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Build A Regulated Battery Charger SERVICING - VINTAGE RADIO - COMPUTERS - AMATEUR RADIO - PROJECTS TO BUILD You'll like the feeling of our new digital troubleshooting scope. -~ -- 1;-:~L~..C!J □ C!l [!:I [:) ~l -:::3 ~f, ~~ Now there's a 100 MHz digital scope that handles just like analog. instantly to the slightest control change. Digital oscilloscopes have certain advantages that are hard to overlook. But for troubleshooting, many engineers still prefer analog scopes. Simply because they like the way they handle. But when it comes to troubleshooting, the HP 54600's digital performance leaves analog and hybrid scopes far behind. At millisecond sweep speeds, the display doesn't even flicker. Low-rep-rate signals are easy to see without a hood. The HP 54600 changes that. It looks like a 100 MHz analog scope. All primary functions are controlled directly with dedicated knobs. And itfeels like one. The display responds It has all the advantages that only a true digital scope can provide. Like storage, high accuracy, pretrigger viewing, hard copy output, and programming. And since it's one ~ ~ I r ... J 4 of HP's basic instruments the HP 54600 gives you all this performance at a very affordable price. So if you like the feel of analog control, you'll like the way our new digital scope handles troubleshooting. To find out more call the Customer Information Centre on 008 033 821 or Melbourne 272 2555. pp] ~i~K~~6 A Better Way. Just released: the HP 54602A scope with bandwidth up to 250MHz Vol.5, No. 10. October 1992. DESIGNED MAINLY for solar power installations, this new 24VDC to 240VAC inverter produces a sinewave output & · can deliver 2kW on a continuous basis. Turn to page 16 FEATURES 4 Manned Electric Flight Across The USA by Leo Simpson A sun-powered glider with flexible solar cells 73 The Philips PM3394 Digital/Analog Scope by Leo Simpson Versatile new design has both analog & digital modes PROJECTS TO BUILD 16 A 2kW 24VDC To 240VAC Sinewave Inverter by John Clarke The heart of a solar power supply 22 A Multi-Sector Home Burglar Alarm, Pt.2 by Mike Zenere Construction, testing & operation 48 Build A Mini Amplifier For Personal Stereos by Darren Yates Enjoy the sound via loudspeakers THIS BATTERY CHARGER has automatic voltage selection for 6V, 12V & 24V lead-acid batteries & is electronically regulated to deliver just the right amount of current. Details page 56. 56 The Thunderblrd Battery Charger by Herman Nacinovich Electronically regulated design for 6V, 12V & 24V batteries SPECIAL COLUMNS ·· 37 Vintage Radio by John Hill Vintage radio repairs made easy 42 Serviceman's Log by the TV Serviceman Confession is good for the soul <2 CONFESSION isgoodfor the soul they say & this month the Serviceman lays bare his sins. His story starts on page 42. 78 Amateur Radio by Garry Cratt How to make transmitter measurements 88 Remote Control by Bob Young Internal combustion motors for R/C models, Pt.3 92 Computer Bits by Byron Miller The inside story on hard disc standards DEPARTMENTS 2 Publisher's Letter 8 Circuit Notebook 32 Order Form 83 Product Showcase 96 Back Issues 98 100 102 104 Ask Silicon Chip Notes and Errata Market Centre Advertising Index HAVE YOU EVER wanted to use your personal stereo player with loudspeakers instead of headphones. This mini stereo amplifier lets you do just that. Turn to page 48. OCTOBER 1992 1 Publisher & Editor-in-Chief Leo Simpson , B.Bus. Editor Greg Swain , B.Sc.(Hons.) PUBLISHER'S LE'I*l'ER Technical Staff John Clarke, B.E.(Elec.) Robert Flynn Darren Yates, B.Sc. Reader Services Ann Jenkinson Sharon Macdonald Sales & Marketing Mgr. Sharon Lightner Phone (02) 979 5644 Mobile phone (018) 28 5532 Regular Contributors Brendan Akhurst Garry Cratt, VK2YBX Marque Crozman John Hill Jim Lawler, MTETIA Bryan Maher, M.E., B.Sc. Jim Yalden, VK2YGY Bob Young Photography Stuart Bryce Editorial Advisory Panel Philip Watson, MIREE, VK2ZPW Norman Marks Steve Payor, B.Sc., B.E. SILICON CHIP is published 12 times a year by Silicon Chip Publications Ply Ltd . A.C .N. 003 205 490 . All material copyright © . No part of this publication may be reproduced without the written consent of the publisher. Printing: Magazine Printers Ply Ltd, Alexandria, NSW; Macquarie Print, Dubbo, NSW. Distribution: Network Distribution Company. Subscription rates: $42 per year in Australia. For overseas rates , see the subscription page in this issue. Liability: Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. Editorial & advertising offices: Unit 1a/77-79 Bassett Street, Mona Vale , NSW 2103. Postal address : PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 979 5644. Fax (02) 979 6503. ISSN 1030-2662 2 SILICON CHIP Solar power will come into its own This month we are proud to present the first article in a series on building a 2 kilow:att sinewave inverter. We think it will be very popular with users of recreational vehicles, boats and those on farms and remote locations far from any mains supply. It has been a marathon effort to produce and is rivalled only by the 16 channel audio mixer we published during 1990 in the amount of time and resources we have had to devote to its development. The ZkW sinewave inverter comes at a time when there is increasing interest in solar power and renewable energy sources and, in fact, the article on the Sanyo solar-powered plane in this issue emphasises the advances that are being made with solar cells. The concept of a solar-powered plane is really intriguing and just shows what can be done in applying presently available technology. In fact , while it would be a fairly costly exercise in terms of the required solar panels and battery storage, it is now quite practical to have a continuous 50Hz 240VAC sinewave supply on farms and other remote locations. When you consider that it can cost $1000 a pole for mains supply to be brought to a remote property, then providing your own power becomes quite an attractive proposition. Furthermore, it would not surprise us if some city dwellers decided to take the plunge and provide their own AC supply and thus be completely independent of mains supplies. While it may not be strictly practical at the moment, we think that many people would like the idea of running their own power supply and being super careful about their energy use. In doing so , they would be minimising their contribution to greenhouse gases. Such a project could be done in stages, by first acquiring a few solar panels, a modest number of batteries and a sinewave inverter to provide at least part of the energy demand. This would have the benefit of providing power during blackouts and could be gradually extended to ultimately provide the full load. Nor would you necessarily need to rely on solar panels in such a project. Many locations in Australia have good potential for wind generators and they don't have to be very big to pump out quite a lot of energy in a 24-hour period. Remember, when the sun is not shining, the wind is often blowing. Leo Simpson Are your customers having trouble getting through to your phone/fax line? and you,ve lost the sale because your exsisting fax switch is not doing what YOU want it to do ? WE HAVE THE SOLUTION! The VSI EASY CONNECT Phone-Fax Line Sharer The most advanced Phone-Fax/Line Sharing Device. Now available in Australia. Integrate ANY fax, with ANY answering machine on ANY telephone system, WITHOUT the limitations of faxswitch devices or 3 in 1 fax systems. ~ ~ ~ ~ NO NO NO NO Confusing Voice Messages Delays or Periods of Silence Unusual Dial Tones Frustrated Callers Why the EASY-CONNECT ? Because the EASY-CONNECT ls the most flexible a nd complete phone-fax line sharing device availab le in Australia today. :::~tf~~e o°nn!n~ ~ei"ei~toiJ"/ s;~::i:;r~1fhout the limltatlons of faxswltch devices or 8 3 ln I fax systems. Other faxswitch systems ? Clumsy fax priority operation. Del a ys. pauses, voice messages. frustrat ed ca llers. The EASY-CONNECT is totally transparent. Your callers will never know it's on the line ! Inflexible a nd limited operation with other dev lees. Must be fitted on first sock.et. Poor bbtory of customer satisfaction. Dedicated fax line ? .,.. More Automatic, More Flexible, More Powerful than any 3 in I fax system . ...- Latest Voice Priority technology . Total Flexibility. ...-Installs in minutes on ANY PHONE SOCKET . ...- Fully Functional with ALL extension telephones. or No restriction to the number or position of extensions. ...-opera te with Fax, Phone, Modem, and Answering Machine on one line . ...-No switches to remember (or forget) when your office is unattended. ...-Proven Reliability backed up with a 2 YEAR EXCHANGE WARRANTY . ...- PROTECTION for the Fax and other devices against lightning or surges. ..- Austel Approved. A90/14B/0342. Made in U.S.A . ...-save installation and rental costs for a separate line. Telecom cba rses effective 25/6/92 without telephone . l year 3 years S years Telecom $442 $983 SIS23 VSI $399 $399 $399 Savinss $44 $584 $1124 Please Note: Due to the unpredictable nature or lightning strikes, 10096 protect/on ror the fax and other devices cannot be guaranteed. The VSI Easy-Connect is not to be confused with other faxswitch systems. RE/JBACf. Weatherproof Monitor/ Sound Column Speakers UHF Ant. UHF/VHF Ant. s.- Extension speal.ers for around the pool, patio, etc . ..,. Rugged extruded aluminium cont ruction. """Superb blacl or white powdercoat finish. llif" Ported enclosure for enhanced bass response. .,.. 30 watts RMS; 84d8 SPL. Dimensions: 230h x 155w x 115d 2.0Kg. Complete with unique "Wacki-Bracket", swivel bracket mounting system. Only $179.00 each or $299.00 per pair {black or white} Rechargeable WFC-308 Digitor l2GHz Handheld Digital Frequency Counter ..-10Hz - 20MHz; 20MHz - 1.2GHz. <F Imp: I MEG Ohm,80pf; SO Ohm. or Max. Volt. IO0V p-p; SV p-p. .,.. Gate Time: 2s, 0.02s, 0.002s. .,.. 8 digit LED display. or 12v S00mA plugpacl required ($22.95). ..,. Ideal measuring radio frequencies. .... 12 months warranty. .I __j ."'"Dlmllili·:, LED's Hyper-Red 5mm 3.5cd $2,50ea. Blue Led 5mm 14mcd $3.95ea. Blue Led 3mm 14mcd $3.95ea. Flashing Red 10mm $2.95ea. :M2851 12.6v C.T. 150mA Transformer was $7.65 <at> Now $5.50 /0+ $4.95 "LIMITED STOCKS" a:.:r Suitable for city & country areas. or Gain: 28d8 VHF; 34d8 UHF. Suitable for combined or seperate aerials . Easy installation. d " Designed & Made in Australia. .,.. Power supply included. B" Improve your TV reception. d" d"' 240V T o D -_::Z -0 To TV PKS02 Only $125.00 ~essage Stopper This inexpensive device, which connects direct to your answering machine will automatically disconnect your answering machine whenever ANY PHONE is answered! If your answering machine answers your call before you do, simply pick: up any phone, your answering machine will immediately disconnect and you can speak: without interference. With the MESSAGE STOPPER you can now leave your answering machine on and not have to worry! It will also prevent "barge-in" from any extension, when a call is in progress. Only $39.95 DB9;15;25 Solder type connectors male or female All one price $1.00 each 100+ $0.80 each Backshells only $1.00 ea. David Reid 127 York St, SYDNEY 2000 Ph: (02) 267 1385 Electronics P.O. Box Q103,SYDNEY 2000 Fax: (02) 261 8905 A.C.N. 001-372-372 KINGRAY MHW34T/ PKS02 Masthead Amplifier For UHF/VHF TV systems EPRO:M's 27C64 27Cl28 27C256 27C512 $7.50 $7.95 $7.95 $11.95 10+ 10+ 10+ 10+ $6.75 $7.15 $7.15 $10.75 Postal Charges $5 - $25 ......... $4.00 $26 - $50 ...... $6.00 $51 - $100 ..... $7.00 $101 - $499 .. $9.00 $500 • ............ FREEi Manned electric flight across the USA Although not well publicised at the time, the first solar powered electric flight across the whole of the USA was accomplished back in 1990. Sponsored by Sanyo and using that company's flexible solar cells, the plane had enough power to take off and climb to considerable heights. By LEO SIMPSON Battery powered electric model aircraft have been around for quite a few years but the difference in technology required for a model and that for manned flight is enormous. Typical electric motor driven model planes are powered by high discharge nickel cadmium batteries with enough capacity to last only a few minutes. In 4 SILICON CHIP that time, such planes can climb to considerable heights and achieve high speeds. But when the batteries run down, the flight must inevitably come to an end. Motors for electric powered models don't last long either. Because they have such a high power input, their brushes and commutators don't last long at all and may have to be renewed completely after just a few flights. Manned flight places much more stringent demands on the technology of batteries and motors. For a start, the motor must not only lift the mass of the plane and its batteries into the air but must also carry the human pilot. The plane The plane is essentially a powered glider with the electric motor and propeller mounted in the tailplane. All the power for the plane came from the solar cells mounted on the wings. The solar cell array was used to charge the battery for a few hours so that the plane could take off and climb as high as necessary to take advantage of CHARGING A MOTOR g QUALITY NO BRAND DISKETTES S2 + DIODE v\ FLEXIBLE SOLAR CELLS At---_HA_LL_E_LE_ME_N_Ts_ _ 8-------, c------,. MOTOR CONTROLLER A t - - - - - - f 9.,___ _ _.......,. Ct-<1-------i~ S3 Fig.1: the electrical system of the Sunseeker solar plane consists of a large array of flexible solar cells charging a 120V 4Ah nicad battery. The motor is a brushless DC type rated at 2.2 kilowatts. thermals. The plane would then soar for long distances while the solar cells continued to charge the battery. During each day's flight, the plane's motor and propeller would only be used as necessary to regain height after soaring for long distances or to increase speed. Solar cells Special flexible amorphous silicon solar cells were made by Sanyo for the record attempt. Called Amorton cells, they have very low weight, making them ideal for the purpose. The entire solar cell array, mounted on the wings and tailplane, has an area of eight square metres and weighs just 1.5kg. The peak power output of the solar array is 300 watts. Amorton solar cell film is only 0.12mm thick and is flexible enough to form a tube only 10mm in diameter. It can be shaped to conform to 3-dimensional surfaces that would not be feasible for conventional flat solar cells. Since it is very light, it yields a power to weight ratio of 200 milliwatts per gram. Other possible applications of Amorton solar cell film are for solar powered dirigibles, cars and boats, solar tents, window shades and roofing materials. The output of the Amorton solar cells is fed via a diode to a specially fabricated nickel cadmium battery with a 4 amp-hour rating at 120 volts . Comparatively little information is available about the control electronics or the motor which is rated at 2.2 kilowatts (3hp). This is referred to as a brushless DC motor by Sanyo engineers but the circuit of Fig.1 reveals it to be a 3-phase induction motor with commutation controlled by Hall Effect sensors. The efficiency of the motor and electronic drive system is quoted as 90%. The battery capacity is sufficient to allow the motor to operate continuously for about 15 minutes. Maximum speed of the plane is quoted at 160km/h and cruising speed is 64km/h. Presumably, both these speeds apply during soaring. Takeoff and climbing speeds would be considerably slower. As the dimensions of the plane . show, it really is a glider, having a wingspan of 17. 