fris tel K COI alL 3 Fa oar Slt LISTEN LINE STEN LINE Fig 1 Circuit diagram for the Headset Communicator This is the same for both the Master and each Slave unit needed in the Master unit to select the slave unit to be communicated with This aspect of operation is looked at later Six volt battery B1 supplies current through On Off switch S1 and diode D2 The diode provides reverse polarity pro tection Thus if the supply were to be con nected in the wrong sense D1 would fail to conduct and no current would flow thus preventing damage to semiconductor devices Note that a Schottky diode is specified for D2 This introduces a smaller forward voltage drop than a conventional diode Capacitor C8 provides a reserve of ener gy and allows peaks of power to be deliv ered especially when the battery is nearing the end of its useful life Light emitting diode D1 is the on indicator and operates through current limiting resistor R12 The microphone section of the headset MIC 1 is connected to the circuit via socket SK1 This microphone is of the electret type and so requires a p
70. up to 72p an issue on UK subscriptions Even overseas readers can get issues posted to them for less than the cover price In these days of pressure on newsagents shelves a subscription may become the best way of ensuring delivery of your magazine Full details and prices are given below AVAILABILITY Copies of EPE are available on subscription anywhere in the world see opposite from all UK newsagents distributed by COMAG and from the following electronic component retailers Omni Electronics and Yebo Electronics S Africa EPE can also be pur chased from retail magazine outlets around the world An Internet on line version can be purchased and downloaded for just 9 99US approx 7 per year avail able from www epemag com FREEBIRD Model glider Hhgha central VIATL TO co PREAMP Tramrior theca od recorda i FLUE SUBSCRIPTIONS Subscriptions for delivery direct to any address in the UK 6 months 15 50 12 months 29 50 two years 54 Overseas 6 months 18 50 standard air service or 27 50 express airmail 12 months 35 50 standard air service or 53 express airmail 24 months 66 standard air service or 101 express airmail Online subscriptions for downloading the magazine via the Internet 9 99US approx 7 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 40
71. via SCART socket and most video recorders Unit runs from 12V DC so ideal for security amp portable applica tions where mains power not available Overall dimensions 66 mm wide x 117 deep x 43 high Supplied BRAND NEW amp fully guaranteed with user data 100 s of applica tions including Security Home Video Web TV Web Cams etc etc Order as LK33 ONLY 79 00 or 2 for 149 00 B SOFTWARE SPECIALS NT4 WorkStation complete with service pack 3 and licence OEM packaged ONLY 89 00 e ENCARTA 95 CDROM Not the latest but at this price 7 95 DOS 5 0 on 3 disks with concise books c w QBasic 14 95 Windows for Workgroups 3 11 Dos 6 22 on 3 5 disks 55 00 Windows 95 CDROM Only No Licence 19 95 Wordperfect 6 for DOS supplied on 3 disks with manual 24 95 shipping charges for software is code B SOLID STATE LASERS Visible red 670nm laser diode assembly Unit runs from 5 V DC at approx 50 mA Orginally made for continuous use in industrial bar code scanners the laser is mounted in a removable solid aluminium block which functions as a heatsink and rigid optical mount Dims of block are 50 w x 50 d x 15h mm Integral features include over tem perature shutdown current control laser OK ouput and gated TTL ON OFF Many uses for experimental optics comms amp lightshows etc Supplied complete with data sheet Order as TD91 ONLY 24 95 a DC POWER SUPPLIES Virtually every type of power supply y
72. whether these advertise ments are printed as part of the magazine or in inserts The Publishers regret that under no circum stances will the magazine accept liability for non receipt of goods ordered or for late delivery or for faults in manufacture TRANSMITTERS BUGS TELEPHONE EQUIPMENT We advise readers that certain items of radio transmitting and telephone equipment which may be advertised in our pages cannot be legally used in the UK Readers should check the law before buying any transmitting or telephone equipment as a fine confiscation of equipment and or imprisonment can result from illegal use or ownership The laws vary from country to country readers should check local laws 707 Constructional Project EPE BOUNTY TREASURE HUNTER THOMAS SCARBOROUGH An inexpensive easy to build induction balance design that will find a comm 7 inch diameter coin at up to 240mm 9 72in depth ETAL detecting is a popular pas M time The author himself with his son located a wreck with an old EE design uncovering among other things small items of gold and pinfire ammunition There are two significant barriers how ever to owning and operating one s own metal detector The first is cost A good metal detector may easily cost a hundred pounds plus and this may not represent an offhand investment particularly for young people The second is complexity A typical metal detector may comprise fifty o
73. which provides the Talk to All function and a Volume control Rotary switch S2 has three associated Le d s Red Yellow and Green which con firm the slave unit selected These will be found useful when the unit is being used under dim conditions Note that while the talk to all switch S3 is being operated only the remote station set by the S2 can be heard SLAVE UNIT Each slave unit is built in a small plastic box having a belt clip attached see photo graph As well as sockets for the headset and the cable leading to the master unit there is an on off switch L e d on indi cator and volume control One particular feature of this circuit is that the operator s voice is heard in his or her own headphones This practice is used in telephony and helps the speaker to regulate his or her voice level It also allows the user to hear someone speaking direct without the muffling effect of the headphones The amount of voice feedback may be adjusted for each station at the setting up stage It may even be reduced to zero if required HOW IT WORKS The basic circuit for the Headset Communicator is shown in Fig 1 and this is the same for both Master and Slave units Each unit may be considered as hav ing one input and one output the Listen L and Talk T lines respectively plus a common Earth By linking the talk line of one unit to the listen line of another and the listen line of the first
74. 0 25W 5 carbon film S2 4 pole 3 way rotary switch 3 d p s t momentary action push to make switch 3mm l e d s one each red yellow green D3 to D5 Sloping front instrument case with alu minium top and plastic sides size 170mm x 143mm x 55 31mm XLR panel mount ing socket 3 off plastic feet solder tag ADDITIONS FOR EACH SLAVE Plastic box size 114mm x 76mm x 38mm panel mounting XLR plug belt clips if required 6V alkaline battery pack 4 x AA with holder and connector clip 1 LISTEN 64 ALK EARTH oy LISTEN 6 TALK EARTH Cr Everyday Practical Electronics October 2002 pim O carried out using a double pole momentary action switch S3 TAKING THE LEAD In the prototype system the intercon necting leads were of the commercial vari ety fitted with a 3 pin XLR line plug on one end and a matching line socket on the other These connectors are widely used in the industry and are normally used for bal anced audio applications Before purchas ing XLR leads check that they are of the standard pattern Some cheap cables intended for unbal anced microphones have only one inner conductor with the screening connected to two of the pins For this circuit you need two available inner conductors plus the screening You could of course use home made leads constructed using two core screened wire and stereo type jack or XLR connectors CONSTRUCTION Constructi
75. 02 SIMPLE PIC PROGRAMMER INCREDIBLE LOW PRICE Kit 857 12 99 INCLUDES 1 PIC16F84 CHIP Power Supply 3 99 SOFTWARE DISK LEAD CONNECTOR PROFESSIONAL EXTRA CHIPS PC BOARD amp INSTRUCTIONS PIC 16F84 4 84 Based on February 96 EPE Magenta designed PCB and kit PCB with Reset switch Program switch 5V regulator and test L E D s and connection points for access to all A and B port pins PIC 16C84 DISPLAY DRIVER Kit 860 19 99 Power Supply 3 99 FULL PROGRAM SOURCE CODE SUPPLIED DEVELOP YOUR OWN APPLICATION Another super PIC project from Magenta Supplied with PCB industry standard 2 LINE x 16 character display data all components and software to include in your own programs Ideal development base for meters terminals calculators counters timers Just waiting for your application PIC 16F84 MAINS POWER 4 CHANNEL CONTROLLER amp LIGHT CHASER WITH PROGRAMMED 16F84 AND DISK WITH SOURCE CODE IN MPASM ZERO VOLT SWITCHING MULTIPLE CHASE PATTERNS OPTO ISOLATED 5 AMP OUTPUTS 12 KEYPAD CONTROL SPEED DIMMING POT HARD FIRED TRIACS Kit 855 39 95 8 CHANNEL DATA LOGGER As featured in Aug Sept 99 EPE Full kit with Magenta feet PCB LCD fits directly on board Use as Data ogger or as a test bed for many other 16F877 projects Kit a udes programmed chip 8 EEPROMs PCB case and all components KIT 877 49 95 inc 8 x 256K EEPROMS ICEBREAKER oo0o0000000 INCLUDES 1 PIC16F84
76. 1s passive the required 60 shift occurs at the frequency at which the series arm has twice the impedance of the shunt arm At that frequency the attenua tion factor is two i e half the voltage is lost This is likely to be much less than at Fe Fig 18 a Three inverter ring b With added phase shift circuits c d Alternative phase shift networks 744 the gain of an inverter so the circuit oscil lates strongly Unfortunately the strong oscillation drives the internal protection diodes into conduction The effect is to raise the fre quency spectacularly but unpredictably It would be possible to add swamping resis tances but a better alternative is to use the circuit in Fig 18d Here the phase shifting is done by incorporating the RC network into an integrator the amplifier being one of the inverters The inverter input terminal is now a virtual earth point and the signal level there is low enough to avoid the worst effects of protection diode conduction In a ring of three such integrators each pro duces a lagging phase shift of 60 The oscillation frequency is theoretically f 0 08 CR As before f is in Hertz when CR is in megohms times microfarads and so on RING VCO If in circuits using Fig 18c the resis tances and capacitances are reduced to zero the circuit reverts to that in Fig 18a It might be expected to display a stubborn stability Far from it It oscillates but at a high frequ
77. 4 zi 5 D Only 99 00 PHILIPS HCS31 Ultra compact 9 colour video monitor with ee dard composite 15 625 Khz video input via SCART socket Ideal for all monitoring security applications High quality ex equipment fully tested amp guaranteed possible minor screen burns In attrac tive square black plastic case measuring W10 x H10 x 13 D 240 V AC mains powered Only 79 00 D INDUSTRIAL COMPUTERS Tiny shoebox sized industrial 40 Mhz 386 PC system measuring only mm 266 w X 88 h X 272 d Ideal for dedicated control appli cations running DOS Linux or even Windows Steel case con tains 85 to 265 V AC 50 60 hz 70 Watt PSU a 3 slot ISA passive backplane and a Rocky 318 PC104 standard single board com puter with 8 MByte NON VOLATILE solid state Disk On Chip RAMDISK System comprises Rocky 318 PC 104 SBC ISA card with 40MHz ALi 386SX CPU 72 pin SIMM slot with 16 Mbyte SIMM AMI BIOS battery backed up real time clock 2 x 9 pin D 16550 serial ports EPP ECP printer port mini DIN keyboard con nector floppy port IDE port for hard drives up to 528 MByte capacity watchdog timer and PC 104 bus socket The 8 MByte solid state disk on a chip has its own BIOS and can be fdisked formatted amp booted Supplied BRAND NEW fully tested and guar anteed For full data see featured item on website Order as QG36 100 s of applications inc firewall routers robotics etc Only 99 00 0 14 59 00 U
78. 8 Wimborne Road East Ferndown Dorset BH22 OND Tel 01202 873872 Fax 01202 874562 Email subs epemag wimborne co uk Also via the Web at http www epemag wimborne co uk Subscriptions start with the next available issue We accept MasterCard Amex Diners Club Switch or Visa For past issues see the Back Issues page BINDERS Binders to hold one volume 12 issues are available from the above address These are finished in blue p v c printed with the magazine logo in gold on the spine Price 6 95 plus 3 50 p amp p for overseas readers the postage is 6 00 to everywhere except Australia and Papua New Guinea which cost 10 50 Normally sent within seven days but please allow 28 days for delivery more for overseas Payment in sterling only please Visa Amex Diners Club Switch and MasterCard accepted Send fax or phone your card number and card expiry date with your name address etc Or order on our secure server via our UK web site Overseas customers your cred it card will be charged by the card provider in your local currency at the existing exchange rate Everyday Practical Electronics October 2002 Editor MIKE KENWARD Deputy Editor DAVID BARRINGTON Technical Editor JOHN BECKER Business Manager DAVID J LEAVER Subscriptions MARILYN GOLDBERG Administration FAY KENWARD Editorial Admin 01202 873872 Advertisement Manager PETER J MEW Frinton 01255 861161 Advertisement Copy Controller
79. 839546 Email yeda cix co uk Web www yeda org uk Note that the address and tel fax details have changed since last year Susie Short of Sevenoaks School with her Programmable Sailing Race Countdown Timer 715 Constructional Project DIGITAL 1 C TESTER JOE FARR Let a PIC and a PC check the health of your digital logic Chips URING project construction many D must have wondered if the reason their masterpiece wasn t working was due to a faulty i c or if the i c they ve just removed from an old board actually works The project described here provides a simple way to quickly test the operation of most TTL and CMOS digital RAS HOW IT WORKS To explain how the Digital I C Tester works let s examine the humble 7400 TTL NAND gate device as an example The datasheet says the package contains four logic gates each one having two inputs and one output which behave according to the truth table in Table 1 Table 1 Truth table for a 2 input NAND gate Input 1 Input 2 Output L L H L H H H L H H H L To test the satisfactory functioning of each of the four gates in the i c package each of the four input logic configurations in Table 1 must be applied to each gate and the resulting logic output levels recorded and compared against the expected results A profile for an i c to be tested is first generated from the device s datasheet Within the profile an instruction sequence is specified that applie
80. 9 95 5 SEAGATE ST 238R 30 mb RLL I F Refurb 69 95 5 CDC 94205 51 40mb HH MFM I F RFE tested 69 95 5 HP 97548 850 Mb SCSI RFE tested 99 00 5 HP C3010 2 Gbyte SCSI differential RFE tested 195 00 8 NEC D2246 85 Mb SMD interface New 99 00 8 FUJITSU M2322K 160Mb SMD I F RFE tested 195 00 8 FUJITSU M2392K 2 Gb SMD I F RFE tested 345 00 Many other floppy amp H drives IDE SCSI ESDI etc from stock see website for full stock list Shipping on all drives is code C TEST EQUIPMENT amp SPECIAL INTEREST ITEMS MITSUBISHI FA3445ETKL 14 Ind spec SVGA monitors 245 FARNELL 0 60V DC 50 Amps bench Power Supplies 995 FARNELL AP3080 0 30V DC 80 Amps bench Suppy 1850 KINGSHILL CZ403 1 0 50V DC 200 Amps NEW 3950 1kW to 400 kW 400 Hz3 phase power sources ex stock POA IBM 8230 Type 1 Token ring base unit driver 760 Wayne Kerr RA200 Audio frequency response analyser 2500 INFODEC 1U 24 port RJ45 network patchpanels TH93 49 3COM 16670 12 Port Ethernet hub RJ45 connectors LD97 69 3COM 16671 24 Port Ethernet hub RJ45 connectors 89 3COM 16700 8 Port Ethernet hub RJ45 connectors NEW 39 IBM 53F5501 Token Ring ICS 20 port lobe modules POA IBM MAU Token ring distribution panel 8228 23 5050N 45 AIM 501 Low distortion Oscillator 9Hz to 330Khz IEEE I O 550 ALLGON 8360 11805 1880 MHz hybrid power combiners 250 Trend DSA 274 Data Analyser with G703 2M 64 i o POA Marconi 6310
81. A RC4 NC X1 R4 10p SJ OSC2 CLKOUT T10SO T1CKI RCO T1OSI CCP2 RC1 CCP1 RC2 SCK SCL RC3 1 16 2 a sit PGDARE7 AAA EN cc M CMS ae PMS E EM RAGIANQIVREF s CAN nn EMW CN nn As ES a M cH nr in wa pats RENANG AN RE2 AN7 CS VV fo si PIC16F877 20P i a 100Q 30 SEE MEX TRI via resistor R3 which in turn applies power to the i c under test via either the power patch pin TP1 or via the dual in line d 1 1 switch module S1 Transistor TRI also supplies 5V to the common pins of the pull up resistors within modules RM4 to RM6 As soon as testing is complete TRI is switched off automatical ly disconnecting power from the test 1 c Capacitor C12 provides smoothing of the switched 5V rail from TRI With power applied to the board and TRI off non test mode the PIC s RB6 and RB7 pins are available to allow an external programmer access to the PIC POWER SUPPLY It is expected that when in service the project will be powered from a sealed plug in mains power supply adaptor Either an a c or d c power supply unit can be used and the connections to the printed circuit board p c b are not polarity sensitive 718 PSPO RDO PSP1 RD1 fill LL Fig 1 Complete circuit diagram for the Digital I C Tester A power supply unit capable of supply ing around 100mA and between 9V to 12V should be ideal If the input voltage exceeds this then it might be necessar
82. ALE THURSDAY OCTOBER 10 Everyday Practical Electronics October 2002 699 wWwWWWw QuasarElectronics comnm Established 1990 QUASAR ELECTRONICS LIMITED PO Box 6935 BISHOPS STORTFORD Herts CM23 4WP TEL 0871 717 7168 ADD 2 00 P amp P to all orders or 1st Class Recorded 4 Next day Insured 250 7 Europe 5 00 Rest of World 10 00 We accept all FAX 0871 277 2728 VISA major credit cards Make cheques PO s payable to Quasar Electronics Prices include 17 5 VAT MAIL ORDER ONLY FREE CATALOGUE with order or send 2 x 1st class stamps refundable for details of over 150 kits amp publications Our electronic kits are supplied complete with all components high quality PCBs NOT cheap Tripad strip board and detailed assembly operating instructions 2 x 25W CAR BOOSTER AMPLIFIER Connects to the output of an existing car stereo cassette player CD player or radio Heatsinks provided PCB 76x75mm 1046KT 24 95 3 CHANNEL WIRELESS LIGHT MODULATOR No electrical connection with amplifier Light modu lation achieved via a sensitive electret microphone Separate sensitivity control per channel Power handing 400W channel PCB 54x112mm Mains powered Box provided 6014KT 24 95 12 RUNNING LIGHT EFFECT Exciting 12 LED light effect ideal for parties discos shop windows amp eye catching signs PCB design allows replacement of LEDs with 220V
83. 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 Complimentary output stage DIGITAL ELECTRONICS V2 0 Digital Electronics builds on the knowledge of logic gates covered in Electronic Circuits amp Components opposite and takes users through the subject of digital electronics up to the operation and architecture of microprocessors The virtual laboratories allow users to operate many circuits on screen Covers binary and hexadecimal numbering systems ASCII basic logic gates monostable action and circuits and bistables including JK and D type flip flops Multiple gate circuits equivalent logic functions and specialised logic functions Introduces sequential logic including clocks and c
84. CESS VISA SWITCH ACCEPTED phone 01273 491490 Fax 491813 Sales bullnet co uk SHUT THE BOX Check out www bullybeef co uk for a range of pub games and magic tricks WANT TO MAKE SOME MONEY STUCK FOR AN IDEA We have collated 140 business manuals that give you information on setting up different businesses you peruse these at your leisure using the text editor on your PC Also included is the certificate enabling you to reproduce and sell the manuals as much as you like 14 Ref EP74 ANICS CO2 GAS POWERED PISTOL Russian handheld pistol powered by Sparklets CO2 cylinders give approx 70 shots fires steel BB Pistol 58 22 Ref AGA101 tub of 1 500 BB shot 5 10 Ref A1015 pack of 5 CO2 cartridges 3 50 Ref GAS5 33 KILO LIFT MAGNET Neodynium 32mm diameter with a fixing bolt on the back for easy mounting Each magnet will lift 33 kilos 4 magnets bolted to a plate will lift an incredible 132 kilos 15 Ref MAG33 Pack of 4 just 39 Ref MAG33AA BSA METEOR AIR RIFLE UK made 22 rifle top quality profes sional air rifle 84 15 Ref BSAMET 500 Lazapell pellets 5 Ref LAZAPELL MAMOD 1313 TE1A TRACTION ENGINE Attractive working model of traditional steam engine 91 Ref 1313 MAMOD STEAM ROADSTER white magnificent working steam model car 121 Ref 1319 MAMOD STEAM WAGON Working model steam wagon finished in blue 130 Ref 1318 Brown version with barrels 122 Ref 1450 POCKET SPY MONOCULAR Cle
85. CIRCUIT 12V RELAY Quite small clear plastic enclosed and with plug in tags 1 Order Ref 205N NOT MUCH BIGGER THAN AN OXO CUBE Another relay just arrived is extra small with a 12V coil and 6A changeover contacts It is sealed so it can be mounted in any position or on a p c b Price 75p each 10 for 6 or 100 for 50 Order Ref FR16 1 5V 6V MOTOR WITH GEARBOX Motor is mounted on the gearbox which has interchangeable gears giving a range of speeds and motor torques Comes with full instructions for changing gears and calculating speeds 7 Order Ref 7P26 Everyday Practical Electronics October 2002 1 BARGAIN PACKS FIGURE 8 FLEX figure 8 flat white PVC flexible with 0 4 sq mm cores Ideal for speaker extensions and bell circuits Also adequately insulated for mains lighting 12m coil Order Ref 1014 SOLENOID COIL 6V DC or 12V AC only needs a plunger which could be a nail you would then have a really efficient solenoid Pack of 10 Order Ref 1 L2 ONE OHM 20W RESISTOR Made for the Admiralty in 1952 but being wirewound is probably just as good as when new Pack of 2 Order Ref 7 19R4 COLVERN 5K POT Totally enclosed with good length spindle Pack of 2 Order Ref 7 19R5 DITTO but 20k Pack of 2 Order Ref 7 19R6 PHILIPS TRIMMER CAP Sometimes called the bee hive trimmer as this is in two sections the top being on a threaded rod Capacity is altered by twisting along the rod Pack of 2 Order Ref 7
86. DOWS E YSTEM MECOMM 32 00 menu This brings up a window like the one of Fig 2 and it is then a matter of scrolling through the list looking for MSCOMM It will not be called MSCOMM in this list though it is more likely to be called Microsoft Communication Control version 6 0 or something similar to this Having found the right entry in the list tick its checkbox and then operate the OK button A yellow telephone icon should then appear in the Toolbox and this enables MSCOMM to be added to the form in the usual way VB or not VB Although VBA seems to be widely regarded as identical to Visual BASIC In addition to MSComm and a form it requires two buttons and a label The cap tions for buttons one and two CommandButtonl and CommandBut ton2 are respectively changed to START and EXIT Listing 1 Private Sub UserForm_Click End Sub Private Sub CommandButton1_Click MSComm1 PortOpen False End End Sub Everyday Practical Electronics October 2002 Private Sub CommandButton2 Click MSComm1 RThreshold 1 MSComm1 InputLen 1 MSComm1 Settings 9600 n 8 1 MSComm1 CommPort 1 MSComm1 InputMode cominputModeText MSComm1 PortOpen True End Sub Private Sub MSComm1_OnComm If MSComm1 CommEvent 2 Then Labell Caption Asc MSComm1 Input End Sub Operating the START button switches on communication with the serial port selects the required port and sets the required operating parameters
87. E 01 301 Magfield Monitor Sensor Board EPE PRINTED CIRCUIT BOARD SERVICE Dummy PIR Detector i A PIC16F87x Extended Memory Software only Order Code Project Quantity Price Stereo Surround Sound Amplifier JULY 01 Perpetual Projects Uniboard 1 Solar Powered Power Supply amp Voltage Reg MSF Signal Repeater and Indicator Repeater Board Meter Board X PIC to Printer Interface Lead Acid Battery Charger AUG 01 Shortwave Loop Aerial XK Digitimer Main Board R F Board Perpetual Projects Uniboard 2 L E D Flasher Double Door Buzzer Perpetual Projects Uniboard 3 cheque PO in sterling only to Loop Burglar Alarm Touch Switch Door Light LED super Torches Red Main Everyday Display Red Practical Electronics White L E D X Sync Clock Driver se X Water Monitor n E MasterCard Amex Diners Camcorder Power Supply CT 01 318 5 94 L P f ae PIC Toolkit Mk3 319 8 24 _ Club Visa or Switch Perpetual Projects Uniboard 4 Gate Sentinel Solar 305 3 00 powered Bird Scarer and Solar Powered Register Teach In 2002 Power Supply CAE NO a de Lights Needed Alert Pitch Switch Capacitance Meter Main Board double sided Card Exp Date Display Board double sided K amp PIC Toolkit TK3 Software onl Signature 4 Channel Twinkling Lights DEC 01 Ghost Buster Mic NOTE You can also order p c b s by phone Fax Email or via our Main Internet site on a s
88. ER Approximately 80mm x 55mm front engraved 0 100 Price 1 50 each Order Ref 1 16R2 D C MOTOR WITH GEARBOX Size 60mm long 30mm diameter Very powerful operates off any voltage between 6V and 24V D C Speed at 6V is 200 rpm speed controller avail able Special price 3 each Order Ref 3P108 FLASHING BEACON Ideal for putting on a van a tractor or any vehicle that should always be seen Uses a Xenon tube and has an amber coloured dome Separate fixing base is included so unit can be put away if desirable Price 5 Order Ref 5P267 MOST USEFUL POWER SUPPLY Rated at 9V 1A this plugs into a 13A socket is really nicely boxed 2 Order Ref 2P733 MOTOR SPEED CONTROLLER These are suitable for D C motors for voltages up to 12V and any power up to 1 6h p They reduce the speed by intermittent full voltage pulses so there should be no loss of power Made up and tested 18 Order Ref 20P39 BALANCE ASSEMBLY KITS Japanese made when assembled ideal for chemical experiments complete with tweezers and 6 weights 0 5 to 5 grams Price 2 Order Ref 2P44 CYCLE LAMP BARGAIN You can have 100 6V 0 2A MES bulbs for just 2 50 or 1 000 for 20 They are beautifully made slightly larger than the standard 6 3V pilot bulb so they would be ideal for making displays for night lights and similar applications SOLDERING IRON super mains powered with long life ceramic element heavy duty 40W for the extra special job complete wi
89. I Gard NO ssricasnrssin innana aan essa a cee Card Exp Date Please allow four working days for UK delivery NOTE Surface mail can take over 10 weeks to some parts of the world Each ESM weighs about 4kg when packed a ai e ee ey mn a et ef i yl 2 mem cd
90. NIT 32 50 WINDICATOR A novel wind speed indicator with LED readout Kit comes complete with sensor cups and weatherproof sensing head Mains power unit 5 99 extra DUAL OUTPUT TENS UNIT As featured in March 97 issue Magenta have prepared a FULL KIT for this excellent new project All components PCB hardware and electrodes are included Designed for simple assembly and testing and providing high level dual output drive KIT 866 Full kit including four electrodes 32 90 1000V amp 500V INSULATION TESTER Superb new design Regulated output efficient circuit Dual scale meter compact case Reads up to 200 Megohms 4 spare electrodes 6 50 Kit includes wound coil cut out case meter scale PCB amp ALL components KIT 848 32 95 EPE PROJECT PICS Programmed PICs for all EPE Projects 16C84 18F84 16C71 All 5 90 each 10 inc VAT amp postage TEACH IN 2000 Full set of top quality NEW components for this educa tional series All parts as specified by EPE Kit includes breadboard wire croc clips pins and all components for experiments as listed in introduction to Part 1 Batteries and tools not included TEACH IN 2000 KIT 879 44 95 MULTIMETER 14 45 SPACEWRITER An innovative and exciting project E Wave the wand through the air and your message appears Programmable to hold any message up to 16 digits long Co
91. OCT 02 369 x Using PICs and Keypads Software only EPE Bounty Treasure Hunter 370 Ice Alarm x x Digital I C Tester 371 Graphics L C D Display with PICs Supp x PIC Pocket Battleships Software only Using the LM3914 6 L E D Bargraph Drivers Multi purpose Main p c b Relay Control L E D Display fE i W PC Audio Power Meter Software only EPE SO ARE Doorbell Extender Transmitter 292 Software programs for EPE projects marked with a single asterisk are available on 3 5 inch Receiver 293 PC compatible disks or free from our Internet site The following disks are available PIC Trans Remote 294 Tutorial Mar May 98 PIC Toolkit Mk2 V2 4d May Jun 99 EPE Disk 1 Apr 95 Dec 98 Rec Relay 295 EPE Disk 2 1999 EPE Disk 3 2000 EPE ra 4 2001 EPE Disk 5 Jan Oa issue to current cover date EPETeach In 2000 EPE Spectrum EPE Interface Disk 1 October 00 aie Hae bug A eal a for Pets APR 01 296 6 50 issue to current cover date k The software for these projects is on CD ROM The 3 5 inch ntruder larm Control Pane disks are 3 00 each UK the CD ROMs are 6 95 UK Add 50p each for overseas surface Main Board 297 6 97 mail and 1 each for airmail All are available from the EPE PCB Service All files can be External Bell Unit 298 4 76 downloaded free from our Internet FTP site ftp ftp epemag wimborne co uk Camcorder Mixer MAY 01 299 6 34 PIC Graphics L C D Scope 300 5 07 Hosepipe Controller JUN
92. ODUCTORY COURSE SECOND EDITION John Morton Discover the potential of the PIC micro controller through graded projects this book could revolutionise your electronics construction work A uniquely concise and practical guide to getting up and running with the PIC Microcontroller The PIC is one of the most popular of the microcontrollers that are transforming electronic project work and product design Assuming no prior knowledge of microcontrollers and introducing the PIC s capabilities through simple projects this book is ideal for use in schools and col leges It is the ideal introduction for students teachers technicians and electronics enthusiasts The step by step explanations make it ideal for self study too this is not a reference book you start work with the PIC straight away The revised second edition covers the popular repro grammable EEPROM PICs P16C84 16F 84 as well as the P54 and P71 families Order code NE36 13 99 UNDERSTANDING PC SPECIFICATIONS R A Penfold Revised Edition If you require a microcomputer for business applica tions or a high quality home computer an IBM PC or compatible is often the obvious choice They are com petitively priced and are backed up by an enormous range of applications programs hardware add ons etc The main difficulty for the uninitiated is deciding on the specification that will best suit his or her needs PCs range from simple systems of limited capabilit
93. PCB LEAD ALL COMPONENTS TURNED PIN 29 99 SOCKETS FOR 18 28 AND 40 PIN ICs e SEND FOR DETAILED Kit 862 Power Supply 3 99 DISASSEMBLER 11 75 INFORMATION A SOFTWARE SUPERB PRODUCT AT AN UNBEATABLE LOW PRICE PIC STEPPING MOTOR DRIVER Kit 863 18 99 FULL SOURCE CODE SUPPLIED ALSO USE FOR DRIVING OTHER POWER DEVICES e g SOLENOIDS INCLUDES PCB PIC16F84 WITH DEMO PROGRAM SOFTWARE DISC INSTRUCTIONS AND MOTOR Another NEW Magenta PIC project Drives any 4 phase unipolar motor up to 24V and 1A Kit includes all components and 48 step motor Chip is pre programmed with demo software then write your own and re program the same chip Circuit accepts inputs from switches etc and drives motor in response Also runs standard demo sequence from memory All prices include VAT Add 3 00 p amp p Next day 6 99 E mail sales magenta2000 co uk 705 EVERYDAY PRACTICAL AUAXQU THE Mai MAGAZINE FOR ELECTRONICS TECHNOLOGY COMPUTER PROJECTS HE technical enquiries cannot be answered over the tele Editorial Offices EVERYDAY PRACTICAL ELECTRONICS EDITORIAL WIMBORNE PUBLISHING LTD 408 WIMBORNE ROAD EAST FERNDOWN DORSET BH22 9ND Phone 01202 873872 Fax 01202 874562 Email enquiries epemag wimborne co uk Web Site www epemag wimborne co uk EPE Online www epemag com EPE Online Shop www epemag wimborne co uk shopdoor htm See notes on Readers Technical Enquiries below
94. PETER SHERIDAN 01202 873872 On Line Editor ALAN WINSTANLEY EPE Online Internet version Editors CLIVE MAX MAXFIELD and ALVIN BROWN READERS TECHNICAL ENQUIRIES E mail 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 international reply coupons All reasonable precautions are taken to ensure that the advice and data given to readers is reliable We cannot however guarantee it and we cannot accept legal responsibility for it COMPONENT SUPPLIES We do not supply electronic components or kits for building the projects featured these can be supplied by advertisers see Shoptalk We advise readers to check that all parts are still available before commencing any project in a back dated issue ADVERTISEMENTS Although the proprietors and staff of EVERYDAY PRACTICAL ELECTRONICS take reasonable precautions to protect the interests of readers by ensuring as far as practicable that advertisements are bona fide the maga zine and its Publishers cannot give any under takings in respect of statements or claims made by advertisers