5 metres and a length of 7 metres. All up weight, without the pilot, was only 90 kilograms. (It Sunseeker solar plane mockup in Australia A mockup of the Sanyo "Sunseeker" solar powered plane will be on display at the Australian International Air Show and Aerospace Expo to be held at the ASTA, Avalon Airport, near Melbourne, during October 1992. A special building is being constructed at ttie entrance to the Expo to house the "Sunseeker" model. Also on show will be a videotape of the plane's record breaking flight. The Air Show and Aerospace Expo will be held from the 21 st to the 25th October 1992 with three trade days and two public days, and will feature extensive flying and ground displays of all aspects of aviation and aerospace. 5.25" 5.25" 3.5" 3.5" DSDD DSHD DSDD DSHD $4.70 $8.95 $8.50 $16.95 II *************** JAPANESE BRAND - - ~-'v1.., FLOPPY DRIVES 3.5" 1.44M 5.25" 1.2M $99.00 $125.00 :s-"sUPER -~ SPECIAL_~ ~7 ~~ ----------EPROMS RAMS 2716 ............. $9.95 2732A ........... $7.50 27C32 ......... $11.50 2764 ............ . $6.50 27C64 ........... $7.00 27128 ........... $7.50 27C128 ........ . $8.00 27256 ........... $8.50 27C256 ......... $9.00 27512 ......... $12.50 27C512 .. ... .. $13.50 27C1001 ..... $23.50 6116 .... ......... $4.50 6264 .. ,. ......... $9.50 62256 ......... $17.50 628128 ....... $60.00 SERIAL PORT CHIPS 8250 ............. $7.50 82450 ......... $17.50 16C450 ....... $18.00 16C550 ....... $29.50 **** ** *** ** *** * ~~~~ ~ . - · ~ ~ t ¥ )if DYNAMIC RAMS 4164-10 ........... $3.25 41464-08 ......... $2.75 41256-08 ......... $2.75 414256-08 ...... $7.95 411000-08 ....... $7.95 256KSIM,SIP. $23.50 IM,SIM,SIP .... $79.00 4M SIM,SIP. $335.00 REGULATORS 7805T .............. $0.50 7812T .............. $0.50 7815T .............. $0.50 7905T .............. $0.60 7912T .............. $0.60 7915T .............. $0.60 317T.. ... $1.50 337T ................ $2.10 723 ............. ..... $0.80 DIODES IN4148 ............ $0.04 IN914 .............. $0.05 IN4004 ............ $0.08 IN4007 ............ $0.1 O IN5404 ............ $0.20 IN5408 ............ $0.25 BRIDGES W04 ................ $0.50 BR64 ............... $1 50 BR104 ............. $2.50 BR254 ............. $3.50 BR354 ............. $3.95 LEDS 5mm RED ........ $0.15 5mm Green ..... $0.25 5mm Yellow .... $0.25 TRANSISTORS BC547/8/9 ........ $0.15 BC557/8/9 ........ $0.15 8D139 .............. $0.45 8D140 ........ ...... $0.45 TIP31C ............. $0.80 TIP32C ............. $0.80 MJ15003 ......... $6.50 MJ15004 ......... $6.50 MJ2955 ........... $2.50 2N3055 ............ $1.50 LINEAR & SPECIAL FUNCTION 1488 ................ $0.50 1489 ................ $0.50 8250 ................ $7.50 82C450 .......... $17.50 16C450 .......... $18.00 16C550 .......... $29.50 XR2206 ............ $8.50 ICL7106 ......... $14.00 324 .................. $0.75 339 .................. $0.50 358 .................. $0.90 555 .................. $0.45 741 .................. $0.55 FREE PRICE LIST UPON REQUEST · IECS ELECTRONICS & COMPUTER SUPPLIERS 289 LATROBE ST MELBOURNE, VICTORIA 3000 PHONE: (03) 602 3499 FAX: (03) 670 6006 MAIL ORDER HOTLINE: (008) 33 5901 ALL MAJOR CREDIT CARDS WELCOME POSTAGE RATES $1.00-$9.99 ......... $3.00 $10.00-$24.99 ..... $3.50 $25.00·$49.99 ..... $4.50 $50.00-$99.99 .... $5.50 $100.00-$199.00 $6.00 $200.00+ ............. FREE OC'l'OflEB 1992 5 Los Ange San D Fig.2: the route of record breaking solar flight across the USA . .Because the weather was not always sunny, the whole journey took place over 7 weeks and a total of 23 flight days. Total flying time was 121 hours. was designed and built by Eric Raymond of Solar Flight Research Co, USA). Record flight The record breaking solar powered flight was made during the northern summer of 1990 across the United States, from the west to the east It started from Desert Center in California on 16th July and, after flying across 10 states, finally reached its destination at Kitty Hawk in Carolina on 3rd September. During this period, there were some days on which the plane could not fly because of poor weather. Thus, the transcontinental journey took a total of 23 flying days. Total flight time for the 3967km journey was 121 hours. Several new world records were set for solar powered flight: (a) longest flight time without landing - 7 hours 35 minutes. (b) longest flying distance without landing - 394.3 kilometres. (c) maximum altitude of 3963 metres (13,000 feet) The previous world record for solar cell powered flight was attained by an American scientist who travelled 322 kilometres while crossing the Dover Straits in 1981. The Sunseeker solar plane has virtually all its horizontal flight surfaces covered with Amorton amorphous silicon solar cells which give a total peak output of 300 watts. No doubt many more solar powered flights will be made in future. Perhaps there will come a day when solar powered planes become popular pleasure craft. SC Protect your valuable issues Silicon Chip Binders These beautifully-made binders will protect your copies of SILICON CHIP. They feature heavy-board covers & are made from a distinctive 2-tone green vinyl. They hold up to 14 issues & will look great on your bookshelf. * High quality with heavy board covers * Each binder holds up to 14 issues * 80mm internal width * SILICON CHIP logo printed in gold-coloured lettering on spine & cover Price: $A 11.95 plus $3 p&p each (NZ $6 p&p). Just fill in & mail the order form on page 32; or fax (02) 979 6503; or ring (02) 979 5644 & quote your credit card number. 6 SIL/CO,\ ' Cl-III' FOR CHIPS... WOOD FOR CHIPS. .. WOOD FOR CHIPS...WOOD FOR CHIPS...WOOD FOR CHIPS... WOOD FOR CHIPS...WOOD FOR CHIPS... WOOD FOR CHIPS... See the review in Electronics Australia March 92 "Electronics Workbench is certainly the easiest simulator I've ever used" Peter Philips Electronic Workbench SCOOP PURCHASES This month we have two bulk buy bargains tor you - 400V, 35A Bridges normally $5.40 each but buy 10 tor just $40.00. Branded, but sorry we aren't allowed to tell you the name! Arlec Tools Drill 'N Drive Handy Probe Multimeter Ideal for tight spots Lab 4 -All you need in a single Frequency Counter instrument! • 1Hz to 100MHz Ideal for the professional and keen hobbyist. Saves bench sp_ace. High accuracy yet low cost. Just check the features - Function Generator APPA 35 CLAMP METER CJ:i ~ G cc [2 4000 count display Autoranging Measures to 350A ac Conductors to 25mm diameter Measures voltage to 750Vac, Ohms to 40kn and continuity with beeper • Large 12.5mm LCD display • Data Hold button • Built-in belt clip $142 .80 $119.00 ex tax () ;£ r 8 25 pin D Conectors Kikusui SCOPES • • • • • CJ clJJ PC-based Protocol · Analyser &Data Line Monitor The new version of Serial/est turns ANY PC into a full-featured serial data protocol analyzer The Electronics Lab you kflBP even laptop and notebook in your PC/ Buy a tray of 50 for just $35.00 Male or Female (not mixed at computers-for both YES you can now bu ild, this price) We also have plastic backshells at $35.00 tor synchronous and async data. simulate and test Analog and Serial/est unleashes the power of Digital Ci rcuits witho ut laying vour 50 or metallised at $80. 00 for 50. your PC for data communications hands on a si ngle componentf Now is the time to stock up! testing with a simple, userIt's so easy with Electronics ,___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __. friendly interface and either! The Workbench®. Do it all with the new Com Probe pluJ}s in to your mouse - drag new parts from the printer port. With Serial/est and parts bin, drop them onto the your PC, there is no longer any breadboard and click to run wires. need to buy or rent expensive, Editing circuits is easy as wires dedicated protocol analyzers. 60MHz 3 Channel Scope are re-routed automatically. Rechargeable two speed drill and • omV/OIV ac to bUMHZ It's much faster than buildin~ screwdriver The Serialtest package includes • 5ns/div to 0.5s/div A and B real ci rcuits. No faulty parts' Its Serialtest software and Frontline's COS5060B $1860.00 •Features· the resu lt of 10 years innovation Two speeds - Orill 325rpm RS-232 Com Probe"' adapter. The and thousands of students, Screwdriver 150rpm Com Probe connects to your hobbyists and engineers have • Forward and reverse operation computer via the paral lel printer been using the Workbench since port (no need for plug-in cards) • Pi lot light for dark corners its introduction in 1988. • Drills timber, metal and and allows Serialtest to work with Analog Module Includes hardened plastic both synchronous and • Comprehensive parts bin Supplied with asynchronous devices. includes op-amps, zeners, Rechargeable batteries transistors etc AC adaRtor Serialtest's monitor mode shows 3 dnl bits - 2.0, 3.0, 4.0mm • Function Generator with sine, you exactly What information is square, triangle etc 2 slotted and 2 Philips flowing between any two serial • Oscilloscope with dual trace, screwdriver bits devices - both data bytes and inVext trigger, nanosecond A really handy tool for just $69 .95 control signals. Source mode . timebase upto 999MHz 40MHz 2 Channel Scope allows yo u to interactively • Bode Plotter for frequencY. simu late either the DTE side or • 5mV/div de to 40MHz responses and phase sh ift OGE side of the communications • 20ns/d iv to 0.5s/div Main (-200 to +200dB) link. • O.~s to 0.5ms/div Delayed • SPICE Simulation plus transient COS5041 $1373 .00 and steady-state simulation Serialtest Async is similar to Serialtest, but is limited to asyncDigital Module includes on ly testing. The package includes • Comp rehensive parts bin with 20MHz 2 Channel Scope Senaltest Async software and gates, fl ip -flops, half adders, • 5mV/d iv de to 20MHz custom cab ling wh ich works in disp lays etc conjunction with the serial ports • Word Generator up to 16x8-bits • 20ns/d iv to 0.5s/div COS5020 on your PC. • Logic Analyser with 8 channels, inVext trigger Anyone who wo rks with serial • Logic Converter converts data communication needs between gate, truth table and Serialtest. Field service engineers boolean · Features and system integrators will • Dual 400/600°C temperature appreciate the portability and Professional version has range ease-of-use. Communication inhanced colou r interface , • 1600W output specialists and network supports maths co• Built-in safety handle supervisors wi ll enjoy the power ~rocessor. Requires IBM AT or • Hanging hook for storage and fle xibility. No matter what the PS/2 with 286 or greater, hard • 12 month warranty indu stry, Serialtest will prove to disk, 640kB RAM, Microsoft Many uses for $59.95 be an indispensable tool. mouse, EGA/VGA and DOS 3.0. $429 .00 Personal Plus Ve rsion is monochrome. Requ ires PC/XT/ AT or PS/2, 2 floppies or hard disk, 512kB RAM , Microsoft mouse, CGA/EGA/VGA/ Hercules graphis adaptor and DOS 3.0 or greater. $299.20 8 Serial Test No need to turn your head to read this multimeter. The readout is right there in the probe' Auto and manual ranging , 3.5 digit large 14mm LCD display - all in a handy Qrobe. Log ic testing function for CMOS/TTL. Data Hold button, Diode test, Contin uity buzzer. Display shows all functions. Protected to 250V • DC Voltage from 200mV to 500V • AC Voltage from 2V to 500V • Resistance from 200Q to 20MQ • AC/DC Current to 200mA • Continuity check to 2kQ • Logic Testing to 1MHz and 1µs • Diode Test 2V • 15mV sensitivity to 60MHz Digital Multimeter e 3 1/2 digit LCD • Auto/Manual ranging Power Supply • Sine, square, triangle, skewed e Oto 50V, 0.5A sine, pulse, TTL level square e 15V 1A and 5V 2A fixed • Covers 0.02Hz to 2MHz Incredible value - $898.10 inc tax $774.20 ex tax $55.00 Save on Ultrasonic Cleaner The latest high-tech way to clean PCB 's, switches, watches, drafting pens - even your dentures' Let the millions of tiny cavitation bubbles clean the surface 40000 times per second . 165x90x50mm container holds half a litre and is made of 304 stainless steel. Some people are charging a lot more. Our's are still on ly $150 c:i Look at ALL these features Protocols: Async, SDLC, Sync, X.25, HDLC, SNA Data Capture: data bytes, control signals, and error conditions. Capture data to RAM and directly to disk with no file size limit. Data Display: rrame/f-'acket level: one decoded frame/packet per line. Byte level.- split-line DTE over DCE or mixed using reverse video for DCE Characters displayed in hex, ASCII, EBCDIC, or Baudot. Nonprintable characters displayed using hex, mnemonics, graphics.dots. Captured data can be searched; search patterns can include wildcard characters. Control Signal Display: Live breakout box includes timing diagrams and counters. Captured control signal transitions can be viewed in relation to captured data bytes using timing diagrams. Timestamping: Absolute or relative display of event time. Delta time and effective data rate calculations. Triggers: Character strings, control signals, and error conditions can be used to activate and deactivate data capture. String triggers can include wildcard characters. Device Emulation: Transmit data entered from the keyboard, Serial/est capture files, or any DOS file. Modify control signals. Use hardware and software flow control including user-defined XON/ XOFF characters. Configuration Management: Name and save an unlimited number of configurations. User Interfaces: Pop-up menus and context-sensitive help allow new users to be up and running quickly. Command line options can be used to further simplify operation. s (Jj ~ Cl <at>s u:. § s 8.30am to 5.00pm Mon to Fri. 8.00am to 12 noon Saturday. Mail Orders add $5.00 min to cover postal charges. Next day delivery in Sydney add $8.00. All prices include Sales tax unless stated otherwise. Tax exemption certificates accepted if the line value exceeds $10.00. BANKCARD, MASTERCARD, VISA, CHEQUES or CASH cheerfully accepted . () ;£ ~ 8 c:i clJJ () ;£ r 8 c:i clJJ () ;£ ~ 8 c:i clJJ 2'ii ~ 8 CJ cllJ ~ SerialTest Sync/Async with Comprobe $2480.00 jex tax) $2536.00 (inc tax). A low $15 P&P. Plug Pack $24.95. · SerialTest Async is still $480 .00. Demo disk $10.00 refundable on purchase Cl 8 clJJ Geoff Wood Electronics Pty Ltd (inc in N SW) 8 c:i ~ 229 Burns Bay Road , Lane Cove West N SW 2 (Corner Beatrice Street) ~ Mail Orders to - P O Box 671 , Lane Cove N S W 2066 ' Telephone : (02) 428 4111 Fax : (02) 428 5198 8 tJ CIRCUIT NOTEBOOK Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates. A__J1.____ Automatic soldering iron timer Do you sometimes forget to turn your soldering iron off? This circuit overcomes that problem by automaticaHy switching the iron off after a preset period. It also briefly sounds a buzzer at the end of the timing period so that you can reset the circuit before the iron goes cold. The circuit uses two 555 ICs wired as monostables, one to control a relay and the other to set the buzzer period. IC1 has a timing range of about 50 seconds to 20 minutes. When the start button (S1) is pressed, pin 3 of IC1 switches high, thus lighting LED 1 and turning on transistor Ql and the relay. The normally open (NO) relay contacts are wired in series with the mains Active line. Thus, when the relay Z40VAC N 8 SILICON CHIP TO SOLOERING IRON VR1 2.ZM 1k 100k IC1 555 I 1lor S1 HARTl + switches on, its NO contacts close and the soldering iron turns on and operates in the usual way. At the end of the timing period (as set by VR1), pin 3 of IC1 goes low again and the soldering iron turns off. At the same time, Ql 's collector is pulled high and this couples a brief Stutter trigger for an audio strobe An effect that can be easily created with MIDI sound equipment is to re-trigger a sample, either continuously, or a preset number of times. This circuit creates the same effect with a non-MIDI sampler. The oscillator based on ICld is normally held reset by a logic .O on pin 12. When the SR flipflop (IClb & IClc) is set by a press of the GO button (S1), the oscillator is enabled and clocks 4017 decade counter IC2. At the same time, the reset is removed from the two 4017s. IC2 divides the clock by 10 and its first output turns on Ql, triggering the sampler. The divided pulse is counted by IC3, and when the preset number of counts has elapsed, resets the flipflop via ICla. IC2 was not initially used in the prototype but it was found that when the circuit started, the first pulse from the clock was noticeably longer than subsequent pulses. / pulse through to Q2 via a .0lµF capacitor. Q2 thus turns on briefly and pulses pin 2 of IC2 low. This in turn initiates the timing period for IC2 which now sounds the buzzer for about 0.25 seconds. Steven Merrifield, Newlyn, Vic. ($15) r-----------------+12V 14 4~~\ CKl"' - - - - - - - IC1a 4093 EXTERNAL TRIGGER INPUT OF SAMPLER +12V 15 12 RESET CO 10k 16 01 BC547 13 By leaving the clock running constantly, a stable pulse width is created but then the position of the clock pulse relative to the GO signal resulted in a variable delay between switch press and the first sample being triggered. As a result, the clock was sped up and IC2 joined the circuit. If y9ur sampler doesn't like an open-collector trigger, a small relay can be connected between Ql 's collector and the +12V rail. Don't forget to install a diode across the relay coil to shunt the back EMF when Ql turns off. G. Sheridan, Ashfield, NSW. ($15) Self-contained autofire module for electronic games . .., 111=> "'~ .... Q Have you ever wanted to play "Revenge Of The Sludge Monster" but couldn't get past level one? Were those Sludge Monsters coming at you so thick and fast that your trigger finger couldn't stand the strain? If so, here is an inexpensive autofire circuit that does not require batteries or disassembly of your (no doubt expensive) joystick. The circuit operates in four modes: Autofire Off (normal fire); Machine Gun; Toggle Autofire (latch on/ latch off); and Non-Stop Autofire. These modes are selected by pressing Sl, which clocks the first four outputs of decade counter IC1. The fifth output (Q4) resets the counter, thus producing a wraparound effect. Mode One (autofire off) passes the fire signal from the joystick (pin 6 of the DB9 socket) through IC2a and then out to the computer via IC4b (which acts merely as a buffer). Mode Two (machine gun) gates on the oscillator formed by IC3a and IC3b for as long as the fire button is pressed. The output from this oscillator then toggles IC4b to produce the machine gun effect. Mode Three (autofire on/off) allows the fire signal to pass through IC2c and clock flipflop IC4a. Because the set pin (7) is held low by ICZd, the flipflop toggles the oscillator on/off. If another mode is selected, ICZd turns off and the flipflop sets via the 10kQ resistor between pins 7 & 16. This sends Q (pin 1) high, thereby turning off the oscillator. In Mode Four (non-stop autofire), the high from Q3 of IC1 is inverted by IC3d and the resulting low gates the oscillator via Dl. Dl prevents the normally high state of IC3d from disabling the oscillator. This mode is good if you tend to get over-excited and inadvertently pull the trigger, only to find that you've turned off the autofire just when you most needed it to obliterate an oncoming Sludge Monster. The rate of autofire is controlled by potentiometer VR1 which should be easily accessible, as some games may require a slower rate of autofire. IC3c buffers the output to drive LED 5. This gives you some idea of the signal going to the computer. (Remember, all joystick signals are active low). DZ is not really needed and may be replaced by a wire link if you use the circuit with a Commodore 64. This is because the Commodore 64 provides +5V on pin 7 of each joystick port. If your computer does not have +5V easily accessible, then you may run the circuit off a 9V battery but be sure to include D2 to prevent the +9V Q output from IC4b from blowing up your computer. An on/off switch should also be added if you use an external battery as the circuit draws about 4-6mA. The circuit is interfaced to the computer via the DB9 plug, while the joystick plugs into the DB9 socket. The construction technique is not critical and the circuit may be built up on a small piece of perf board using point-to-point wiring techniques. G. Cattley, Sydney, NSW. ($25) OCT0HEH 1992 9 ;::::;::;:::::=;;:::::::=;::;:;;:=;:;;====:;'"''""'""""'""4 r""""'""'"'""==========~:.':.':.':.':.~"""'"'r r''"'"'"""""""""=='=-=='=-==";";:"":=':""==='""'"="'""""'"""""'i; RITRON 286-16rs are RITRON ADD PRICE TO BASE SYSTEM COST. now only $1349 with , __ EXECUTIVE PLUS $25-$100 INSTALLATION .:::~~:a,rat~la,11it·•~!;.~!~!!!!!.., 1 MEG RAM EXP TO 8 MEG ,---,,--,---. 31Mhz LANDMARK SPEED TEST Genuine 1.2M JAP F.D.D. 512K VGA CARD Au•t ralian, Fully 85M HARD DISK DRIVE, Upgradable 101· EXTENDED "CLICK" KEYBOARD DR DOS 5.o MINI CASE & 200W POWER SUPPLY supplied wi th SUPA VGA COLOUR MONITOR every sySt em. 1024 x 768 Res 0.28" D.P DOS 5 $ 50 extra SERIAL PARALLEL GAMES PORTS 4 YEAR PARTS & LABOUR WARRANTY IBM' COMPATIBLE SPREADSHEET, WORDPROCESSOR & DATABASESOFTWARE INCLUDED. • SHAREWARE SOFTWARE ASSEMBLED & TESTED IN AUSTRALIA. $1 449 TAX INC. SOFTWARE INCLUDED. 'SHAREWARE SOFTWARE Genuine $1 629 ' ASSEMBLED & TESTED IN AUSTRALIA. RITRON EXECUTIVE EXTRA RAM IM add $55 2M add $110 4M add $220 • WINDOWS 3.00.$69 WINDOWS 3.1.$159 SOUND CARDS SOUND COMMANDER............................. $149 THUNDER BOARD.................................. $199 SOUNDBLASTER II ................................. $175 SOUNDBLASTER PRO............................. $369 FLOPTICAL DRIVE add........................... $695 21 M/BYTE DISC TO SUIT...................... $39 CD ROM SOUND BLASTER PACK. ........... $949 PARRADISE WINDOW ACCELERATOR..... $325 TAX INC. $1 ,379 TAX EX RITRON EXECUTIVE RITRON EXECUTIVE Q•• • ••~. ~.§., e.§ • ••• •w 4••1~§•~~•~•• 1 , 80386-40 CPU 64K CACHE ON Genuine BOARD Australian, Fully 1 MEG RAM EXP TO 16 MEG Upgradable 65 Mhz LANDMARK SPEED TEST DR DOS 6.0 85 MEG HARD DISK 12ms ACCESS supplied wtth TIME every system. 1.2M JAPANESE BRAND F.D.D DOS 5 $50 extra 101 EXTENDED "CLICK" KEYBOARD MINI CASE & 200W POWER SUPPLY SERIAL, PARALLEL, GAMES PORTS 512K VGA CARDSUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28" 4 YEAR PARTS & LABOUR WARRANTY SPEADSHEET, WORDPROCESSOR & DATABASE SOFTWARE INCLUDED. •SHAREWARE SOFTWARE Genuine 80486SX•20 CPU Australian, Fully 1 MEG RAM EXP 10 32 MEG Upgradable 75Mhz LANDMARK SPEED TEST OR DOS6.0 85 MEG HARD DISK supplied with 1.2M JAPANESE BRAND F.D.D every system. 101 EXTENDED "CLICK" KEYBOARD DOS 5 $50 extra MINI CASE & 200W POWER SUPPLY 4 YEAR PARTS & LABOUR WARRANTY SERIAL, PARALLEL, GAMES PORTS, 1MEG VGA CARD SUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28" DP SPEADSHEET, WORDPROCESSOR & DATABASE SOFTWARE INCLUDED. 'SHAREWARE SOFTWARE $2,249 $1,909 .. TAX INC. TAX EX. · $1 649 ' $1,399 TAXEX. 80486•33 CPU 256K ON BOARD CACHE. 4 MEG OF RAM 80486·50 CPU 256K ON BOARD CACHE. 4 MEG OF RAM 157Mhz LANDMARK SPEED TEST Genuine 200+Mhz LANDMARK SPEED TEST Genuine 200 MEG HARD DISK Australian, Fully 200 MEG HARD DISK 12ms ACCESS Australian, Fully 12ms ACCESS TIME Upgradable TIME 1.2M JAPANESE BRAND F.D.D Upgradable 1.2M JAPANESE BRAND F.D.D DR DOS 6.0 3.5" 1.44M JAPANESE BRAND F.D.D DR DOS 6.0 3.5" 1.44M JAPANESE BRAND F.D.D supplied with 101 EXTENDED "CLICK" KEYBOARD supplied wtth 101 EXTENDED "CLICK" KEYBOARD every system. SERIAL, PARALLEL, GAMES PORTS SERIAL, PARALLEL, GAMES PORTS DOS 5 $50 extra 1 MEG VGA CARD. IBM' COMPATIBLE 0 ;:;~::;;a 1 MEG VGA CARD. IBM' COMPATIBLE - - - - -1 ... 1TOWER CASE & 220W POWER SUPPLY .___ _ _ __. TOWER CASE & 220W POWER SUPPLY SUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28" DP SUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28" DP 4 YEAR PARTS & LABOUR WARRANTY 4 YEAR PARTS & LABOUR WARRANTY SPEADSHEET, WORDPRCESSOR & DATABASE ~";1 wos:i:R~ii6'R& DATABASE SOFTWARE. $3,395 $2,895 TAXINC. TAX INC. ASSE!;~~:R~STED IN AUSTRALIA. $3895 IDEAL CAD MACHINE! $3299 ROD IRVING ELECTRONICS Est:1977 MAIL ORDER HOTLINE: 008 33 57 57. ORDER FAX LINE: (03) 543 4871 ENOUIRES(03) 543 7877 HEAD OFACE: 56 RENYER RD, CLAYTON. PH: (03) 543 2166. FAX (03) 543 2648 MELBOURNE: 48 A'BECKETTST. MELBOURNE, PH. (03) 6391640. FAX: 6391641. OAKLEIGH: 240C HUNTING DALE RD, OAKLElGH. PH: (03) 562 8939 FAX: (03) 562 8940 NORTHCOTE 425 HIGH ST. NORTHCOTE, PH. 499 8866. FAX: 489 8131. SYDNEY:74 PARRAMATTA RD, STANMORE. PH: (02) 519 3134. FAX: (02) 516 5024. NEW STORE. ADELAIDE: 241-243 WRIGHT ST, ADELAIDE. PH~08) 211 7200 FAX: (08) 211 7273 BLUESTAR COMPUTERS: MELBOURNE: 271 MAROONDAH HWY, RINGWOOD, PHONE: (03) 870 1800 FAX: (03) 879 3027 i:::~:~ SPREADSHEET, WORDPROCESSOR 6 DATABASE SOFTWARE. $2,149 $1,829 WITH 200 MEG DRIVE TAXINC. TAX EX. $2,749 TAX INC $2,339 TAX EX 3..-::....,,,..,..,.,~srt:~....J~ ;ii~tt ..··b. ·.::::.:::.::::.::.::.::.::.-:::.."' · RITRON ;,:~~~; ! {]) ,~~~;- ~ Ass~:!t~~:A1;;:TED • • 1;~~ -~':..~~-~~-~BOARD ) SERIAL, PARALLEL, GAMES PORTS C• 512K VGA CARD. IBM' COMPATIBLE ..· SVGA COLOUR MONITOR (1024 x 768 Resolution) 0.28''DP MIN1 CASE & 200W POWER SUPPLY 4 YEAR PARTS & LABOUR WARRANTY $2,249 TAX INC. $1,909 TAXEX. INC. RITRON < ~••••1 §em •1•e •~• • ~ \ 80486-33 CPU ( 256K ON BOARD CACHE. 1 MEG OF RAM :> 157Mhz LANDMARK SPEED TEST ) 85 MEG HARD DISK ASSEMBLED & TESTED IN AUSTRALIA. TAX WITH 200 MEG DRIVE WITH 200 MEG DRIVE lM VGA CARD .. $100 85M HD add $120126M HD add $175 105M HD•• $150 200m HD add $595 170M HD•• $495 ·• 1 MEG RAM EXP TO 16 MEG Australian, Fully •• 57Mhz LANDMARK SPEED TEST Upgradable ·: 85 MEG HARD DISK DRDOS6.0 •: 1.2M JAPANESE BRAND F.D.D supplied wtth C: 101 EXTENDED "CLICK" KEYBOARD every system. •· SERIAL PARALLEL GAMES PORT DOS 5 $50 extra :: MINI CASE & 200W POWER SUPPLY SUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28" DP 512K VGA CARD (256 COLOURS) IBM' COMPATIBLE 4 YEAR PARTS & LABOUR WARRANTY SPEADSHEET, WORDPROCESSOR & DATABASE ' RITRON 512K VGA CARD .. $50 TO CHANGE A 40M HARD DRIVE TO A TAXINC. TAX EX. -~~~~-,!1~ ( ' 80486-EISA CPU 256K ON BOARD CACHE. 4 MEG OF RAM ) : 167 Mhz LANDMARK SPEED TEST Genuine ) i 200 MEG HARD DISK 12ms ACCESS Australian, Fully /( TIME 1,2M JAPANESE BRAND F.D.D Upgradable •<>• 3 5" 1 44M JAPANESE BRAND f; D D 60 / 101 EXTENDED "CLICK" KEYBOARD DR DOS • ) / SERIAL, PARALLEL, GAMES PORTS i) 1 MEG VGA CARO, IBM' COMPATIBLE C:} TOWER CASE & 220W POWER SUPPLY {: SUPA VGA COLOUR MONITOR (1024 x 768 Res) 0.28'' DP f 4 YEAR PARTS & LABOUR WARRANTY )\ SPEADSHEET, WORDPRCESSOR & DATABASE ••••••• )• ) Asse:~~:RT~STED IN AUSTRALIA. . IDEAL CAD MACHINE! FREIGHT CHARGE BASED oN 35KG COMPUTER SYSTEM Melb-Metro.$12.00 Sydney..,_.. $18.00 Adelaide.. -.$18.00 Bribane.. _.. $23,00 Canberra. ... S18.00 Darwin .... -.$40.00 Perth,_,,_,,_$33.00 TasmaniL,-$55.00 Vic country.. _$23.00 NSW country.$39.00 S.A country_,$39.00 OLD country.$55.00 ' W.A country.. $75.00 Insurance:• $1 I $100 Value. $4699 $3999 TAX EX 1-9 boxea 10+ OXE LIFETIM HI+ 50+ 1-9 5 1/4" 5 1/4" 3 1/2" 3 1/2" WARRANTY 100+ 500+ DS/DD $4.75 $4.60 $4.40 $4.20 $3.95 DS/HD $8.50 $8.25 $8.10 $7.50 $6.60 DS/DD $7.90 $7.20 $6.90 $6.50 $6.00 DS/HD $14.95 $12.90 $11.95 $10.50 $9.90 31/2"DD $19.95 3 1/2"HD $45.95 5 1/4"DD $14.95 51/4"HD $23.95 $18.95 $42.95 $12.95 $22.95 1-9 boxN 3 1/2"DD $23.95 31/2"HD $44.50 5 1/4"DD $17.95 5 1/4"HD $24.95 10+ 1-9 boxe• 10+ $22.95 $42.50 $16.95 $22.95 31/2"DD $21.95 31 /2"HD $39.95 51/4"DD $11.95 5 1/4"HD $18.95 YOU'LL HAVE TO GO A LONG WAY TO FIND DISK PRICES LIKE THESE. SAVE ON OUR GREAT RANGE OF EPSON PRINTERS ~ Matrix, 180 Cps Draft 30 Cpa NLO, Pull Tractor C22ll54 ................... $249 SQ•2SS0 80 Col, 24 Nozzel Ink jet, 600 Cpa Draft, 198 Cps LO, Push Tractor, Smart Park Feature, C22099.........................$1995 Matrix, 240 Cps Draft 48 Cos NLO, Push Tractor, Sn1 ut Park Feature C22074 .................... $365 Matrix, 264 Cps Draft. 54 Cps NLO, Push Tractor, Smart Park Feature. C22067 .........................$925 SQ•BS0 80 Col, 24 Nozzel ink jet, 600 Cpa Draft, 198 Cps LO, Push Tractor, Smart Park Feature. C22052 ....................... $1 ,22 5 . - . ·· ··-~.· . ., . .,'"·" ,;" '" '"'" f:i,} 200 Cpa Draft, 72 LO, Built-in sheet feeder,8 fonts, 2 scalable fonts. C22070 ............................. $475 · . r----------------------------- lADELAIDE STORE NOW OPEN! 1241-243 WRIGHT ST, ADELAIDE. 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C22068 ........................$575 LQ-1170136 Col, 24 Pin Dot Matrix, 350 Cpa Draft., 110 Cps NLO, Scalable Fonts, 8 to 32 point, 11 LO Fonts, 360 x 360 DPI, Top, Rear, Bottom, and Front Paper Feedpaths, Convertable Push/Pull Tractor C22127..........................$1, 149 LQ-870 80 Col, 24 Pin Dot Matrix,330 Cps Draft, 110 Cps NLO, Scalable Fonts, 8 to 32 points, 11 LO Fonte , 360 x 360 DPI, Top, Rear, 1 Bottom, & Front paper Feed paths Convertable Push/Pull Tractor. C22072........................$895 a - LQ-1060 136 Col, 24Pin Dot Matrix' 292 Cps Draft, 98 Cps LO, Colour Standard,Puah Tractor, Smart Park Feature. C22096 ...............................$1,395 I Fax: (08) 211 7273 I L-----------------------------~ WE WONT BE BEATEN ON PRICE! PRICES ARE WITHOUT SAVE BIG DOLLARS ON THESE PADDLE CARDS & BRACKETS DRASTICALLY REDUCED IBM 40M SEAGATE DRIVE................................... $329 CARDS! 85M HD 17ms ACCESS. VOICE COIL. PRINTER CARD ...... .. $19 6M RAM CARD .........;:'< .... $249 2 YEAR WARRANTY...................................... $425 105M HD 19ms ACCESS ............................... $495 2 PORT SERIAL CARD.. :.. ........... $39 126M HD 16ms ACCESS. VOICE COIL. GAMES CARD ................................ $19 2 YEAR WARRANTY...................................... $545 CLOCK CARD................................. $39 170M 2 YEAR WARRANTY.......................... $695 512/576K RAM CARD OK RAM ..... $69 2 WAY FDD CONT................. , ....... $89 212M HD 12ms ACCESS. VOICE COIL. 4 WAY FDD CONT. . . .· .. .. .·....... . $129 2 YEAR WARRANTY...................................... $795 VGA 16 BIT 256K ......." . .. ... $59 LN_E_W_34_o_M_H_._D_.D_._ .._..._..._.._..._..._.. _..._..._.. _ ..._..._.. _ ..._..._.$_1_29__,5 VGA 16 BIT 512K.......... . ........... $79 MOTHERBOARDS VGA 16 BIT 1 MEG ........................ $129 16M HD CACHE CARD OK RAM ... $495 286·16/21.............. ................ $119.00 HDD IDE /FDD ................................. $19 386SX-16............. .. .. $190.00 HDD IDE/FDD/SPG ........................ $39 386SX-25/31....... .. .... $199.00 8 BIT ETHERNET CARD ................. $195 386SX·33/41 ..... · ....... $265.00 16 BIT ETHERNET CARD...............$245 386•25........................ •...... $365.00 AT HD CONTROLLER .................... $149 386-33 64K CACHE................... .. ...... $375.00 MULTI 1/0 CARD ............................. $99 386•40 64K CACHE................................. $395.00 MONO COLOUR CARD .................. $69 386~33 128K CACHE............................... $425.00 EGA CARD...................................... $99 486SX·20 .................................................