95. Programmable 2 to 22 GHz sweep generator 4500 Marconi 2022C 10KHz 1GHz RF signal generator 1550 HP1650B Logic Analyser 3750 HP3781A Pattern generator amp HP3782A Error Detector POA HP6621A Dual Programmable GPIB PSU 0 7 V 160 watts 1800 HP6264 Rack mount variable 0 20V 20A metered PSU 475 HP54121A DC to 22 GHz four channel test set POA HP8130A opt 020 300 MHz pulse generator GPIB etc 7900 HP A1 AO 8 pen HPGL high speed drum plotters from 550 HP DRAFTMASTER 1 8 pen high speed plotter 750 EG G Brookdeal 95035C Precision lock in amp 1800 Keithley 590 CV capacitor voltage analyser POA Racal ICR40 dual 40 channel voice recorder system 3750 Fiskers 45KVA 3 ph On Line UPS New batteries 4500 Emerson AP130 2 5KVA industrial spec UPS 1499 Mann Tally MT645 High speed line printer 2200 Intel SBC 486 133SE Multibus 486 system 8Mb Ram 945 Fai a FE FES I TFE a i h k d h i h h k h m u E m u t Ls bal ote La LL Li Lh F EF 4 T F F a I I F k 4 a ru rf I a I I hk kd h hh hkdh h h GONIEC ALL MAIL TO Dept PE 29 35 Osborne Rd Thornton Heath Surrey CR7 8PD Open Mon THE ORIGINAL SURPLUS WONDERLAND THIS MONTH S SELECTION FROM OUR VAST EVER CHANGING STOCKS IC s TRANSISTORS DIODES OBSOLETE SHORT SUPPLY BULK 10 000 000 items EX STOCK For MAJOR sav nGs CALL or see web site www distel co uk COMPUTER MONITOR SPECIALS Legacy products High spec genuine m
96. R BLUMLEIN Robert Charles Alexander This book is the definitive study of the life and works of one of Britain s most important inventors who due to a cruel set of circumstances has all but been overlooked by history Alan Dower Blumlein led an extraordinary life in which his inventive output rate easily surpassed that of Edison but whose early death during the darkest days of World War Two led to a shroud of secrecy which has covered his life and achievements ever since His 1931 Patent for a Binaural Recording System was so revolutionary that most of his contemporaries regard ed it as more than 20 years ahead of its time Even years after his death the full magnitude of its detail had not been fully utilized Among his 128 patents are the princi pal electronic circuits critical to the development of the world s first elecronic television system During his short working life Blumlein produced patent after patent breaking entirely new ground in electronic and audio engineering During the Second World War Alan Blumlein was deeply engaged in the very secret work of radar development and contributed enormously to the system eventually to become H25 blind bombing radar Tragically during an experi mental H2S flight in June 1942 the Halifax bomber in which Blumlein and several colleagues were flying crashed and all aboard were killed He was just days short of his thirty ninth birthday Order code NE32 16 99 420
97. R DETECTOR MODULE 3 lead assembled unit just 25x85mm as used in commercial burglar alarm systems 3076KT 8 95 INFRARED SECURITY BEAM When the invisible IR beam is broken a relay is tripped that can be used to sound a bell or alarm 25 metre range Mains rated relays provided 12VDC operation 3130KT 12 95 SQUARE WAVE OSCILLATOR Generates square waves at 6 preset frequencies in factors of 10 from 1Hz 100KHz Visual output indicator 5 18VDC Box provided 3111KT 8 95 PC DRIVEN POCKET SAMPLER DATA LOG GER Analogue voltage sampler records voltages up to 2V or 20V over periods from milli seconds to months Can also be used as a simple digital scope to examine audio amp other signals up to about 5KHz Software amp D shell case provided 3112KT 18 95 20 MHz FUNCTION GENERATOR Square tri angular and sine waveform up to 20MHz over 3 ranges using coarse and fine frequency adjust ment controls Adjustable output from 0 2V p p A TTL output is also provided for connection to a frequency meter Uses MAX038 IC Plastic case with printed front rear panels amp all components provided 7 12VAC 3101KT 69 95 30 in ONE Electronic Projects Lab Great introduction to electronics Ideal for the budding electron ics expert Build a radio burglar alarm water detector morse r code practice circuit simple computer circuits and much more NO soldering tools or previous electronics knowledge required Ci
98. Receivers Transmitters Antenna Systems Broadcasting Satellites Personal Communications Appendix Basic Calculations 263 pages Order code NE30 15 99 PROJECTS FOR RADIO AMATEURS AND S W L S R A Penfold This book describes a number of electronic circuits most of which are quite simple which can be used to enhance the performance of most short wave radio systems The circuits covered include An aerial tuning unit A simple active aerial An add on b f o for portable sets A wavetrap to combat signals on spurious responses An audio notch filter A parametric equaliser C W and S S B audio filters Simple noise limiters A speech processor A volume expander Other useful circuits include a crystal oscillator and RTTY C W tone decoder and a RTTY serial to parallel converter A full range of interesting and useful circuits for short wave enthusiasts Order code BP304 4 45 92 pages AN INTRODUCTION TO AMATEUR RADIO I D Poole Amateur radio is a unique and fascinating hobby which has attracted thousands of people since it began at the turn of the century This book gives the newcomer a com prehensive and easy to understand guide through the subject so that the reader can gain the most from the hobby It then remains an essential reference volume to be used time and again Topics covered include the basic aspects of the hobby such as operating procedures jar gon and setting up a station Technical topics
99. SMOKE ALARMS Mains powered made by the famous Gent company easy fit next to light fittings power point Pack of 5 15 Ref SS23 pack of 12 24 Ref SS24 CCTV CAMERAS FROM 25 Check out our web site at www cctvstuff co uk and www home cctv co uk 14 WATT SOLAR PANELS Amorphous silicon panel fitted in an anodised aluminium frame Panel measures 3ft by 1ft with 3m leads for easy connection 3ft x 1ft solar panel 79 Ref MAG45 Unframed 4 pack 8 9W 3ft x 1ft 99 Ref SOLX 35 watts of solar power for just 99 4 panels each one 3ft x 1ft and pro ducing 8W min 13V Pack of four 99 Ref SOLX AIR RIFLES FROM LESS THAN 40 CROSSBOWS WIDE RANGE OF BB GUNS AMMO TARGETS PISTOLS REPLICA GUNS UZI MACHINE GUN REPLICAS BB REPEATERS LASER SIGHTS ELECTRIC BB GAS BB www airpistol co uk DE EU Eu ON L INKJET CARTRIDGES FROM JUST 3 AT I www officebits co uk oo oo POWERSAFE DEEP CYCLE BATTERIES 6V 100AH NOW ONLY 19 EACH NEW 12V 12in SQUARE SOLAR PANEL Kevlar backed 3 watt output copper strips for easy solder connections 14 99 Ref 15P42 Pack of four just 39 95 Ref 15P42SP NEW UNIVERSAL SOLAR CHARGER Charges AAAs AAs Cs and D type NiCads 9 99 Ref UNISOL 12V SOLAR POWER WATER PUMP Perfect for many 12V d c uses from solar fountains to hydroponics Small and compact yet powerful works direct from our 10W solar panel in bright sun Max HD 17ft max flow 8 Lpm 1 5A Ref AC88
100. Stepping Motors MD38 Mini 48 step 8 65 MD35 Std 48 step 9 99 MD200 200 step 12 99 MD24 Large 200 step 22 95 MOSFET MkII VARIABLE BENCH POWER SUPPLY 0 25V 2 5A Based on our Mk1 design and preserving all the features but now with switchin pre regulator for much higher effi ciency Panel meters indicate Volts and Amps Fully variable down to zero Toroidal mains transformer Kit includes punched and printed case and all parts As featured in April 1994 EPE An essential piece of equipment 704 PIC PIPE DESCALER e SIMPLE TO BUILD e SWEPT e HIGH POWER OUTPUT FREQUENCY e AUDIO amp VISUAL MONITORING An affordable circuit which sweeps the incoming water supply with mc WATER variable frequency electromagnetic D SCALER signals May reduce scale formation dissolve existing scale and improve lathering ability by altering the way salts in the water behave Kit includes case P C B coupling coil and all components High coil current ensures maximum effect L E D monitor KIT 868 22 95 MICRO PEsT SCARER Our latest design The ultimate scarer for the garden Uses special microchip to give random delay and pulse time Easy to build reliable circuit Keeps pets pests away from newly sown areas play areas etc uses power source from 9 to 24 volts e RANDOM PULSES e HIGH POWER e DUAL OPTION ie ore eT eee ee eee ee POWER UNIT 3 99 KIT SLAVE U
101. TH amp 32 BIT DIVISION I recently asked Peter Hemsley how easy it would be to expand his PIC 16 bit 16 bit divi sion routine in the PIC Tricks folder on our ftp site to 32 bit 16 bit He replied If there is a Carry out from the Shift left then force the subtraction as in the following This has not been thoroughly tested but seems to work OK By the way a 32 32 divide would involve a 32 bit comparison and a 32 bit sub traction A tiresome job in PIC language divide movlw 32 32 bit divide by 16 bit movwf bitcnt clrf remdrH clrf remdrL Clear remainder clrc Set quotient bit to 0 Shift left dividend and quotient rlf dividO Isb rlf divid1 rlf divid2 rlf divid3 rlf remdrL Isb into carry and then into partial remainder rlf remdrH Check for overflow skpne goto subd movfw divisH Compare partial remainder and divisor SHOCK HORROR 2 Dear EPE Regarding the Shock Horror Tale from Stan Hood in Readout Sept 02 I d just like to empha sise the point that anything delivering shocks should always be properly investigated It might be only static but equally it might not A couple of years ago I noticed I was receiv ing tiny shocks from our refrigerator Subsequent investigation suggested that the actual source of the current causing these shocks was probably capacitive coupling to the motor windings unlikely to be dangerous but it should have been conducted to earth long bef
102. Vol 31 No 10 Easy to build metal detector NY wii ities mr New Technology Update one sh sen i Copyright 2002 Wimborne Publishing Ltd Allen House East Borough Wimborne Dorset BH21 1PF 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 Maxfield amp Montrose Interactive Inc are copyrighted You are permitted to make a backup copy of the downloaded file and one 1 hard copy of such materials and works for your personal use International copyright laws however prohibit any further copying or reproduction of such materials and works or any republication of any kind Maxfield amp Montrose Interactive Inc and Wimborne Publishing Ltd have used their best efforts in preparing these materials and works However Maxfield amp Montrose Interactive Inc and Wimborne Publishing Ltd make no warranties of any kind expressed or implied with regard to the documentation or data contained herein and specifically disclaim without limitation any implied warranties of merchantability and fitness for a particular purpose Because of possible variances in the quality and condition of materials and workmanship used by readers EPE Online its publishers and agents disclaim any responsibility for the safe and proper functioning of reader constructed projects b
103. W LISTEN LIKE CONNECTS WIRE TO METAL ECC EARTH SLAVE END PLUG REAA VIEW zamm STEREG JACK SOCKET TALK VA REAR VIEW OA TO SUIT HEADSET THR CONNECTIONS LIKED TOGETHER ALL CONNECTIONS rel BE IEOLATED FROM EAATH TN 3 a LISTER LINK MIRE CONNECTS TO METAL BODY EARTH Everyday Practical Electronics October 2002 Fig 5 Interwiring details for one Slave unit 3 5m STEREO JACK SOCKET OF TO SUIT HEADSET TF CONNECTIONS LIKED TOGETHER must be connected to earth OV However it will probably be mounted next to the phones socket for cosmetic reasons If it is on plastic you will need to hard wire its sleeve connection to the solder tag Note the sense of the wiring to the Volume control VR3 potentiometer tags This gives conventional operation clock wise rotation increasing the volume Note also that only one current limiting resistor R13 is needed for the slave indi cator l e d s This is because only one L e d can be illuminated at a time SLAVE UNITS Choose plastic boxes of appropriate size for the Slave units and fit the belt clips if required Check the layout of internal parts General layout of components on the Master unit metal front panel EW BATTERY SLEEVE CORMECTION 4 4mm STEREO JACK SOCKET OF TO SUIT HEADSET TIP CONNECTIONS LINKED TOGETHER ALL CONNECTIONS MUST BE ISOLATED FROM EARTH VAs REAR VIEW and drill holes for them Do no
104. al points arising 751 DIRECT BOOK SERVICE 760 A wide range of technical books available by mail order plus more CD ROMs PRINTED CIRCUIT BOARD AND SOFTWARE SERVICE 763 PCBs for EPE projects Plus EPE project software ELECTRONICS MANUALS 764 Essential reference works for hobbyists students and service engineers Wimborne Publishing Ltd 2002 Copyright in all drawings photographs and articles published in ADVERTISERS INDEX 768 EVERYDAY PRACTICAL ELECTRONICS is fully A i protected and reproduction or imitations in whole or SPECIAL SUPPLEMENT Collecting and Restoring Vintage Radios in part are expressly forbidden by Paul Stenning Between pages 732 and 733 Our November 2002 issue will be published on x P Thursday 10 October 2002 See page 699 for details Readers Services Editorial and Advertisement Departments 707 Everyday Practical Electronics October 2002 697 Visit our website www distel co uk GIANT 10 7 SEGMENT DISPLAYS A bulk purchase enables us to bring to you these GIANT 7 segment digital displays at a now affordable price The 10 character size gives exceptional read ability at long distances and enables a host of applica tions including score boards digital clocks coun ters event timers etc As the units are a simple electromechanical device and operate from 12V DC simple switching via switches relays PIC or PC may be used to control single or multiple digits Units feature integral
105. and chip manufacturers need mass production and the LM3909 went the way of many other interesting chips The Zetex ZSCT1555 is a bipolar low voltage 555 equivalent that is described as a precision single cell timer A supply operation of just 0 9V is guaranteed by the makers but to get the best out of the chip you will need to be skilled in low power design The maker s data sheet shows a 1 5V to 5V voltage converter circuit that an average reader could build designed as a low voltage equivalent for the 555 and is claimed to operate at 0 9V For a traditional discrete 5V logic cir cuit there are several ways of powering it from batteries the crudest way would be with a Zener diode perhaps running from 6V except that Zeners have relatively poor tolerances and are wasteful of energy The 6V battery pack does not provide much headroom either so it isn t long before the total power supply voltage falls below 5V anyway A better way might be to use a 5V fixed voltage regulator but unless a low dropout type is used these devices have a typical dropout voltage of 2V to 3V or so dissi pating valuable battery power in the process implying a battery voltage of 7V to 8V d c or more is required A 9V bat tery would then be the most obvious choice because it will take longer before the supply falls below a useful level The bottom line is that for typical dis crete projects there isn t much choice about the typ
106. ans that when changing logic levels are trying to be captured there is a possibility of inconsistent or unexpect ed results being displayed Also no matter what settings you select the PIC frantically transfers data as fast as it can to the PC and does not store any of the results internally This means that the capture speed is limited to the maximum speed of the serial inter face making it quite slow in relation to today s computer speeds CONCLUSION The Digital I C Tester has successfully tested a variety of i c s without any prob lem including 74 74F 74LS 74HC and CMOS 4000 series The only slight excep tion to this was with the HC series These refused to test correctly with the original prototype which used 330Q buffer resistor modules RMI to RM3 These were swapped for 1009 ones as specified for this published version and then the offend ing 1 c s tested fine The design aims to give a go no go logic report on the 1 c being tested It is beyond the scope of the tester to attempt to measure the i c s analogue operational parameters and compare them with its technical specifi cation Perhaps when a PIC is available with 24 onboard analogue to digital converters the author will revisit the design ACKNOWLEDGEMENT The author would like to thank his brother Peter for supplying a large selection of test subjects most of which looked like they belong in the Science Museum RESOURCES All soft
107. ased on or from information published in these materials and works In no event shall Maxfield amp Montrose Interactive Inc or Wimborne Publishing Ltd be responsible or liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or any other damages in connection with or arising out of furnishing performance or use of these materials and works GAS MASKS RUSSIAN new and boxed NATO filter 39 CCTV SYSTEM Low cost outdoor IR illumination complete with cables and p s u Just 22 99 Ref CCTVCAMS LOW COST NIGHT VISION system Russian handheld complete with infra red illuminator I00m range Runs on 2 AA batteries just 109 95 COBRA NIGHT VISION equipment also stocked more info on our web site at www cobra optics co uk ELECTRIC SCOOTERS 18kph 24V motor 6 hour charge time 22kg weight max load 90kg running time up to 1 hour range 15km 8 5A motor 24V direct drive Our Price 229 95 Ref ESCOOT VOICE CHANGERS Hold one of these units over your phone mouthpiece and you can adjust your voice using the controls on the unit Battery operated 15 Ref CC3 LIGHTWEIGHT DOME TENTS 120cm x 210cm 8 Ref TENTA EMMINENCE LOUDSPEAKERS 12in dia 50W nom 100W peak 16 ohm impedance Pack of 4 just 19 95 Ref SPEAK39 PIR SECURITY SWITCHES These brand new swivel mounting PIR units will switch up to 2 kilowatts Adjustable sensitivity light level and time delay 9
108. at is a sharper transition between silence and singing while a lower value will provide a gentler transition For best results the search head is moved slowly to and fro over the ground just skimming its surface May you be rewarded with much bounty L Finished control box mounted to the handle and search head shaft Everyday Practical Electronics October 2002 It may surprise you but buying an Antex soldering iron costs less than you think in the long run British made to exacting standards they last significantly longer than imported brands And with a wide range of thermally balanced soldering irons you can pick up a fixed temperature or in handle temperature model that will suit your needs perfectly None of which will burn a hole in your pocket If your hobby demands the best iron for the job but you don t want to get your fingers burnt by the cost visit our website or your electronics retailer for the coolest models around Pickup an f e a ANTEX ele es Not just any old iron A 3 r M 000 sm SOL m www antex co u 2 Westbridge Industrial Estate Tavistock Devon PL19 8DE Tel 01822 613565 713 A roundup of the latest Everyday News from the world of electronics VIRTUAL KEYBOARDS Will anyone ever produce a virtual keyboard asks Barry Fox BA company UbiNetics has patent ed but already lost interest in a device which could have finally
109. at they are correctly orientated their Faraday shield connections being side by side see the Sas a Mounting of the p c b controls and sounder in the case shaft Search Coils cross head earlier Adjust VR2 VR3 and VR4 to their mid points Adjust VRI to 780 ohms Attach a 12V battery pack and switch on The circuit should be singing that is beeping loud ly and continuously Now slowly move the coils apart When they are somewhere past the halfway mark the piezo sounder will fall silent This is where the voltages in the receiver Rx coil null Note that there may be a few peaks and troughs in the volume as you move the coils apart you need to find a place of vir tually complete silence Continue to move the coils apart At a precise point in a very narrow slice between silence and singing the piezo sounder will crackle or it might hum and then crackle Now edge the coils closer together again ever so slightly adjusting preset VR4 as you go so as to maintain a loud singing in the piezo sounder not just a hum until the coils cannot be edged any closer while still maintaining the loud 20mm OUTER DIA P V C APPROX 160mm 5mm x 30mm Je THROUGH BOLTS 2 WASHERS Y AND NUTS M 7 TL amp 90 ANGLE BEND TO SUIT 20mm OUTER DIA P V C SCREENED AUDIO CABLE 5mm x 30mm ____ THROUGH BOLTS WASHERS AND NUTS Case mounted between the
110. atch the headset to the MICI and Phones wires Note that the sleeve of the microphone plug must connect to right hand MIC1 wire on the p c b that is the one connected to the OV line In the proto type unit the microphone plug was a 3 5mm stereo jack type but either tip connection could be used because they were connected together internally The prototype headphones were also wired to a 3 5mm stereo jack plug In this case each tip connection was responsible for one unit while the sleeve was common to both This enables the head phones to be used individually for stereo applications Here both tips need to be connected together so that the units appear in parallel and provide mono operation The common tips connect to one wire and the sleeve to the other This procedure may need to be modified depending on the plugs fitted to the headsets Referring to Fig 5 the Slave unit wiring solder potentiometer VR3 tags to its wires in the sense shown Adjust it to approxi mately mid track position Insert the i c s into their sockets Since these are CMOS devices they could be damaged by static charge which may have accumulated on the body To avoid possible problems touch something which is earthed such as a metal water tap before unpacking them and handling the pins Do not throw away the packaging because it will be needed again IT S WORKING Do not put the headset on initially in
111. atile Bench Power Suppl 333 PIC Spectrum Analyser FEB 02 334 7 13 Printed circuit boards for most recent EPE constructional projects are available from Versatile Current Monitor 335 4 75 the PCB Service see list These are fabricated in glass fibre and are fully drilled and Guitar Practice Amp 336 5 39 roller tinned All prices include VAT and postage and packing Add 1 per board for X PIC Virus Zapper MAR 02 337 airmail outside of Europe Remittances should be sent to The PCB Service RH Meter Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road PIC Mini Enigma Software only East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 Programming PIC Interrupts Software onl E mail orders epemag wimborne co uk On line Shop www epemag PIC Controlled Intruder Alarm wimborne co uk shopdoor htm Cheques should be crossed and made payable to PIC Big Digit Display Everyday Practical Electronics Payment in sterling only Wachina Roady Indie NOTE While 95 of our boards are held in stock and are dispatched within eS cae eet seven days of receipt of order please allow a maximum of 28 days for delivery AUdio Circuits 1 LM386N 1 overseas readers allow extra if ordered by surface mail TDA7052 Back numbers or photostats of articles are available if required see the Back TBA820M Issues page for details a cared Please check price and availability in the latest issue
112. ationwide and I am seeking to attract both written and broadcast TV media Therefore I believe that capturing environmental data will further give credibility to the project as a worthwhile thing for others to do as well We can therefore show the actual improvement of the local environment in terms of lower temper ature moisture retention and reduced levels of CO and CO I also have a budget constraint I would like it all to cost including the computer less than 1 000 and will do the installation myself Rune Kongshaug New York via email We are not familiar with such things Rune except in the context of hobbyist weather moni toring However in the UK we have a big envi ronmental greenhouse type project covering many acres called the Eden Project Perhaps they might use such monitoring equipment their web address is www edenproject com I ve recently been there and it s fascinating RELAYING INFO Dear EPE I am an Electrical Engineering student at the Cape Technikon South Africa I was reading your magazine when I saw the types of relays that you sell I was wondering if you could send me the information on the different applications of the relays I need this information to finish my project Miss Babalwa Cosa via email Sorry to disappoint you but we don t actually sell components that s the role of our advertis ers and we suggest that you contact any of those who sell relays for more informa
113. bat FREE WITH EACH TEACH IN CD ROM Electronics Hobbyist Compendium 80 page book by Robert Penfold Covers Tools For The Job Component Testing Oscilloscope Basics ELECTRONICS IN CONTROL Two colourful animated courses for students on one CD ROM These cover Key Stage 3 and GCSE syllabuses Key Stage 3 A pictorial look at the Electronics section featuring animations and video clips Provides an ideal introduction or revision guide including multi choice questions with feedback GCSE Aimed at the Electronics in many Design amp Technology courses it covers many sections of GCSE Electronics Provides an ideal revision guide with Homework Questions on each chapter Worked answers with an access code are provided on a special website Single User 29 inc VAT Multiple User 39 plus VAT Student copies available only with a multiple user copy 6 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices MODULAR CIRCUIT DESIGN Contains a range of tried and tested analogue and digital circuit modules together with the knowledge to use and interface them Thus allowing anyone with a basic understanding of circuit symbols to design and build their own projects Version 3 includes data and circuit modules for a range of popular PICs includes PICAXE circuits the system which enables a PIC to be programmed without a programmer and without removing it from the circuit Shows where to obtain free software downloads to e
114. ble sup plied 9V operation 3021KT 15 95 kit form only TRVS TAPE RECORDER VOX SWITCH Used to automati cally operate a tape recorder not supplied via its REMOTE sock et when sounds are detected All conversations recorded Adjustable sensitivity amp turn off delay 115x19mm 3013KT 9 95 AS3013 21 95 700W power PCB 48mm x 65mm Box provided 6074KT 17 95 3 INPUT MONO MIXER Independent level con trol for each input and separate bass treble controls Input sensitivity 240mV 18V DC PCB 60mm x 185mm 1052KT 16 95 NEGATIVE POSITIVE ION GENERATOR Standard Cockcroft Walton multiplier circuit Mains voltage experience required 3057KT 10 95 LED DICE Classic intro to electronics amp circuit analysis 7 LED s simulate dice roll slow down amp land on a number at random 555 IC circuit 3003KT 9 95 STAIRWAY TO HEAVEN Tests hand eye co ordi nation Press switch when green segment of LED lights to climb the stairway miss amp start again Good intro to several basic circuits 3005KT 9 95 ROULETTE LED Ball spins round the wheel slows down amp drops into a slot 10 LED s Good intro to CMOS decade counters amp Op Amps 3006KT 10 95 12V XENON TUBE FLASHER TRANSFORMER steps up a12V supply to flash a 25mm Xenon tube Adjustable flash rate 3163KT 13 95 LED FLASHER 1 5 ultra bright red LED s flash in 7 selectable patterns 3037MKT 5 95
115. bulbs by inserting 3 TRIACs Adjustable rotation speed amp direction PCB 54x112mm 1026KT 15 95 BOX for mains opera tion 2026BX 9 00 DISCO STROBE LIGHT Probably the most excit ing of all light effects Very bright strobe tube Adjustable strobe frequency 1 60Hz Mains powered PCB 60x68mm Box provided 6037KT 28 95 ANIMAL SOUNDS Cat dog chicken amp cow Ideal for kids farmyard toys amp schools SG10M 5 95 3 1 2 DIGIT LED PANEL METER Use for basic voltage current displays or customise to measure temperature light weight movement sound lev els etc with appropriate sensors not supplied Various input circuit designs provided 3061KT 13 95 IR REMOTE TOGGLE SWITCH Use any TV VCR remote control unit to switch onboard 12V 1A relay on off 3058KT 10 95 SPEED CONTROLLER for any common DC motor up to 100V 5A Pulse width modulation gives maximum torque at all speeds 5 15VDC Box provided 3067KT 12 95 3 x 8 CHANNEL IR RELAY BOARD Control eight 12V 1A relays by Infra Red IR remote control over a 20m range in sunlight 6 relays turn on only the other 2 toggle on off 3 oper ation ranges determined by jumpers Transmitter case amp all components provided Receiver PCB 76x89mm 3072KT 52 95 PRODUCT FEATURE COMPUTER TEMPERATURE DATA LOGGER PC serial port controlled 4 channel temperature meter either deg C or F Requires no external power Allows continuous temperature data logging of u
116. ccepts open dipole Ground Plane 5 8 J or YAGI antennas 12 18VDC PCB 70x220mm SWS meter needed for alignment 1021KT 99 95 SIMILAR TO ABOVE BUT 25W Output 1031KT 109 95 STABILISED POWER SUPPLY 2 30V 5A As kit 1007 above but rated at 5Amp Requires a 24VAC 5A transformer 1096KT 27 95 MOTORBIKE ALARM Uses a reliable vibration sensor adjustable sensitivity to detect movement of the bike to trigger the alarm amp switch the output relay to which a siren bikes horn indicators or other warning device can be attached Auto reset 6 12VDC PCB 57x64mm 1011KT 11 95 Box 2011BX 7 00 CAR ALARM SYSTEM Protect your car from theft Features vibration sensor courtesy boot light voltage drop sensor and bonnet boot earth switch sensor Entry exit delays auto reset and adjustable alarm duration 6 12V DC PCB 47mm x 55mm 1019KT 11 95 Box 2019BX 8 00 PIEZO SCREAMER 110dB of ear piercing noise Fits in box with 2 x 35mm piezo elements built into their own resonant cavity Use as an alarm siren or just for fun 6 9VDC 3015KT 10 95 COMBINATION LOCK Versatile electronic lock comprising main circuit amp separate keypad for remote opening of lock Relay supplied 3029KT 10 95 ULTRASONIC MOVEMENT DETECTOR Crystal locked detector frequency for stability amp reliability PCB 75x40mm houses all components 4 7m range Adjustable sensitivity Output will drive external relay circuits 9VDC 3049KT 13 95 PI
117. cept in deep rural areas cells are only a few miles wide and in urban areas there may be several per mile So if the network tracks the speed at which a cellphone moves from cell to cell it gives a good indication of the cellphone s movements Tracking a large number of phones increases accuracy To overcome disadvantages of previously proposed systems and avoid the clutter of misinformation which will come from inevitably tracking phones carried by walkers cyclists or train passengers NEC weights the information gathered so that phones used to call up for traffic information will have most effect on the average speed deduced from cell hand overs in any area This can create a virtuous circle If cellphone users know they are contribut ing to the accuracy of a service they will be more inclined to access the service for information especially if whatever sub scription they pay to receive the traffic flow information is reduced in return for agreeing to let their phones be used as a source of information for the service DONATE YOUR OLD PC TOUGH new legislation will come into force in the UK by 2005 banning the scrapping of old computers Computer Aid International the world s largest non profit supplier of computers to developing countries is calling on cor porates and the public sector to donate their end of life PCs to schools and com munity groups for worthwhile projects overseas The charity is seeki
118. conduit handle and search head singing It is at this precise point not a fraction of a millimetre this way or that that the coils need to be set The main purpose of preset VR4 is to find the precise point at which there is a crisp transition from silence to singing With the correct setting any intermediate hum should be eliminated While the hum does not affect performance it may be a distraction MAKE YOUR MARK Take a marker pen and mark a series of holes in the baseplate around both sides of the coils These holes are used to pass 2 5mm cable ties through to hold the coils tightly to the baseplate Use five or six cable ties for each coil to ensure that they are firmly and flatly secured before pour ing the resin Also use cable ties to secure the audio cables as well Further glue some light weight wooden ribs across the bottom of the search head to the baseplate across the centre of the coils Their purpose is to CONTROL BOX AUDIO CABLES RUN THROUGH SHAFT 20mm OUTER DIA P V C SHAFT APPROX 1 2M PLASTIC W C SEAT HINGE NUT AND BOLT SET SQUARE DOWNPIPE SOCKET HALVED SECURED WITH 4mm CABLE TIES SEARCH HEAD Fig 5 General construction of the hardware items The finished search head 712 Everyday Practical Electronics October 2002 limit shrinkage in the resin since this could seriously unbalance the circuit Use some Blu tack or Pres stik to tight