$425.00 DIAGNOSTIC CARD....................... $795 486-33 64K CACHE................................. $895.00 TTL PRINTER CARD ...................... $79 486·33 256K CACHE............................... $995.00 FAX CARD ....................................... $595 486•50 256K CACHE............................... $1695.00 6M AT ~X/EXP................................. $225 ~ MEMORY 1-e 41256•08 ..... $2.95 44256•08 ..... $7.95 44256•07..... $8.95 SIMMS 1-9 10-24 25+ 1 21 19 11 1 256 K-ao 1M x 9.70 $49 $48 $47 $ 1M x 9-60 $79 $n $75 $ 4M x 9-80 $219 $209 $199 $1 SIPPS 1M x 9-80 $79 $69 $59 $55 s s s s IM•)~lii•l;l-'i:.i::('iMf1 ...,. ••••• ■■- ■--~~r~~~~ONITOR ._. 11 . "3 YEAR WARRANTY" ,. •· -. This stylish and reliable c::::::::::::c:::,..monitor has been designed for Australian conditions & .comes with a 3 year warranty. SPECS: cte: 14" 90° deflection, dark tint, non-glare. Display size: 245-tlSmm x 180+/-Smm x 180+/•Smm Resolution: (max): 1024 x 768. Dot Pitch: 0.28" •• , $439.00 TECO i: SUPER VGA MULTISCAN COLOUR MONITOR NON-INTERLACED . 1024 X 768............. $599.00 11 ,_,.,,.,,,,......,.,,,,._ Microsoft MS-DOS 15 Upgrade MORE MEMORY, MORE PRODUCTIVITY MORE FEATURES. ORE CONVENTIONAL MEMORY FOR 2Mb AND UP MACHINES) hen you lnetall MS-DOS 5 on an 80286 or 80386 baaed ayatem you can map the DOS code Into Hi gh Memory e memory which atart• at the 1024 Kb boundary In your eyatem. The DOS code (about 100k) can be remapped up Into the atart of the eecond 1 Mb of memory.<- fig 1.). Thie allow• a full 620Kb of conventional memory for appllcationa. MS-DOS s·s NEW UNDO FACILITY DOS 5 can now retrieve deleted filea and recover accldenUy formatted Hard and Floppy diakL THE MS-DOS TASK MANAGER Under DOS 5 you can now run load two applications and "HOT KEY" between them, cutting out the time onaumlng loading and exiting of DOS programa. HE NEW LOOK MS-DOS The new graphical shell which looks very much like the ndow• 3.0 file manager. Thi• helps working th DOS a lot easier. THE NEW SYSTEM EDITOR A new full ecreen editor has replaced the old ELDIN to make writing batch file even easier. ALL NEW BASIC (OBASIC INTERPRETER) The new OBulc has replaced good old GWBaalc to give you a much more powerful and friendly programing tool. •• OW ONLY $95.00 WINDOWS Operating System • j~ 3.1 M The Microsoft Windows operating system enhanc~a DOS®Co make your PC easier to use. Discover the point• and•cllck almpllclty of Windows I Create terrific output with applications for the Windows operating ayatem. 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Don't loae those precloua memories protecl tht>m by lamlnatlng them with your own laminating machine Important Bualneae carde, memberahlp carde, recipes etc. last a life time longer when lemlnated. Now ROD IRVING ELECTRONICS have lmporled this lamlnator that your budget can afford. Don't pay hundred• of dollare for eome big machine Pay a 1/4 of the price for an attractive compact lamlnator that le ao elmple to uae. Heate up In only 2 to 3 minutea. oo............................. A911 $ 95.oo Laminate Sheets .... 95mm x 57mm (2.25" x 3.25") for business cards A91110•• $18.95 pack of 100 Laminate Sheats .... 156mm x 112mm (4.25" x 6.75") for photos with punch holes for photo album A91111 ........... $1 1.95 pack of 24 Laminate Sheats ••••135mm x 95mm (3 3/4" x 5 5/16") for photos and cards A91113 ..................... $8.95 pack 0124 Laminate sheats .. .. 110mm x 170mm (4.25" x 6.2'5") A91112 .. .....$10.95 pack of 24 BUBBLE JET PRINTER BJ-10ex Welcome to a whole new world in printing with the BJ-10ex Bubble Jet Printer. this BJ•10ex is unlike any printer you ha-oe e-oer known. The differences lie in the compact size, the high qualit'!f printing, tmd the quiet operation and durabilit'!f made by the original bubble jet printing technology. 1HE BUBBLE JET PRINTING SYSTEM The bubble jet printing system prints characters and graphics by firing ink drops at the paper from thin nozzles produces bubbles that quickly exptmd imd eject the ink. The heat is generated by applying electrical pulses to the heating elements built into each nozzle. C22240 ............. .$589.00 Canon Nicad Batterypack NB-150 To suit BJ-10ex printer C22242 ....................$95.00 atep X17040......................................$799.00 Thi• la not your average EPROM Eraaerl Sure It eraeee your EPROM•a quickly and eafely and will erase up to 8 x 24 pin device• In about 40 mlnutea.(leea for Iese chlpe). But with Ihle one you don't have to waste your time atandlng around waiting for them. Thla EPROM eraeer h• timer to allow you to "eet and forget". By uelng the timer function you not only eave money by reuelng your EPROM'a but you alao eave precloue time by doing other jobe while the eraser la working. And you·11 never have to worry about forgetting to turn It off and "cooking" your EPROM•L Chooee from a range of different aettlnga from 15 minutes to 40 minute• depending on the Intensity of the UV source. • The chip door hae a conductive foam pad. • High Intensity at the chip aurface anauree EPROM·• are thoroughly erased. • Engineered to prevent UV expoaure SPECS: Operating Voltage: 1oov-120v -60Hz 200V-240V -60Hz Power Coneumptlon: 8 watta nmer: 15 to 40 mlnutee Capacity: 8 of 24 pine UV Source Wavelengthe: 253.7nm UV lntenalty: 7mW/cm2 Tube Ufe: approL ~ Thie la the big daddy of them all. Get the moat out of your power points with thla 12 way power board. Don·t kll youaelf by loading up the power point with Double adaptors. This le the 11ve and neat way to uee 12 appliance• out of the one aockel . Cornea with a 1 metre fitted cord ana plug and la rated 1oampa, 2400 watta. Also h• overload protection. P1 8038...... $34.95 Thi• I• the new look In extanalon leade. Makea other extension leade look old faahlonl 11·, a 240 Volt, 10A extension lead which la fitted with a eocket on one end and a piggy beck double adaptor plug on the other. Turns your one point power point Into two while giving you the benefit of an extension cord. 1 Metre P18060.................. $5.95 2 Metre P18070 .................. $6.95 4 Metre P18080 ......; ........... $9.95 6 Metre P18090 ..................$11.95 ~~:: M MOUSE Microsoft compatible. Free mouae houee & mat plua free pop up aoltware. X19955 ----~59.95 NEW ___....BUDGET ,..-:,_~ \_ MOUSE "".""Q...J Mlcroaoft compatible steamllne design an amazing X199,~S:"-l---MICROSOFTc:g, -- , MOUSE . Thatopof the rangel Supporte lOO'e of apollcatlonL FREE p•l11tbruah aoltwara X199,~sa..__ _ __ 3000 hra Dimensions: 21.7(H) 16.8(W) x 8(D)cm X14955............ $169.00 qi{(-- '.» SPARE UV TUBE FOR EPROM ERASER X14957.............. S17.85 PRINTER SWITCHES NEW POWER OUTLETS PIGGY BACK EXTENSION LEADS Tha Video Sluter la the next logical In multlmedla. uat Imagine being able to Integrate Ylcleo and audio source from laser dlac, VCR, or camera, and combine VGA graphics Into a brand new peychedellc wortd of multimedia preaenlltlona.Video blaster aupporta lifelike coloura on your standard VGA monitor. The characterlatica of Red, Green & Blue • brightneas, contrast, hue - can be controlled: atereo audio volume can alao be Individually mixed via the software. With Video Sluter, video lmagea can be digitized and captured through the Video Blaster for uae with other program• for storage, presentation, and even animation! Experience the thrills and eeae of graphics overlayed with video aourcea through the Video Blaster.Cropping, acaling, maeldng and zooming are standard featurea aupported by the Video Blaster. Aleo Included with Video Blaster "TEMPRA GIF'. • An Imaging tool that allows you to edit Images with 256 colour, • Aleo support 32767 Hlcolour mode. TEMPRA SHOW• A tool for t:reatlng multimedia preaentatlon • Aleo lncludea Connection cablea • VIDEO KIT eoftware • VB DEMO A simple demonstration program for Video blaster Great for aavlng a aerial port. 2 Free telepalnt disks.Save $30 ONLY RS232 2 WAY.................$39 RS232 4 WAY.................$58 RS232 X OVER.............$59 RS232 WAY AUT0........ $69 CENTRONtCS 2 WAY••••$39 CENTRONICS X-OVER••· - - - -..$58 CENTRONICS 2 WAY AUTO $8'1 CENTRONICS AUTO 4 WAY AUTO $6'1 i::;.""''~ ·--~··· "• ONE COMPUTER CA RUN TEN VGA MONITOR USING TH U-SYNC BUFFER • Utility for Analog Signal Input • Great for exhibition demonstrations & illustrations purpou • Ideal for schools factories, shops, car 9 mm hole, available 3 colours S14030 Red ......... $1.20 S14032 Green ..... $1.45 S14034 Yellow.... $1.45 Diecaat boxea are excellent for RF eheildingand strength. Screws are provided with each box. H11451 100 x SO x 2Smm........ $8.95 H11452 110 X 60 X 30mrn. •••••••$9.50 H11453 120 x 65 X 40mm....... $10.SO H11461 120 x 94 x 53mm...... $13.95 H11462 188 x 120 x 78mm.... $15.95 H11464 . 188 x 188 x 64mm.... $29.SO ,, ·~ ~ . GREYFL; RIBBON CABLE no. 2614 2616 2620 2624 2625 2626 2634 2636 2640 2650 2660 14way 16way 20way 24way 25way 26way 34way 36way 40way 50way 60way $/Mtr $1.90 $2.20 $2.50 $2.90 $3.20 $3.60 $3.90 $3.90 $4.90 $5.90 $6.90 10TURN WIRE WOUND POTENTIOMETER Spectrol Model 5341/4" shaft. Equivalent (Bourns 3540S Beckman 7256) Dials to suit 16-1-11, 18-1-11, 21-1-11. R14050 SOR R14100 SK R14055 100R R14110 10K R14060 200R R14120 20K R14070 SOOR R14080 1 K R14090 2K 1-9 10+ $12.95 $10.90 R14130 SOK. ............. $16.95 R14140 1001<............ $15.95 0 0 0 000 0 0 0 0~<at>1 Unencoded keypad, 10 igit keys plus two utility keys. Light grey in co.lour. OUTPUT ARRANGEMENT: Output Pin No. Symbol 1••••.....•• •.••...••.. N.A. ······················Shleld plate ·······················co1umn 2 .............•......... Row1 ...........•........... Column3 ..........•........... Row 1 ..........•........... Column 1 ..........•...•....... Row2 9 ....•....••........... Row 3 10..................... N.A. al C19030 1-9 2.95 Cat No. Z10135 Z10105 Z10107 Z10110 Z10115 Z10119 PN100 REPLACES: PN2221, PN2222, PN2222A, PN3585, PN3568, PN3569, PN3643, PNS 133, 2N2219A, 2N2222A, 2N3414, 2N3415, 2N3416, 2N3417, 2N3700, 2N3704, 2N3904, 2N4123, 2N4124, 2N4401, 2NS088, 2N5210. PN200 REPLACES: PN2907, PN2907A, PN3638, PN3638A, PN3640, PN3644, PN4121, PN4143, PN4248, PN4249, PN4250, PN4355, PN4916, PN4917, PN5910, 2N290SA, 2N3467, 2N3702, 21'(3906, 2N4125, 2N4126, 2N4291, 2N4402, 2N4403, 2NS086, 2NS087, 2NS447. PN100 ......T90001 PN200 ......T90002 100+ , 1-9 10+ $0.20 $0.18 $0.15 ---·------- SUPER BRIGHT LEDS • RED .......••.......• Z10146 • GREEN ........... Z10147 • YELLOW•••.•... Z10148 1-9 10+ $1 .00 $0.90 100+ $0.04 $0.05 $0.06 $0.07 $0.14 $0.16 1000+ $0.03 $0.04 $0.05 $0.06 $0.13 $0.15 10K $0.02 $0.03 $0.04 $0.05 $0.11 $0.14 POWER SUPPLIES XT P.S lJf)W........... $139.00 FULL TOWER 220W P.S ..........••... $149.00 MINI TOWER 200W P.S...........•... $89.00 BABY AT P.S 200W................. $89.00 SLIMLINE BABY AT P.S. 200W...•...........$89.00 J I. Save ■ small fortune on these .. Direct Import"· low profile IC sockets! PCB mounting solder tall. All tin plated phosphor bronze or berrylllum and dual wipe for rallablllly. 1·9 10+ 100+ P1osso 8 pin 1se 12e 1oe P10560 14pin 20e 1ae 1se PI0565 16pin 20e 18e 1se P10567 18pin 30e 25c 2~ P1056s 20pln 35e 30e 25e P10569 22pin 35e 30e 26C P10570 24pin 3Se 30c 26C P10572 28pin 4SC 35c 3°' BREAD BOARDS This inexpensive range of modular interlocking units enables a quick easy way of experimenting with new circiuts and ideaa. There are two main units consisting of a terminal strip or distribution and a central plug in unit. • 100.holee. P11000 ....•••.•.•.••.. $2.75 •840 + 100 holes P11007............... $14.95 • 1280 +100 holes • P11010 ..••.•..••.. $26.95 •2560 + 700 holes • P11018 ..•.•........ $69.95 ~ ~ . WIRE WRAP IC SOCKETS Those quallly 3 level wire phosphor bronze. P10579 Spin $1.50 $1.40 P10580 14pln $1.85 $1.70 P10585 16pln $1.95 $1.80 P10587 18pin $1.95 $1.80 P10590 20pin $2.95 $2.75 P10592 22pin $2.95 $2.70 P10594 24pin $3.95 $3.50 P10596 28pin $3.95 $3.50 P10598 40pin $4.95 $4.50 WOW! WHAT PRICES! IDCPLUGS & SOCKETS WOW I FROM $1.00 COMPUTER CABLES • SJx conductor lhtelded computer Interface cabt.e, W12670 • CIC6 6 con. 1-9M 10M+ 100M+ $1.30M $1.10M $1.00M W12672 • CIC9 9 con. 1·9 M 1CN+ 100M+ $1.60M $1.SOM $1.20M W12674 • CIC12 12 con. ·1.sM 10M+ 100M+ $2.SOM $2.20M $1.90M W12676 • CIC16 16 con. 1-SM 10M+ 100M+ $3.SOM $3.20M $2.SOM W12678 • CIC25 25 con. 1-9M 1OM+ D TYPE JDC PLUGS 1.9 10+ 100+ • DE9P Spin plug P12166 $1.50 $1.20 $1.00 • DA1SP 15pln plug P12168 $1.50 $1.20 $1.1)() • DB25P 25 pin plug P12170 $4.50 $3.95 $3.50 100M+ $3.90M $3.40M $3.00M DTYPE JDC SOCKETS 1-11 10+ 100+ P12167 $1.50 $1.20 $1.00 • DA 15S 15 pin •oeket NICADS 1"SPACING P12060 10pin P12062 20pln P12064 26pln P12066 34pln P12068 40pln P12070 SOpln $3.95 $4.25 $4.50 $4.95 $5.95 $6.95 1-11 10+ 2155 24GV 6-1SY 1A M12155 ...•....$8.95· $7.95 2156 240V 6-1 SV A2 M12156 .......$13.95 $12.95 2851 24GV 12-GY CT 250mA M12851 .........$4.95 .• $4.50 6672 240V 15 30vc 1A IApped M16672 ...... .$12.95 $11.95 •QUALITY 3mm I.EDS 1-ll 10-a 100+ 1000+ Z10140(R) S0.15 S0.12 S0.10 10141(0).. S0.20 So.18 S0.15 Z10143(Y).. $0.20 $0.18 S0.15 1014510~. so.20 so.1a so.15 Save a fortune on expensive throw away batteries with these quality Nicada and Rechargeral Size AA 4SOmAH 1-9 10+ $2.95 $2. 75 SlzeC 12.AH $9.95 $9.50 100+ $2.50 P12169 $1.50 $1.20 $1.00 • DB25S 15 pin 1ockel P12171 $4.50 $3.95 $3.50 12VDCFANS so x so x 25.4mm 12Y DC.1.7 Watt 0.14 Amp T12469 ......•••...... $18.95 10+ fans, only $17.95 FANS QUALITY 5mm LEDS Z10150(R). $0.15 S0.12 S0.10 SO.OS Z10151(0). S0.25 S0.20 S0.18 S0.12 Z10152(Y).. S0.25 $0.20 S0.18 $0.12 ---- power amp1 1 computer hotspot cooling otc. Anywhoro you noed plenty of air. 240V 4 518·· T12461..$16.95 115V 4 518"' T12463 .. $16.95 240V 31/2.. T12465 .. $16.95 "~l'J"M TOGGLE SWITCHES $2.95 1111==: RED GREEN YELLOW 10. 11,0+ 20C 15C 12C 20C 1SC 12C 20C 1SC 12C DB25 CONNECTOR SPECIALS 1.e 10+ 100+ P10880 DE9P $1.00 $0.80 $0.60 P10885 DE9S $1.00 $0.7'0 $0.60 P10881 DA15S$1.00 $0.70 $0.60 P10892 DA1SC$1.00 $0.90 $0.60 P10885 DA15S $1.00 $0.80 $0.60 P10902 DB25C $1.00 $0.80 $0.60 P10S0. DB25P $1.00 $0.80 $0.60 P10905 DB25S $1.00 $0.80 $0.60 1-9 10+ S11010 S.P.D.T$1.20 $1.10 S11020 D.P.D.T$1.30 $1.20 MOSFET SPECIALS ICBVOLTAGE REGULATORS BARGAINS Deacrtpdon 1-9 10+ 100+ 7805UC $0.50 7812UC $0.50 7815UC $0.50 7905UC $0.60 7912UC $0.60 7915UC $0.60 78L05 $0.40 78L12 $0.40 LM324 $1.00 SSS $0.40 741 $0.50 $0.45 $0.45 $0.45 $0.55 $0.55 $0.55 $0.30 $0.30 $0.90 $0.38 $0.45 $0.40 $0.40 $0.40 $0.50 $0.50 $0.50 $0.28 $0.28 $0.80 $0.33 $0.39 ( ~ - • \ I ~ 9 PIN D SWITCH BOXES 2 WAY....•......••.. $59.95 4 WAY....•........•. $69.95 MONITOR & KEYBOARD SWITCH BOXES $69.50 MINIATUR HOBBY VICE • Lever operated auction base grip for instant mounting & portability. • Mounta on smooth non-porou. surfaces • Ideal for holding & other amall objecta • $6.9,5 $8.95 . RECTANGULAR LEDS 1-11 Quallty fans for use In :g:~·~··!i· ..... JDC CENTRONICS 36 WAY PLUG & SOCKET 100+ SO.OS $0.12 $0.12 so.12 FLASHING LEDS RED Smm 1-9 10+ 210159 $1.10 $1.00 wrap sockets are tin plated • DEBS 9 pin 1oekat CARD EDGE CONNECTORS ECONOMY TRANSFORMERS ~ GENER~ PURPOSE TRANSISTORS PN100: a NPN general purpose medium power amp and switch with continuous collector current up to SOOmA. PN200: a PNP general purpose amp at collector currents to 1 AMP. Both are T0~2 plastic package. 10+ $0.05 $0.06 $0.08 $0.10 $0.18 $0.20 IN4148 IN4002 IN4004 IN4007 IN5404 IN5408 HOLDER . ~.. Better than an ~ extra pair of hands,.,. A must for all PCB work. T12444 .......•.•...• $9.95 1-9 $9.50 $10.00 $8.50 $9.50 $9.50 $9.50 2SJ49 2SJS6 2SK134 2SK176 2SJSO 2SK1:l_S M/ ~ 10+ $8.00 $9.50 $8.00 $8.90 $8.50 $8.50 100+ $7.00 $8.50 $7.00 $ 6.90 $7.00 $7.00 ELECTRET MIC INSERTS ., WUh pine tor ...., board ln•rtlon. C10170 1-11 10-89 100+ 1000+ $1.20 $1.00 $0.90 $0.70 TRANSISTORS BUY IN BULK & SAVEi 1-11 10+ 100+ BC 547 $0.15 $0. 10 $0.07 BC 548 $0.15 $0.10 $0.07 BC 549 $0.15 $0.10 $0.07 BC 557 $0.15 $0.10 $0.07 BC 558 $0.15 $0.10 $0.07 BC 559 $0.15 $0.10 $0.07 BC 327 $0.20 $0.15 $0.12 BC 337 $0.20 $0.15 $0.12 BD 139 $0.75 $0.60 $0.50 BO 140 $0. 75 $0.60 $0.50 II PCB MOUNTING SCREW TERMINALS (INTERLOCKING ENDS) These terminala feature Interlocking ends to fonn any number of coMectlona. Standard 5mm apacing pins. P10520 1-11 100+ so.rs P10521 $1.00 THE FIRST BOOK OF 1-2·3 RELEASE 2.4 THE FIRST BOOK Of MS-DOS 5 Combines Qulck•Step lessons with end of chapter questions & answers for effective Instruction. Explains functions, commands, & Installation of DOS. Also Includes tips on file management & more advanced programming with the latest features of DOS version 5 822008.....• ~······················$34.95 Beginners will find Just what they need to become proficient with 1·2•3 In this stepby•step guide. Provides a clear presentation of program fundamentals. Offers practical, business-oriented examples, numerous screen shots, & quick steps to frequently used procedures Includes new Smartlcon Tips that highlight handy shortcuts THE FIRST BOOK OF WINDOWS 3.1 second edition. Simple Instructions show readers how to navigate, customize, & manage Windows plus gain maximize performance with the Windows accessories. Learn how to use the popular programs for Windows & run standard DOS applications 822002 ........................$34.95 822006•...•........................••.$34.95 ,l,? i. -, ~- Tl1• flrnt Boct or \V( )l<DPt•'.Rl<'l•X;r 5.1 I 1...... THE FIRST BOOK OF WORDPERFECT 5.1 Offers easy to read, conslce Introduction for first time users as well as a handy reference for experienced users. It covers all of the latest features of this newest release. Quick steps, key notesreference tables &reviews are Included to help guide the reader quickly through the text. 822000...................: .•..••..•.$34.95 i THE FIRST BOOK OF EXCEL 4 THE FIRST BOOK OF WORDPERFECT 5.1 for WINDOWS Excellent beginner's guide for Wordperfect•s newest product. Easy•to•use quick step lessons take the reader through the most Important functions. Users then move on to more advanced subject, such as automating WordPerfect with macros & formatting style sheets. version to 1.1. 822004 ..••.•....•... $34.95 The step-step style provides readers with a quick, practlcal, approach to learning this popular spreadsheet for Windows. • Teaches users how to Implement the basics of the programs functions. • Covers setting up spreadsheets, databases, & charts as well as Including graphics. • Includes FY Idea notes for using features in a new way. 822010 ................ $34.95 FOR QUICK TIPS AND HANDY HINTS YOU CAN'T BEAT THESE QUICK REFERENCE BOOKS WORDFOR WINDOWS2 QUICK REFERENCE The beat selling quick guide to uaing Word for Window• 2. • Alphabetic listings mak• command• easy to find. • Provides an overview of Word for Windows Basics • Includes tipa on the draw feature and graphic integration• 823000 .......................$19.95 PCTOOLS7 QUICK REFERENCE Extensive reference for all users of DR DOS. • Alpfabetized commands explain syntax, •wltche ■, and other parameters • Includes the ViewMAX Shell command map. Provides common configurations files 823002 ..•.........•...•••..$19.95 DOW UICK EFERENC The quick guide to using Excel for ·Windowel • Provide• alphabetical liatings to make commands easy to find • Features a sections on Excel basics • Covers Worksheets and macro functions. A compact & instan reference for the m often used comman test enhancements ling utilities prog miller with the lea at can make file ma 1cient & more effec 21302 ••..•....•.. 823004 .................... $19.95- Mlt--•1:1 Alphabetic . listing make information easy WINDOWS 3.1 QUICK REFERENCE to ftndl • Covers EDIT, configuration system, and batch commands Helpa readers determine proper syntax and use of DOS commands • lnclues batch flies and keyboard shortcuta 166 pages. . Ths quick and easy reference to all Windows commands) Alphabetical listings ere task oriented • Include• tlpa and cautions • Provides step-by-etep procedures for maJor Windows featurea. 821267........... $19.95 821306 .....................$19.95 WordPerfect 5.1 QUICK REFERENCE • Instant reference for vital operations • Alphabetical listing make Information ea to find. 1268........ .. information that makes 1-2-3 speadsheets, graphs and reports effeicient and effective. • Create detailed worksheets • General<, full featured graphs and reports • Track your income and expences • Enhance your worksheets with the Wysiwyg features. • Speed up your 1-2-3 operations with Smarticona. 821264.................... $19.95 IC ENCAPSULATED SOLAR CELL MODULE SOLAR BICYCLE WARNING LIGHT AND BATTERY CHARGER. for 2 'AA' size batteries 219056 ••• ~,--··--·:·····$19.95 11111,, 0.45V 200mA These are ideal for simple solar experimemts. Can be connected with other solar cells. 219001 This Is a great starter kit consisting of a 0.9V 400mA aolar cell and a small motor with a 48" wi111. Great for beginner or just the curious! ,. ..._, 219040 ................ $9.95 RECHARGABLESOLAR GARDEN LIGHT Automatically turns on & off at night & day. • Detachable solar panel for indoor & outdoor use. • Unique protection for low voltage discharge circuitry makes charging quick & easy •Easy to install, equipped with accessories for easy assembly. Place It beside the house number, pathway, or in the garden, S PEEDY CHARGING : ONLY 6 HOURS OF CHARGING WILL GIVE 12 HOUR OF USE AT NIGHT. SOLAR/ DYNAMO RADIO SOLAR CAR BATTERY CHARGER Never worry about your car battery going flat when left without being used over a prolonged period of time. Simply place the solar power unit on your dash or near a window In your garage and plug It Into your car cigarette lighter. The unit consists of solar cell• In a housing with 1 metre of cable and cigarette lighter plug. :"li1ft;._~ \. . 219054 •• "'"'""'"" ...$29.95 I--~ ;1 KEYCHAIN BATTERY ANALY2ER FOR TESTING ALL SIZES OF BATTERIES 219062 •••••••••..•••••.•• $4.95 SOLAR PANELS ON SPECIAL THIS MONTH! ' "'· OY~:~~~9:elii 8"'f 'SAVE' jjij : ~ ,~~<;, 'l " 12V. Voc 16V (max) 18V lsc 400mA (max) 500mA WAS $99.00 Z19028 .... NOW $89.00 ;~! 0 ~i·:, - 6 12V Voc 16V (max) 18V lsc 800mA (max) 1ooomA WAS $199 Z19036 .... NOW.$179.00 - ·~-~ ~ ,~~"' . off~~~o~~~­ 'l'•t SOLAR BATTERY .CHARGER FOR 'AA' SIZE BATTERIES Z19050 .. ................$12.95 • Copy area 9 1/2" x 11" • Sliding line glide • Flat metal base 021000 ....... ~ ; · SOLAR MUSICAL KEYCHAIN WITH LIGHT. Never lose your keys again with this clever little device. The solar powered keychain with light will let you find where you left your keys where you left them just by listening to music. The solar powered light will always let you find that illusive keyhole In the dark. A very handy Idea and all run on FREE powerl 219060 ..•••••••••••.•.••.$4.95 219060 ..................$39.95 Build great llttle solar powered wooden models with this kill There are 3 different model• to choose from a helicopter with working motor, aeroplane with working motor and gramophone that plays music. Each kit contains • set of precut plywood, PVA cement, assembly instruction aheet, solar cell module, musical IC or small DC motor, wire and aand paper. 219044 Aeroplane •••••••••••$17.95 219046 Gramophone ••••.•$17.95 219048 Hellcopter..•...•....$17.95 ENERGY KIT Learn what Solar power ia. With this great kit you can make an electrical circuit Learn how to increase voltage, increase current. 219040....... .. .............$9.95 MEMORY EPROM Cat No. Type Price U20550 2716 ...... $11.75 U20560 2732...... $9.00 U20590 2764 ...... $6.95 U20540 27128 ....$7.50 U20542 27256 .•.• $9.00 U20544 27512 ....$12.50 12V 16V (max) 18\1" ""'-''-',__. lsc 1200mA (max) 1500mA WAS $299 219038.......... NOW .$259.00 Never be caught short of power again. 4 power sources, Solar dynamo by manual winding, DC and battery. 219064 ..•• $49.95 NEW GENIUS SCANNER 4500 I/ COPY HOLDER YU- H32 _.{ Adjustable arms allows easy positioning ·• Copy area 9 1/2" x 11" ." Sliding line glide • Clamping Mounting C21062 •••...••••••••••... $39.95 CMOS EPROM Cat. No. Type Price U20591 27C32.... $14.95 U20592 27C64 .... $5.50 U20593 27C128 •. $7.50 U20594 27C256 .. $9.00 U20595 27C512 ..$11.50 U20546 27C010 .. $22.50 SIMM SOCKETS ~ 1-.1 _ - -~-r-~ J SINGLE P10536 ..... $5.95 .• ~-;,______ . __._j ~ ~?vwmm+omL'tfttlrtettlttttr-• - - ~ Black, White & Grey• Emulation scanner with powerful Photo/Image Editor & Multilingual Omnifont OCR. Three grey emulation modes allows you to bring excellent reproductions of pictures Into your reports, brochures, ate.Perfect tor scanning line art. Scan objects in resolutions from 100 to 400 dpl. GRIP CLIP COPY HOLDER • Attaches to the top your monitor • Put your copy right where you need it • Spring clip to hold paper • Velcro at mount for easy removal C21065 •••• •••.•••..••••••$14.95 The RITRON POWER 200 is a pocket sized Inverter with punch. It will power a myriad of appliances Including TV's, Video's, drills, lights, laptops and computers, just to name a few! Continuous power rating Is 140 watts, However it will run most appliances with a name plate rating of 200 watts. Surge rating is a very real 400 watts . several scans. It can even DEALER & WHOLESALE ENQUIRES WELCOME. $299.00 INTEL CO-PROCCESSORS ■ Cat No. U21841 U21851 U21854 U21855 Type Price 287XL $210.00 387DX $459.00 387SX-16 · $310.00 387SX_:-2~~.oo 3 /12"PLASTIC • DISK HOLDER • Holda 5 disks Comes In 6 different colour• C16050 Red C16054 Yellow C16052 Orange C16056 Green Cl 60S8 Blue C16060 Grey Only ..............$3.50 Each. • Holda 6 floppy This package includes the GO-CR Optical Character Recognition (OCR) program. GO-CR scans text Images into computer readable text files. The multilingual capabilities allows you to recognize documents in any one of 80 languages. GO-CR is the supreme PC typist! Edit, enhance and design professional•q uaility images with iPhoto Deluxe. Combine Images from ............ PLASTIC DISK HOLDERS 5'/4" PLASTIC [ DISK HOLDER / ] ·' · . GO-CR :~::~:t~~~~:~~~!c:l~ite format. The ease of it's Windows based operation makes the power of this professional utility accessible to everyone. DOUBLE P10538............$6.95 These are good quality SIMM aockets with metal clips at the ends and not the plastic one• which tend to break. ..........................$159.00 DON'T PAY ~ O . disks C16030..... $3.50 51/4" DISK STORAGE CASES • Made of Sturdy illack flexible plaatlc. • Holda 10 or more 5 1/4" diaka. • Display poaltlona 1·9 10+ c, 2820........... $3.95 $3.50 MEMOREX 3.S"Plaatic disk . ~ --.·.·,, ~ . 1 ~~ •~~~'." :ie:s 10 Disks C12840 ..... $3.95 For recreational vehicles & farms A 2kW 24V/240VAC This high power inverter can deliver 2000 watts (continuous) at 240VAC. It operates from a 24V battery supply to produce a sinewave output - the same as from the 50Hz AC mains supply. The availability of 240VAC mains power is almosta prerequisite for modern living. We rely on it for powering such items as refrigerators, washing machines, microwave ovens, power tools and hifi and video equipment. In fact, just about all domestic appliances are designed to operate from mains power. It is only when mains power is unavailable that its importance is fully realised. At remote building sites, mains power is required for circular saws, drills and sanders, while many farm houses and sheds are unserviced by mains power simply because the cost of bringing the power in from the national grid can be prohibitive. The only practical alternatives to mains power are either motor generators or a solid state inverter. Motor generators work well but they are expensive to run, cause air pollution and can be noisy. By contrast, an in- verter is completely silent and causes no pollution. It can operate from a battery bank which is charged by a solar cell array. Up till now though, there have been few high power inverters available and most have not had sinewave output. To our knowledge, this is the first really high power inverter to be described in any magazine throughout the world and it is certainly the first do-it-yourself design to produce a genuine sinewave output. Basic waveforms Fig.l(a) shows the sinewave output of the new inverter. It has a peak output of close to 340V, similar to that from a normal 50Hz mains supply. Most commercial and kit inverter designs on the market provide only a square wave or a modified square wave output (Fig. lb & Fig. le). This type of waveform may not be suitable for powering all appliances and may result in the appliance overheating or malfunctioning. To understand why this can happen we need to examine the differences between a sinewave with an RMS value of 240VAC and a square wave with the same RMS value of 240VAC. For the sinewave, the peak of the waveform is just under 340V while for the square wave it is only around 240V. As an improvement on this, the modified square wave is often used to provide a higher peak voltage. To maintain the 240VAC output, the duty cycle of the waveform is decreased. The lower peak voltage from the square wave inverter can be a disadvantage when powering appliances which rely on the peak voltage being at 340V. Any appliance which uses a rectifier and filter to obtain a DC voltage for its internal power supply usually depends on the peak voltage for correct operation. Examples of these appliances are hifi equipment, TVs, VCRs and microwave ovens. On the other hand, many TV sets and most computers use switchmode power supplies and most of these can function satisfactorily with the lower peak voltages provided by square wave inverters. The reason they do so is simply because they are designed to +300V +240v- -240 V (b) SQUAREWAVE -300V (a) SINEWAVE Fig.I: many DC to AC inverters produce a square wave (b) or a modified square wave (c) instead of a sinewave as in (a). This can lead to problems when driving some types of equipment, such as electric motors. · 16 SILICON CHIP (c) MODIF IED SQUAREWAVE By JOHN CLARKE Sinewave Inverter This project sponsored by Rod Irving Electronics, 1992. The 2kW sinewave inverter will power fridges, washing machines, microwave ovens, power tools, lights & video/hifi equipment. It runs from 24V DC&, used in conjunction with a solar panel array, could form the basis of an electricity supply system on farms & in other remote locations where no mains supply system is available. function over a large range of mains voltages. Electric motors can also present problems when driven by square wave inverters. The high harmonic content can lead to higher power dissipation in the motor and more buzz from the windings and laminations. In commutator motors, the low peak voltage can result in a lower top speed, while the lagging power factor can cause problems for induction motors be- cause the motor will be drawing substantial current when the drive tran~ sistors are being switched. While lagging power factor in induction motors still presents problems for sinewave inverters, this new design has enough power to start and run just about any domestic appliance using an electric motor (apart from airconditioners). In normal use, we expect that this inverter will be used to power fridges, washing machines, vacuum cleaners, TVs, VCRs, lights , microwave ovens, power tools and video and hifi equipment. We would not normally expect it to be used to power appliances such as electric jugs, frypans or radiators since it would be far more efficient to use nat)-lral gas or LPG for heating and cooking. Physical dimensions The new sinewave inverter is not a small package and nor could you expect it to be since it delivers such high power. It is large and bulky. It measures 452mm wide x 170mm high x 400mm deep and weighs 12kg. On OCT0BER1992 17 the lefthand side of the front panel is the DC power switch, LED power indicator and fuseholder while at the right is the double general purpose output (GPO) socket. At the rear of the fabricated aluminium enclosure are the heavy duty cables for connection to the 24V battery. These carry DC currents of more than 100 amps at full load. Both the left and righthand sides of the case carry large vertical heatsinks to dissipate the heat from the switching devices in the inverter circuitry. Not only is the inverter case large and bulky but the circuitry inside is heavy duty. As already noted, it draws input currents of more than 100A at 24V and this is used to generate voltages as high as 3 70V DC. This high voltage means that this inverter must be treated with the same caution and respect as the 240VAC mains supply. Fig.2 shows the basic arrangement of the inverter circuitry. 