119. covered include propagation receivers transmitters and aerials etc Order code BP257 5 49 150 pages VALVE RADIO AND AUDIO REPAIR HANDBOOK Chas Miller This book is not only an essential read for every profes sional working with antique radio and gramophone equipment but also dealers collectors and valve tech nology enthusiasts the world over The emphasis is firm ly on the practicalities of repairing and restoring so technical content is kept to a minimum and always explained in a way that can be followed by readers with no background in electronics Those who have a good grounding in electronics but wish to learn more about the practical aspects will benefit from the emphasis given to hands on repair work covering mechanical as well as electrical aspects of servicing Repair techniques are also illustrated throughout A large reference section provides a range of infor mation compiled from many contemporary sources and includes specialist dealers for valves components and complete receivers Order code NE34 20 99 288 pages Computers and Computing MULTIMEDIA ON THE PC lan R Sinclair In this book you ll find out what a CD ROM is how it works and why it is such a perfect add on for a PC allowing you to buy programmes text graphics and sound on a CD It also describes the installation of a CD ROM drive and a sound card pointing out the common problems that arise and then shows how to use them to creat
120. creative experimenter all based on inverting logic gates principles which allow CMOS invert ers to be used as oscillators conclud ing with an example of a Colpitts oscillator We conclude this two part series by first examining a ccrystal oscillator circuit CRYSTAL OSCILLATOR The high frequency crystals used to set the clock frequency in computers can replace L in the Colpitts circuit of Fig 10 The circuit is then sometimes called a Pierce oscillator Fig 11 although this nomenclature is dubious Since a crystal blocks d c a resistance R1 must be added to allow d c negative feedback to set the working point This resistance should be high enough not to impair the oscillation Crystal manufacturers specify the value of shunt capacitance needed to trim the frequency to its nominal value In the pi net work the two capacitances are effectively in series so each should be twice the quoted shunt capacitance The frequency can be fine tuned by adjusting one or both of them It is possible that oscillation may be too violent A feedback control VR1 may also be used as with the Colpitts oscillator Crystal manufacturers may specify a safe operating voltage and VRI can be set to AST month we examined the basic CRYSTAL Fig 11 Pierce crystal oscillator Here the crystal replaces L in the Colpitts circuit 742 ensure that it is not exceeded Generally speaking it is sufficient to set VR1 so that reliable
121. cted again thus leaving the enemy in position 16h In this program the effect of a ship trying to move out of the screen area will therefore result in a no move instruction and this will apply to both the enemy ship and the cursor The program could easily be changed so that if the above occurred the enemy position could become 10h simply by loading ENMY with 10h when 17h is detected instead of subtracting Olh from this register If this was made to apply only to the ENMY register and not to the AIM cursor register the enemy ship would become much harder to catch This could be done by setting or clearing a spare bit in the FLAG register bit 4 say and on this basis either subtracting Olh or resetting the target register to 10h as required Pressing the move right switch when the cursor is at position 16h however will still result in the enemy warship moving in accordance with the contents of the RND register at that instant although the cursor will not move CONSTRUCTION The PIC Pocket Battleships control cir cuit is assembled on a piece of stripboard 24 strips long by 24 holes wide This accommodates all of the components except the switches and the battery which are connected to the board by flying leads The component layout and track cut details are shown in Fig 4 First make the 24 required breaks in the tracks using a 2 5mm diameter drill bit or the special tool available for this purpose Next
122. d and ultrasonic and also explore the possibilities provid ed by using an additional third motor For the less experienced RCX code programs accompany most of the featured robots However the more adventurous reader is also shown how to write programs using Microsoft s VisualBASIC running with the ActiveX con trol Spirit OCX that is provided with the RIS kit Detailed building instructions are provided for the fea tured robots including numerous step by step pho tographs The designs include rover vehicles a virtual pet a robot arm an intelligent sweet dispenser and a colour conscious robot that will try to grab objects of a specific colour Order code BP902 14 99 298 pages ANDROIDS ROBOTS AND ANIMATRONS Second Edition John lovine Build your own working robot or android using both off the shelf and workshop constructed materials and devices Computer control gives these robots and androids two types of artificial intelligence an expert sys tem and a neural network A lifelike android hand can be built and programmed to function doing repetitive tasks A fully animated robot or android can also be built and pro grammed to perform a wide variety of functions The contents include an Overview of State of the Art Robots Robotic Locomotion Motors and Power Controllers All Types of Sensors Tilt Bump Road and Wall Detection Light Speech and Sound Recognition Robotic Intelligence Expert Type Using a S
123. d look for any solder splashes or bridges that might have occurred during assembly Using a multi meter set to ohms check the resistance across capacitor C4 to ensure that there is no short circuit A brief reading may be obtained whilst C3 and C4 charge If all is OK continue testing otherwise do not attempt to apply power until the problem has been removed as ICI the bridge rectifier or the power supply unit could be damaged Making sure that the board is not resting on anything conductive connect a suitable Everyday Practical Electronics October 2002 power supply Switch on the power and Le d D1 should illuminate Switching the multimeter to d c volts measure the volt age on pins 11 VE and 31 GND of the socket for IC3 A reading of approximately SV within a few percent should be seen If the 5V rail is not present or L e d D1 does not illuminate carefully check around ICI and IC3 for short circuits or dry joints and check the polarity of the D1 Switch off the power supply and discon nect it from the mains supply when making any changes to the board ASSEMBLY COMPLETION Once everything seems to be in order insert IC2 and IC3 being careful of correct orientation and not to let any of the i c pins bend under whilst being inserted The PIC IC3 can either be a preprogrammed ver sion see later or if a suitable in circuit programmer is available Toolkit Mk3 TK3 for instance it can be programmed on
124. ding Comprehensive instruction through 39 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 Virtual PlCmicro C FOR PiCmicro VERSION 2 The C for PlCmicro microcontrollers CD ROM is designed for students and professionals who need to learn how 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 PICmicro 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 PICmicro devices
125. ding of digital electronics Those who prefer the Teach In approach or would rather experiment with some simple circuits should find the book s final chapters on printed circuit board produc tion and project ideas especially useful fol eee NTI 19 99 88 pages 5 49 250 pages large format A BEGINNER S GUIDE TO TTL DIGITAL ICs R A Penfold This book first covers the basics of simple logic circuits in general and then progresses to specific TTL logic integrated circuits The devices covered include gates oscillators timers flip flops dividers and decoder cir cuits Some practical circuits are used to illustrate the use of TTL devices in the real world 142 pages Order code BP332 5 45 HOW TO USE OP AMPS E A Parr This book has been written as a designer s guide covering many operational amplifiers serving both as a source book of circuits and a reference book for design calculations The approach has been made as non math ematical as possible Order code BP88 4 49 CIRCUIT SOURCE BOOK 2 R A Penfold This book will help you to create and experiment with your own electronic designs by combining and using the vari ous standard building blocks circuits provided Where applicable advice on how to alter the circuit parameters is provided The circuits covered are mainly concerned with signal generation power supplies and digital electronics The topics covered in this book
126. dows Explorer and the newly installed Powertoys you need to open a command window in the installation direc tory see Fig 5 Once the command window has opened you need to execute the following instruc tion from the command line see Fig 6 Allowio tk3prog exe a Following the execution of the above command you will have TK3PROG run ning on your Windows XP machine It is suggested that the Check PCB functional ity within TK3 is used to ensure that all communications from the PC to the PIC programming hardware are working OK TESTING UNDER 2K To test the installation under Windows 2000 you need to open a CMD window in the installation directory note that this is different to a Command window that is available within the same operating system The easiest way to achieve this is to use Windows Explorer to select the installa tion directory and then open a CMD win dow Windows 2000 will automatically Biain O ir age Hi i a Geo ew Ee at Fig 7 Opening a CMD window at a chosen location within Windows 2000 note Toolkit3 selected within Windows Explorer Everyday Practical Electronics October 2002 open the window at the directory selected within Windows Explorer see Fig 7 To open the command window follow the path Start gt Run and then type CMD into the run line and press lt ENTER gt Once the CMD window has opened you need to execute the following instruction from the CMD line Allowio tk3pro
127. e a complete multimedia presentation that con tains text photos a soundtrack with your own voice recorded as a commentary even animation and edited video footage Order code PC112 12 95 HOW TO BUILD YOUR OWN PC Third Edition Morris Rosenthal More and more people are building the own PCs They get more value for their money they create exactly the machine they want and the work is highly satisfying and actually fun That is if they have a unique begin ners guide like this one which visually demonstrates how to construct a state of the art computer from start to finish Through 150 crisp photographs and clear but minimal text readers will confidently absorb the concepts of computer building The extra big format makes it easy to see what s going on in the pictures For non special ists there s even a graphical glossary that clearly illustrates technical terms The author goes under the hood and shows step by step how to create a socket 7 Pentium and non intel chipsets and a Slot 1 Pentium Il computer covering What first time builders need to know How to select and purchase parts How to assemble the PC How to install Windows 98 The few existing books on this subject although badly outdated are in steady demand This one delivers the expertise and new technology that fledgling computer builders are eagerly looking for 224 pages large format SRo E CL ER 20 99 184 pages PIC YOUR PERSONAL INTR
128. e changeover Pack of 10 Order Ref 1053 PAXOLIN PANEL Approximately 12in x 12in Order Ref 1033 CLOCKWORK MOTOR Suitable for up to 6 hours Order Ref 1038 HIGH CURRENT RELAY 12V d c or 24V a c oper ates changeover contacts Order Ref 1026 3 CONTACT MICROSWITCHES operated with slight est touch pack of 2 Order Ref 861 HIVAC NUMICATOR TUBE Hivac ref XN3 Order Ref 865 or XN11 Order Ref 866 2IN ROUND LOUDSPEAKERS 50Q coil Pack of 2 Order Ref 908 5K POT standard size with DP switch good length Yin spindle pack of 2 Order Ref 11R24 13A PLUG fully legal with insulated legs pack of 3 Order Ref GR19 OPTO SWITCH on p c b size 2in x 1in pack of 2 Order Ref GR21 COMPONENT MOUNTING PANEL heavy Paxolin 10in x 2in 32 pairs of brass pillars for soldering bind ing components Order Ref 7RC26 HIGH AMP THYRISTOR normal 2 contacts from top heavy threaded fixing underneath think amperage to be at least 25A pack of 2 Order Ref 7FC43 BRIDGE RECTIFIER ideal for 12V to 24V charger at 5A pack of 2 Order Ref 1070 TEST PRODS FOR MULTIMETER with 4mm sockets Good length flexible lead Order Ref D86 LUMINOUS ROCKER SWITCH approximately 30mm square pack of 2 Order Ref D64 MES LAMPHOLDERS slide on to in tag pack of 10 Order Ref 1054 HALL EFFECT DEVICES mounted on small heatsink pack of 2 Order Ref 1022 LARGE MICROSWITCHES 20mm x 60mm x 10mm changeover contacts pac
129. e of battery We would be very happy to see energy efficient low voltage projects using say a couple of coin cells on p c b holders which strikes one as a sensible way of powering projects that a hobbyist could perhaps assemble Our series of solar powered projects Perpetual Projects EPE July 2001 onwards illustrates what can be done with simple low power designs ARW 121 New fechnology Update HIS month there are two items of new technology each in a different area but both related to electronics The first is a fascinating new technique used to move minute particles around using a light beam The second relates to superconductors Moving Particles In some recent developments it has been shown that it is possible to manipulate minute particles using laser beams It is anticipated that this could have applica tions in the manufacture of semiconductors and it is of particular interest and impor tance because particles as small as mole cules or even atoms could be moved using the new technique It may also have other applications in non electronics fields including biomedicine where the process could be used as a form of optical tweez ers to pick up viruses and cells The work by Bath University researchers was reported in a number of papers the latest of which was presented at the Laser and Electro Optic Quantum Electronics and Science Show in May 2002 In this presentation the researchers outlined tha
130. ea Lord with our interoretation of the age old pen and paper game normally played by two players with pencil and paper Its aim is for each opponent to sink the other s fleet before their own fleet is sunk The ships are nor mally marked on a 10 x 10 grid of squares and each player calls out a grid reference in turn to which the other player responds by saying whether it is a hit of a miss The variant of the game described here provides the excitement of the sea chase for just one player who pits his wits against a PIC microcontroller as the other opponent The position of the enemy set by the PIC program is unknown and there are five merchant ships to be protect ed by the battleship These six ship positions are shown on a 5 x 7 light emitting diode l e d matrix display used horizontally T renowned game of Battleships is This 5 x 7 matrixed l e d display measures 39mm x 23mm PLAYING THE GAME When the unit is first switched on the positions of the five merchant ships are indicated by l e d s that are lit continuous ly The position of the battleship is repre sented by a flashing Le d the cursor The enemy battleship is at the centre of the display but its position is not indicated The flashing cursor can be moved to any position on the display by means of four push switches that control movement in the horizontal and vertical direction one position at a time Each time the cursor is moved however
131. ecure server i woe Ey onesies 2 ce http www epemag wimborne co uk shopdoor htm Everyday Practical Electronics October 2002 763 WHETHER ELECTRONICS IS YOUR HOBBY OR YOUR LIVELIHOOD YOU NEED THE MODERN ELECTRONICS MANUAL and the ELECTRONICS SERVICE MANUAL The essential reference work for everyone studying electronics Over 800 pages In depth theory Projects to build Detailed assembly instructions Full components checklists Extensive data tables Manufacturers web links Easy to use Adobe Acrobat format Clear and simple layout Comprehensive subject range Professionally written Regular Supplements EVERYTHING YOU NEED TO GET STARTED AND GO FURTHER IN ELECTRONICS The revised CD ROM edition of the Modern Electronics Base Manual MEM contains practical easy to follow information on the following subjects BASIC PRINCIPLES Electronic Components and their Characteristics 16 sections from Resistors and Potentiometers to Crystals Crystal Modules and Resonators Circuits Using Passive Components 10 sections Power Supplies The Amateur Electronics Workshop The Uses of Semiconductors Digital Electronics 6 sections Operational Amplifiers Introduction to Physics including practical experiments Semiconductors 5 sections and Digital Instruments 3 sections CIRCUITS TO BUILD There s nothing to beat the satisfaction of creating your own projects From basic principles like soldering and
132. ed Universal mid range PIC programmer module Book Experimenting with PIC Microcontrollers Book Experimenting with the PIC16F877 2nd edition Universal mid range PIC software suite E PIC16F84 and PIC16F872 test PICs 157 41 UK Postage and insurance 7 50 Europe postage amp Insurance 13 00 Rest of world 24 00 Experimenting with PIC Microcontrollers This book introduces the PIC16F84 and PIC16C711 and is the easy way to get started for anyone who is new to PIC programming We begin with four simple experiments the first of which is explained over ten and a half pages assuming no starting knowledge except the ability to operate a PC Then having gained some practical experience we study the basic principles of PIC programming learn about the 8 bit timer how to drive the liquid crystal display create a real time clock experiment with the watchdog timer sleep mode beeps and music including a rendition of Beethoven s Fur Elise Finally there are two projects to work through using the PIC16F84 to create a sinewave generator and investigating the power taken by domestic appliances In the space of 24 experiments two projects and 56 exercises the book works through from absolute beginner to experienced engineer level Ordering Information Telephone with Visa Mastercard or Switch or send cheque PO for immediate despatch All prices include VAT if applicable Postage must be added to a
133. eed to use a changeover two way switch with two pull up resistors as shown If the receiver output has glitches then you will need to remove these before they can interfere with the toggle s clock signal One way of doing this is by only letting through pulses that are longer than a cer tain period The circuit in Fig 5 shows a possible implementation A clock e g from a CMOS oscillator or 555 circuit dri ves a shift register The configuration of the AND gate means that the output is only Logic 1 if the input was Logic 1 for 3 clock cycles sim ply set the clock rate to a suitable one In the case of a light switch for example you could make the clock quite slow so that you would have to hold the switch down say for half a second before it took effect The circuit in Fig 5 can be made a little more sophisticated by using another AND gate on the Q Q NOT Q ARW outputs and combining the two AND gate outputs to control a SR flip flop which in turn dri ves the toggle clock Fig 6 Power on reset Lastly another issue with toggling cir cuits is that they may power up in arandom state unless you provide a power on reset POR A POR circuit is shown in Fig 6 when the power is first applied the capaci tor is discharged so the output would be 1 In the moments after the power supply is switched on the capacitor charges up though the resistor eventually crossing the logic threshold of the inverter and s
134. ency The explanation is simple We may have removed our Rs and Cs but the cir cuit has its own built in equivalents R is now the output resistance of each invert er and C the input capacitance of the following one In a particular case R might be 10kQ and C might be 10pF These act like those in Fig 18c The 60 frequency is fa VGRO 3MHz approximately Both the output resistance and the input capacitance of an inverter are affected by the operating voltage The output resis tance is especially strongly affected In experimental tests using a CMOS 4069 inverter biased to operate in the lin ear region of the input output curve the output resistance measured 16kQ when 189 was 5V falling to 5kQ when Ve was This means that the zero component ring of Fig 18a is in reality a voltage con trolled oscillator with Vec as its control voltage Oscillation may be possible at Vcc down to 2V where the frequency is quite low At high Voc it may be tens of megahertz Note that there is a real risk at high Vec of the current drawn becoming excessive and overheating the chip Note also that while standard CMOS c s like the 4069 Everyday Practical Electronics October 2002 are rated to work at up to 15V their modern equivalents like the 74HC04 have much lower maximum Ve ratings It is possible to bring down the fre quency while retaining voltage control Add real capacitors for C while leaving R at zero
135. ents The device recently won CE safety approval in Europe but has not yet got a green light from the US Federal Drug Administration The implant works like a heart pacemak er but is buried in the stomach wall From there it sends out low power electric shock waves which slow the natural peristalsis of the alimentary tract and make the esophageal and pyloric sphincters contract So food takes much longer to pass through and the patient feels full and sated Transneuronix spokesman Stephen Adler says he wants to stay away from details on how the system works but the interna tional patent filings WO 02 43467 claim best results with an implant in muscle near the nerve centres of the lesser curvature of the stomach releasing 12 pulses a per minute each lasting two seconds and being made from a train of much shorter pulses At 5V and 10mA the patient feels no shock The pacemaker can work all the time or be switched on when the patient feels the urge to eat Eighteen hospitals in the US Europe and Australia have been fitting devices it takes an hour under general anaesthesia Dr Cigaina has now published the results of his first tests begun in 1995 Obesity Surgery 12 6S 11S www obesity surgery com All patients lost weight We have had no deaths or major complica tions says Stephen Adler GOODBYE RCS RADIO Component Specialists who you might also know as Baker Loudspeakers Ltd tell us that after 50 years fo
136. ess costly to build yet far more efficient This particular design was developed at the Atomic Energy Commission of NEGEV in Israel 10 set Ref F CVL1 VOICE SCRAMBLER PLANS Miniature solid state system turns speech sound into indecipherable noise that cannot be under stood without a second matching unit Use on telephone to prevent third party listening and bugging 6 set Ref F VS9 PULSED TV JOKER PLANS Little handheld device utilises pulse techniques that will completely disrupt TV picture and sound Works on FM too Discretion advised 8 set Ref F TJ5 BODYHEAT TELESCOPE PLANS Highly directional long range device uses recent technology to detect the presence of living bodies warm and hot spots heat leaks etc Intended for security law enforcement research and development etc Excellent security device or very interesting science project 8 set Ref F BHT1 BURNING CUTTING CO2 LASER PLANS Projects an invisible beam of heat capable of burning and melting materials over a con siderable distance This laser is one of the most efficient convert ing 10 input power into useful output Not only is this device a workhorse in welding cutting and heat processing materials but it is also a likely candidate as an effective directed energy beam weapon against missiles aircraft ground to ground etc Burning and etching wood cutting plastics textiles etc 12 set Ref F LC7 MICRO SCALES Measure 1g to 120g 1g resolution 80
137. et Hodet Photo 5 The testing screen There are four main areas to this win dow The Start and Stop buttons are used to begin and terminate the testing process accordingly The Performance panel is used to get additional information dis played during the testing process If Update Pin Display has a check mark displayed a representation of the i c being tested will be displayed on the screen As the logic levels change on the actual device being tested they will be reflected on this display this is useful when the Single Step option is also selected The function Update Logic Trace will record a trace similar to a storage oscillo scope that can be studied after the testing process has been completed Enabling the Real time Plot option will keep the trace updated as the testing progresses instead of just displaying the results at the end of the test These options if selected will impact on the performance of slower PCs To get the best possible speed do not enable these options However for now enable all three so you can see exactly what happens The Test Mode panel controls how the testing is performed Normally Single Test would be selected If you suspect that a device has an intermittent problem though you can set the software to do a Continuous Test The test cycle will then be repeated up to 999 times Abort On Error will terminate the testing cycle if any error is detected in the 1 c Single
138. etting is select ed and macros are blocked if the highest level is used If you are used to VBA and its version of the BASIC dialect VBA programs can be a valid approach to producing soft ware for your PC projects Even if you do not have MSCOMM on your computer system VBA can still be used with third party add ons such as Inpout32 dil to access the serial and parallel ports One of the free versions of Visual BASIC probably represents a_ better Private Sub etter Clich ii Fig 4 The serial transmission program Values set on the slider control are transmitted from the serial port In this case the VBA program can be much the same as its Visual BASIC equiva lent It is the routine for the scrollbar that actually transmits the data and the new value is sent each time that a change occurs The Chr function is used to convert the value from the scrollbar into an equivalent ASCII character which is then sent to the serial port for transmission The unprocessed value is displayed on the label component so that the user can see what values are being sent Again the VBA pro gram works as well as the Visual BASIC version and it is shown running in Fig 4 Lockout Situation Programs are saved using the Save Document option under the Edit menu Once the document has saved this option changes to Save XXXX where XXXX is the program name that you Everyday Practical Electronics October 2002 starting point for those startin
139. f obtaining the software and preprogrammed PICs The circuit should work correctly when power is switched on provided it has been wired correctly There are no adjustments to be made PROGRAM VARIATIONS The use of a microcontroller enables various features to be added to the game to make it more interesting and these are lim ited only by the programmer s imagina tion especially as no extra components are required Some of these possibilities have already been mentioned One promising additional idea is to limit the quantity of ammunition carried by your own warship to say ten firings before the ship has to return to port position 40h to replenish its supply A new register defined to count the number of times the fire button is pressed could be used to control this and the register could be reset to ten or some other value each time the cursor went to position 40h A similar idea would be to limit the range of your warship to say 20 moves When this total expired the ship could automatically return to port by loading 40h into the AIM register or perhaps need to make its way back before its fuel ran out A ship that could not return to port would be lost and a new one could appear at the home port In this case the number of warships could be limited to say three so that if these were lost the enemy would win the game This game could also be modified so that each time the enemy ship entered the port
140. f your vehicle s movements It has a large storage capacity for 210 000 positions and if set to record at one minute intervals it can save 145 days of drive time information Designated the G 5010 the recorder is compatible with any PC running Windows con tains a 12 channel GPS receiver and accessory kit comprising external antenna a c power supply cigarette lighter adaptor and control centre software It can also be linked with a GSM modem for remote tracking and data retrieval Two versions of the InfoMap 7 0 mapping software are available Street Router and the Professional The Trip Recorder G 5010 weighs only 120g measures 11 3cm x 5 2cm x 3 3cm and the recommended retail prices for the various models start at 199 99 including VAT For more information contact Directions Ltd Dept EPE PO Box 296 Sevenoaks Kent TN3 1WY Tel 01732 741123 Fax 01732 743345 Email sales directions ltd uk Web www directions Itd uk 714 CAN ELECTRONICS CURE OBESITY By Barry Fox AN ITALIAN inventor and US medical com pany think that implanting an electric shocker in a fat person s stomach can curb wayward appetites Clinical trials suggest it may work and be a lot nicer than having your intestines sewn up stapled together or cut down Italian doctor Valerio Cigaina first tried it on humans in 1995 and Transneuronix of New Jersey has now bought his patents and implanted electrical anti obesity devices in 300 pati
141. ftware that might be installed EPE Teka hes emcouniered a problem and needs jo dot We ane ao loi the incon I sou wasn an fhe meddle of comethang de ninuman pou peste cali on FR baa Lt ee have neaei on nor sepa thal ou can send ious we vali est thoy pagent au conddendil ang ror yt Tones whai dala hn tor report cod e cock bere Serta ot Fig 3 Error generated when running TK3PROG under Windows XP TRSPROG exe has genetsted anpii ard wal be choia by Windows You well need bo resale the program An error bog i beng cregied Fig 4 Error generated when running TK3PROG under Windows 2000 MODIFICATIONS The next step to getting TK3 to run under Windows XP or 2K requires the download of a utility called AllowIO This is available at www beyondlogic org porttalk portta IK21 zip Once downloaded open the zip file and extract the Allowlo exe file into your installation directory in this case C Toolkit3 Also extract the porttalk sys file as follows For Windows XP extract to c windows system32 drivers For Windows 2000 extract to c winnt system32 drivers D Tee ites D Dre ni CF Cire Psia D p Cie Siege ate b J Hej Coin 2 Piste Cases LI ls Preem A 5 Cr eb te E F Fig 5 Opening a command window in the installation directory CW INDOWS ps den fiom aue Fig 6 Executing command line instruc tion in installation directory TESTING UNDER XP Using Win
142. g from scratch Either way it is possible to get into visual programming at no cost Binary Mode A couple of readers have pointed out methods of using MSCOMM in binary mode so that the string conversions can be avoided This is a subject that will be considered in detail when the problem has been investigated fully Strangely the Microsoft documenta tion recommends that the text mode is used for all data transfers using MSCOMM A possible reason for this is that some facilities of MSCOMM seem to disappear when the binary mode is used The text and conversion method is a bit cumbersome but it does have the saving grace that it actually works quite well 747 EPE IS PLEASED TO BE ABLE TO OFFER YOU THESE ELECTRONICS CD ROMS ELECTRONICS PROJECTS Electronic Projects is split into two main sections Building Electronic Projects contains comprehensive information about the components tools and techniques used in developing projects from initial concept through to final circuit board production Extensive use is made of video presentations showing soldering and construction techniques The second section contains a set of ten projects for students to build ranging from simple sensor circuits through to power amplifiers A shareware version of 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