24V DC from the battery is stepped up to around 365V DC in a transformer driven DC to DC converter. This high voltage then feeds a switchmode sinewave converter which essentially chops up Specifications Input voltage ...... ............ .. ............... 22 - 28VDC (24V lead acid batteries) Output voltage ............... .. ...... .. ..... ... 240VAC sinewave (EMI suppressed) Power rating ............ ... .. .. ........ ................................ .... ...... 2kW continuous Peak power ... ... ...................... ... ... ... ................... ........... .. ... 3kW for 300ms Standby current ...... ..................... ....... ... .. ... .................... .............. . 3 amps Full load cu rrent ................................... ................ ... ...... .... .. . 114 amps DC Output regulation ...... ... .. ... .... ... .... .......... .. .................... .. ................... < 8% Efficiency .... ... ........... ... .. ... .. ......... .. .... ........................ ......... > 80% at 2kW Harmonic content ..... .. ................................ .................. .... < 10% distortion 50Hz accuracy ... ... .... ..... ............... ............ ................. .... ...... crystal locked 24V BATTERY - DC TO DC CONVERTER 24V TO 36SVOC - SWITCH MODE SINEWAVE CONVERTER - FILTER - 240VAC OUTPUT Fig.2: the block diagram of the 2kW sinewave inverter shows that it involves two processes; DC to DC conversion and DC to sinewave conversion. the 365V DC to form a pulse train with a duty cycle calculated to give the same RMS value as a 240VAC 50Hz sinewave. This varying duty cycle pulse train is then fed to a filter to remove all the high frequencies, leaving an essen- tially clean 50Hz sinewave. So in effect, there are two processes: DC to DC inversion and then DC to AC sinewave conversion. Because the DC to DC inverter runs at a high frequency, as does the sinewave conversion process, there is no MOSFET DRIVERS AND CONTROLLER 24V BATTERY STEP•UP 1--...........i TRANSFORMER x1B HIGH VOLTAGE FULL WAVE RECTIFIER HIGH VOLTAGE FILTER 1--CAPACITOR +36SV ---<t---------+--......- - - - - -- -~ ISOLATED VOLTAGE FEEDBACK SWITCH 1 A SWITCH 2 L1 SWITCH MODE SINEWAVE GENERATOR 0 y C SWITCH 3 0 DY Fig.3: this more detailed block diagram of the 2kW inverter illustrates the isolated voltage feedback system and the H-pack output drive which provides the sinewave conversion. 18 SJUCON CHIP L2 C1 X MAINS GPO This inside view of the prototype 2kW inverter was taken at a late s.tage of its development. In the lower section of the chassis is the large high-frequency transformer which is driven by the circuitry immediately below it. In the top lefthand corner is the high voltage rectifier & filter capacitor & the sinewave filter circuitry, while at top right is the PROM-based sinewave generator circuitry. Note the 100-amp cartridge fuse in the bottom lefthand corner of the chassis. The vertical board at the top of the photograph carries the H-pack switching devices. OCT0BER1992 19 vx DV 1Dms 1Dms VY OV t - - - -- - -- - --- +365V "------ 50Hz FILTERED SINEWAVE provides us with an accurate and precise 50Hz sinewave. The way in which points X and Y are switched is depicted in the waveforms of Fig.4. The top waveform shows the voltage at point X (Vxl while the second waveform shows the voltage at point Y (Vy). The difference between these two waveforms is the voltage between points X and Y and when this voltage (Vxy) is filtered by the output filter consisting of Ll, Cl and L2, the result is a 240VAC 50Hz sinewave. In effect, Fig.4 shows point Y being held high for the first 10ms while point X is rapidly switched between 365V and 0V. For the next 10ms, point X is held at 365V while point Y is rapidly switched between 365V and ov. Fig.4: the switching process used in the H-pack drive circuit. The switching sequence for half the sinewave is stored in memory and the resulting difference between Vx and Vy is Vxy which becomes a 50Hz sinewave after filtering. large and heavy 50Hz ZkW transformer employed. Such a transformer could be expected to weigh 25kg or more. The DC to DC inverter does employ a transformer but it is a high- frequency design weighing less than 3kg. Detailed block diagram Fig.3 shows a more detailed schematic arrangement of the inverter. Here the 24V battery voltage is fed to the just mentioned high frequency step-up transformer which is driven by power Mosfets in a push-pull configuration . The step-up ratio is x18 and the resulting AC voltage is rectified by a full-wave bridge and filtered with a high voltage capacitor. · The optically-isolated voltage feedback circuit adjusts the duty cycle of the Mosfet switching so that the DC voltage from the inverter remains more or less constant regardless of the load current. Readers may be wondering why the transformer step-up ratio is x18 when this multiplied by the 24VDC input will give 67V more than the required 365VDC. The extra leeway is needed to make up for losses in the inverter, the rectifier diodes and the filter so that we can still obtain around 365V at the full 2kW load. The 365V supply rail is floating with respect to the 24V battery termi20 SILICON CHIP nals to provide full high-voltage isolation. This isolation is provided by the insulation between the primary and secondary windings of the transformer and the optically coupled voltage feedback. This prevents the battery terminals from being at a high and lethal voltage above ground should a fault occur in any equipment powered by the inverter. Sinewave converter Across the 365V DC supply rail are connected four switches, in an H-pack configuration. Switch 1 is in series with switch 3 and switch 2 is in series with switch 4. The junction between switch 1 and switch 3 is point X and the junction between switch 2 and switch 4 is point Y. If switch 1 is turned on and switch 3 is off, point X is pulled up to 365V. Conversely, if switch 3 is on and switch 1 is off, then point X is pulled down to 0V. Similarly, point Y can be pulled up to 365V or down to 0V, depending on the closure of switch 2 or switch 4 respectively. The switchmode sinewave generator has four outputs which drive switches 1, 2, 3 and 4. The duration and sequence of switching are stored in a Programmable Read Only Memory (PROM) which is driven by counters clocked by a crystal oscillator. This Notice that the series of switchings between 365V and 0V varies from very narrow 0V going pulses at the start and end of the sinewave half cycle to being at 0V for almost all of the time at the peak of the sinewave. The switching sequence stored in the PROM actually only gives half the sinewave but when the difference is taken between the voltages at points X and Y we get the full sinewave. To make the waveform diagrams of Fig.4 easier to read, we have shown only 10 switchings for each 10ms period whereas there are actually 40 switchings per 10ms halfwave interval, or 80 switchings per 50Hz cycle. In other words, the four switches of the H-pack circuit are switched at 4kHz, with a constantly varying duty cycle. Full high-voltage isolation is provided between the sinewave generator outputs at A, B, C and D and switches 1, 2, 3 and 4 across the 365V DC supply. This is achieved by using fast optocouplers for the signals and miniature transformers to supply the necessary power required for each of the switches. Switches 1, 2, 3 and 4 are high power insulated-gate bipolar transistors (IGBTs). These have a very high voltage and current rating and are superior in this application to power Mosfets. Only four of these devices -are used in the H-pack circuit and they provide the full 2 kilowatt output from the inverter. Next month we shall continue the circuit description and feature the full parts list. SC Whether you speak 01010011 or analog, Philips provides you with a complete analog and digital oscilloscope in one instrument. With a sampling rate of 200 megasamples per second and a bandwidth up to 200 MHz our easy- to-use 4-channel oscilloscopes represent state-of-the-art technology. With direct access functions. Innovations like a probe mounted button which allows you to recall set ups. Perform Autoset. Freeze display as well as display measured results. In the analog mode, extremely fast update and infinite display resolution allow you to see three dimensionally. For instance, the distribution of time-jitter. The digital mode is impressive. Logic triggering creates a true 4-channel logic analyzer, It is prepared for HDTV triggering. The powerful DSO specifications give you extensive trace storage possibilities. And processing capabilities like FFT. At Philips, we're on your wavelength. Which is why we promise you one thing. You'll measure better performance For furthe r information please contact your local Philips Test & Measurement Organisation : SYDNEY (02) 888 0416 MELBOURNE (03) 881 3666 PERTH (09) 277 4199 WELLINGTON 104) 88 9788 BRISBANE 107) 844 0191 ADELAIDE (08) 348 2888 AUCKLAND (09) 89 4160 PHILIPS Build a multi-sector burglar alarm, Pt.2 Last month, we described the features of this versatile home burglar alarm & gave the circuit details. In this article, we show you how to build & operate it. By MIKE ZENERE Because it's built around a microprocessor and relies on software , the circuit uses relatively few components for such a versatile unit. In fact, by making some slight software changes, two more features have been added to the unit since last month. First, the user can now select whether or not power is maintained 22 SILICON CHIP to the remote keypads during a mains failure. Previously, the user had no choice; if the mains failed, the remote keypads could not be used and the backup battery only supplied power to the main keypad. You can now elect to maintain power to the remote keypads, although this will decrease the battery back-up time. Second, the user can now select whether or not the unit beeps when an entry is detected, prior to sounding the main alarm. If you're the sort of person who always remembers to turn an alarm off, the warning beeps can be disabled. The choice is yours. There's also been a slight change to the main circuit (Fig.2) that was published last month. First, a larger relay with higher-rated contacts has been substituted for the original unit and this has necessitated the addition of a simple 1-transistor driver circuit- see Fig.5. Second, a LED (LED 1) and a lkQ series resistor has been connected to pin 28 of ICl. This LED is used to confirm that the oscillator based on IC2e is operating correctly before the MCU (!Cl) is plugged in, but otherwise plays no part in the circuit operation. The necessary changes have been made to the relevant PC board. Most of the assembly simply involves installing parts on the PC boards; there is very little interboard wiring involved: However, it is important to follow the procedure outlined below, as certain sections are assembled and tested before moving on to the next stage. Processor board assembly Construction begins with the processor board (Fig.6) and its numerous individual circuits. First, install all the links, PC pins and terminal blocks. This done, install the following parts: BRl, Cl, C2, C31, C32, Rl, R2, R3, R8 (mounted 10mm above the board), D17, ZD4, D2, D3, D16, FCl, FC2, FC3, FC4, FC5, FC6, FUSE 1, FUSE 2 & FUSE 3. When all these parts are in, attach REGl and REG2 to their heatsinks as shown in Fig. 7 and then mount the two regulators on the board (be careful not to transpose them). You are now ready to test the power supply circuit. To do this , connect the 16VAC plugpack supply to the board with a l0Q 1W resistor in series with one of its leads. This resistor will limit the current if there is. a short on the board. Apply power and check for the following DC voltages: (1). Positive terminal Cl = 20V (approx). (2). Output of REGl = 5V. (3). Output of REG2 = 15V. (4). Pin 7 ofTBl = 15V. (5). Pins 3, 6 & 7 of ICl = 5V (6). Pin 14 of IC2 = 5V. (7). Pin 20 of IC3 = 5V. (8). Pin 14 of IC4 = 5V. If all of the above are OK, switch off the power and install R3, R4 (mounted 10mm above the board), R5-R13 (but not R8), R20-R22, R62-R65, C6, C7, Ql-Q4, Qll, Q12, Dl, D4-D8, ZD3 and the battery leads. Now install temporary links between (1) the +5V output ofREGl and the anode ofD4; and (2) the output of REGl and pin 19 of ICl. This will enable you to check the battery charge circuit. Apply power and check for the following voltages: (9). Positive lead of battery= 14V (approx). (10). Voltage across R4 = 0V. (11). Collector ofQl = 19V (approx). (12) . Cathode of ZD3 = 14V (approx) . r-------.