143. g by selecting the Tools menu and then Configuration which produces a display such as in Photo 2 A short cut is to click the spanner icon on the toolbar CCC x Conmaricatorn Coturs Paths Setings Loge anatyser Seal Port COM Pot har res Trjg Interface Speed 19200 19 200 Beau chant Py werta 7 600 eth PL memed din he PL moy meraj bo perse of 19 000 Be thet Fi retaled sri wath a DOME Cr stal Changing he intertace perd eA Mingta FC oltva ae PI eal cir the onana hot ba Brel tottectl Run the banter at the lower paad u i a s conert operation has been vente ee TH Photo 2 Serial communications con figuration screen From here you can change settings that control communication default display colours directories or folder locations and some other ad hoc settings Change the COM port to the required setting and click OK All configuration changes are stored for later use Next you need to test the actual commu nication link between the PC and the Digital I C Tester Again select Tools from the top and this time select Confirm Communication Interface at the bottom of the menu A screen will be displayed detailing some checks you should first make When you are ready click the Start but ton You will see some text scroll up in the panel on the right hand side of the window and perhaps L e d D4 flickering on the tester The panel on the window will turn green if the communications
144. g exe a Following the execution of this com mand you will have TK3PROG running on your Windows 2000 machine It is again suggested that the Check PCB func tionality within TK3 is used to ensure that all communications from the PC to the PIC programming hardware are working OK TIDYING UP To enable easy running of TK3PROG a little tidying up is necessary First you need to create a file to issue the necessary command to the AllowIO executable From Windows Explorer browse to the installation directory and in the right hand side of the Explorer screen right click with the mouse and select New gt Text Document and call it TK3PROG which will automatically be given a TXT extension see Fig 8 for Windows XP Within Windows 2000 the graphics may differ but the process is exactly the same Fig 8 Creating a new text document Now open the new text document by double clicking on it and insert the follow ing text Allowio tk3prog exe a Save the file and exit your text editor Notepad by default Next open a Command window in the installation directory as previously explained depending on your operating system and issue the following command Rename tk3prog txt tk3prog bat Next right click with the mouse in some clear space on the Desktop and select New gt Shortcut Once the Create Shortcut wizard starts the first thing to do is to browse to the now renamed tk3prog bat file as the target Once the wizard
145. g more efficiently Too Many Favorites Usually the first thing a user does when they find an interesting web site is to bookmark it in their Favorites Inevitably a large num ber of bookmarked addresses accrue over time the tools that Microsoft include in MSIE that supposedly help you organise your Favorites are limited to dropping Favorites into suitably named folders A useful tip when surfing you can drag a web URL from Internet Explorer s address bar and drop it onto the desktop into a suitable Favorites folder if you keep your Favorites open on the sidebar Netscape 6 offers more flexibility plus the ability to type in a few handy ContentSaver Professional also lets you organise your web docu ments into categories and you can create notes and add comments highlight text jot down Ideas and save out images if desired You can easily annotate web links for future reference The program does a very good job of helping you to organise your offline files in a user friendly way You can also save and exchange ContentSaver documents with other users on a network so the program goes much further than merely sending a web site URL to colleagues If you like the Microsoft Office way of doing things then this pro gram is definitely worth trying but it will take a little practice to get the best out of it If you want to download an entire web site or certain parts of it then tools such as Web Copier www maximu
146. ge BACK ISSUES ONLY 3 50 each inc UK p amp p Overseas prices 4 each surface mail 5 50 each airmail We can also supply issues from earlier years 1998 except Jan to May July Nov Dec 1999 2000 except Feb July 2001 except May Oct Where we do not have an issue a photocopy of any one article or one part of a series can be provided at the same price ORDER FORM BACK ISSUES PHOTOCOPIES INDEXES LC Send back issues dated CL Send photocopies of article title and issue date CL Send copies of last five years indexes 3 50 for five inc p amp p Overseas 4 surface 5 50 airmail L_ I enclose cheque P O bank draft to the value of L_ Please charge my Visa Mastercard Amex Diners Club Switch CANO sees osc a aes Card Expiry Date SEND TO Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail orders epemag wimborne co uk On line Shop www epemag wimborne co uk shopdoor htm Payments must be in sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order Send a copy of this form or order by letter if you do not wish to cut your issue Everyday Practical Electronics October 2002 741 Special Feature LOGIC GATE INVERTER OSCILLATORS GEORGE HYLTON Part Two A compendium of practical oscillator circuits for the
147. gger IC2 a CMOS 555 monostable timer The timing period was set for 100 milliseconds which was the required stimulus pulse The monostable was fed to a transistor L e d circuit which acts as clock The flux surrounding its motor is detected by the coil and fed to a two transis tor amplifier consisting of TR1 and TR2 The output from the amplifier is then coupled through capacitor C3 to a string of six CMOS a driver and indicator output stage Coil The coil L1 consists of about 2 500 turns of 40s w g 38 American Wire Gauge of QUARTZ CLOCK 3V ue copper wire u a ferrite rod 10mm Cin dia x 45mm 1 4in approximately The coil was placed in close proximity to the small quartz driven clock which was pur chased for 99p It would be possible to take the signal direct from the stepper coil in the clock something that some experimenters might like to try In my case by noting the time of switching the system on and off a record of the number of stimulus pulses was obtained It would also be possible to further divide or multiply the pulses to suit individual applications H King Manchester HCF4069UBE FERRITE ROD k D2 D1 1 75IN x 0 375IN 1N4148 4 COIL LENGTH IN APPROX 2500 TURNS Ca 40 S W G ENAMELLED 10n COPPER WIRE LOW CURRENT OUTPUT 100mS PULSE PER SECOND Fig 1 Circuit diagram for the One Second Crystal Clock Some clocks without seconds hands do not impulse every second 730 Eve
148. h are very cramped at the high frequency end Frequency sweeps max min of 10 are then a practical limit though the circuit will oscillate over a wider sweep The circuit can be used as a selective amplifier with input injected via a high impedance buffer A3 In this case VR2 is a sharpness control and for greatest selectiv ity is set for Just not oscillating The buffer amplifier may also be used if required to inject a frequency locking sig nal into the oscillating circuit An injected signal of a few mV can syn chronise the oscillator How long it stays synchronised depends on the frequency stability of both the oscillator and the sync input Injecting a larger signal increases the locking range but at the risk of false locks where one frequency bears some fractional relation to the other Often the waveform then shows some periodic dis tortion Multi band operation is possible by switching in different pairs of capacitors C For consistent performance each pair must be very accurately matched DUAL INTEGRATOR OSCILLATOR An inverter with feedback from output to input via a capacitor as with Al and A3 in Fig 17 has a gain which falls off as the frequency is raised In a sine wave oscillator this reduces the harmonics which result from distortion The ability to yield good sine waves without special amplitude control circuitry is especially useful at very low frequencies where conventional control using ther
149. has been calculated that the cost of electricity for running a motor used in an industrial pump may be over 100 times the cost of the motor itself when the whole life of the motor is taken into account This means that methods of reducing running costs are far more impor tant than many people realise In addition to this superconducting machines can be made far smaller than their conventional equivalents Large Scale Applications A new start up company in the UK named Diboride Conductors is set to exploit a material called magnesium diboride that promises to bring supercon ductivity to large scale commercial appli cations For many large applications it is expected that magnesium diboride will be far cheaper than the high temperature superconductors and it will also cost less than a third of a machine using copper when all the life time costs are included Conductors are made by filling a metal tube possibly an iron or copper tube with magnesium diboride powder The tube is then drawn in length using a similar process to that used when manufacturing ordinary wire During this process the powder is crushed so that it becomes very much finer Once prepared the wire can be incorporated in the machine as required The one drawback of the material is that it requires temperatures around 20 K for it to operate as a superconductor Whilst this is too low for liquid nitrogen coolers using liquid helium can be used and when all cos
150. have been inserted the wrong way round Are the 1 c s if any inserted the right way round Look at the soldering as well checking for dry grey joints or shorts Otherwise perhaps it relates to the quality or rating of the mains transformer or even a problem with the relay coil specification It does sound as though there isn t enough juice to power the relay coil adequately but it is hard to be more specific Some years ago EPE published my own design for a UV exposure timer unit based on a 555 monostable A timer helps to ensure you get consistent results when developing and etching the board Under exposure is the worst problem because it is often impossible to align register the art work again and re expose for a further period so a timer helps avoid that problem However during prototyping it was found that the timer would re trigger after timing out which was caused by spikes outputted from the mains operated fluores cent lighting A combined delta capacitor and choke suppressor was_ inserted between the timer s output and the UV box by building an in line suppressor unit and this cured the problem ARW Battery Eliminator Why do people keep using 9V batteries in projects They are the most expensive way to power any circuit I use AAA cells which are slightly larger but it does not make the project any less portable I say ban 9V batteries from magazine projects Why use 9V on so many circuits anywa
151. he installation disk in order to add VBA The presence or absence of MSCOMM probably depends on the exact software installed on the PC The more upmarket the software the greater the chances of success It would certainly seem to be the case that it is not included with all ver sions of Microsoft Office It is not difficult to ascertain whether MSCOMM is present on a PC Launch Windows Explorer and then use the search facility to scan the hard disk for a file called MSCOMM OCX The MSCOMM ActiveX control is not installed if this file is not pre sent on the hard drive If this file is present it would probably be possible to use it with one of the free versions of Visual BASIC as well as with VBA s ne Same Difference VBA is not really intended for produc ing normal software and its usual role is in the production of extra commands for applications programs However at a pinch it can be pressed into service as a means of producing software for use with PC based projects The first task is to launch VBA from within the host application and it is normally accessed via the Tools menu 746 Mhie Taura With Microsoft Word for example it is launched by selecting Macro from the Tools menu and choosing Visual BASIC Editor from the submenu No form is produced when VBA has finished loading but a form can be added by selecting User Form from the Insert menu You then have something like Fig 1 which is similar t
152. he search head this is the critical part of the operation which we shall complete after having constructed the circuit Last of all wind long 20mm wide strips of absorbent cloth around each coil thin dishwashing cloth would suit using a lit tle all purpose glue to keep them in place Later when resin is poured over the coils the cloth meshes the coils into the resin CONSTRUCTION EPE Bounty s printed circuit board p c b measures just 76mm x 46mm The GAP IM FOIL BEGINNING BEGINNING TX AND AX COILS WIND A 20mm WIDE STRIP OF FOIL AROUND ALL BUT 1Omm OF CIRCUMFERENCE 100 TURNS 33 3 0 0 ENAMELLED COPPER WIRE g SECURE WITH STUBS OF INSULATING TAPE THEM BIND TIGHTLY ALL ROUMDO WIND 4 20mm WIDE STRIP OF ABSORBENT CLOTH ARDUND TX AND RX COILS oo SHIELD AGAIN BIND TIGHTLY ALL FOUND WITH INSULATING TAPE eaa cuie fy SAPIN FROM SPELD FOIL END WIND A 20mm WIDE STRIP OF FOIL AROUND ALL BUT 10mm OF CIRCUMFERENCE AGAIN BIND TIGHTLY ALL ROUND WITH INSULATING TAPE POSTION AND SECURE TX AND AX COILS WITH CABLE TIES ON AIGID BASE ADD ABS BRACKET AND ELU TAK TO BASE BEFORE POURING RESIN Smm DIA WOOD DOWEL Fig 3 Search head construction for the EPE Bounty topside component layout off board inter wiring and full size underside copper foil master pattern details are shown in Fig 4 This board is available from the EPE PCB Service code 370 Component values and
153. high current triac S f 138 The Street Little Clacton Clacton on sea Brunning Software Essex CO16 9LS Tel 01255 862308 152 Everyday Practical Electronics October 2002 Constructional Project HEADSET COMMUNICATOR TERRY de VAUX BALBIRNIE Portable three channel communication system HIS communication system was originally designed to help in the production of short commercial videos With it the director is able to hold a two way conversation with any one of up to three camera operators It is also possible to speak to all the operators simultaneously No doubt such a system could find many other uses such as in amateur stage work concerts and sports events etc WIRED FOR SOUND In the prototype arrangement the direc tor sits at a small desk console and the remote operators wear units clipped on to their belts Cables which may be of any reasonable length link the remote stations to the main unit The director Master and remote Slave operators wear headsets which are plugged into their units These headsets consist of a pair of headphones or a single headphone having a small boom micro phone attached see photograph FREE SPEECH For the target applications headsets are more convenient than loudspeakers They provide hands free operation and allow the remote operators to move around freely within the limits set by the interconnect ing cables Incoming
154. ics In Control Single User Electronics In Control Multiple User Modular Circuit Design Single User Modular Circuit Design Multiple User OOOOOO OO dododd i SONAE Se oes EE ee OG ee a he EEE EEE E E A L enclose cheque PO in sterling payable to WIMBORNE PUBLISHING LTD for J Please charge my Visa Mastercard Amex Diners Club Switch Card expiry date I card NOs ae gaa eee Bee ees ck Here eek WR Bae Al a ee he eet ae te Switch Issue No a ms Chat TRE Note The software on each version is the same only the licence for use varies HUME jame en eA ew Rae NU de ak oh eee bide os rue POS COUG ne ntt is Tel No ORDERING ALL PRICES INCLUDE UK POSTAGE Student Single User Standard Version price includes postage to most countries in the world EU residents outside the UK add 5 for airmail postage per order ee50b READOUT E mail editorial epemag wimborne co uk John Becker addresses some of the general points readers have raised Have you anything interesting to say Drop us a line WIN A DIGITAL MULTIMETER A 31 2 digit pocket sized I c d multime ter which measures a c and d c volt age d c current and resistance It can also test diodes and bipolar transistors Every month we will give a Digital Multimeter to the author of the best Readout letter All letters quoted here have previously been replied to directly LETTER OF THE MON
155. ies up to complex systems that can happily run applications that would have been considered beyond the abilities of a microcomputer not so long ago It would be very easy to choose a PC system that is inadequate to run your applications efficiently or one which goes beyond your needs and consequently represents poor value for money This book explains PC specifications in detail and the subjects covered include the following Differences between types of PC XT AT 80386 etc Maths co processors Input devices keyboards mice and digitis ers Memory including both expanded EMS and extended RAM RAM disks and disk caches Floppy disk drive formats and compatibility Hard disk drives including interleave factors and access times Display adaptors including all standard PC types CGA Hercules Super VGA etc Contains everything you need to know if you can t tell your EMS from your EGA Order code BP282 5 45 270 pages 128 pages Everyday Practical Electronics October 2002 Theory and Reference Bebop To The Boolean Boogie By Clive call me Max Maxfield Specially imported by EPE Excellent value An Unconventional Guide to Electronics i Fundamentals ar Components and Processes This book gives the big picture of digital electronics This indepth highly readable up to the minute guide shows you how electronic devices work and how they re made You ll discover how transistors operate how
156. ilters 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 men dew eee 2g pe ed a Filter synthesis ELECTRONICS CAD PACK PCB Layout Electronics CADPACK allows users to design complex circuit schematics to view circuit animations using a unique SPICE based simulation tool and to design printed circuit boards CADPACK is made up of three separate software modules These are restricted versions of the full Labcenter software ISIS Lite which provides full schematic drawing features including full control of drawing appearance automatic wire routing and over 6 000 parts PROSPICE Lite integrated into ISIS Lite which uses unique animation to show the operation of any circuit with mouse operated switches pots etc The animation is compiled using a full mixed mode SPICE simulator ARES Lite PCB layout software allows professional quality PCBs to be designed and includes advanced features such as 16 layer boards SMT components and an autorouter operating on user generated Net Lists ROBOTICS amp MECHATRONICS i a 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
157. imensions 150 x 80 x 50mm 14 pin d i l socket 8 pin d i l socket link wire solder pins sol der etc 3m quality single core screened audio cable 2m 20mm wide strips of aluminium foil 100mm stripped single core wire 2 off control knobs 2 off quality insulating tape all purpose glue Hardware White masonite 230mm x 200mm search head baseplate 1m x 5mm dia wooden dowel baseplate surround to contain resin 1 5m 20mm outer diameter p v c conduit shaft and upper handle 90 angle bend to suit 20mm p v c conduit hand grip Square rainwater downpipe socket swivel bracket on search head plastic w c seat hinge nut and bolt set swivel bracket 500ml polyester resin and hardener catalyst 2 5mm nylon cable ties 12 off 4mm nylon cable ties 4 off 5mm x 30mm nuts and bolts 4 off 5mm washers 16 off 200g Blu tack Pres stik epoxy glue excluding headset amp batts Approx Cost Guidance Only HARDWARE Suggested hardware construction using p v c piping and joints is shown in Fig 5 The author again chose a minimalist approach Attach the base of the detector s shaft the longest piece of p v c conduit to the search head by means of a swivel joint Use 4mm nylon cable ties to secure the brackets to the search head The author made the brackets from a square rainwater downpipe sock et sawn in two The large plastic nut and bolt of the swivel joint were taken from a w c seat hinge set Do not use any
158. in Fig 2 This board is available from the EPE PCB Service code 371 It is recommended that good quality i c sockets are used for IC2 C3 and the three 10092 resistor modules RM1 to RM3 Assemble the board in any order you pre fer but preferably making the link wire connections first t sai 2 is 4i ve be int re ee Dea a8 The two link wires located to the left of SK2 the 9 pin RS232 connector between TP7 TP8 and TP9 TP10 help determine which type of serial cable will be used see Fig 3 If a straight through serial cable is to be used pin 2 to pin 2 pin 3 to pin 3 then these links should be parallel to each other as shown in Fig 3b If a cross over serial cable is being used pin 2 to pin 3 and pin 3 to pin 2 as in Fig 3a then the links should be crossed as in Fig 3c Place a small piece of sleeving over one of the link wires so that they do not short together TP7 TP8 TP9 TP10 PIN3 TO PIN3 STRAIGHT CABLE PIN2 TO PIN 2 AND CROSS OVER CABLE PIN2 TO PIN 3 AND PIN3 TO PIN2 Fig 3 Links to be made in respect of serial lead type see text Be careful to observe the correct polari ty of the semiconductors electrolytic capacitors and l e d s It is also worthwhile orientating the i c sockets as shown even though they are not actually polarity con scious in the normal sense Doing so helps to ensure that the i c s themselves are inserted the correct way round Do
159. inate There are five possible ways that the enemy ship can move following a switch being pressed up down left right or remain in its current position The counter is therefore programmed to count to four and when five is reached it is reset to zero thus giving five different states When a switch is pressed the counter s value is read and the appropriate move is made Bit 0 of this counter is also tested to determine the result of an encounter between the two opposing warships and thus provide an ele ment of chance in the result The chances of one of these options occurring more often than the others can be increased by readers who are familiar with PIC programming The software could be written to have more states than five and having a count of say one and two corresponding to the move up com mand while three four and five corre spond to the move left command for example Alternatively making provision for the raider to move two squares on some of the counts could make the game more difficult Adding or subtracting 02h instead of Olh from the enemy position register to move it horizontally or 20h instead of 10h to move it vertically would do this The first part of the position controlling subroutine EPOS decodes the random S1 RIGHT S2 A B C D E F G H J K L M N O O O O O O DO O Q O O p OOO OD D 0 C pDTD OT OO 0 ofofo ofofo MAOGI xXTEZZO oye
160. include 555 oscillators sinewave oscillators function generators CMOS oscilla tors voltage controlled oscillators radio frequency oscillators 555 monostables CMOS monostables TTL monostables precision long timers power supply and regulator circuits negative supply generators and voltage boosters digital dividers decoders etc counters and dis play drivers D A and A D converters opto isolators flip flops noise generators tone decoders etc Over 170 circuits are provided which it is hoped will be useful to all those involved in circuit design and applica tion be they professionals students or hobbyists Order code BP322 5 45 160 pages 192 pages For a further selection of books see the next two issues of EPE 162 Project Building amp Testing ELECTRONIC PROJECTS FOR EXPERIMENTERS R A Penfold Many electronic hobbyists who have been pursuing their hobby for a number of years seem to suffer from the dreaded seen it all before syndrome This book is fairly and squarely aimed at sufferers of this complaint plus any other electronics enthusiasts who yearn to try some thing a bit different No doubt many of the projects fea tured here have practical applications but they are all worth a try for their interest value alone The subjects covered include Magnetic field detector Basic Hall effect compass Hall effect audio isolator Voice scrambler descrambler Bat detector Bat style echo
161. ingle Board Computer Programmed in BASIC Robotic Intelligence Neutral Type Using Simple Neural Networks Insect Intelligence Making a Lifelike Android Hand A Computer Controlled Robotic Insect Programmed in BASIC Telepresence Robots With Actual Arcade and Virtual Reality Applications A Computer Controlled Robotic Arm Animated Robots and Androids Real World Robotic Applications Order code MGH1 16 99 224 pages 760 DIRECT BOOK SERVICE NOTE ALL PRICES INCLUDE UK POSTAGE The books listed have been selected by Everyday Practical Electronics editorial staff as being of special interest to everyone involved in elec tronics and computing They are supplied by mail order to your door Full ordering details are given on the last book page For a further selection of books see the next two issues of EPE BASIC RADIO PRINCIPLES AND TECHNOLOGY lan Poole Radio technology is becoming increasingly important in today s high technology society There are the traditional uses of radio which include broadcasting and point to point radio as well as the new technologies of satellites and cellular phones All of these developments mean there is a growing need for radio engineers at all levels Assuming a basic knowledge of electronics this book provides an easy to understand grounding in the topic Chapters in the book Radio Today Yesterday and Tomorrow Radio Waves and Propagation Capacitors Inductors and Filters Modulation
162. iometer Le d indicators and sockets The headset socket should be located on a plastic part if possible Decide whether commercial XLR leads are to be used or whether leads are going to be made up so that the appropriate connec tors may be chosen In the prototype XLR sockets were used in the master with a matching plug on each slave unit Drill holes for all these parts Mark out and drill the holes for mount ing the p c b battery holder and any remaining parts including one for the solder tag in a metal part Drill small holes to correspond with the anti rotation tabs on the rotary switch and TO SOLDER TAG EARTH TIP GOAN MEE T HONS LINKED TOGETHER 1mm STEREO JACK SOCKET OA TO SUIT HEACSET Fig 4 Interwiring from the Master circuit board to off board components 738 potentiometer This prevents their bodies possibly turning in service and breaking off soldered connections INTERWIRING Attach all internal components and referring to Fig 4 complete the interwiring to off board components Note how resis tor R13 is connected Apply some sleeving to the joints at the L e d leads and any bare wires to prevent short circuits Using a multitester check that the solder tag makes good contact with the metal part of the case The wires connected to it should be twisted together and hooked through the hole before soldering Note that neither Phones socket connec tion may make contact with OV earth
163. ion You do this by RUT reate WH Profile Photo 9 Creating an i c pin function profile Everyday Practical Electronics October 2002 Photo 10 Creating an i c test proce dure profile repeatedly clicking on each pin in the usage column Additionally you can create short tags descriptions for each pin which are displayed along with the pin numbers on the Logic Trace screen When ready click the Next button TEST EXAMPLE You must now tell the Tester what logic levels to send to the i c and what the expected results will be see Photo 10 To test a 7400 quad 2 input NAND gate for example 10 instructions are required Sequence 1 Reset This sends a Reset command to the PIC and should always be included unless there is a specific reason not to You can include as many Reset com mands as required and at any location with in the script Sequence 2 VE On This switches on the 5V supply to the i c under test It also applies 5V via transistor TR1 to the three commons of the pull up s 1 1 resistor modules RM4 to RM6 Sequence 3 Send Here we are send ing low logic levels to pins 1 2 4 5 9 10 12 and 13 These pins were defined on the previous screen as inputs You can only send logic levels to pins defined as inputs 725 ae lest Script IC Tester Command C vOn Configure Send Read wow ont oN Delete Line Photo 11 Example of a profile
164. ired Resistors 10k 1k 2 off ae OP TALK page R10 R11 47k 8 off R12 270Q Rx 56k Ry 22k Rx and Ry not needed if IC2 is as specified see text All 0 25W 5 carbon film Potentiometers VR1 VR2 22k sub min enclosed preset vertical 2 off VR3 10k min rotary carbon log Capacitors Ci C4 4u7 radial elect 16V 2 off 22u radial elect 16V 2 off C2 C5 C3 C6 C9 C10 10u radial elect 16V 4 off C7 100n ceramic C8 220u radial elect 16V Semiconductors 3mm red l e d D2 1N5817 1A Schottky rectifier diode TLO72 dual op amp TDA7052 no suffix power amplifier see text Fig 2 How the Master console unit is connected to the three Slave units MASTER SOCKETS SOCKET A Approx Cost C3 Guidance Only ES aes one Slave excl headset leads case amp batts Miscellaneous S p s t rocker or toggle switch SK1 SK2 3 5mm stereo jack socket or as required for headsets used see text regarding head phone socket 2 off B1 6V alkaline battery pack 4 x AA with holder and connector clip Printed circuit board available from the EPE PCB Service code 369 headset having electret microphone and an ear phone or earphones impedance 30 ohms approximately 8 pin i c socket 2 off commercial XLR leads or home made leads total of 3 required con necting wire small fixings solder etc ADDITIONS FOR MASTER R13 2702
165. ivers Cassette Recorders Video Recorders Personal Computers etc TECHNICAL NOTES Commencing with the IBM PC this section and the regular Supplements deal with a very wide range of specific types of equipment radios TVs cassette recorders amplifiers video recorders etc REFERENCE DATA Detailing vital parameters for Diodes Small Signal Transistors Power Transistors Thyristors Triacs and Field Effect Transistors Supplements include Operational Amplifiers Logic Circuits Optoelectronic Devices etc ELECTRONICS SERVICE MANUAL ESM Printed version only Basic Work Contains around 900 pages of information Edited by Mike Tooley BA Regular Supplements Unlike a book or encyclopedia this Manual is a living work continuously extended with new material If requested Supplements are sent to you on approval approximately every three months Each Supplement contains around 160 pages all for only 23 50 2 50 p amp p You can of course return any Supplement within ten days which you feel is superfluous to your needs You can also purchase a range of past Supplements to extend your Base Manual on subjects of particular interest to you Presentation Durable looseleaf system in large A4 format Price of the Basic Work 29 95 to include a recent Supplement FREE The essential work for servicing and repairing electronic equipment Around 900 pages Fundamental principles Troubleshooting techniques Servicing
166. k link at the top saying FTP Site Downloads then click on PUB then on PICS and then look for the appropri ately named folder Software is also available on disk from the Editorial office Battleships is on EPE Disk 5 but the C Tester is on its own CD ROM To order these disks see the EPE PCB Service page which also gives their prices That s it for now Dave will be back with you next month PLEASE TAKE NOTE Ingenuity Unlimited July 2002 The locations of VR1 and R1 in the Car Battery Trickle Charger page 487 should be reversed so that R1 is placed between the output and adjustment and VR1 between adjustment and ground 125 Regular Clinic CIRCUIT URGERY ALAN WINSTANLEY and IAN BELL Our surgeons look at interfacing a simple remote control with external logic and they answer the question why do so many of our projects use 9V when low voltage chips are widely available Toggle CMOS Interface Our thanks to Alister M Bottomley of Glasgow who wrote with a problem regarding the remote control of lighting or similar on off applications This month we start by looking at interfacing the remote control system using a discrete logic system outlining the potential pitfalls of toggle controls Alister writes I recently purchased a two channel 418MHZ remote control system the idea being that one channel could operate the pump and the other the lighting in a small fish pond The ou
167. k of 2 Order Ref 826 COPPER CLAD PANELS size 7in x 4in pack of 2 Order Ref 973 100M COIL OF CONNECTING WIRE Order Ref 685 WHITE PROJECT BOX 78mm x 115mm x 35mm Order Ref 106 LEVER OPERATED MICROSWITCHES ex equip ment batch tested any faulty would be replaced pack of 10 Order Ref 755 MAINS TRANSFORMER 12V 0V 12V 6W Order Ref 811 QUARTZ LINEAR HEATING TUBES 360W but 110V so would have to be joined in series pack of 2 Order Ref 907 REELS INSULATION TAPE pack of 5 several colours Order Ref 911 LIGHTWEIGHT STEREO HEADPHONES Order Ref 989 THERMOSTAT for ovens with in spindle to take control knob Order Ref 857 MINI STEREO 1W AMP Order Ref 870 BT TELEPHONE EXTENSION WIRE This is a proper heavy duty cable for running around the skirting board when you want to make a permanent extension Four cores properly colour coded 25m length only 1 Order Ref 1067 VERY THIN DRILLS 12 assorted sizes vary between 0 6mm and 1 6mm Price 1 Order Ref 128 EVEN THINNER DRILLS 12 that vary between 0 1mm and 0 5mm Price 1 Order Ref 129 MES BATTEN HOLDER Pack of 6 Order Ref 26 SCREW DOWN TERMINAL Can also take 4mm plug Mounts through metal panel with its own insulators and 2 quite hefty nuts for securing the cable Pack of 3 Order Ref GR42 Only red ones available 1000 WATT FIRE SPIRALS Useful if you are repair ing old types of porcelain body heaters pack of 4 Order Ref 223
168. k size defaults to 4 Way If this is changed to 8 Way indicating that you have opted to fit the 8 way switch for S1 the Setup DIPS DIPS referring to the other name dual in line package by which d i l switches are sometimes known button will be enabled Selecting Setup DIPS allows you to specify how you have wired the additional four switches The printer icon allows a template to be printed that contains all the texts required to label the Digital I C Tester Also a cus tom legend is printed that can be affixed next to the d 1 1 switch S1 All configuration options are saved and automatically used the next time the PC software is started vaig View Ro Test Tools Help ee Logic Analyser FFFFFFFFFFF FFF VER rrrerrrrrrrrr Errr Photo 12 Logic analyser experimental screen It is worth noting that in most cases holding the mouse pointer over a control or button will provide some additional infor mation on its use EXTERNAL LOGIC ANALYSING An additional feature was added to the software to experiment with displaying logic states for i c s running in circuit on other p c b s and this has been left in the published software for reader s own exper imentation purposes see Photo 12 A test connector consisting of an i c test clip connected to a piece of ribbon cable and terminated with a 24 pin 1 c header plug allows the Digital I C Tester to be connected to the in circuit 1 c Once con
169. l trophy to retain for one year a hand painted cer tificate signed by His Royal Highness and a Think Pad com puter courtesy of IBM UK Ltd We were interested to learn that a prize winner from last year Martin Rosinski 17 whose achievements we publicised last September also featured in this years awards list Martin is from the Ponteland Community High School Ponteland Newcastle upon Tyne He won the John Eggleston Prize for outstanding or sustained achievement in YEDA with his Lance a Global Data Acquisition System As in many YEDA ceremonies over the years Radley College Abingdon Oxon featured again We have a particular interest in this college as one of contributors Max Horsey is a teacher there This year his pupils Josh Arkell 14 and Adam Wolley 14 designed a Drive Alert which won them the Best Under 15 Project Award receiving 500 and a trophy We are pleased to say that we expect to publish this design in the future Max Horsey s latest series of projects which teachers will find of interest on behalf of their pupils starts next month They are based on the PICAXE microcontroller and allow many simple functions to be programmed easily and at minimal expense For a full list of the YEDA finalists the many organisations who sponsor YEDA and how your school or college can participate next year contact The YEDA Trust PO Box 2118 Pulborough West Sussex RH20 1XQ Tel 01798 839548 Fax 01798
170. lUs etc from all six issues PROJECT CODES All the available codes for the programmable projects in these issues including those for Interface VOL 6 CONTENTS BACK ISSUES July 2001 to December 2001 all the projects features news lUs etc from all six issues PROJECT CODES All the available codes for the programmable projects in these issues including those for nterface EXTRA ARTICLES ON ALL VOLUMES BASIC SOLDERING GUIDE Alan Winstanley s internationally acclaimed fully illustrated guide UNDERSTANDING PASSIVE COMPO NENTS Introduction to the basic principles of passive components HOW TO USE INTELLIGENT L C Ds By Julyan llett An utterly practi cal guide to interfacing and programming intelligent liquid crystal display modules PhyzzyB COMPUTERS BONUS ARTICLE 1 Signed and Unsigned Binary Numbers By Clive Max Maxfield and Alvin Brown PhyzzyB COMPUTERS BONUS ARTICLE 2 Creating an Event Counter By Clive Max Maxfield and Alvin Brown INTERGRAPH COMPUTER SYSTEMS 3D GRAPHICS A chapter from Intergraph s book that explains computer graphics technology in an interesting and understandable way with full colour graphics EXTRA ARTICLE ON VOL 1 amp 2 THE LIFE amp WORKS OF KONRAD ZUSE a brilliant pioneer in the evolution of computers A bonus article on his life and work written by his eldest son including many previously unpublished photographs 740 NOTE These mini CD ROMs a
171. led f Tuning is conveniently effected by using a two gang potentiometer for the two controlling resis tors R1 and R2 so that they are always equal In this way balance is maintained as these resistors are adjusted Everyday Practical Electronics October 2002 Cil C2 C R1 R2 R fo 1 2nCR R3 2R4 Fig 13 Wien bridge In oscillators use is made of the fact that RC arms of the bridge form a frequen cy selective voltage divider whose output is greatest at f At frequencies away from fo Output falls When this network is used as a positive feedback path in an amplifier Fig 14 and the gain is just sufficient for oscillation a sine wave at f is generated Unfortunately the Wien network is only very weakly frequency selective It does a poor job of discriminating against harmon ics produced by the amplifier overloading The waveform is distorted A solution used in commercial Wien oscillators for audio work is to provide a dis tortionless means of automatically restrict ing gain to be just sufficient for oscillation Very pure sine waves can then be obtained A common method is to use a negative tem perature coefficient n t c thermistor for the R3 resistance As oscillation builds up the signal warms the thermistor whose resis tance falls This increases the negative feed back to the inverting input terminal damp ing down the oscillation The standard circuit Fig 14 does not translate into inverter
172. link is satisfactory If it turns red this indicates that the com puter cannot establish a communications link with the tester Perform the checks as detailed and try again Most often the com munications failure is due to the wrong COM port being selected or an incorrect cable being used 122 If all is well you can now proceed to test an i c but note that if L e d D4 illuminates constantly during the testing process this indicates a possible communications prob lem In which case check the serial cable and the PC software speed settings in the configuration window TESTING AN I C The software is supplied with profiles for a selection of common TTL and CMOS devices For the following testing example we Shall use a TTL 74LS00 a quad 2 input NAND gate To properly follow this dis cussion now it is best to have the PC soft ware running Drop the i c to be tested into the test socket making sure that the bottom right hand pin of the 1 c is located in the bottom right hand pin of the socket Different i c s can have their power rail pins located in different positions Typically the bottom left hand pin is GND and the top right hand pin is VE but this is by no means always the case The rows of turned pin sockets alongside the test socket can be used to route power to the correct pins but more on this in a moment Next you need to tell the PC software which 1 c type is going to be tested To do this you need to
173. listened to with caution in case the Volume controls have been wired in the wrong sense and a sud den loud noise develops Test the operation between the Master and each Slave unit Preset VR1 should be adjusted in each unit so that the maximum volume set by VR3 is not too great and that there are no signs of instability Adjust pre set VR2 in each unit for the preferred degree of voice feedback Check the talk to all function When satisfied attach the lids of the cases and label the controls You will know when the batteries need to be replaced because the sound will become weak or distorted and the l e d s will glow less brightly In use always start with the volume turned down to minimum and switch on all units before wearing the headsets This will avoid any loud clicks ALTERNATIVE POWER AMPLIFIER If it is impossible to obtain the speci fied power amplifier i e a TDA7052 without a suffix letter and you must use one having a d c volume control its gain will need to be configured to maxi mum to match the characteristics of the specified unit This may be done by sol dering resistors Rx and Ry in the unused positions on the p c b Resistor Rx will be in the upper position which connects to IC2 pin and Ry to the lower position which connects to C2 pin 4 Resistor Ry may need a IuF capacitor connected in parallel with it This could be placed on the underside of the p c b Note that this set up has not
174. ll orders UK postage 2 50 per book 1 00 per kit maximum 7 50 Europe postage 3 50 per book 1 50 per kit Rest of World 6 50 per book 2 50 per kit Web site www brunningsoftware co uk Mail order address NEW 32 bit PC Assembler Experimenting with PC Computers with its kit is the easiest way ever to learn assembly language programming If you have enough intelligence to understand the English language and you can operate a PC computer then you have all the necessary background knowledge Flashing LEDs digital to analogue converters simple oscilloscope charging curves temperature graphs and audio digitising Kit now supplied with our 32 bit assembler with 84 page supplement detailing the new features and including 7 experiments PC to PIC communication Flashing LEDs writing to LCD and two way data using 3 wires from PC s parallel port to PIC16F84 Book Experimenting with PCs 21 50 Kit 1a made up with software 52 00 Kit 1u unmade with software 45 00 C amp C for the PC Experimenting with C amp C Programmes teaches us to programme by using C to drive the simple hardware circuits built using the materials supplied in the kit The circuits build up to a storage oscilloscope using relatively simple C techniques to construct a programme that is by no means simple When approached in this way C is only marginally more difficult than BASIC and infinitely more po
175. loca tion Noise cancelling LED stroboscope Infra red torch Electronic breeze detector Class D power amplifier Strain gauge amplifier Super hearing aid Order code BP371 5 45 ELECTRONIC PROJECT BUILDING FOR BEGINNERS R A Penfold This book is for complete beginners to electronic project building It provides a complete introduction to the practi cal side of this fascinating hobby including the following topics Component identification and buying the right parts resistor colour codes capacitor value markings etc advice on buying the right tools for the job soldering making easy work of the hard wiring construction meth ods including stripboard custom printed circuit boards plain matrix boards surface mount boards and wire wrap ping finishing off and adding panel labels getting prob lem projects to work including simple methods of fault finding In fact everything you need to know in order to get start ed in this absorbing and creative hobby Order code BP392 5 49 PRACTICAL FIBRE OPTIC PROJECTS R A Penfold While fibre optic cables may have potential advantages over ordinary electric cables for the electronics enthusiast it is probably their novelty value that makes them worthy of exploration Fibre optic cables provide an innovative interesting alternative to electric cables but in 138 pages 135 pages most cases they also represent a practical approach to the problem Thi
176. lock 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 Venndiagrams 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 FILTERS Filters is a complete course in designing active and passive filters that makes use of highly interactive virtual laboratories and simulations to explain how filters are designed It is split into five chapters Revision which provides underpinning knowledge required for those who need to design filters Filter Basics which is a course in terminology and filter characterization important classes of filter filter order filter impedance and impedance matching and effects of different filter types Advanced Theory which covers the use of filter tables mathematics behind filter design and an explanation of the design of active filters Passive Filter Design which includes an expert system and filter synthesis tool for the design of low pass high pass band pass and band stop Bessel Butterworth and Chebyshev ladder f
177. ly drawn illustrations 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 inter ested in the inner workings of computers then don t dare to miss this Over 800 pages in Adobe Acrobat format 21 95 including VAT and p amp p Order code BEB2 CD ROM ELECTRONICS MADE SIMPLE lan Sinclair Assuming no prior knowledge Electronics Made Simple presents an outline of modern electronics with an empha sis on understanding how systems work rather than on details of circuit diagrams and calculations It is ideal for students on a range of courses in electronics including GCSE C amp G and GNVQ and for students of other subjects who will be using electronic instruments and methods Contents waves and pulses passive components active components and ICs linear circuits block and circuit diagrams how radio works disc and tape record ing elements of TV and radar digital signals gating and logic circuits counting and correcting micro processors calculators and computers miscellaneous systems Order code NE23 13 99 199 pages SCROGGIE S FOUNDATIONS OF WIRELESS AND ELECTRONICS ELEVENTH EDITION S W Amos and Roger Amos Scroggie s Foundations is a classic text for anyone work ing with electronics who needs to know the art and craft of the subject It covers both the theory and practical aspects of a
178. ly for you on the screen In the case of the i c represented in Photo 7 it actually failed during the testing process The right hand panel shows that the problem occurred with pattern sequences 0007 and 0008 Sequence 0007 shows what the Digital IC Tester sent to the i c Sequence 0008 shows what the device profile says should be the response from the i c The next line shows what the response from the i c actually is An X means Don t Care about the logic level Whilst this is helpful it is not too clear exactly what the problem is The trace on the left hand side of the screen shows the logic levels present on each pin of the 1 c during the test The trace is updated after each Read operation is performed The display has four yellow traces which are the outputs of each of the four NAND gates Since they should all behave the same it s quite clear that there is a problem with the gate whose output is on pin 11 In some cases though the actual problem might not be clear especially if the i c only contains one or two gate arrays If you select Diff on the Pin Logic Trace the trace display will change and look similar to that in Photo 8 The dotted line indicates what the pro file is expecting back as a response from the 1 c under test As can be seen with pin Photo 8 Test screen in difference highlighting mode Digital IE Tester Version Li LE f Fle ie TC Test Toole Window Help Q
179. ly seal the holes underneath the baseplate before pouring the resin polyester resin iS very runny and sticks faster than many glues Make sure the baseplate s dowel surround is resin tight Carefully bend the coils at the centre of the baseplate until you reach the exact balance at which there is nei ther silence nor singing from the piezo sounder but a crackle Also this is important cover a small section about 40mm of one of the coils at its centre with Blu tack Pres stik giving the Blu tack vertical walls This will be removed after the resin has set and allows for final bending of this small section of coil Now you are ready to mix and pour the resin Use about 80 per cent of the recommended amount of catalyst so that there is not too much heat and shrinkage in the resin Pour the resin over the cloth which surrounds the coils so as to soak it and keep on pouring until the entire baseplate is well covered with resin The circuit may no longer function correctly at this point until the resin has hardened so make no more adjustments but switch off Wait at least 24 hours until removing the Blu tack from the small section of coil which will leave the section exposed Set tuning controls VR2 and VR3 to their mid points and bend the exposed section of coil likely inwards until a crackle is heard between silence and singing Now pour resin over this patch also to fill it Finall
180. ly to be encountered This may not be enough voltage to test blue Le d s so a 5 1V Zener diode could be used instead with the 3 9 volt Zener switched in parallel by a high low switch Low brightness dud L e d s or super bright types can easily be distinguished Of course the L e d indicator used in the circuit should be of known quality to allow meaningful comparisons The tester can also be used for tests on fuses or filament lamps Colin Menear Birmingham SQUIRES MODEL amp CRAFT TOOLS ANTEX SOLDERING STATIONS ANTEX 660TC Temperature control range 65 450 C Thumb wheel potentiometer control 50 Watt Iron Included 25W Optional Extra Wide range of spare bits 0 5mm 6 0mm Normal Price 114 95 Now 89 95 Post Free to UK addresses Post Telephone or Fax your orders to Squires 100 London Road Bognor Regis West Sussex PO21 1DD Tel 01243 842424 Fax 01243 842525 ANTEX 690SD Temperature control range 65 450 C Digital readout temperature control 50 Watt static dissapative iron included Wide range of spare bits 0 5mm 6 0mm Normal Price 169 95 Now 129 95 Post Free to UK addresses OUR 600 PAGE POST FREE MAIL ORDER CATALOGUE IS AVAILABLE FREE OF CHARGE TO ADDRESS IN THE UK OVERSEAS CATALOGUE FREE POSTAGE CHARGED AT COST TO CREDIT CARD Shop Open 9 5 30 Monday Friday 9 5 Saturday Everyday Practical Electronics October 2002 731 Learn About Microcontrollers
181. making printed circuit boards to the tools needed for circuit building the Modern Electronics Manual and its Supplements describe clearly with appropriate diagrams how to assemble a radio loudspeaker circuits amplifiers car projects a computer interface measuring instruments workshop equipment security systems medical and musical circuits etc The Base Manual describes 12 projects including a Theremin and a Simple TENS Unit ESSENTIAL DATA Extensive tables on diodes transistors thyristors and triacs digital and linear i c s EXTENSIVE GLOSSARY Should you come across a technical word phrase or abbreviation you re not familiar with simply look up the glossary included in the Manual and you ll find a comprehensive definition in plain English The Manual also covers Safety and provides web links to component and equipment Manufacturers and Suppliers The most comprehensive reference work ever produced at a price you can afford the CD ROM edition of THE MODERN ELECTRONICS MANUAL provides you with all the essential information you need THE MODERN ELECTRONICS MANUAL MEM CD ROM version only Revised CD ROM Edition of Basic Work Contains over 800 pages of information in Adobe Acrobat format Edited by John Becker Regular Supplements Additional CD ROMs each containing approximately 500 pages of additional information on specific areas of electronics will be available for 19 95 each Information on the availability and co
182. mes pre loaded with MERRY XMAS Kit includes PCB all components amp tube plus instructions for message loading KIT 849 12V EPROM ERASER A safe low cost eraser for up to 4 EPROMS at a time in less than 20 minutes Operates from a 12V supply 400mA Used extensively for mobile work updating equipment in the field etc Also in educational situations where mains supplies are not allowed Safety interlock prevents contact with UV KIT 790 eat ea eters 29 90 SUPER BAT DETECTOR 1 WATT O P BUILT IN SPEAKER COMPACT CASE 20kHz 140kHz NEW DESIGN WITH 40kHz MIC A new circuit using a full bridge audio amplifier i c internal speaker and headphone tape socket The latest sensitive transducer and double balanced mixer give a stable high perfor mance superheterodyne design KIT 861 24 99 ALSO AVAILABLE Built amp Tested 39 99 ULTRASONIC PEsT SCARER Keep pets pests away from newly sown areas fruit vegetable and flower beds children s play areas patios etc This project produces intense pulses of ultrasound which deter visiting animals e KIT INCLUDES ALL COMPONENTS PCB amp CASE e EFFICIENT 100V TRANSDUCER OUTPUT RANGE PIC16F877 now in stock e COMPLETELY INAUDIBLE TO HUMANS some projects are copyright KIT 812 p s tar E A LE pr rowk Src e UP TO 4 METRES e LOW CURRENT DRAIN Everyday Practical Electronics October 20
183. mistors is difficult The resistance of the control device varies over the oscillation cycle and causes distortion An inverter with capacitive feedback produces a phase shift Two inverters each giving a phase shift of 90 in the same direction give a total of 180 which is phase inversion When cascaded with a simple inverter and connected in a ring the overall feedback is positive at the 90 fre quency Here this is the frequency for which the reactance of C equals R An inverter with capacitive feedback is often referred to as a Miller integrator or just an integrator The frequency generated by the type of circuit in Fig 17 is the same as for a Wien network oscillator f 0 16 RC With the values shown the 743 fo 1 2nCR Fig 17 Dual integrator oscillator Oscillation level is set by VR2 The two outputs V1 and V2 are equalized by VR1 and are 90 apart in phase range is roughly 300Hz to 3300Hz The range can be switched by substituting other pairs of capacitors accurately matched When R is in megohms and C is in microfarads the frequency is in Hertz Hz Because of the good discrimination against harmonics it is easier to achieve a respectable sine wave than with the Wien oscillator The circuit also has the useful property of yielding two equal output voltages V1 and V2 phased 90 apart in quadra ture On the other hand setting up to achieve a good performance over the tun ing band b
184. mm x 110mm 3 AAA batteries required 49 94 Ref SCALEB ALTERNATIVE ENERGY CD packed with hundreds of alternative energy related articles plans and information etc 14 50 Ref CD56 WIRELESS DRIVEWAY ALARMS Detect someone entering your driveway 400ft range no wiring will protect any entrance uses built in PIR detector 24 99 Ref DWA NICKEL PLATING KITS 55 Ref NIK39A GOODIE PACKS 10kg packs of clearance items mainly suitable for the electronics enthusiast Ref 10KGP WHEELCHAIR MOTORS Left and right hand new and second hand 100s in stock New ones 99 each secondhand 59 returns 19 95 Geared 24V complete with electric brake www bullnet co uk ISSN 0262 3617 PROJECTS THEORY NEWS COMMENTS POPULAR FEATURES ACTICAL Sy CRONIES INCORPORATING ELECTRONICS TODAY INTERNATIONAL www epemag wimborne co uk EPE Online www epemag com Projects and Circuits EPE BOUNTY TREASURE HUNTER by Thomas Scarborough 708 Inexpensive easy build design that has good penetration and discrimination capabilities helping you find the valuables but not the iron and tin dross I C TESTER by Joe Farr 717 Let a PIC and PC check the health of your digital logic chips INGENUITY UNLIMITED hosted by Alan Winstanley 730 One second Crystal Clock L E D and Fuse Checker HEADSET COMMUNICATOR by Terry de Vaux Balbirnie 734 Forget the megaphone This system is ideal for directors who don t wish to sh
185. msoft com or Teleport Pro www tenmax com are worth investigating A web site designer needing to take a look at a web site may use such a tool in order to fetch the site onto local disk after which it can be examined in an authoring program such as Dreamweaver If you have a broadband connection reminders alongside any bookmarked address or folder Netscape also lets bts Qiendier Gime 4 a Cesar pees Hae you add your own choice let of keywords which are Fm fully searchable Overall 7a the bookmark management eine of Netscape 6 is far superi E Hatetwst tstienes or to Internet Explorer and i Eu the latest unremarkable hebrew version of MSIE has done nothing to enhance or sim plify the user s task of cop ing with a vast amount of online information One tool that is a useful free download is DzSoft s Favorites Search www dzsoft com which can be _Gugic 3 misd Gsm Semi Giardia ChP i fe you could perhaps set up scheduled downloads to fetch a web site onto disk in between busy times Low Interest Rates Back to the subject of BT s thermometer see Net Work last month and www bt com broadband which is their online display of the level of local interest related to having a tele phone exchange converted for ADSL Another 88 exchanges have been assigned trigger levels but GUO YADI J courses kee E Hoo eE loaded as a toolbar in MSIE It will sca
186. n choose one or all of the packages below to use with the Development Board Makes it easier to develop PICmicro projects Supports low cost Flash programmable PICmicro devices Fully featured integrated displays 13 individual l e d s quad 7 segment display and alphanumeric c d display Supports PlCmicro microcontrollers with A D converters Fully protected expansion bus for project work All inputs and outputs available on screw terminal connectors for easy connection HARDWARE ee 145 including VAT and postage 12V 500mA plug top PSU UK plug 7 25 way D type connecting cable 5 SOFTWARE Suitable for use with the Development Board shown above ASSEMBLY FOR PiCmicro V2 Formerly PiCtutor Assembly for PICmicro microcontrollers V2 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 sleep modes The CD makes use of the latest simulation techniques which provide a superb tool for learning the Virtual PlCmicro 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 understan
187. n CD ROM Robotics INTRODUCING ROBOTICS WITH LEGO MINDSTORMS Robert Penfold Shows the reader how to build a variety of increasingly sophis ticated computer controlled robots using the brilliant Lego Mindstorms Robotic Invention System RIS Initially covers fundamental building techniques and mechanics needed to construct strong and efficient robots using the various click together components supplied in the basic RIS kit Then explains in simple terms how the brain of the robot may be programmed on screen using a PC and zapped to the robot over an infra red link Also shows how a more sophisticated Windows programming language such as Visual BASIC may be used to control the robots Details building and programming instructions provided including numerous step by step photographs 288 pages large format WOKE A N 14 99 MORE ADVANCED ROBOTICS WITH LEGO MINDSTORMS Robert Penfold Covers the Vision Command System Shows the reader how to extend the capabilities of the brilliant Lego Mindstorms Robotic Invention System RIS by using Lego s own accessories and some sim ple home constructed units You will be able to build robots that can provide you with waiter service when you clap your hands perform tricks see and avoid objects by using bats radar or accurately follow a line marked on the floor Learn to use additional types of sensors including rotation light temperature soun
188. n VBA The latter is used to generate the values that are transmitted and its MAX setting should be set at 255 It will then generate integers from 0 to 255 or single bytes of data in other words Listing 2 Private Sub CommandButton1_Click MSComm1 PortOpen False End End Sub Private Sub CommandButton2 Click MSComm1 PortOpen True End Sub Private Sub Labell_Click End Sub Private Sub MSComm1_OnComm End Sub Private Sub ScrollBar1_Change MSComm1 Output Chr ScrollBar1 Value Label1 Caption ScrollBar1 Value End Sub Private Sub UserForm_Click End Sub chose Note that the main Word docu ment can be empty and there is no need to add any dummy text To use the pro gram on another occasion load the rele vant document and go to the Visual BASIC Editor again This should contain the program There can be a problem when tying to run the program with an error message appearing This points out that Macros have been disabled and that the program cannot be run Macros are disabled by default as a means of reducing the risk from macro viruses Selecting Macros from the Tools menu followed by Security from the submenu enables the security setting to be changed A dialogue box appears and it has radio buttons that offer three levels of security The lowest level enables macros to be run with no questions asked You will be asked whether or not you wish to run the program if the middle s
189. n your saved URLs and help you to locate a Favorite address For example searching for the word pub lists all my bookmarked addresses containing that expression in my case Personal Publisher and CompuBank were turned up by the search tool No pubs though unfortunately DzSoft s program has proved useful when trying to recall a long forgotten bookmark and their web site 1s worth check ing out Both Netscape and MSIE allow you to go File Save web pages to store them on disk and of course you can try to view the site from your browser s cache by choosing File Work Offline and then typ ing in the URL However it is possible to improve the handling of offline content a lot more by using programs designed to manage any web content that has been saved to disk ContentSaver ContentSaver Professional free demo from www macropool com en is a very versatile program styled like Microsoft Office which can help you to organise your collection of browsed web sites This quite sophisticated program lets you save any complete web pages as rendered in Internet Explorer to get the most out of the program you need MSIE 5 5 The software installs a toolbar within the browser and by clicking a Save button any page you are viewing is saved to a folder on your disk web pages Everyday Practical Electronics October 2002 it seems that the minimum number of 200 registrations needed before an exchange will be upgraded In
190. nable BASIC programming Essential information for anyone undertaking GCSE or A level electronics or technology and for hobbyists who want to get to grips with project design Over seventy different Input Processor and Output modules are illustrated and fully described together with detailed information on construction fault finding and components including circuit symbols pinouts power supplies decoupling etc Single User 19 95 inc VAT Multiple User 34 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices Electronics Hobbyist Compendium Toal and Golfering Campenient Tee lan Oetilloscome asics DIGITAL WORKS 3 0 i FREE BOOK eee et LES WITH TEACH IN Coie 2000 CD ROM O 2 project Digital Works Version 3 0 is a graphical design tool that enables you to construct digital logic circuits and analyze their behaviour It is so simple to use that it will take you less than 10 minutes to make your first digital design It is so powerful that you will never outgrow its capability e Software for simulating digital logic circuits e Create your own macros highly scalable e Create your own circuits components and i c s Easy to use digital interface e Animation brings circuits to life e Vast library of logic macros and 74 series i c s with data sheets e Powerful tool for designing and learning Hobbyist Student 45 inc VAT Institutional 99 plus VAT Institutional 10