-+12V 013 PN200 Fig.5: the modified relay driver circuit. The circuit is driven by the PB5 output (pin 17) ofICl. (13). Collector of Q4 = 0V. (14). Pin 1 of TB3 = 15V (approx). Now connect the leads to the battery with your multimeter in series with one leg of the circuit and check the charging current. It should be somewhere between 0mA and 35mA. If this checks out, remove the meter from the circuit, reconnect the battery and check that the following voltages are correct: (15). TBl pins 11 and 12 = 12V. (16). Output terminal of REGl = 5V. (17). Pin 7 ofTBl = 12V. (18). Pin 1 TB3 = 12V. Assuming these values are OK, remove the 5V temporarily applied to G) Fig.6: parts layout for the processor board. It should be assembled & tested exactly as described in the text. OCT0RER1992 23 HEATSINK 10220 DEVICE NUT ~ ~ i l SIL;AD ~ SCREW j lllIIlllI{3 Fig.7: attach REGt & REG2 to their heatsinks as shown in this diagram. The "silpad" is there to aid heat transfer. D4 and pin 19 ICl and do the following checks: (19). Collector ofQ3 = 12V (approx). (20). Collector-emitter voltage of Q2 = 1V (approx). (21). Voltage across R4 = llV (approx). (22). Pin 1 TB3 = 0V. If all of the above are correct, switch off, remove the temporary links, and corn plete the board assembly. A socket is used for ICl but before this is soldered in, make sure that D4 is in place, as it sits under the socket. Display board assembly Fig.8 shows the assembly details for the display board. Initially, all of the parts can be soldered into place, except for the display and the three ICs. Note that the beeper (BEEPl) is soldered to the copper side of the board and that the LEDs should all be mounted above the board so that they will later protrude through the front panel - see Fig.9. Check that all LEDs are correctly oriente::d; the anode lead is always the longer of the two. The keypad is mounted flush against the board by removing its mounting tabs and securing it with a small amount of adhesive . Short lengths of tinned copper wire are then used to make the connections. This done, locate the two 16-way IDC connectors and crimp both plugs on to the ribbon cable as shown in Fig.10. Make sure that pin 1 of the first connector is terminated to pin 1 of the second connector, as a wrong termination will cause disaster on the display board. The two IDC connectors can now be soldered to the processor and display boards. Now power up and check for 5V at the following points on the display board: pin 8 ofJl ; pin 20 oflC1 & IC2; and pins 3, 5, 9 & 18 of DISPl. If all is OK, switch off and solder in the ICs and the display, noting that pin 1 of this device is as shown in Fig.11. Be careful - there are no second chances with this chip. Before plugging in the MCU, it's advisable to take a few extra moments to test the rest of the circuit. To do this , first install lOkQ resistors between the 12V outputs ofTBl and the siren and strobe light outputs. This done, install a lOkQ "end-of-line" re- sistor on each of the sector inputs (ie, between each sector input and the input ground). Apply power and check the following on the processor board: (1). LED 1 should be flashing on and off at around 2Hz. (2). Pin 2 of ICl should have a waveform on it of 50Hz at 2V p-p (check using an oscilloscope), while pin 6 of IC2 should be oscillating at a high frequency. (3). Pins 3, 4, 10 & 11 of IC4 should all be at 5V. Now short out all four of the lOkQ end-of-line resistors in turn and check that pins 3, 4, 10 & 11 of IC4 are all at 0V. If one of the outputs does not go to 0V, check the circuitry around the relevant gate carefully. If everything is OK, remove the shorts from the resistors. Installing the MCU Switch off the plugpack and make sure that the battery is disconnected. You are now ready to plug in the MCU (ICl) but make sure that it is correctly oriented. Apply power again and check that the reset status LED (LED 1) now stays on. If it does, this indicates that the processor is correctly servicing its interrupt routine once every 20ms. At the same time , the alphanumeric display on the display board should flash the message "UNIT OK", while all the LEDs on this board should be off. If the reset status LED continues to RESISTOR COLOUR CODES I I I I 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No. Value 4-Band Code 5% 5-Band Cod_ e (1%) 1 2 1 1 8 2 8 23 3 11 7 1 14 1 1 1 1 1 820kQ 470kQ 220kn 180kn 150kQ 100kQ 75kQ 68kQ 47kQ 10kQ 4.7k.Q 1.5k.Q 1k.Q 270Q 100.Q 33Q 15Q 3.9Q grey red yellow gold yellow violet yellow gold red red yellow gold brown grey yellow gold brown green yellow gold brown black yellow gold not applicable blue grey orange gold yellow violet orange gold brown black orange gold yellow violet red gold brown green red gold brown black red gold red violet brown gold brown black brown gold orange orange black gold brown green black gold orange white gold gold grey red black orange brown yellow violet black orange brown red red black orange brown brown grey black orange brown brown green black orange brown brown black black orange brown violet green black red brown blue grey black red brown yellow violet black red brown brown black black red brown yellow violet black brown brown brown green black brown brown brown black black brown brown red violet black black brown brown black black black brown orange orange black gold brown brown green black gold brown orange white black silver brown SILICON CHIP ~ --ao- G r--7 r--7 -aa- c,::= IC3 --aD---CID------CBD--- L.f"'W ; L.f"'W LEm ® LED2 ® . cs::= [ L[D3 ® LED4 ® LEDS ® KEYPAD! LED8 ® N□ T USED LJ Fig.8: the display board accommodates the keypad, the alphanumeric display & a handful of other parts. Jl accepts one end of the 16-w ay header plug. flash , ch eck the watch dog circuit for mistakes. If none are foun d , you can temporarily disable th e watch dog circuit by placing a lkQ resistor in parallel with R14. This will cause the processor to come out of the reset state and you w ill be able to test for th e fo llowing: (1) . On th e processor board: (a) continuous data on pins 8-1 1 and 20-2 7 of the MCU; and (b) data on pin 19 of IC3. (2) On the display board: (a) data on pins 2-9 and 11 ofICl an d IC2; an d (b) data on pins 1, 2, 6 -8 and 11-17 of DISP1. . Mounting the boards The two PC boards can n ow be in stalled in the case. This is suppli ed pre-pu nched for easy assembly. First , peel the backing off th e label and carefu lly affix it to the front panel. Th e display board is now mounted on th e back of th e li d on 6mm standoffs and secured using seven M3 x 5x5mm LEDS Fig.9: mount the LEDs on the display board exactly as shown here, so that they later protrude through the 'front panel by the correct amount. Kit Availability A complete kit of parts for the home burglar alarm is available from the author. This kit includes all elec. tronic components, the PC boards, a pre-punched case with the front sticker, mounting hardware , a 16VAC plugpack supply, and the 12V 2.6Ah battery (remote keypads not included). The price is $195 plus $16 p&p, or$175 plus $16 p&pwithout the case. Kits for the remote keypads are available at $44 each (includes all parts) . Completely assembled and tested units are also available. These are priced at $240 for the alarm panel and $50 each for the remote keypads. What if you can't get it going? If that happens, the PC boards only can be returned to the author, along with a cheque for $35 to cover the cost of repair. This fee covers return postage, labour and all parts except for the microprocessor. The author reserves the right to return any boards and the repair fee if the boards have been so badly assembled as to make repair too difficult. The following accessories are also available (prices include p&p). Passive infrared detectors (1) Rokonet 3001 PIRO, 64 x 44 x 35mm-$65. (2) Rokonet 6000 PIRO, 105 x 65 x 46mm-$72. Glass breakage detectors (1) C+K OualTec, 7.6-metre range, 95 x 62 x 19mm -$70. (2) C+K FlexGaurd, 4.5-metre range, 98 x 61 x 20mm - $63. Miscellaneous Horn speakers- $12. Strobe light - $25. Piezo siren - $17. 4-core cable (for PIROs), 100metre roll - $42. Figure-8 cable (for strobe light, siren , etc), 100-metre roll - $20. HPOL 2416 alphanumeric display - $16. Please make cheques payable to Michael Zenere, 7 Hayfield Rd, Mt Waverley, Victoria 3149. Telephone (03) 803 1831. Allow up to 15 working days for delivery. Alternatively, kits and assembled units may be purchased directly from the above address. Note: copyright of the PC artworks associated with this project is retained by the author. OCTOBE R1 992 25 and solder one lead of each LED only. This done, remove the cardboard and align the LEDs before soldering the remaining leads. The second line of LEDs can now be installed in the same manner. Once the LEDs are in, the remaining parts can be installed on the board. Bend the leads of the regulator (REG1) so that it lies flat against the PC board (see photo). A 28 -pin socket is used for the MCU (IC1) but don't insert the IC just yet. Note that because parts must be mounted under the IC, the socket will have to be cut into two single rows - see Fig.12. The wiring can now be completed by running seven 8cm-long leads between the board and the keypad. The eighth terminal on the keypad (adjacent to the "3" button) is not used. Remote keypad testing Take great care with the orientation of the alphanumeric display (DISPl) when installing this part on the PC board (see Fig.11). The keyboard is secured to the PC board by its connecting links & a small amount of adhesive. 12mm countersunk screws and nuts. This job will be easi er if you install the middle standoff and mounting screw assembly first. The four 10mm tapped standoffs are used to mount the processor board on the rear panel and are secured to the case using four M3 x 6mm countersunk screws. This done, use four M3 x 6mm panhead screws to secure the board to the spacers, then install the 6.5mm rubber grommet in the power entry hole. Run the plugpack cable through this grommet, clamp the cable so that it cannot be pulled out, and solder the wires to the PC pins. Finally, attach the battery leads to the battery and close the lid. Keypad construction Fig.12 shows the assembly details 26 SILICON CHIP for the remote keypads. Start the assembly by installing the parts that go under the MCU. These include the crystal (XTALl), resistors R7, RB & R9, and capacitors C3 & C5. When this has been done, the seven LEDs can be installed. These are in two rows. The top row consists of three LEDs and these are, from left to right: green, orange and red. The bottom row, from left to right, consists of three orange LEDs and one red LED. The LEDs must all be mounted exactly 15mm above the board (ie, so that their tops are about 20mm above the board). To do this, cut a 15mm wide cardboard strip about 40mm long and thin enough to fit between the legs of the LEDs. Position this strip of cardboard edge-on along one line of LEDs, then install the LEDs over it At this stage, it is a good idea to do a preliminary test of the board. This is done by applying 10-15V to the terminal block and checking for the following voltages : (1). Pins 3, 6 & 7 of IC1 = 5V. (2). Pins 1 & 2 of IC1 = 0V. (3). Pins 20, 21 & 22 of IC1 = 5V. If these checks are OK, disconnect the power and install IC1. Now reapply power and check that the green LED lights (all other LEDs off). Testing of the keypad is now complete and the unit may be installed in its plastic case. The plastic case is supplied partially drilled; all you have to do is make the hole for the keypad. This is quite straightforward since the shape of the hole· is scribed into the plastic on the inside of the lid. To make the hole, drill a series of small holes around the inside perimeter of the marked area, then knock out the centre piece and file for a smooth finish. The four 10mm tapped spacers can now be secured to the bottom of the case using M3 x 6mm countersunk screws - see Fig.13 . This done, attach the keypad (via its tabs) to the inside of the case using superglue (top towards the three LEDs) . Finally, secure the PC board to the spacers using four roundhead M3 x 6mm screws and clip the two halves of the case together. Setup & operation As well as turning the unit on or off, the front panel keypad is used to Introducing the Tektronix 2212 Value Priced at $345 0 * Real Analog - Real Digital Storage No Compromise ■ 60 MHz Bandwidth ■ Analog ■ Auto and Digital Storage Operation setup ■ 20MS/sec Maximum Digitizing Speed ■ On - Screen Parameter Readout ■ 4K Record Length ■ Parallel Printer Interface (STD) ■ 2 1Ox Probes Included ■ Fully Programmable via RS-232/GPIB (Opt) ■ 3 Year Warranty 0 For further information on Tektronix 2212 Portable Oscilloscope Call Toll Free (008) 023342 or contact your local Tektronix office. Tektronix /rest and Measurement Sydney (02) 888 7066 Melbourne (03) 836 3355 Brisbane (07) 394 1155 Adelaide.(08) 223 2811 Perth (09) 242 4688 Canberra (06) 251 6111 *Price does not include sales tax. 16-WAY JDC CONNECTOR 16-WAY IOC CONNECTOR PIN 1 Fig.10: wire the JDC pin connectors to the 16-way cable exactly as shown here. This cable connects the display board to the processor board. WRli~~~ :1~iNG-I HPOL2416 DISPLAY LX DL2416 I ,-;-'I,~1I~I1---,---11 PIN'-r--1 Fig.11: pin 1 of the HPDL2416 display is adjacent to the type number that's printed along one side. select, view and modify a number of variables, and to perform the various test functions. There are two main buttons used to call up the different options and these are the function button (*) and the return button (#). The 0-9 buttons are used in conjunction with the(*) button to select the variable to be viewed. At the very first power up , the on/ off code is set to 6805. This code will also allow you to modify the preset variables. These variables and their initial settings (in brackets) are listed in Table 1. Note that the variables are locked in and cannot be changed unless the user knows the current on/off code. This was done for obvious security reasons. The five locked codes are the entry delay, exit delay, siren duration , on/off code and the soft switches. Let's assume that the unit has never been powered up. In this case, all the sectors will all be off; the entry delay, exit delay and siren duration times will be set to 30 seconds, 3 minutes and 3 minutes respectively; the on/ off code will be 6805; and the soft switches will be set to 019X (ie, the keypads will be disabled during mains failure; the unit will beep on entry; and the alarm can sound up to 9 times in one 12-hour period). The user now can decide which options, if any, are to be changed. RU R16 RI:! <at>~-<at>O<at>O. 0 Once these are programmed in, you can forget about them unless of course you wish to change them again. In everyday use, you'll only change the sector settings and turn the alarm on KEYPAD ~ TERMINAL BLOCK 'i"' e_oA_R_□--~□~/-cASE _ P_c ! M3x10mm TAPPED SPACERS ~~ M3x5mm CSK SCREWS a Fig.13: this sectional view & the accompanying photo show the assembly details for the remote transmitter. The keyboard tabs are glued to the top of the case using a suitable adhesive. or off using the 4-digit code. The test function will also be used occasionally to check the siren, strobe light and on-board relay. In most cases, you can use the default settings although you will want to change the on/off code. To do this , press buttons (* ) (8), note that the display flashes ****• and enter the current code on/off (initially 6805). The display will now show the current code with the first digit flashing. Enter the new code (eg, 5739), then press the(#) key to store the new code and exit the code setting function. To show you how quick and easy the alarm is to use, let's assume that you wish to activate the alarm with sectors 1 and 2 on. We'll also assume that, initially, all sectors are off and that on/off code is 5739. The procedure is as follows: First, activate the two sectors by pressing(* ) (1) (2) (#) - the two LEDs TABLE 1: ALARM PANEL OPERATION Buttons Initial Status Function Instructions (*) (1) Sector 1 on/off switch Off Press (*) (1) (#) to toggle sector 1 on or off. (*) (2) Sector 2 on/off switch Off Press (*) (2) (#) to toggle sector 1 on or off. (*) (3) Sector 3 on/off switch Off Press (*) (3) (#) to toggle sector 1 on or off. (*) (4) (*) (5) (*) (6) Entry delay setting Exit delay setting Siren duration setting 30 seconds Press(*) (4). Display flashes to show current setting (first two digits= minutes; last two digits= seconds). To change, enter on/off code. Unit now flashes first digit. Enter new entry delay period (0959 max.) , then press (#). 3 minutes Press (*) (5) . Display flashes to show current setting (first two digits = minutes; last two digits = seconds). To change, enter on/off code. Unit now flashes first digit. Enter new exit delay period (0959 max.), then press(#). 