191. nected the Logic Analyser function can be selected from the Tools menu The Logic Analyser monitors and reports the logic levels on between 1 and Everyday Practical Electronics October 2002 24 pins The pins to be monitored are selected in the Monitor Pins panel An optional trigger pattern can be specified if required A tick indicates a high logic state and the absence of a tick indicates a low logic state When all monitored pins have the specified trigger pattern the Analyser is triggered There are two primary modes of operation for the Analyser The mode Only Detect Pattern Changes displays each new logic pat tern as it changes Free Running grabs the logic levels as fast as possible If Free Running is selected an optional delay can be specified from 0 to 9999ms between each sample being made Update Pin Display and Logic Display work as previously discussed The Activate Device Pull Ups controls whether the s i l pull up resistor modules RMA to RM6 have their common connec tions powered or not When the logic analyser starts it instructs the PIC to grab logic level sta tus information as fast as possible and transmit this to the PC The PC then attempts to process and display this infor mation Because of this the analyser has several practical limitations Firstly due to the hardware design and the way the PIC operates internally the PIC s I O ports are read at slightly different times This me
192. ng Pentium PCs and aims to source 50 000 of them for shipment to developing countries in which 99 per cent of children leave school without ever touching a computer in the classroom For the price of just one new PC the charity can supply 20 refur bished machines For further information about Computer Aid International visit www comput eraid org email info computeraid org or call 020 7281 0091 Everyday Practical Electronics October 2002 YEDA 2002 P Josh Arkell and Adam Wolley of Radley College with their Drive Alert THE 2002 Young Electronic Designer Awards YEDA were presented on 9 July at the Science Museum in London during a special celebration dinner in their honour attended by 200 guests including HRH The Duke of York parents teachers local dignitaries and members of the business community The Awards now in their seventeenth year recognise the achievements of stu dents who have used modern technology to devise solutions to everyday problems and which they have identified Projects include safety and security devices for the home and for travel PC and internet devices devices to help the physically handi capped and to enhance enjoyment and performance in sport This year the Duke of York s Award for the most imaginative concept went to Susie Short aged 17 from Sevenoaks School Sevenoaks Kent She designed a Programmable Sailing Race Countdown Timer She shares 1000 with her school receives a crysta
193. ng the enemy battleship CIRCUIT DIAGRAM The complete circuit for PIC Pocket Battleships is shown in Fig 3 It is based around a PIC16C54 microcontroller one of the earlier PIC types having a UV erasable structure and window which is operated in RC resistor capacitor mode as precise tim ing of the software is not necessary Resistor Everyday Practical Electronics October 2002 R18 and capacitor C1 set the PIC s clock fre quency at about 4MHz The Le d display X1 is multiplexed which means that only one row is switched on at any one time During this period the appropriate column drives are activated in sequence Only the L e d at the junction of the active column and row is turned on As each row is switched on the column drives are altered and because this is done very fast all the merchant ship Le d s appear to be on at once The rows are dri ven via pnp driver transistors TRI to TRS from PIC pins RAO to RA3 plus RB3 buffered by resistors R13 to R17 To switch on a particular row the correspond ing output port goes low The column drives are output from the remaining lines of Port B via current limiting resistors R3 to R9 These lines also have to go low to switch on the corresponding l e d The function game play selection switches SI to S5 are also multiplexed to the lines connecting to the L e d columns They are additionally buffered by resistors RI and R2 The PIC scans the switches t
194. nless marked NEW items in this section are pre owned HP6030A 0 200V DC 17 Amps bench power supply 1950 Intel SBC 486 125C08 Enhanced Multibus MSA New 1150 Nikon HFX 11 Ephiphot exposure control unit 1450 PHILIPS PM5518 pro TV signal generator 1250 Motorola VME Bus Boards amp Components List SAE CALL POA Trio 0 18 vdc linear metered 30 amp bench PSU New 550 Fujitsu M3041R 600 LPM high speed band printer 1950 Fujitsu M3041D 600 LPM printer with network interface 1250 Siemens K4400 64Kb to 140Mb demux analyser 2950 Perkin Elmer 299B Infrared spectrophotometer 500 Perkin Elmer 597 Infrared spectrophotometer 3500 VG Electronics 1035 TELETEXT Decoding Margin Meter 3250 LightBand 60 output high spec 2u rack mount Video VDA s 495 Sekonic SD 150H 18 channel digital Hybrid chart recorder 1995 B amp K 2633 Microphone pre amp 300 Taylor Hobson Tallysurf amplifier recorder 750 ADC SS200 Carbon dioxide gas detector monitor 1450 BBC AM20 3 PPM Meter Ernest Turner drive electronics 75 ANRITSU 9654A Optical DC 2 5G b waveform monitor 5650 ANRITSU ML93A optical power meter 990 ANRITSU Fibre optic characteristic test set POA R amp S FTDZ Dual sound unit 650 R amp S SBUF E1 Vision modulator 775 WILTRON 6630B 12 4 20GHz RF sweep generator 5750 TEK 2445 150 MHz 4 trace oscilloscope 1250 TEK 2465 300 Mhz 300 MHz oscilloscope rack mount 1955 TEK TDS380 400Mhz digital realtime di
195. nt a music score What sort of a soundcard do need What hardware and software do need How do connect a key board to my PC Just a few of the questions you ve probably asked Well you ll find the answers to all these questions and many more in this book It will show you what can be done what it all means and what you will need to start creating your own music on your PC It s an easy read it s fully illustrated and it will help you understand how a computer can be used as a creative music tool It covers soundcards sequencers hard disk digital audio recording and editing plug ins printing scores with notation software using your PC as a synthesiser getting music onto and off the Internet using Windows sample PC music set ups FAQs a glossary advice on hardware and software and a list of industry contacts 116 pages Order code PC117 11 95 HIGH POWER AUDIO AMPLIFIER CONSTRUCTION R A Penfold Practical construction details of how to build a number of audio power amplifiers ranging from about 50 to 300 400 watts r m s includes MOSFET and bipolar transistor designs Order code BP277 4 49 96 pages 761 Circuits Data and Design PRACTICAL ELECTRONIC FILTERS Owen Bishop This book deals with the subject in a non mathematical way It reviews the main types of filter explaining in sim ple terms how each type works and how it is used The book also presents a dozen filter based projects wi
196. ntent of each Supplement CD ROM will be sent to you as they become available Presentation CD ROM suitable for any modern PC Requires Adobe Acrobat Reader which is included on the MEM CD ROM Price of the Basic Work 29 95 POST FREE ORDER BOTH MANUALS TOGETHER AND SAVE 10 A mass of well organised and clearly explained information Is brought to you by expert editorial teams whose combined experience ensures the widest coverage Regular Supplements to these unique publications keep you abreast of the latest technology and techniques if required ELECTRONICS SERVICE MANUAL PRINTED VERSION ONLY EVERYTHING YOU NEED TO KNOW TO GET STARTED IN REPAIRING AND SERVICING ELECTRONIC EQUIPMENT SAFETY Be knowledgeable about Safety Regulations Electrical Safety and First Aid UNDERPINNING KNOWLEDGE Specific sections enable you to Understand Electrical and Electronic Principles Active and Passive Components Circuit Diagrams Circuit Measurements Radio Computers Valves and Manufacturers Data etc PRACTICAL SKILLS Learn how to identify Electronic Components Avoid Static Hazards Carry Out Soldering and Wiring Remove and Replace Components TEST EQUIPMENT How to Choose and Use Test Equipment Assemble a Toolkit Set Up a Workshop and Get the Most from Your Multimeter and Oscilloscope etc SERVICING TECHNIQUES The regular Supplements include vital guidelines on how to Service Audio Amplifiers Radio Receivers TV Rece
197. o determine if a change in the cursor posi tion is required or the fire button has been pressed During scanning RB7 is taken low and the three lines RBO to RB2 are redefined as inputs and read in turn 755 ovoz Zr asa ION MoO K1 SWITCH VERO OoO0O0O0O 008 QM0e08 0008 00 000000 O O O O O Ooee000Qe0Q0 ee o 0 0 000 O O O O OO 0080006800 00 O Ole efo OOO Oe 0 eM0e 00e 0 e 0600000000 O O O O e O 0080000000 CO 60 D 0 00 0 0 O O ofo ofo o ofe ef ofo FOsesososoge O O O O O O O O O O O O o o efogofo O O O O O O O O O O O O O O OO O0Oe OO OO 0 O O O O O O O O O O O O O O O efo ojo oje opo ojo ofo ofo ofo ofo ofo TO SWITCH VERO TAC TO nn MO OX gt TO MAIN e O O O e Component layout and stripboard track view for Fig 4 left the main control O O O O O O O OO0O0000000 0 9 0O000000000Q OO OOOOOOO oo0o0o0o0000 0 00000000 80 O 8e00000000 08000004 9000068004 ofo OFOsOoRoFo OFogeqogo O O O OROKORORelIO OF OFOFOFOFO gt wWOUMnOI cxr lt zZOTODO O O O O O O O O O O Transistors TRI to TRS are turned off during this process This prevents switch presses from shorting out column lines and causing erroneous displays Pressing more than one key at a time will still cause an erroneous display but the game is not intended to be used in this way
198. o the normal arrangement in Visual BASIC The next task is to go in search of the MSCOMM control and the first step is to choose Additional Controls from the Tools En Get es e yra oe jah yis mp ae AH i eel eee E Aditioneal Lontrois Fig 1 above The Visual BASIC for Applications VBA set up and ready to use Upload Control version 1 5 Mecrosoft ADO Data Control version 6 0 OLEDE M crosott Agent Control 2 0 Microsoft Animation Control version 5 0 SP2 Mecrosof Animation Control werssan 6 0 J Microsoft Chart Control version 6 0 OLEDE Mecrosot Common Dislog Control warsion 6 0 Mecrosott Coolbar Control version 6 0 there are differences The fact that VBA is not designed to produce standalone pro grams enforces a few changes but there are differences in the code such as the exact structure of conditional routines Programs written for Visual BASIC will usually require at least a small amount of rewriting in order to make them work with VBA This point is demonstrated in the first VBA listing Listing 1 which is for a simple program that reads single bytes from a serial port and displays them on a label component Fig 2 below Adding MSCOMM if it is available inal Microsoft DetaComba Control version 6 0 OLEC shi Microsatt DataGrid Control Version 6 0 OLED Fr Betacied tana Only Li Microsof Communications Control version 6 0 Location C MIN
199. oblems that are very difficult to resolve with a digital computer The EPE Hybrid Computer combines the best of both worlds an analogue computer to solve those real world problems plus a digital processor MCU to analyse and output the results to a PC The analogue system is programmed by connecting its modules using wires through a patch panel The MCU has access to the analogue control circuits through the patch panel and has the capability of converting analogue signals to digital Programming of the MCU a Basic Micro ATOM is carried out in BASIC and communication is via a serial link The PC s Windows software is totally self contained it is written in Visual Basic but does not need VB to be resident on your PC running as a standalone EXE program PICAXE PROJECTS For everyone who would like to use PICs without a major learning curve or expense a three part series of constructional articles based on PICAXE microcontrollers Such controllers are a modified version of Microchip s PIC16F627 they have been modified by Revolution Education to allow them to accept program code written in a form of BASIC Known as the PICAXE 18 these devices do not need special programming hardware and are simply programmed by means of a serial link to your PC There are nine simple and inexpensive designs presented in the series Egg Timer Dice Machine Four Input Quiz Monitor Temperature Sensor Voltage Sensor VU Display
200. on of the Headset Communi cator is based on four identical single sided printed circuit boards p c b s This of course assumes that three slaves are required These boards are available from the EPE PCB Service code 369 The p c b topside component layout and full size underside copper foil master pat tern are shown in Fig 3 Begin construction of each p c b by drilling the two fixing holes as indicated Next solder the 1 c sockets in position also the link wire connecting C2 pin 2 with Volume control VR3 sliding contact all resistors including the presets and the capacitors Apart from C7 the capacitors are all electrolytics so take care with their orientation Note that there are four holes which will have been left empty see later Now solder pieces of stranded connect ing wire to the talk T listen L and earth E points on the completed p c b Connect similar pieces of wire to the MICI and VR3 positions Use different colours to avoid errors later Adjust presets VRI and VR2 to approximately mid track position TESTING It is advisable to check the operation of each circuit board at this stage because it is then much easier to correct 57 5mm Fig 3 Printed circuit board component layout and full size copper foil master minor problems Solder the battery con nectors to the 6V and OV p c b pads taking care over the polarity red wire for 6V Solder jack sockets or the required type to m
201. ore I got to feel it Probing further I found the mains earth connec tion to the fridge casing had come unscrewed and far worse the earth connection of the power wiring to the wall socket into which it was plugged had corroded away altogether so noth ing plugged into that socket had any earthing at all Soon fixed though once discovered Scary stuff if in doubt investigate and if you doubt your abilities find someone qualified to check it for you Andy Flind via email Thanks Andy well advised We ve both had near misses And no doubt we ve both had the real thing in various ways I vividly recall from subwf remdrH w skpz goto testgt Not equal so test if remdrH is greater movfw divisL_ High bytes are equal compare low bytes subwf remdrL w skpc Carry set if remdr gt divis goto remrlt Subtract divisor from partial remainder movfw divisL subwf remdrL skpc Test for borrow decf remdrH Subtract borrow movfw divisH subwf remdrH bsf dividL 0 Set quotient bit to 1 Quotient replaces divi dend which is lost decfsz bitcnt goto dvloop return Peter Hemsley via email That s brilliant Peter I ll add it to PIC Tricks Thank you from me and all PIC Trickers the mid 60s in the days before I knew anything worthwhile about electronics buying ancient and usually unworking TVs from market stalls and trying to get them to work again Boy oh boy They can
202. ork The Internet Page PROJECTS e Digitimer e Lead Acid Battery Charger Compact Shortwave Loop Aerial Perpetual Projects 2 L E D Flasher Double Door Buzzer FEATURES e Controlling Power Generation Ingenuity Unlimited e Interface Circuit Surgery e New Technology Update Net Work SEPT 01 Photocopies only PROJECTS e Water Monitor e L E D Super Torches Synchronous Clock Driver Perpetual Projects 3 Loop Burglar Alarm Touch Switch Door Light Solar Powered Rain Alarm FEATURES e Controlling Flight Ingenuity Unlimited Practically Speaking Circuit Surgery e New Technology Update Net Work The Internet Page oT on matt Photocopies only PROJECTS e PIC Toolkit Mk3 e Camcorder Power Supply 2 Valve SW Receiver Perpetual Projects 4 Gate Sentinel Bird Scarer In Out Register FEATURES e Traffic Control e Ingenuity Unlimited e New Technology Update e Circuit Surgery Interface e Net Work The Internet Page Free 2 CD ROMs Microchip 2001 Tech Library NOV 01 PROJECTS e Capacitance Meter e Pitch Switch Lights Needed Alert e Teach In 2002 Power Supply FEATURES e Teach In 2002 Part 1 Practically Speaking Circuit Surgery e New Technology Update Ingenuity Unlimited e Net Work The Internet Page Free 16 page Supplement PIC Toolkit TK3 For Windows DEC 01 PROJECTS e Ghost Buster PIC Polywhatsit Twinkling Lights Mains Failu
203. oscillation in the face of falling supply voltage etc is just feasible For crystals designed to generate fre quencies below about 1MHz or above about 1OMHZz special circuit arrangements may be needed Consult the manufactur er s data sheet TWO TERMINAL LC The need for transformers or twin capacitors can be avoided by using a so called two terminal oscillator circuit This means that the frequency determining LC circuit can be connected by just two leads those marked X in Fig 12 fo 1 2n VLC Fig 12 Two terminal LC oscillator A2 provides the required phase inversion A3 can be added as a output buffer With R1 R2 A2 has a gain close to one so it is just a voltage inverter Then Al must provide the gain needed for oscilla tion The critical condition is that VRI should be just less than the effective resis tance of the LC circuit at its resonant frequency f The effective resistance is called the dynamic resistance and is Q times the reactance of L or C at f For a usable coil the Q quality factor is unlikely to be less than five and may be several hundred Good sine waves are obtainable at the LC circuit when VRI is considerably less than the critical value but to get a pure waveform at A2 output VRI must be set so that the circuit just oscillates It may be simpler to pick off a sine wave output at Al and extract it via buffer A3 This has a gain of R4 R3 The circuit may be used up
204. oscillator form because an inverter has only one input ter minal It can however be adapted to a 2 inverter circuit as illustrated in Fig 15 Inverters Al and A2 are used in their linear mode and the parallel RC arm now creates negative feedback to Al while the series RC arm conveys positive feed back from A2 to Al The circuit oscillates at f when the gain of A2 adjusted by VR2 slightly exceeds two An extra preset Fig 14 Wien bridge oscillator using an operational amplifier resistance VRI has been added Without it the circuit would cease to oscillate as R is reduced towards zero The oscillation frequency is f ACR VRI In fact there is a hidden component in the series arm this is the output resistance of inverter A2 and it must be compensated for by an increased resistance in the paral lel arm If this is not done feedback varies as R is adjusted and it is impossible to obtain a good waveform over the tuning range AMPLITUDE LIMITING No device for automatic amplitude lim iting is shown in Fig 15 The job could be done by substituting a thermistor for the feedback resistance across A2 as in Fig 16 VR2 would then provide oscillation level adjustment and should have a mid value equal to the working thermistor resistance Unfortunately there are really no suit able thermistors available to the average hobbyist The sub miniature bead thermis tors needed are very expensive Cheap
205. ou can imagine Over 10 000 Power Supplies Ex Stock Call or see our web site RELAYS 200 000 FROM STOCK Save s by choosing your next relay from our Massive Stocks covering types such as Military Octal Cradle Hermetically Sealed Continental Contactors Time Delay Reed Mercury Wetted Solid State Printed Circuit Mounting etc CALL or see our web site www distel co uk for more information Many obsolete types from stock Save s ALL ENQUIRIES 0208 653 3333 FAX 0208 653 8888 me f LI HL a D 8 e 26 All prices for UK Mainland UK customers add 17 5 VAT to TOTAL order amount Minimum order 10 Bona Fide account orders accepted from Govemment Schools Universities and Local Authorities minimum account order 50 Cheques over 100 are subject to 7 working days clearance Carriage charges A 3 50 B 6 50 C 10 D 15 00 E 18 00 F CALL Allow approx 3 days for shipping faster CALL All goods supplied to our Standard Conditions of Sale which can be viewed at our website and unless stated guaranteed for 90 days All guarantees on a retum to base basis All rights reserved to change prices specifications without prior notice Orders subject to stock Discounts for volume Top CASH prices paid for surplus goods All trademarks tradenames etc acknowledged Display Electronics 2002 E amp O E EPE HYBRID COMPUTER Analogue computers can solve many real world pr
206. out comprises master console and three slave units PIC POCKET BATTLESHIPS by Bart Trepak 754 Become a Sea Lord with our interpretation of the age old pen and paper game Series and Features CIRCUIT SURGERY by Alan Winstanley and lan Bell 726 Toggle CMOS Interface Troublesome UV Timer Battery Eliminator NEW TECHNOLOGY UPDATE by lan Poole 728 Laser light as tweezers and new materials for superconductors LOGIC GATE INVERTER OSCILLATORS Part 2 by George Hylton 742 A compendium of practical oscillator circuits for creative experimenters VOL 31 No 10 OCTOBER 2002 Cover illustration by jgr22 EPE BOUNTY INTERFACE by Robert Penfold 746 Adding MSCOMM Active X control to your PC NET WORK THE INTERNET PAGE surfed by Alan Winstanley 753 Too Many Favourites ContentSaver Low Interest Rates USING TK3 WITH WINDOWS XP AND 2000 by Mark Jones 758 By popular request how to get EPE Toolkit TK3 operating under these other systems Regulars and Services EDITORIAL 707 NEWS Barry Fox highlights technology s leading edge 714 Plus everyday news from the world of electronics SHOPTALK with John Becker 725 The essential guide to component buying for EPE projects PLEASE TAKE NOTE Car Battery Trickle Charger i u 725 BACK ISSUES Did you miss these Many now on CD ROM 740 CD ROMS FOR ELECTRONICS 748 A wide range of CD ROMs for hobbyists students and engineers READOUT John Becker addresses gener
207. ower supply for its inter nal preamplifier This is derived from the nominal 6V supply through resistor R1 The speech signal is applied via capacitor Cl and input resistor R2 to the inverting input pin 2 of operational amplifier op amp ICla This is one half of a dual unit The function of the other section IC1b will be looked at presently COMPLETELY BIASED The non inverting input of IC1 pin 3 is connected to a nominal 3V reference derived from the potential divider com prising fixed resistors R3 and R4 work ing in conjunction with capacitor C2 Since the op amp is powered from single supply rails 6V and OV this proce dure allows for a false zero to be set allowing both the positive and negative half cycles of the input waveform to be amplified Fixed resistor R5 and preset VRI con nected in series apply negative feedback between ICI output pin 1 and the invert ing input pin 2 The value of the feed back resistance divided by that of input resistor R2 determines the gain With preset VRI at minimum adjust ment this will be unity and when at maximum 23 In fact these values are negative but this has no practical conse quence here Preset VR1 will be adjusted Everyday Practical Electronics October 2002 at the end of construction to provide a suitable gain for the particular micro phone used If tests prove the gain to be too small the value of resistor R2 could be decreased TALK TO ME
208. owered off eight AA batteries in Everyday Practical Electronics October 2002 IC1a b TX OSCILLATOR SEARCH HEAD PREAMPLIFIER COMPARATOR HYSTERESIS PEAK DETECTOR BIEZ SOUNDER Fig 1 Block diagram of the EPE Bounty Treasure Hunter series 12V which should provide about 100 hours of continuous use when using cheap batteries CIRCUIT DESCRIPTION The complete circuit diagram for the EPE Bounty Treasure Hunter is shown in Fig 2 The search head of a typical I B metal detector comprises two coils a transmitter coil Tx and receiver coil Rx In this case the Tx coil is driven by a square wave oscillator which sets up an alternating magnetic field in the coil The receiver coil is positioned in such a way that it partly overlaps the transmitter coil see Fig 3 By adjusting the amount of overlap a point can be found where the voltages in the Rx coil null or cancel out so that little or no electrical output is produced A metal object which enters the field then causes an imbalance resulting in a signal being generated The transmitter oscillator built around IC1a is a simple clock generator based on a single gate of a 40106 hex Schmitt inverter i c While such oscillators tend to be unstable in operation this is unimpor tant for our purposes here we merely need to set up the alternating magnetic field in the coil Tx So that Cla is not unduly loaded IC1b is used as a buffer Cla
209. p to four temperature sensors located 200m from motherboard PC Ideal use for old 386 486 comput ers Users can tailor input data stream to suit their purpose dump it to a spreadsheet or write your own BASIC programs using the INPUT command to grab the readings PCB just 38mm x 38mm Sensors con nect via four 3 pin headers 4 header cables supplied but only one DS18S20 sensor Kit software available free from our website ORDERING 3145KT 23 95 kit form AS3145 29 95 assembled Additional DS18S20 sensors 4 95 each SOUND EFFECTS GENERATOR Easy to build Create an almost infinite variety of interesting unusu al sound effects from birds chirping to sirens 9VDC PCB 54x85mm 1045KT 8 95 ROBOT VOICE EFFECT Make your voice sound similar to a robot or Darlek Great fun for discos school plays theatre productions radio stations amp playing jokes on your friends when answering the phone PCB 42x71mm 1131KT 8 95 AUDIO TO LIGHT MODULATOR Cortrols intensi ty of one or more lights in response to an audio input Safe modern opto coupler design Mains voltage experience required 3012KT 8 95 MUSIC BOX Activated by light Plays 8 Christmas songs and 5 other tunes 3104KT 7 95 20 SECOND VOICE RECORDER Uses non volatile memory no battery backup needed Record replay messages over amp over Playback as required to greet customers etc Volume control amp built in mic 6VDC PCB 50x73mm 3131KT 12 95
210. pages Everyday Practical Electronics October 2002 VIDEO PROJECTS FOR THE ELECTRONICS CONSTRUCTOR R A Penfold Written by highly respected author R A Penfold this book contains a collection of electronic projects specially designed for video enthusiasts All the projects can be simply con structed and most are suitable for the newcomer to project construction as they are assembled on stripboard 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 sound tracks and a basic computer control interface Also there s a useful selection on basic video production techniques to get you started Complete with explanations of how the circuit works shop ping lists of components advice on construction and guid ance on setting up and using the projects this invaluable book will save you a small fortune Circuits include video enhancer improved video enhancer video fader horizontal wiper improved video wiper negative video unit fade to grey unit black and white keyer vertical wiper audio mixer stereo headphone amplifier dynamic noise reducer automatic fader pushbut ton fader computer control interface 12 volt mains power supply Order code PC115 10 95 124 pages PC MUSIC THE EASY GUIDE Robin Vincent How do make music on my PC Can record music onto my PC What s a sequencer How can get my PC to pri
211. r a hundred components even without the hardware and this would represent a seri ous challenge to many constructors not to mention the time involved Alternatively one can settle for a sim pler and cheaper design However while such designs may initially provide good fun they typically have poor depth of pen etration a predilection for rusty iron and poor stability The author s aim with this design was to create a minimalist induction balance I B metal detector while also achieving good performance This method of metal detection has a good depth of penetration and distinguishes well between ferrous and non ferrous metals It is also capable to a large extent of rejecting iron and also tin foil This is a boon for anyone who is searching in the first instance for coins or noble metals GOING DIGITAL The reason for the simplicity of the design is that it largely dispenses with ana logue circuitry and uses a digital transmit ter and digital peak detector instead The full block diagram for the EPE Bounty Treasure Hunter is shown in Fig 1 As the search coils pass over metal only digital signals of a certain amplitude break through Since these are in the audio range they are immediately transferred to 708 a piezo sounder WD1 or headphones This has the added bonus in some coun tries of eliminating the need for an operat ing licence GOOD DETECTION The resulting circuit as simple as it is
212. r a Send command you will perform a Read But this is not always the case For the Read you can specify that a pin designated as an output should have either a High or Low logic level or that it doesn t matter X Once the required instructions have been created press OK to save the profile The up and down arrow buttons allow lines to be moved up and down in the exe cution order The Delete Line button allows instruction lines to be removed from the profile CONFIGURATION OPTIONS The configuration options can be select ed from the main menu and are located 724 under Tools Configuration see Photo 2 earlier When selected there are five groups of configuration settings that can be changed The first group deals with the serial interface characteristics The COM port and interface speed are changed here At the bottom of the screen there is a Timing Adjustment button In certain circum stances it is possible to under run the PC s serial buffer Increasing this value forces the PC software to wait longer for incom ing data the drawback being that the soft ware will run slightly slower To check that this setting is correct insert a known good 1 c into the tester and set for continuous testing If after the default 999 tests no failures have been reported then the setting is correct If any failures are detected then this value should be increased by a value of 1 and the test performed again
213. r form on next page Hobbyist Student Institutional Schools HE FE Industry Flowcode Institutional Institutional 10 user Network Licence Site Licence 45 inc VAT 99 plus VAT 70 plus VAT 249 plus VAT 599 plus VAT UK and EU customers add VAT at 17 5 to plus VAT prices TEACH IN 2000 LEARN ELECTRONICS WITH EPE EPE s own Teach In CD ROM contains the full 12 part Teach In series by John Becker in PDF form plus the Teach In interactive software covering all aspects of the series We have also added Alan Winstanley s highly acclaimed Basic Soldering Guide which is fully illustrated and which also includes Desoldering The Teach In series covers Colour Codes and Resistors Capacitors Potentiometers Sensor Resistors Ohm s Law Diodes and L E D s Waveforms Frequency and Time Logic Gates Binary and Hex Logic Op amps Comparators Mixers Audio and Sensor Amplifiers Transistors Transformers and Rectifiers Voltage Regulation Integration Differentiation 7 segment Displays L C D s Digital to Analogue Each part has an associated practical section and the series includes a simple PC interface so you can use your PC as a basic oscilloscope with the various circuits A hands on approach to electronics with numerous breadboard circuits to try out Sine wave relationship values 12 45 including VAT and postage Requires Adobe Acrobat available free from the Internet www adobe com acro
214. rcuits can be built and unassembled repeatedly Comprehensive 68 page manual with explanations schematics and assembly diagrams Suitable for age 10 Excellent for schools Requires 2 x AA batteries Order Code EPLO30 ONLY 14 95 phone for bulk discounts 130 300 and 500 in ONE also available Everyday Practical Electronics October 2002 Secure Online Ordering Facilities Full Kit Listing Descriptions amp Photos Kit Documentation amp Software Downloads ddl PACD Ml re 89L Z Z Lil Z 4 ie 1 BARGAIN PACKS PIEZO ELECTRIC SOUNDER also operates effi ciently as a microphone Approximately 30mm diame ter easily mountable 2 for 1 Order Ref 1084 LIQUID CRYSTAL DISPLAY on p c b with i c s etc to drive it to give 2 rows of 8 figures or letters with data Order Ref 1085 30A PANEL MOUNTING TOGGLE SWITCH Double pole Order Ref 166 SUB MIN TOGGLE SWITCHES Pack of 3 Order Ref 214 HIGH POWER 3in SPEAKER 11W 8ohm Order Ref 246 MEDIUM WAVE PERMEABILITY TUNER It s almost a complete radio with circuit Order Ref 247 HEATING ELEMENT mains voltage 100W brass encased Order Ref 8 MAINS MOTOR with gearbox giving 1 rev per 24 hours Order Ref 89 ROUND POINTER KNOBS for flatted in spindles Pack of 10 Order Ref 295 REVERSING SWITCH 20A double pole or 40A single pole Order Ref 343 LUMINOUS PUSH ON PUSH OFF SWITCHES Pack of 3 Order Ref 373 SLIDE SWITCHES Single pol
215. re suitable for use on any PC witha CD ROM drive They require Adobe Acrobat Reader available free from www adobe com acrobat 1 2 45 each Including VAT the Internet Order on line from www epemag wimborne co uk shopdoor htm or www epemag com USA prices or by phone Fax E mail or Post BACK ISSUES MINI CD ROM ORDER FORM I I I 1 Please send me quantity BACK ISSUES CD ROM VOL 1 Please send me quantity BACK ISSUES CD ROM VOL 2 Please send me quantity BACK ISSUES CD ROM VOL 3 Please send me quantity BACK ISSUES CD ROM VOL 4 1 Please send me quantity BACK ISSUES CD ROM VOL 5 Please send me quantity BACK ISSUES CD ROM VOL 6 l l l l l l I Price 12 45 each includes postage to anywhere in the world Name s cae wbeke Ss nwedbdwee G4 8k be Ob ob ew Sheed he ed I l AddreSS dia Bic d die dada I I Poona act eke fs Gs Jee Saye tae an D Re a tate ar ne a D ar ca tna eh I ae ci I I I E EE TEE E EE EEE Post Code I _ l enclose cheque P O bank draft to the value of Please charge my Visa Mastercard Amex Diners Club Switch Expiry Date Switch Issue No SEND TO Everyday Practical Electronics Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 E mail orders epemag wimborne co uk Payments must be b
216. re Alarm FEATURES e Teach In 2002 Part 2 Marconi The Father of Radio Interface e Ingenuity Unlimited Circuit Surgery New Technology Update e Net Work The Internet Page 2001 Annual Index JAN 02 PROJECTS e PIC Magick Musick e Time Delay Touch Switch e Versatile Bench Power Supply Forever Flasher FEATURES e Teach In 2002 Part 3 Practically Speaking Ingenuity Unlimited e New Technology Update e Circuit Surgery Net Work The Internet Page DID YO ge di PROJECTS e PIC Spectrum Analyser Guitar Practice Amp e HT Power Supply Versatile Current Monitor FEATURES e Teach In 2002 Part 4 Ingenuity Unlimited Russian Space Shuttle Revisited e Circuit Surgery Interface New Technology Update e Net Work The Internet Page PROJECTS e MK484 Shortwave Radio e PIC Virus Zapper e RH Meter PIC Mini Enigma FEATURES e Teach In 2002 Part 5 Ingenuity Unlimited Programming PIC Interrupts 1 e Circuit Surgery Practically Speaking New Technology Update Net Work The Internet Page APR 02 PROJECTS e Electric Guitar Tuner e PIC Controlled Intruder Alarm Solar Charge and Go e Manual Stepper Motor Controller FEATURES e Teach In 2002 Part 6 Interface e Programming PIC Interrupts 2 e Circuit Surgery e Ingenuity Unlimited e New Technology Update e Net Work The Internet Page FREE Giant Op Amp Data Chart MAY 02 PROJECTS e
217. ries gt Windows Explorer The default folder shown on opening Windows Explorer is your personal My Documents folder For the purposes of this Everyday Practical Electronics October 2002 exercise we will install the software at a higher level within the structure Within Windows Explorer on the left hand side of the screen click the sign next to My Computer then click on Local Disk C naming may vary depending on your per sonal setup In the right hand side of the screen you now need to right click with the mouse and select New gt Folder and call this folder Toolkit3 For Windows XP and 2K see Fig 2 Within Windows 2K the graphics may differ but the process is exactly the same PROGRAM INSTALLATION Follow the instructions for the TK3 installation by unzipping the three zip files into the new folder WinZip is a good tool to undertake this task with and an evalua tion copy of the tool is available for free download from www winzip com It is imperative that older versions of WinZip should not be used since they might truncate file names to the old DOS limit of eight characters which would cause 7 K3 to crash Note that once all the files have been unzipped any immediate attempt to run the TK3PROG executable EXE will result in an error message being generated by the operating system for Windows XP see Fig 3 for Windows 2000 see Fig 4 some PCs may show slightly different displays depending on other so
218. rocess you may be asked to restart your computer if you have not previously installed the Visual Basic 6 runtime components or they are out of date Reboot the computer and restart the setup process as required The temporary directory C ICTester can be deleted if no longer required once the setup is complete If running the instal lation from the EPE CD ROM insert the disk into the disk drive and run the Setup exe program located on it as described above then follow the prompts Once complete the Setup program will create a new program group called Digital I C Tester You can find it be clicking the 121 Start icon on the lower left hand side of the main Windows screen and then selecting programs You should see it listed there TESTING THE INTERFACE Connect the serial cable and power sup ply unit and switch on The Le d D1 should illuminate Also to confirm that the PIC is running and executing its firmware Le d D4 should also illuminate Start the PC program running and you will be presented with the main working area similar to Photo 1 Photo 1 Main working area toolbar on PC screen By default the PIC firmware and the PC software are set to communicate at 19 2K baud TP4 TP6 link excluded see earlier The PC software must be configured to use the COM port that you have connected the serial cable to By default the software uses COM 1 If you are not using COM 1 you can change this settin
219. ryday Practical Electronics October 2002 L E D and Fuse Checker kamay Unit A1 Rue Flg 2 Circuit diagrams for the L E D and Fuse Checker Ti circuits shown in Fig 2 were designed for testing light emitting diodes l e d s and also act as a continuity or fuse tester A light emitting diode can be tested with a 3V battery and series 39 ohm resistor but the tester here has some advantages It has its own l e d indicator which is useful in gaug ing the comparative brightness of an L e d under test In Fig 2a Rl D1 and TRI form a voltage regulator giving about 3 volts at TR1 emitter with TR2 acting as a standard current limiter shunting from the Zener to lower the voltage and limiting TRI current to about 20mA Capacitor Cl was found necessary to stop oscillation The transistor types are not criti cal and may be any small signal type such as the BC184 The circuit shown in Fig 2b was devised after further experiment and performs the same function TRI is the voltage regulator and TR2 limits the current Since the current limiting resistor is not in series with the out put it gives a slightly higher output voltage WHY NOT SEND US YOUR CIRCUIT IDEA Earn some extra cash and possibly a prize a NE LE ein T J F x F ha ay LA The 3V level was chosen as this is the rat ing for the L e d s in a digital display connect ed in reverse the lowest rating like
220. s as clearly as possible Send your circuit ideas to Alan Winstanley Ingenuity Unlimited Wimborne Publishing Ltd 408 Wimborne Road East Ferndown Dorset BH22 9ND We do not accept sub missions for U via E mail Your ideas could earn you some cash and a prize il TEA En ieee 5 pe R EL EL EL WIN A PICO PC BASED OSCILLOSCOPE WORTH 586 100MS s Dual Channel Storage Oscilloscope 50MHz Spectrum Analyser Multimeter Frequency Meter Signal Generator If you have a novel circuit idea which would be of use to other readers then a Pico Technology PC based oscilloscope could be yours Every 12 months Pico Technology will be awarding an ADC200 100 digital storage oscilloscope for the best IU submission In addition a DrDAQ Data Logger Scope worth 69 will be presented to the runner up One Second Crystal Clock A Second Source TE One Second Crystal Clock circuit dia gram shown in Fig 1 was devised through necessity A simulator was required for a Bio Botanical experiment at home The requirements were for a cheap and quick con struction portability low voltage current and a means of recording expired time periods The solution consists of a sensitive pick up coil LI placed close to an analogue quartz inverters ICla to IC1f to square up the pulse from the coil The output from the inverters is shaped by a capacitor resistor diode network C4 D1 and R6 which is used to tri
221. s book provides a number of tried and tested circuits for projects that utilize fibre optic cables The projects include Simple audio links FM audio link PW M audio links Simple d c links P W M d c link PW M motor speed control RS232C data links MIDI link Loop alarms R P M meter All the components used in these designs are readily available none of them require the constructor to take out a second mortgage Order code BP374 5 45 132 pages RADIO BYGONES We also carry a selection of books aimed at readers of EPE s sister maga zine on vintage radio Radio Bygones These books include the Comprehensive Radio Valve Guides five books with a Free copy of the Master Index for just 15 Also Jonathan Hill s excellent Radio Radio a comprehensive book with hun dreds of photos depicting the develop ment of the British wireless set up to the late 1960s The three volumes of our own Wireless For the Warrior by Louis Meulstee are also available These are a technical his tory of radio communication equipment in the British Army from pre war through to the 1960s For details see the shop on our UK web site at www epemag wimborne co uk or contact us for a list of Radio Bygones books 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
222. s could provide greater reliability a fact which may well be appreciated in the type of situation in which this unit is intended to be used PIC Pocket Battleships Except for one item all components in the P C Pocket Battleships project are perfectly standard which we expect any supplier to keep in stock This fun game uses a PIC microcontroller but it is not one that appears frequently in EPE projects It is the PIC16C54 which is one of the earlier PICs long before the 84 etc and which is not electrically erasable requiring exposure to UV light to do so through a window set into the device This PIC is available pre pro grammed only from the author Bart Trepak 20 The Avenue London W13 8PH It costs 5 50 inclusive overseas add 1 for P amp P payment made out to B Trepak and only in ster ling and drawn on a British Bank although UK postal orders are accepted Software is available separately as stated below Note that Toolkit TK3 is not designed for use with PIC16C54 devices Printed Circuit Boards and Software Apart from Battleships which is built on stripboard this month s projects all have p c b s Their code numbers are quoted in the respective Components Lists and are available as stated on the EPE PCB Service page page 763 All the software required is available for free download from our ftp site The easiest access route to this is via the main web page at www epemag wimborne co uk use the clic
223. s defined logic lev els to the specified input pins and records the results generated on the output pins The actual results received are com pared against those that are expected and from this it is possible to ascertain if the i c is functioning correctly It should be noted that some i c s require a great many individual logic operations to test them completely For example the 7430 8 input NAND gate requires 256 sep arate input logic level permutations to be tested CIRCUIT DESCRIPTION The complete circuit diagram for the Digital I C Tester is shown in Fig 1 When power is supplied to the board it first pass es through bridge rectifier REC1 If the input supply input is a c REC1 converts it to d c If the input is already d c it ensures that the polarity is correct for ICI which then regulates the voltage down to approx imately 5V Capacitors C1 to C4 plus C11 provide smoothing A PIC16F877 20 microcontroller des ignated as IC3 is used as the core of the circuit and is run at its maximum speed of 20MHz as defined by crystal X1 Since this design uses RS232 protocol to inter face to a serial port on a PC a voltage level converter is employed to convert the PIC s SV logic levels to the 12V levels required by the RS232 standard many PCs do not actually require this higher voltage for ser ial comms input and will accept 5V 0V inputs Ed This is accomplished by IC2 a MAX232 line driver Capacitors C5 to
224. s every synthesiser has The three steps to synthesis How to create phat bass sounds How to generate filter sweeps Advanced synth modules How to create simple and complex synth patches Where to find soft synths on the Web If you want to take your synthesiser of the hardware or software variety past the presets and program your own sounds and effects this practical and well illustrated book tells you what you need to know Order code PC118 7 45 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 MP3s work How to tune into Internet radio stations How to create your own MP3s How to record your own CDs from MP3 files Other digital audio music formats Whether you want to stay bang up to date with the lat est music or create your own MP3s and join the on line digital music revolution this book will show you how 60 pages Order code PC119 7 45 60 pages
225. s now being optimised In some of the early experiments light leaked through the capillary tubes and reduced the efficiency This problem has now been solved and photonic crystal fibres confine the light to the centre of the tube Using the new fibre and an 80mW laser polystyrene spheres that were Sum in diameter have been moved at a velocity of 1 1cm s It has also been possible to move particles over the full fibre length of 150mm Although work is still progressing on developing the technique it is expected to find uses in the semiconductor industry where the push to achieve smaller dimen sions is forcing the need for new tech niques such as this It will be interesting to see how this develops in the coming years Superconductors have been known for many years Despite the fact that they are well established they still appear to con tradict the basic laws of electricity by hav ing their resistance fall to zero when the temperature is reduced far enough Although many new substances that exhib it superconductivity are being discovered superconductors are only used in a limited number of applications One of the reasons for this is cost New high temperature superconductors have been discovered but they are very expensive to manufacture Even low temperature types are still rea sonably expensive and require costly refrigeration plants The combined cost makes them appear not to be viable in many applications However it
226. sk drive FFT etc 2900 TEK TDS524A 500Mhz digital realtime colour display etc 5100 HP3585A Opt 907 20Hz to 40 Mhz spectrum analyser 3950 PHILIPS PW1730 10 60KV XRAY generator amp accessories POA VARIACS Large range from stock call or see our website CLAUDE LYONS 12A 240V single phase auto volt regs 325 CLAUDE LYONS 100A 240 415V 3 phase auto volt regs 2900 rip secs Ete Fri 9 00 5 30 18 Million Items On Line Now Secure ordering Pictures Information www distel co uk email admin distel co uk Surplus always wanted for cash 19 RACK CABINETS Europe s Largest Stocks of quality rack cabinets enclosures and accessories Over 1000 Racks from stock oats O oh This month s special 33 42 47 U High Quality All steel Rack Cabinets Made by Eurocraft Enclosures Ltd to the highest pos sible spec rack features all steel construction with removable side front and back doors Front and back doors are hinged for easy access and all C gt lockable with five secure 5 lever barrel locks ee The front door is constructed of double walled a steel with a designer style smoked acrylic front panel to enable status indicators to be seen through the panel yet remain unobtrusive Internally the rack features fully slotted rein forced vertical fixing members to take the heavi est of 19 rack equipment The two movable vertical fixing struts extras available are pre f
227. solved the age old problem of squeezing a large key board into a small computer device Ubinetics patent application GB 2 370 395 tells how to create a virtual keyboard by projecting its image onto any flat surface such as a table top or book A PDA pocket computer or cellphone has a solid state laser which rapidly proj ects with flickerfree scans at 25Hz or higher the image of a conventional com puter keyboard The size and focus of the zero mass image is adjusted to suit the available surface area and the language and keyboard layout are chosen from a menu to suit the owner s nationality and wishes A sensor in the device picks up light reflected from the image through a half silvered mirror When the user fingers a virtual key it interrupts the light and the device registers a key click and displays the key character on its screen So the vir tual keyboard allows normal typing The patent was filed in December 2000 naming Alun Morris as inventor but the UbiNetics spokeswoman surprisingly con firms that UbiNetics is no longer involved in the consumer side as it used to be and is concentrating purely on developing GPRS 3G technologies But surely a large zero mass keyboard that folds into zero space is just what will be needed to make 3G and GPRS phones and PDAs usable The company no longer produces the projection keyboard you were inquiring about says Ms Lewis cryptically Sleight of Hand Cashing
228. speech cannot enter any microphone used to pick up the sound of the performance and cannot be heard by the audience Headsets while worn are free from acoustic feedback the howling noise which is produced when the sound from a loudspeaker re enters a microphone and builds up in a loop The close proximity of the microphone to the speaker s mouth provides very clear communication even when there is a lot of extraneous sound or when he or she only whispers Power is supplied using four AA size alkaline cells housed inside each unit The current requirement is 25mA approximate ly 40mA for the master unit and the spec ified batteries should provide at least 50 hours of operation For safety reasons the system MUST NOT be operated using a mains derived supply such as a plug in adaptor 734 The Headset Communicator system units showing left to right the master unit three slave units and a headphone with boom mic MASTER UNIT The Master unit is built in a sloping front instrument case see photograph The headset is plugged into a pair of sock ets on the front and sockets on the rear panel connect the cables leading to the slave units On the top there is an on off switch and associated L e d light emitting diode On indicator There is also a three position Slave Select rotary switch S2 which selects which slave A B or C is to be placed on line a momentary action push button switch
229. ssex RH17 5PA Telephone 01444 881965 E mail jnfactors aol com 703 GENT ELECTRONI CS Tel 01283 565435 Fax 546932 http www magenta2000 co uk E mail sales magenta2000 co uk LT D EE242 135 Hunter Street Burton on Trent Staffs DE14 2ST All Prices include V A T ADD 3 00 PER ORDER P amp P 6 99 next day MAIL ORDER ONLY e CALLERS BY APPOINTMENT EPE MICROCONTROLLER P I TREASURE HUNTER The latest MAGENTA DESIGN highly stable amp sensitive with I C control of all timing functions and advanced pulse separation techniques High stability drift cancelling e Easy to build amp use e No ground effect works in seawater e Detects gold silver ferrous amp non ferrous metals e Efficient quartz controlled microcontroller pulse generation Full kit with headphones amp all hardware KIT 847 PORTABLE ULTRASONIC PEsT SCARER A powerful 23kHz ultrasound generator in a compact hand held case MOSFET output drives a special sealed transducer with intense pulses via a special tuned transformer Sweeping frequency output is designed to give maximum output without any special setting up KIT 2 PPS 22 56 68000 DEVELOPMENT TRAINING KIT e NEW PCB DESIGN e 8MHz 68000 16 BIT BUS e MANUAL AND SOFTWARE e 2 SERIAL PORTS e PIT AND I O PORT OPTIONS e 12C PORT OPTIONS KIT 621 gt 99 95 e ON BOARD 5V REGULATOR e PSU 6 99 e SERIAL LEAD 3 99
230. t 15A 250V It is easy to fix in a small space Its operating toggle is labelled off for up and on for down Pack of 3 Order Ref 1 11R27 IN LINE FUSEHOLDERS Just cut the wire and insert fully insulated Pack of 4 Order Ref 969 MINI MONO AMP 3W into 4 ohm speaker or 1W into 8 ohm Order Ref 495 15V DC 150mA PSU Nicely cased Order Ref 942 6V 1A MAINS TRANSFORMER Upright mounting with fixing clamps Pack of 2 Order Ref 9 SUCK OR BLOW OPERATED PRESSURE SWITCH or it can be operated by any low pressure variation such as water level in tanks Order Ref 67 12V SOLENOID Has good Lin pull or could push if modified Order Ref 232 NEON INDICATORS In panel mounting holders with lens Pack of 6 Order Ref 180 12V ALARMS Make a noise about as loud as a car horn Use one lead and case for DC all brand new Pack of 2 Order Ref 221B PANOSTAT Controls output of boiling ring from simmer up to boil Order Ref 252 OBLONG PUSH SWITCHES For bell or chimes these can switch mains up to 5A so could be foot switch if fitted in pattress Pack of 2 Order Ref 263 MIXED SILICON DIODES Pack of 25 Order Ref 293 SHADED POLE MAINS MOTOR in stack so quite powerful Order Ref 85 TERMS Send cash uncrossed PO cheque or quote credit card number If order is 25 or over deduct 10 but add postage 3 50 if under 2 kilo 6 if under 4 kilo J amp N FACTORS Pilgrim Works Dept E E Stairbridge Lane Bolney Su
231. t forget the small hole needed for the Volume control potentiometer anti rotation tab Attach all slave parts and referring to Fig 5 complete the internal wiring leaving plenty of slack in the wires Note that cer tain connections will be close together so make sure they do not touch and cause a short circuit Use additional insulation as necessary Check that the connections to the plug pins allow the interconnecting lead to make the appropriate connections Talk to distant Listen and Listen to distant Talk In the prototype pin 2 was used for listen and pin 3 for the talk Connect pin 1 to the solder tag on the plug that connects to the metal body Take care over the sense of the connections to the potentiometer tags Attach the control knobs to the spindles of the switches and potentiometers in all units Leave the lids removed from the cases for the moment to allow presets VR1 to be adjusted Observing the usual anti static precau tions insert all the 1 C S into their sock ets taking care over the orientation FINAL CHECKS Begin final checking with all Everyday Practical Electronics October 2002 Packing the components into the Slave unit the units switched off Fit the batteries then plug in the interconnecting leads and headsets with integral microphone booms Turn all the Volume controls to minimum and switch the units on The L e d On indicators should operate The headphones should be
232. t they had been able to move and guide particles in a hollow core pho tonic crystal using laser light However work on the concept has been progressing steadily for a number of years Photonic Crystals One of the key elements in the research is what are termed photonic crystals These form light waveguides and have been known about for a few years They were first demonstrated by the members of the Physics department at the University of Bath They are unique because they enable a beam of light to be trapped inside a nar row bore hollow tube of glass This is a remarkable because it appears to reverse the laws of physics In a tube of this nature light propagates by undergoing total inter nal reflection However this only takes place when a ray of light passes from a more dense to a less dense medium and this is not the case with a hollow glass tube Normal optical fibres consist of solid glass and the light is contained within the glass itself so total internal reflection can take place as the glass is more dense than the surrounding air For the new fibres that are a hollow tube the researchers have been able to overcome the problem of the light passing from a less dense to a more dense medium by using what is called a photonic band gap This is a phenomenon that can be observed if the glass used in the new hollow optical fibre has tiny air holes spaced throughout its 728 lan Poole comments that laser light could be
233. tatic coupling in the search head The shield is made with some long 20mm wide strips of aluminium or tin foil Scrape the enamel off the base of the Tx coil s end and Rx coil s beginning wires Now solder a 100mm length of stiff bared wire to each scraped area and twist this around the coil over the insulating tape This provides an electrical contact for the Faraday shield Beginning at the base of this wire the foil is wound around the circumference of the coil so that no insulating tape is still visible underneath it but the foil does not complete a full 360 degrees Leave a small gap say 10mm so that the foil does not meet after having done most of the round Do this with both coils Each coil is now again tightly bound with insulating tape around its entire circumference Attach each of the coils to quality single core screened audio cable micro phone cable with the Faraday shields being soldered to the screen Do not use stereo or twin core audio cable as this may cause interference between the coils Gently bend the completed coils until each one is reasonably flat and circular with the wires facing away from you Both coils beginning wires should be to the left of their end wires The Faraday shield con nections should be side by side Now bend the coils further see Fig 3 until they form lopsided ovals like capital Ds The backs of these Ds overlap each other slightly on t
234. techniques Choosing and using test equipment Reference data Easy to use format Clear and simple layout Vital safety precautions Professionally written Regular Supplements Sturdy gold blocked ring binder Our 30 day money back guarantee gives you complete peace of mind If you are not entirely happy with the Electronics Service Manual for whatever reason simply return it to us in good condition within 30 days and we will make a full refund of your payment no small print and no questions asked All we ask is that you pay the return postage Overseas buyers also have to pay our overseas postage charge Sorry but we can only make exchanges on the Modern Electronics Manual CD ROM version if the CD ROM is faulty we cannot offer a money back guarantee on this product as the content can be printed out i Elele eeel ee eee eM ed eee et en elelee ed eee fet CEE eh ed een fet et eed etd ede ee fee en et ee eed ede ee en fen EEEE EEE fet ene feed feed ed ee eee eee eee et ee eed eed ed ee eee eee eee eee eee Wimborne Publishing Ltd Dept Y10 408 Wimborne Road East Ferndown Dorset BH22 9ND Tel 01202 873872 Fax 01202 874562 Online shop www epemag wimborne co uk shopdoor htm E s a a PLEASE send me ORDER FORM l Simply complete and return the order form with your l L THE MODERN ELECTRONICS MANUAL CD ROM version only payment NO MIC OHOWING RUES i Wimborne Publishing Ltd Dept Y10 408 Wimborne l
235. th applications in and around the home or in the constructors workshop These include a number of audio projects such as a rythm sequencer and a multi voiced electronic organ Concluding the book is a practical step by step guide to designing simple filters for a wide range of purposes with circuit diagrams and worked examples Order code BP299 DIGITAL ELECTRONICS A PRACTICAL APPROACH FREE With FREE Software Number One ZZA Systems EASY PC Professional XM and Pulsar Limited Functionality Richard Monk Covers binary arithmetic Boolean algebra and logic gates combination logic sequential logic including the design and construction of asynchronous and synchro nous circuits and register circuits Together with a consid erable practical content plus the additional attraction of its close association with computer aided design including the FREE software There is a blow by blow guide to the use of EASY PC Professional XM a schematic drawing and printed circuit board design computer package The guide also con ducts the reader through logic circuit simulation using Pulsar software Chapters on p c b physics and p c b production techniques make the book unique and with its host of project ideas make it an ideal companion for the integrative assignment and common skills components required by BTEC and the key skills demanded by GNVQ The principal aim of the book is to provide a straightfor ward approach to the understan
236. th plated wire stand and 245mm lead 3 Order Ref 3P221 YOU WILL RECEIVE THIS MONTH S 14 PAGE LIST OF BARGAINS WITH YOUR GOODS IF YOU ORDER IF NOT PHONE OR WRITE FOR THIS LIST RELAYS We have thousands of relays of various sorts in stock so if you need anything special give us a ring A few new ones that have just arrived are special in that they are plug in and come complete with a special base which enables you to check volt ages of connections of it without having to go under neath We have 6 different types with varying coil volt ages and contact arrangements Coil Voltage Contacts Price Order Ref 12V DC 4 pole changeover 2 00 FR10 24V DC 2 pole changeover 1 50 FR12 24V DC 4 pole changeover 2 00 FR13 Prices include base MINI POWER RELAYS For p c b mounting size 28mm x 25mm x 12mm all have 16A changeover contacts for up to 250V Four versions available they all look the same but have different coils 6V Order Ref FR17 24V Order Ref FR19 12V Order Ref FR18 48V Order Ref FR20 Price 1 each less 10 if ordered in quantities of 10 same or mixed values RECHARGEABLE NICAD BATTERIES AA size 25p each which is a real bargain considering many firms charge as much as 2 each These are in packs of 10 coupled together with an output lead so are a 12V unit but easily divideable into 2 x 6V or 10 x 1 2V 2 50 per pack 10 packs for 25 including carriage Order Ref 2 5P34 4
237. these have a higher imped ance than a loudspeaker 30 ohms approxi mately the available power is reduced However only a small amount of power is needed to drive the headphones at full volume so this method works well The headset volume may be adjusted using VR3 The specified power amplifier type TDA7052 having no suffix does not require a connection to pin 4 However there are variants of this device having a suffix and which have a d c volume con trol If one of these must be used then pin 4 will be used to control its gain To match the characteristics of the spec ified unit it would be necessary to impose a voltage greater than 1 5V on pin 4 which sets it to maximum This could be done using a potential divider and more will be said about this later MASTER SECTION How the Master console is connected to the slaves is shown in Fig 2 The master Listen and Talk lines are directed to one of sockets A B or C using switch S2 This switch is a 4 pole 3 position type The talk and listen lines are connected via switch S2a and S2b respectively while the L e d corresponding to the chosen sock et receives current via S2c and current lim iting resistor R13 Pole d is not used The All Talk function enabling the Master to speak to all slave units simulta neously is provided by connecting the master talk line to all three sockets This is 736 COMPONENTS ALL UNITS Master and Slaves as requ
238. they measure pres sure temperature and humidity Model RS80 good stripper at 15 Ref SONDE AIR WIND POWER MODULE Produces nearly 400 watts of power from the wind 1 14m blade 12V d c output 3 year war ranty built in battery regulator 549 Ref AIR1 WORMERIES The ideal solution for your kitchen waste Supplied complete with worms Turn your rubbish into liquid feed Two sizes available small ideal for 1 2 people 25 45 Ref WM2 and a large one ideal for 4 or more 42 44 Ref WM1 COMPLETE WIRELESS CCTV SYSTEM Includes monitor cam era up to 100m range audio and video UK legal complete with infra red lights 169 Ref WMS333 PELTIER MODULES 56W 40mm x 40mm 16V sealed edges new and boxed Supplied with 18 page Peltier design manual fea turing circuit designs design information etc 1 module and manu al is 29 99 Ref PELT1 pack of 4 modules and manual is 99 99 Ref PELT2 The manual on its own is 4 Ref PELTS DC MOTOR 12V d c general purpose model motor 70mm x 50mm 12V d c permanent magnet 4mm x 25mm shaft 6 Ref GPM1 pack of 10 is just 40 Ref GPM2 180R P M MAINS MOTOR Induction type 90mm x 70mm 50mm x 5mm shaft 12A continuous rating thermal protected 22 Ref MGM1 SOLID STATE RELAYS P C B mounting these relays require 3V to 32V d c to operate but will switch up to 3A a c mains Pack of 4 5 Ref SPEC1B 12V RELAYS 2 x 2 c o 16A contacts p c b mount will fit Vero
239. tion on them Curious how many people think we sell com ponents we don t We are publishers and apart from p c b s plus some CD ROMS and videos that s as far as we go We ve got lots of excellent advertisers though and it s worthwhile getting catalogues from all of them if you want to get the best out of your hobby UNUSED PIC PINS Dear EPE I remember reading somewhere I can t remember where that you should leave PIC pins which are not going to be used in a certain state Trouble is I also can t remember which state Is it all set to inputs and tied to ground or all set to outputs and tied to Vg or set to something and left floating I believe this optimum state what ever it is will reduce power consumption and may make the whole thing more stable Gerard Galvin via email It seems to be common practice to leave a PIC s unused I O pins in an unconnected state and in input mode I can t actually find what Microchip say on the subject Can anyone clari fy and maybe tell me I m wrong 751 SURFING THE INTERNET NET WORK ALAN WINSTANLEY F YOU RE anything like the writer you re inundated with informa tion from all corners of the Internet leading to the nightmare of trying to digest save or discard mountains of data in the shortest possible time In this month s Net Work we take a look at a number of programs that may help you to organise the fruits of your web browsin
240. tionality is available within Windows 2000 without modification For Windows XP users this functionali ty is available within the Microsoft Windows XP Powertoys which are avail able for download at www microsoft com WINDOWSXP home downloads powertoys asp Install the Powertoys as per Microsoft s instructions Readers may be interested in any sub set of the offered functionality but the item we are interested in here is Open Command Window Here so ensure that this item of functionality is selected for download as a minimum Note that Powertoys are not available for Windows 2000 The first step in the installation process is to install the basic program itself For the sal atin Li Fig 2 Creating a new folder within Windows XP purposes of this article the installation illustrated will be from the TK3 CD ROM Readers should be able to modify the step by step instructions below to suit their par ticular circumstances e g installing from an EPE ftp site download Following the instructions contained in the ReadMe file on the TK3 CD the first step is to create a directory for installation The easiest way to undertake this is to use Windows Explorer which is available from the PC s Start menu Within Windows XP it is found by fol lowing the path Start gt All Programs gt Accessories gt Windows Explorer Under Windows 2000 it is found by fol lowing the path Start gt Programs gt Accesso
241. to WEB http www QuasarElectronics com email epesales QuasarElectronics com gp PROJECT KITS SURVEILLANCE High performance surveillance bugs Room transmitters supplied with sensitive electret microphone amp battery holder clip All transmit ROOM SURVEILLANCE MTX MINIATURE 3V TRANSMITTER Easy to build amp guar anteed to transmit 300m 3V Long battery life 3 5V operation Only 45x18mm B 3007KT 6 95 AS3007 11 95 MRTX MINIATURE 9V TRANSMITTER Our best selling bug Super sensitive high power 500m range 9V over 1km with 18V supply and better aerial 45x19mm 3018KT 7 95 AS3018 12 95 HPTX HIGH POWER TRANSMITTER High performance 2 stage transmitter gives r ike greater stability amp higher qual ity reception 1000m range 6 12V DC operation Size ja 70x15mm 3032KT 9 95 AS3032 18 95 MMTX MICRO MINIATURE 9V TRANSMITTER The ultimate bug for its size performance and price Just 15x25mm 500m range 9V Good stability 6 18V operation 3051KT 8 95 AS3051 14 95 VTX VOICE ACTIVATED TRANSMITTER Operates only when sounds detected Low standby current Variable trigger sen sitivity 500m range Peaking circuit supplied for maximum RF out put On off switch 6V operation Only 63x38mm 3028KT 12 95 AS3028 24 95 HARD WIRED BUG TWO STATION INTERCOM Each station has its own amplifier speaker and mic Can be set up as either a hard wired bug or two station intercom 10m x 2 core ca
242. to about 1MHz If VRI is calibrated it can be used to obtain a reasonably accurate indication of the dynamic resistance of the LC circuit Simply adjust VRI to the maximum value for oscil lation Then VRI is the dynamic resistance From this the Q can be calculated Q dynamic resistance reactance of L or C at f This circuit has overall d c positive feedback It would latch up if the d c gain of Al exceeded one Fortunately the low d c resistance of L keeps gain well below one so it is d c stable Resistors R1 and R2 set the gain of A2 to unity 1 Driving A2 directly would cause over violent oscillation The ratio R2 R1 could be increased to up the loop gain but this is not necessary with typical LC values In A3 R3 and R4 set the gain and work ing point and R3 also provides some buffering With VRI set correctly there is no protection diode conduction This implies a VRI of slightly less than the dynamic resistance 27fLQ or Q 27fC However VRI can be less than optimum without seriously impairing the sine wave at the LC WIEN BRIDGE SINE WAVE OSCILLATOR The reactive RC arms of a Wien bridge Fig 13 can be used to set the frequency of a sine wave oscillator formed around an op amp Fig 14 In a Wien bridge when R1 R2 Cl C2 the usual case balance zero output is obtained when V2 V3 in which case C then has a reactance equal to R This occurs when the input frequency f is 1 27CR usually cal
243. toy or for minors 6 set Ref F XP1 TELEKINETIC ENHANCER PLANS Mystify and amaze your friends by creating motion with no known apparent means or cause Uses no electrical or mechanical connections no special gimmicks yet produces positive motion and effect Excellent for science projects magic shows part demonstrations or serious research and development of this strange and amazing psychic phenomenon 4 set Ref F TKE1 ELECTRONIC HYPNOSIS PLANS amp DATA This data shows sev eral ways to put subjects under your control Included is a full vol ume reference text and several construction plans that when assembled can produce highly effective stimuli This material must be used cautiously It is for use as entertainment at parties etc only by those experienced in its use 15 set Ref F EH2 GRAVITY GENERATOR PLANS This unique plan demonstrates a simple electrical phenomena that produces an anti gravity effect You can actually build a small mock spaceship out of simple mate rials and without any visible means cause it to levitate 10 set Ref F GRA1 TESLA COIL LIGHTNING DISPLAY GLOBE PLANS Produces up to 750 000 volts of discharge experiment with extraordinary HV effects Plasma in a jar St Elmo s fire corona excellent science project or conversation piece 5 set Ref F BTC1 LG5 COPPER VAPOUR LASER PLANS Produces 100mW of visible green light High coherency and spectral quality similar to argon laser but easier and l
244. tput from the receiver is an open collector pnp transistor capable of supplying 500mA at up to 16V However I now realise that the output is non latching so I would need one channel to latch the device and the other to break it although this means I would not RECEIVER OUTPUT TRANSISTOR Fig 1 Receiver with open collector output FROM 4 RECEIVER p RECEIVER O OUTPUT TRANSISTOR Fig 2 Open collector receiver output interfaced using logic to an open collector output transistor 726 be able to turn both circuits on and off My idea was therefore to use a relay on the output momentarily switching the input to a CMOS 4013B configured as a toggle switch I would welcome advice as to the interface between the open collector and the input of the 4013 From your description we assume that the circuit at the receiver is basically as shown in Fig l You are correct in thinking that a 4013 CMOS dual D type flip flop could be used to implement a toggle operation In principle this is very straightforward the open collector output is easily turned into a logic output simply by replacing the load with a resistor The logic circuit can then drive another pnp transistor TR1 in Fig 2 or a Darlington transistor see last month s Circuit Surgery to switch the load TO LOAD TOGGLE LOAD ON OFF Fig 3 Using a clock as a toggle control seems like a great idea until you get glitches or switch bounce
245. trength of 2 2 gauss We have tested these on a steel beam running through the offices and found that they will take more than 170lb 77kg in weight before being pulled off Supplied with keeper 19 95 ea Ref MAG77 HYDROGEN FUEL CELL PLANS Loads of information on hydro gen storage and production Practical plans to build hydrogen fuel cell good workshop facilities required 8 set Ref FCP1 STIRLING ENGINE PLANS Interesting information pack covering all aspects of Stirling engines pictures of home made engines made from an aerosol can running on a candle 12 STIR2 12V OPERATED SMOKE BOMBS Type 3 is a 12V trigger and 3 smoke cannisters each cannister will fill a room in a very short space of time 14 99 Ref SB3 Type 2 is 20 smaller cannisters suitable for mock equipment fires etc and 1 trigger module for 29 Ref SB2 Type 1 is a 12V trigger and 20 large cannisters 49 Ref SB1 BRAND NEW NATO ISSUE RADIATION DETECTORS SALE PRICE JUST 69 95 Current NATO issue standard emergency services unit Used by most of the world s military personnel New and boxed Normal retail price 400 Bull s bargain price just 69 95 Ref PDRM INFRA RED REMOTE CONTROL WATCHES 16 99 VIBRATING WATCHES vibrate when your phone rings 16 99 PULSE WATCHES display your pulse 16 99 www quemex co uk STEPPER MOTORS Brand new stepper motors 4mm fixing holes with 47 14mm fixing centres 20mm shaft 6 35mm diameter 5V phase 0 7A
246. ts are considered the solution is more cost effective than other machines using conventional wire or even superconduc tors using more established superconduct ing materials Development is under way to improve its resistance to magnetic fields It is expected that this will increase the number of appli cations for which it can be used although it is still viable for use in many motors generators and pumps With the distinct cost advantages it should be interesting to see what take up there is of the new mate rial in the years to come Further information about new technolo gy as well as information in general about radio and electronics can be found at www radio electronics com Everyday Practical Electronics October 2002 INGENUITY UNLIMITED Our regular round up of readers own circuits We pay between 10 and 50 for all material published depending on length and technical merit We re looking for novel applications and circuit designs not simply mechanical electrical or software ideas Ideas must be the readers own work and must not have been submitted for publication elsewhere The circuits shown have NOT been proven by us ngenuity Unlimited is open to ALL abilities but items for consideration in this column should be typed or word processed with a brief circuit description between 100 and 500 words maximum and full circuit diagram showing all relevant component values Please draw all circuit schematic
247. types are not crit ical although high grade components will improve performance The author s pre ferred choice for ICI was the SGS Thomson HCF40106BEY although any 40106 i c should work adequately Begin construction by soldering the 8 solder pins the 14 pin and 8 pin d i l sockets and resistors in position Finish up with diode D1 note the cathode k is marked by a band and points away from the edge of the p c b and the capacitors Once soldering is complete carefully check the p c b for any solder bridges and wiring errors CASING UP Prepare the case for the audio cable switch S1 potentiometers VR2 and VR3 and piezo sounder WD1 Drill four holes for the steel nuts and bolts which will hold the two lengths one long one short of p v c conduit see Fig 5 Mount VR2 and VR3 where quick and easy adjustment is possible Wire up piezo sounder WD1 tuning controls VR2 and VR3 switch S1 and the battery clip to the p c b Keep all wires short Choose poten tiometers with metal cans bodies and The search coils positioned with cable ties prior to potting 710 The potted coils with a small section left for final adjustment Everyday Practical Electronics October 2002 TO BATTERY Fig 4 PC B layout and wiring and full size master foil pattern plastic shafts for VR2 and VR3 and connect the cans to OV on the p c b perhaps via the potentiometers washers this is important for circuit
248. types are physically too bulky and do not heat up enough at the small signal levels in the circuit VR2 e Fig 16 Using a thermistor in place of RE in Fig 15 V out must drive enough current through the thermistor to reduce its resistance suf ficiently to obtain low distortion Since CMOS inverters cannot deliver much cur rent it is desirable to keep the thermistor resistance fairly high say 10k The a c voltage across it is unlikely to exceed about 3V r m s The power available to warm the thermistor is then 0 9mW For reliable operation over a range of ambient temperature this amount of power must cause a temperature rise of at least 20 C If very low distortion is not required a fairly good sine wave can be obtained from the circuit as shown in Fig 15 if set up carefully as follows Set R to maximum Set VR2 for just oscillating Set R to minimum zero Without altering VR2 set VRI for just oscillating Repeat this procedure then if necessary make minor adjustments so as to obtain the best compromise perfor mance over the tuning range The final result will depend on how well the two sections of the potentiometer are matched Linear law two gang pots are usually better than log law but give tuning Everyday Practical Electronics October 2002 fo 2nC R VR1 Fig 15 Inverter gate version of Wien oscillator The A3 sec tion can be added to inject an external synchronising signal scales whic
249. uad 2 Input MANC Model Loaded Tester Reset Ok Base I O configuration Starting Test Taster Reset Base I O configuration Tester 4 5V On Sendi COx00x2x00z00x Exp 0010012100100 Essd O00100101001001 Send OlxOlzezx0ls01s Exp 011011x101101 x Faad 01101101011011 Send lOxlOxxxlOxlix Exp 101101 110110 Read 10110101100101 IC Failed Test Send llxllexcllells Exp LLOLLOZOLIOLI Read 11011000110111 3 Tasting Aborted Elapsed time 0 234375 Secs ECC Photo 7 Typical screen display during testing on this occasion showing that the i c is faulty see text 11 the logic level dropped from high to low before it was expected Another option available is GND located directly under the Diff option Enabling GND forces a dotted line showing where the low logic level for each pin would be on the display This makes a useful trace separator when the screen starts looking crowded CREATING PROFILES Since the number of i c devices on the market is constantly changing the tester would soon become obsolete if the user did not have the ability to add new profiles as required To create a new profile select Create IC Profile on the main Tools menu see Photo 9 You will need to enter the i c s type number and a brief description about the device Next select how many pins the device has and specify which pins are des ignated as inputs outputs power or have no internal connect
250. ultysync CGA EGA VGA SVGA Mitsubishi FA3415ETKL 14 SVGA Multisync colour monitor with fine 0 28 dot pitch tube and resolution of 1024 x 768 A vari ety of inputs allows connection to a host of computers including IBM PC s in CGA EGA VGA amp SVGA modes BBC COMMODORE including Amiga 1200 ARCHIMEDES and APPLE Many features Etched faceplate text switching and LOW RADIATION MPR specification Fully guaranteed in EXCELLENT little used condition Tilt amp Swivel Base 4 75 VGA cable for IBM PC included On ly 1 29 Order as CG73 External cables for other types of computers available CALL Generic LOW COST SVGA Monitors We choose the make which includes Compaq Mitsubishi IBM etc Supplied ready to run with all cables Standard RTB 90 day guarantee 15 17 69 00 79 00 Supplied in good used condition Shipping code D VIDEO MONITORS PHILIPS HCS35 same style as CM8833 attractively styled 14 colour monitor with both RGB and standard composite 15 625 Khz video inputs via SCART socket and separate phono jacks Integral audio power amp and speaker for all audio visual uses Will connect direct to Amiga and Atari BBC computers Ideal for all video monitoring security applications with direct connection to most colour cameras High quality with many features such as front concealed flap controls VCR correction button etc Good used condition fully tested uaranteed Dimensions W14 Y a23
251. unded in 1952 they have decided to cease trading at the end of October Many long term hobbyists will know the name and much regret its passing Over the years their adverts featuring PA equipment amplifiers lighting speakers discos compo nents and accessories have regularly appeared in the hobbyist electronics maga zines including us in our various guises of PE EE HE ETI and EPE as well as others such as Practical Wireless Wireless World and Practical Television Their address at 337 Whitehouse Road Croydon Surrey probably features in the address books of many of you We send our best wishes to the Director of RCS Frank Jackson and wish him a long and happy retirement Everyday Practical Electronics October 2002 MOBILISING TRAFFIC By Barry Fox NEC s UK Research Centre has come up with a clever way to track traffic flow without the expense of erecting cameras Details have escaped because the compa ny has recently filed a patent application NEC GB 2 369 709 The scheme could let a new company compete economical ly with the current Trafficmaster system The idea is to use cellphones as a tell tale of traffic movement In the future advanced phones will have GPS chips built in but even current GPS less phones can be tracked by the cellphone network with a fair degree of accuracy because they are continually moving from one radio cell to another and this is automatically registered by the network Ex
252. used as optical tweezers and new materials could allow superconductors to become more widely used length in a carefully determined crystalline pattern The actual operation of this is quite complicated but enables the light to be contained within the fibre As the fibre is hollow it is used to trap both the light and the particle to be moved In this way the particle can be moved over distances up to several metres including around comers Particle Movement The fact that light can move small parti cles results from the forces that are set up when the laser light strikes the particle in the tube When a beam strikes a small transparent particle the rays of light obey Snell s law and they are refracted accord ingly If the light is more intense on one side of the particle than the other as is most likely to be the case then some of the energy is transferred to the particle moving it in the direction of the light beam In a vacuum the particles are able to move more freely but in air the molecules damp any movement and it is found that the particle settles in the middle of the light beam which is in the lowest energy posi tion Momentum is also transferred to the particle in the direction of the laser beam causing it to accelerate These two forces permit particles to be held in suspension cancelling the effects of gravity and in this way it can effectively be used as a pair of optical tweezers The process i
253. user 199 plus VAT Site Licence 499 plus VAT ELECTRONIC COMPONENTS PHOTOS A high quality selection of over 200 JPG images of electronic components This selection of high resolution photos can be used to enhance projects and presentations or to help with training and educational material They are royalty free for use in commercial or personal printed projects and can also be used royalty free in books catalogues magazine articles as well as worldwide web pages subject to restrictions see licence for full details Also contains a FREE 30 day evaluation of Paint Shop Pro 6 Paint Shop Pro image editing tips and on line help included Price 19 95 inc VAT Minimum system requirements for these CD ROMs Pentium PC CD ROM drive 32MB RAM 10MB hard disk space Windows 95 98 NT 2000 ME XP mouse sound card web browser Please send me CD ROM ORDER FORM L Electronic Projects LC Electronic Circuits amp Components V2 0 Analogue Electronics Digital Electronics V2 0 O Hobbyist Student Filters Institutional Electronics CAD Pack C Institutional 10 user Robotics amp Mechatronics L Site licence Assembler for PICmicro C for PICmicro Flowcode for PiCmicro Digital Works 3 0 Version required PlCmicro Development Board hardware Development Board UK plugtop power supply Development Board 25 way connecting lead Teach In 2000 FREE BOOK Electronic Components Photos Electron
254. ver folding monocular with 8 x 21 magnification made by Helios with case 14 99 Ref MONOC CCTV SYSTEMS 24 99 Complete with camera 20 metres of cable p s u and info simple connection to scart 24 99 Ref CCTVCAN2 FM BROADCAST BAND HIGH POWER TRANSMITTERS can be viewed and bought online at www veronica kits co uk TONER CARTRIDGES FOR COPIERS AND PRINTERS can be bought online at www nationaltoners co uk VELOSOLEX Traditional French style two stroke moped engine over front wheels black only 695 Ref VELO Delivered direct in a box you need to fit the pedals etc then register it with your local DVLC HYDROPONIC GROWING SYSTEMS Complete everything you need apart from plants and light contains grow tank nutrients pump tester etc GT205 710mm x 390mm NFT system 31 45 Ref GT205 GT424 1070mm x 500mm NFT system 58 65 Ref GT424 ELECTRIC BIKES 679 Viking built in indicators radio lights 13mph 5 hour charge Shimano gears up to 50 mile range horn 26in wheels suspension no licence needed key operated 679 Ref VIKING NEBULISER WATER ATOMISER Ultrasonic module that you place in water atomises the water into a very fine mist many applications from special effects to scientific 69 Ref NEB6 PORTABLE X RAY MACHINE PLANS Easy to construct plans on a simple and cheap way to build a home X ray machine Effective device X ray sealed assemblies can be used for exper imental purposes Not a
255. ware for this project is available for free download from the EPE ftp site or on CD ROM for which a charge applies from the EPE Editorial office see the EPE PCB Service page for details The PIC pro gram software is supplied in MPASM for mat ASM and HEX See this month s Shoptalk page for details of obtaining pre programmed PICs The datasheet for the MAX232 is avail able from the Maxim website at wWww maxim ic com Datasheets for the majority of TTL 1 c s can be found on Texas Instruments web site at www ti com with John Becker EPE Bounty Treasurer Hunter Looking down the components list for the EPE Bounty Treasure Hunter there is nothing in the way of electronic components that should need a treasure hunter to find them Although the author preferred to use the SGS Thomson HCF40106 in an application such as this any hex Schmitt inverter having the code 40106 in its identity will perform the job Ignore the prefix that s only the manufacturer s code By and large with any digital logic i c it s only the number itself which is important not the manufacturer Make sure of course that the device is one having normal pins that go into a p c b and is not a surface mount device The hardware may present you with a bit more of a search requirement this is where your large local DIY stores come in handy and you enjoy browsing those anyway don t you I C Tester Once again there are no components
256. werful C programmers are always in demand Ideal for absolute beginners and experienced programmers Book Experimenting with C amp C 24 99 Kit CP2a made up with software 32 51 Kit CP2u unmade with software 26 51 Kit CP2t top up with software 12 99 The Kits The assembler and C amp C kits contain the prototyping board lead assemblies components and programming software to do all the experiments The made up kits are supplied ready to start The top up kit is for readers who have already purchased kit 1a or 1u The kits do not include the book Hardware required All systems in this advertisement assume you have a PC 386 or better and a printer lead The experiments require no soldering Experimenting with the PIC16F877 The second PIC book starts with the simplest of experiments to give us a basic understanding of the PIC16F877 family Then we look at the 16 bit timer efficient storage and display of text messages simple frequency counter use a keypad for numbers letters and security codes and examine the 10 bit A D converter The 2nd edition has two new chapters The PIC16F627 is introduced as a low cost PIC16F84 We use the PIC16F627 as a step up switching regulator and to control the speed of a DC motor with maximum torque still available Then we study how to use a PIC to switch mains power using an optoisolated triac driving a
257. witch ing the reset signal to its inactive state O in this example Schmitt trigger gates are designed so that they are able to cope with slowly changing inputs which cause prob lems for normal logic gates that expect a fast transition from 0 to 1 and 1 to 0 I hope that helps JMB Troublesome UV Timer I built a small ultraviolet box for expos ing my own printed circuit boards using a dual fluorescent lamp base and a timer cir cuit but I ve run into a problem with the relay and lamps not holding on The problem is that as soon as the pushbutton is released the whole thing turns off The circuit uses a transformer that is 22V off load falling to 12V on load which is ideal for the lamps I tried to increase the smoothing capacitor from 1 000uF to 10 000uF but no cure Am I overloading the transformer which is why it s dropping so low Thanks from Chris Brown in the EPE Chat Zone We don t have a circuit diagram for guid ance so try these general pointers If the supply voltage drops alarmingly when you close a switch then start by checking the obvious things first Look at the wiring and component values around the push switch If you have the wrong components then perhaps you are shunting part of the circuit with a low resistance value observe the resistor colour stripes and confirm that the correct resistors have gone into the right locations Transistors and diodes also cause prob lems if they
258. y Most i c s are either 5V or 3V aren t they Bob Biglan in the EPE Chat Zone It s certainly true that modern devices run at ever lower voltages e g the Philips 74LV logic range runs at 3 3V but we sel dom need to be involved with miniaturisa tion or with state of the art low power chips so we unashamedly use 9V batteries for portable projects Many constructional projects are not intended to be classed as low power and they use traditional dis crete components anyway leaving the designer with little choice for the battery supply You only have to look at the shrinking size of mobile phones or Mini Disc players to know that commercial chips are getting smaller and more heavily integrated as are the custom designed Li ion batteries that Everyday Practical Electronics October 2002 power them Inevitably they use low power surface mount parts and techniques that render them generally beyond the scope of hobbyists A clue for catalogue readers is the letters SO small outline near a part number meaning that it s sur face mount On the subject of chip voltage some hobbyist friendly chips were specially designed for low voltage operation the wonderfully clever and sadly missed LM3909 l e d flasher by National Semiconductor was one example pack aged in an 8 pin d i l chip it could flash an l e d for many months on a 1 5V cell It was great fun to use but industry needs miniaturisation
259. y preset VR1 serves as an emergency measure to alter the gain at the inverting input of preamplifier IC2a without destabil ising the rest of the carefully balanced circuit around IC2a IC2b Use VRI in case the setting of the coils did not go well and the bending of the small section of coil proves fruitless IN USE Keep the search head away from all metal and away from com puter equipment which may cause serious interference with the cir cuit and switch on Adjust VR2 until the EPE Bounty is at a point where a crackle is heard between silence and singing use VR3 for fine tuning Carefully experiment with board mounted preset VR4 in case a low level hum has been interjected between the silence and singing For best results keep front panel controls VR2 and VR3 tuned for a fast crackle While a slow crackle is more pleasing to the ear this will reduce sensitivity Move a coin over the search head and piezo sounder WD1 should sing In actual use the adjustment of the EPE Bounty Treasure Hunter will be affected by the mineralisation of the ground you are search ing as well as temperature and voltage variations While the design has good stability some readjustments to tuning controls VR2 and VR3 are inevitable An investment in a metal case for the electronics while costing a few pounds more would maximise stability but this is not essen tial A higher value for resistor R6 will give the detector a sharper edge th
260. y adjusting VRI and VR2 involves using an oscilloscope and doing a fair amount of fiddling Start with VRI and VR2 set halfway Trim VRI to equalise VI and V2 Trim VR2 for the best waveform The tuning range is somewhat affected by these set tings To achieve the best amplitude sta bility one of the fixed resistances in series with the tuning resistances may need to be trimmed at the h f end of the band RING OSCILLATORS The three inverters of Fig 18a are con nected in a loop or ring If the input to Al is positive then the output of A3 is nega tive Since this is fed back to Al it oppos es the positive input The ring is a negative feedback loop with total feedback and accidents barred it will be stable Accidents do happen though as will be shown later Referring to Fig 18b if we now inter pose between successive stages networks which produce 60 phase shift to signals at some frequency then going round the loop the three phase shifts add up to 180 This is inversion The reactance is twice the resistance for series C shunt R and the reverse for series R and shunt C The fed back signal at Al is now in step with the original signal Feedback is there fore positive and the circuit oscillates If the 180 phase shift occurs at only one fre quency then that will be the frequency of oscillation PHASE SHIFTERS Two standard ways of achieving phase shift are shown in Fig 18c to Fig 18d The first
261. y card or in Sterling cheque or bank draft drawn on a UK bank Normally supplied within seven days of receipt of order Send a copy of this form or order by letter if you do not wish to cut your issue Everyday Practical Electronics October 2002 THE a MAGAZINE FOR ELECTRONICS TECHNOLOGY amp COMPUTER PROJECTS We can supply back issues of EPE by post most issues from the past three years are available An EPE index for the last five years is also available see order form Alternatively indexes are published in the December issue for that year Where we are unable to provide a back issue a photocopy of any one article or one part of a series can be purchased for the same price Issues from Nov 98 are available on CD ROM see next page and issues from the last six months are also available to download from www epemag com JUNE 01 PROJECTS e Hosepipe Controller e In Circuit Ohmmeter Dummy PIR Detector e Magfield Monitor FEATURES e Controlling Jodrell Bank e PIC1687x Extended Memory Use e Practically Speaking Ingenuity Unlimited New Technology Update e Circuit Surgery e Net Work The Internet Page JULY 01 PROJECTS e Stereo Surround Sound Amplifier e PIC to Printer Interface Perpetual Projects 1 Solar Powered Power Supply and Voltage Regulator e MSF Signal Repeater and Indicator FEATURES e The World of PLCs Ingenuity Unlimited Circuit Surgery New Technology Update Net W
262. y to fit a larger heatsink to ICI The prototype draws approximately 30mA when in standby rising when testing The exact current drawn will depend on the i c being tested TEST SOCKET There are several possible choices for the method that will be used to connect 1 c s to the tester via socket SK3 The preferred method is a ZIF Zero Insertion Force sock et They are available in different sizes and formats but one should be chosen that accepts i c s of up to 24 pins and different package widths a universal type The ZIF socket can be mounted directly on the board or a 24 pin turned socket can be fitted first and then the ZIF pushed firmly into that This allows the ZIF to be easily removed and used elsewhere if required If a turned pin socket is not avail able two rows of turned pin socket strips can be used instead Provision has been made on the p c b to accommodate two pairs of turned pin socket strips one pair of 10 pins within the SK3 area and one pair of 12 pins TB2 and TB3 which may be used if it is decided not to use a ZIF socket This allows narrow i c packages of up to 20 pins or the wider packages of up to 24 pins to be tested Though not as convenient as a ZIF this does make a cheaper option D LL SWITCH OPTIONS Power can be applied to the i c under test either via the jumper patch pins TP1 and TP2 or predefined power configura tions can be selected from the 4 way d i l switch bank

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