3 minutes Press (*) (6) . Display flashes to show current setting (first two digits = minutes; last two digits = seconds) . To change, enter on/off code. Unit now flashes first digit. Enter new siren period (0959 max.), then press (#). Digit 1: Remote keypad on or off during mains failure 0 (Off) Digit 2: Beep on/off during entry delay 1 (On) (*) (7) (*) (8) (*) (9) (*) (0) Digit 3: Alarm lockout count 9 Digit 4: alarm tamper setting 1 On/off code setting Past status indication Test mode: (1) Siren test; (2) Strobe light test; (3) Relay test 6805 Press(*) (8) . Display flashes****. Enter current on/off code (initially 6805) . Unit now shows code with first digit flashing . Enter new code , then press(#). None If the alarm has sounded, the memory LED on the front panel will be on. Turn off the alarm & press (*) (9) - hold the (9) button down. The LED(s) for the sector(s) that tripped will come & the display will indicate how many times the alarm tripped (up to 99 times). This feature is useful for tracking down a sector that intermittently false triggers. II 11 Press (*) (7). Display now shows the current state of the three soft switches (initially 0191 ). To alter, enter the on/off code. Set the first digit to Oto disable the keypads during mains failure , or to 1 to maintain power during mains failure. Set the second digit to Oto disable the beeps during the entry delay, or to 1 to enable the beeps. The third digit designates the number of times the alarm is allowed to sound in one 12-hour period (range 1-9). Entering 0 allows the alarm to sound every time an intrusion is detected. Set the fourth digit to 0 so that the alarm is not triggered by cutting the siren or strobelight lines, or to 1 to trigger the alarm for one cycle if a line is cut. Press (#) when all settings are correct. Press (*) (0). The display flashes the word TEST to indicate the test mode. Hold down button (1) to test the siren (the display will flash the letters SIRN & the siren should sound); hold down button (2) to test the strobe light; hold down button (3) to test the on-board relay. Press (#) when testing is complete. General notes: (1 ). The alarm panel is turned on or off by entering the current 4-digit on/off code (sectors can be left on when alarm is off). ' (2). Variable settings can only be altered when the alarm panel is turned off & by entering the current on/off code . (3). If the on/off code is forgotten, it can be viewed as follows: (a) Remove battery power & then the AC power ; (b) Hold down the (1) key & apply AC power to the unit~(c) Release the (1) key & reconnect the battery; (d) Press (*) (8) - the display will now show the current on/off code; (e) Pr ss (#) to exit. After this, pressing(*) (8) will display the usual****. (4). If the function(*) key is pressed , the next key must be pressed within 5 seconds for the function to be selected. 30 SILICON CHIP associated with these sectors should light. Next, arm the alarm by pressing (5) (7) (3) (9) . The ON LED should light and, assuming that the default exit delay setting is unchanged, you now have three minutes to leave the house. To re-enter the house, you simply enter (5) (7) (3) (9) to turn the alarm off again before the entry delay period expires. The ON LED should now turn off but note that the sector LEDs remain lit unless you toggle the sectors off again. In most cases, you'll leave the sectors on, so that you don't have to activate them again the next time you leave the house. PLUG·PACK ,:]lr>-16VAC_ : :.r:-r BATTERY 12V 2.6A -"I'.._____!___ I I 12V HORN SPEAKER I I I 12V STBOBE LIGHT The location of the main alarm box will depend on whether or not remote keypads are used. If the remote keypads are not used, then the box must be accessible to the user, so that the alarm can be turned on and off. Even so, it should be mounted in a concealed area, such as a linen press or kitchen cupboard. The remote keypads should be mounted inside the premises, as they are not weatherproof. Fig.14 shows how external devices are connected to the processor board. Don't forget the end-of-loop resistors for the sector inputs (see Fig.1 in last month's issue). Fig.15 shows how up to two remote keypads can be connected to the system. In particular, note how TX on the remote keypads is connected to RX on the processor board and vice versa. Be very careful here - it's all too easy to get these connections mixed up . +12V1.5A SIREN DRIVER PROCESSOR PC BOARO STROBE LIGHT DRIVER (S) +15V 400mA s SECTOR 3 INPUT (I) GNO FOR INPUTS s 24 HOUR SECTOR INPUT (S) SECTOR 2 INPUT e GNO FOR INPUTS SECTOR 1 INPUTS ,Mif rt t~ 1 - - - - -- - - - - -cl:UJTs TO REMOTE KEYPADS Fig.14: follow this wiring diagram when linking external devices & peripherals to the processor board. Note that the sector inputs must be terminated using 1okn end-of-loop resistors, as shown last month in Fig.1. that the alarm still functions if the first is disabled by a determined thief. Generally, a horn speaker is mounted under the eaves inside a metal cover and this serves as the main siren. The second siren can be a piezo type and should be mounted out of sight in the roof cavity. Deciphering the beeps Finally, a word on deciphering the various beep signals from the unit. There are four different patterns: (1) the unit beeps once each time a key is pressed; (2) the main unit and remote keypads beep four times every second during the entry delay; (3) the main panel beeps three times if you try to enter an illegal setting; and (4) if there is a fault in the system, the main unit and remote keypads beep twice every 15 seconds. SC ·"' ~ ""LJ PROCESSOR PC BOARD TB3 [ (1) <]) - Passive infrared sensors A large range of passive infrared detectors (PIRDs) is available on the market and these can be purchased from about $50.00 upwards . However, some of the cheaper units are prone to false triggering, so it's worth paying a few dollars more for good quality sensors. The PIRDs listed in the panel are both very reliable units. When installing them, make sure that they do not face towards windows to avoid false triggering. They should also be positioned so that are not in a direct line with sunlight. It's also a good idea to have a second siren connected to the system, so 0 (I) (S) SECTOR INPUTS (SEE Fig. 1) Installation +12V1.5A Q) GNO FOR PERIPHERALS I PASSIVE INFRARED DETECTOR (SUPPLY CONNECTIONS ONLY) (l) ~~ 0 - - ALARM OK TO ON ENTERQ 0 QM EMORY 000 REMOTE KEYPAD 2 REMOTE KEYPAD 1 +15V OV TX RX - 1 ' ' I FAULT 9 0 0 DETECTED __J L_/~ SECTOR SECTOR SECTORQ 2 ~+15V :...-., r I l f\ I NOTXECTION RX TO TX, TX TO RX ov -Tx 'I RX 0000 3 Fig.14: connections between the remote keypads & TB3 on the processor board are run using 4-way cable. In particular, note how TX on the keypad boards connects to RX on the processor board & vice versa. The LED functions are indicated on the remote keypad at left. OCT0BER1992 31 ORDER FORM BACK ISSUES* MONTH · YEAR MONTH YEAR MONTH YEAR MONTH YEAR *Back issues are $A5 each (incl. postage). Overseas orders add $A1 per issue for postage. BINDERS Please send me _ _ SILICON CHIP binder(s) at $A 14.95 each (incl. postage). Overseas orders please add $A3.00 each for postage. TOTAL PRICE $A SUBSCRIPTIONS 0 New subscription - month to start 0 Renewal - Sub. No. r------------, 0 RATES (please tick one) 2 years (24 issues) 0 0 0 0 0 Australia Australia with binder(s)* NZ & PNG (airmail) Overseas surface mail Overseas airmail I I I I I I I I I I Gift subscription ~ 1 year (12 issues) 0 0 0 0 0 $A84 $A105 $A130 $A130 $A240 $A42 $A53 $A65 $A65 $A120 *1 binder with 1-year subscription; 2 binders with 2-year subscription I I YOUR DETAILS Your Name (PLEASE PRINT) Address Daytime telephone number Postcode 0 Cheque/Money Order Card No. 0 Bankcard 0 Visa Card GIFT SUBSCRIPTION DETAILS Month to start Message Gift for: Name I- (PLEASE PRINT) I Address I I I I I I I Postcode I State I IL _ _ _ _ _ _ _ _ _ _ _ _ JI Signature 0 Master Card I I I I II I I I II I I I II I I I I Phone (02) 979 5644 Fax (02) 979 6503 9am-5pm Mon-Fri. Please have your credit card details ready Fax the coupon with your credit card details 24 hours 7 days a week Card expiry date I Mail coupon to: Freepost 25 Silicon Chip Publications PO Box 139, Collaroy Beach 2097 No postage stamp required in Australia 32 SILICON CHIP I I I I I I I I I I Door/Window Reed Switch - wireless Cat LA-5210 Normally $69 Wireless Passive Infra Red Detector Cat LA-5205 Normally $129.95 Wireless Remote Keypad Control Cat LA-5215 Normally $129 NOW$59 NOW $119.95 NOW $115 Hand Held Remote - wireless Cat LA-5208 Normally $59 NOW$49 m ... .::i Jl'\ll..,1-\M CLCl.., I nU f',1 11..,V Jf-\ ll..,1-\l""I CLCl.., l nU l'l,lll..,V JM Tl..,/'-\M l:LCl.., 1 n Ul\Ul.., V JH Tl.., 1-\M t:LCl.., I rlU l'l,l l VV ,J ,-.. I VHn CLCV I r\U l'I IVV ,JM I vnn C:..LC:..V I nUl'ilV0 ,JI"\! vnn LL.t:V l nV l '\11\.~--") ,JH I VHn CLC:V I nvn11v0 ...,,..., 1 VMI\ L IICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELFCTRONICS JAYCAR ELECTRONICS JAYCAR ELECTf,ONICS JA YCAR ELfCTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR E JIGS JAYCAR ELECTRONIC5 JAYCAR bLFCTRONICS JAYCAR FLECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELFCTRONICS JAYC AR ELECTRONICS JAYCAR ELECTRONICS JAYCAR le IICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYC AR ELECTRONICS JAYCAR ELECTRONICS IICS JAYCAR ELECTRONICS JAYC AR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS IICS JAYCAR ELECTRONICS ,JAYCAR ELECTRONICS JAYCAR ELECTRONICS JAYCAR F LFCTRONICS JAYCAR FLFCTRONICS JAYCAR ELECTRONICS JAYCAR ELECTRONICS .JAYCAR FLEC TRO NICS HCS JAY.rllR .=1 1-rTun/\11rc::: 1ll.vri'i.R i;._1 1=rn:::i n/\11r' c::: 1l'.ivr'i'i.R i::1 i::r'TonP\1J('C: 1 vr A 1=1 i=rn:::in,..11rc: 111.vrt,o ~~11-rTAnr-1 re.: 1A v rl'.iA i=1 i=rn:::inr- 11rc... 1/\VC'llA i:-1 1-r-ronP\11r'c::: ll'.i V r'l'.iA 1=11=r~TRnN1r.s CIROt, ·Clf<OtJ ,CTRON That's correct, this is a high quality alarm system that is so cheap you can buy two, and keep one as a spare. ·cmoN BRAND NEW HOME/OFFICE/WAREHOUSE ALARM AT LESS THAN HALF PRICE T TROr-J CTRON CTRON CTROIJ CTRON CTRON CTRON CTROtJ CTROt CTRO~ CTRON STRON CTRON CT RON CTl10N CTRON STf-~ON CTRON CTRON rRON :TRON TRON ;TRON ,TRON CTRON The company we bought these from has a new model out now, and they have asked us not to mention their name. We can tel l you though, that they sell and install their own brand of burglar alarms and intercoms. The quality is unsurpassed and if your home hasn't a burglar alarm now, then this is the time to buy one. THE ALARM The LA-5050 is a versatile micro-processor controlled system with memory analysis which is displayed on the unit It is housed in an attractive grey ABS box, which incorporates all the control functions, includ ing the access buttons, digital status display, panic button, etc. It wil l mount in a wall just inside the front door and requires a cutout hole 300 x 140mm. The control panel can be mounted in the ceiling, etc., if the optional remote keypad is purchased. There is also a small quantity of telephone diallers available. The alarm has many features - some of which include - aclock, automatic mode - which enables you to program the system to arm and disarm itself at preset times, 4 zones including some 24 hour zones (for arming the perimeter of the house at night leaving the inside PIR's off}, alarm activation recall - the unit wi ll record thetime of day the system was activated together with the zone number that triggered the alarm. What can be connected? • Remote keypad • telephone dialler • strobe • panic switch • 4 zones i.e. 4 PIR's etc • 2 horns • backup battery The system is supplied with a very comprehensive, easy to follow 22 page instruction manual. Overal l front panel size 400(W) x 210(H) x 100(D)mm. Also required:- plugpack to run from240 volt Cat MP-3021 $22.50. Backup battery 1.2Ah Cat SB-2480 $26.50 TELEPHONE DIALLER CTRON CTRON rrnoN , TRON ; TRON .:TRON ~TRON ' TRON TRO N TRON ,TRON 'TRON TRON :TRON ;TRON ;TRON CTRON CTRON STRO"- CTRON :::TRON STRON CTRON ;TRON CTRON ·:TRON CTRON CTRON CTRO ' TRON ~TF.~N ;TRON ;TRON (; TRO N CTRON :TRON CTRON C:TRON WAS $242 UNBELIEVABLE CLARION CAR SPEAKER BARGAIN Another surplus deal. These are Clarion brand Japanese made 5· twincone high power speakers complete with quality black gri ll. Power handling is a massive 40 watts maximum and they sound amazing. Impedance is 4 ohms. They wi ll work in small enclosures and we were staggered at how good they sound. Ideal for cars, or simply use one or two together in a box for Hi Fi extension speakers. Features: • 40 Watt power handling • Japanese Clarion brand • High quality • Complete with grill Dimensions: Grill 126mm sq Mounting holes 124mm diagonal et' Spk frame 120mm sq 51'0 Depth including grill 50mm \,JP Cat AS-3011 Only I ABOUT 1/2 PRICE I BATTERY CHARGER DO)IE SEN'l 1UY WlllEtESS BOX CTRON CTRON : TRON CTRO ALARM SYSTEM 1 - control :::mo protector ;moN This is basically an Arlec Charger 4 Car Battery Charger less the trasnformer and eutout you can build yourself a charger for about half price. What you get is: 1 The box. This is featured in other electronic catalogues and sells for $15.95 2 Two car battery clips with cable attached 3 2 core power lead 4 PCboard with 5 LEDs Limited quantity - grab one while they last. Cat. HB-5980 Al.JUUi SAU~ See 1992 catalogue page 63. :TRON ;TRON CTRON CTRON CTRON CTRO GTRON CTRON CTRON CTROt, CTRO CTRON CTRON CTRO CTRO CTRO CTRON CTRON CTRO ta0"' $12.95 ea unit 1 - door 1 - pass ive infrared detector 2 - remote control s cat LA-5230 WAS $259 NOW $199 SAVE $60 Optional extras Wireless PIR Cat LA-5232 TERMINAL STRIP BARGAIN This is a high quality terminal strip with 20 screw down connectors. All screws have awire protector under them which holds and protects the wi re. Each of the 20 connectors has a PC pin for easy soldering lo a PC board. Pin spacing is about 7.5mm. Made with ABS black plastic. Dimensions length 155mm width 12.5mm. Height excluding pins 12mm. Cat. HM-3204 ·~-~~~•••*•••~-A~~~~ h ~ • .. .. .. ,. • 'W "" 8 .. ># ,~:;:. ~ ,, I WAS SELLING FOR $428 l?Jl / ,/4)'j OJI ......... c. ........ f.:/J// ../ 10" WIDERANGE SPEAKER BARGAIN These speakers were purchased from Phi lips, manufactured in Asia and designated for a stereo system that never happened. We are happy to pass on the savings we made to you. The speakers are atwincone widerange unit with a foam roll surround. The cone is black, with the twincone's white. Their impedance is 4 ohms. These would be ideal for use in car stereos or extension speakers for Hi Fi. Most stereos wi ll happily accept 4 ohm loads. Power handl ing is 50 watts RMS. Full Specifications Power Handling Impedance Resonant Freq. Freq. Response SPI Magnet Weight Total Weight S0WRMS 4ohms 38Hz 38- 20kHz 90dB 1 watt 17.7 grams 1,500 grams Cat. CE-2330 $20ea i!lh MKT Capacitor Pack JAYCAR - ONE STOP ELECTRONICS "" I igh Quality Polycarbonate/ Window protector cat LA-5234 WAS .. r-.... ONLY $12.95 WAS $49.50 NOW $39.50 SAVE $10 $1.00 ea Cat. LA-5150 $199.50 / 1\i~,,; $129.50 Cat LA-5152 ~TAO STRON ' TRON ; TRON :TRON :TRO N ;TRON CTRON :TRON CTRON CTRON PANEL- ~ ~ :,.. ~..., h t.,. ~ . ~ , \ iL "' - ½;;:}~~ ~~\\ ~ ~ This pack includes approximately 75 high quality capacitors They are mostly Phi lips and Wima brand high quality European maae capacitors. Capacitance values include: 270pF, 0.0015, 0.015, 0.022, 0.033, 0.047, 0.068, 015, 018,022. 027, 0.33, 0.39, 0.47, 0.56, 0.68, 0.82µF in voltages including 50V, 63V, 100V, 250V, 400V, -. 630V, and 1OOOV. 75 pieces for $10 represents an absolute bargain. 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JAYCAR EL J AYCAR H ELECTRONICSJAYCAR EL ELECTRONICS JAYCAR EL ELECfRONICSJAYCAR EL t:LFCTRONICS JAYCAR F I VINTAGE RADIO By JOHN HILL Vintage radio repairs made easy Old valve radios should be carefully checked for faults before power is applied to them after years of neglect. Often, they have multiple faults & these must all be tracked down to restore the set to working order. A few weeks ago , a young lad came to visit me with an old pre-war receiver that was much in need of repairs. He had collected several valve radios which he had been able to repair himself simply by replacing a burnt-out valve. But this particular set had him tossed because there was nothing visually wrong with it. His repair techniques had not developed beyond that level. Looking back, I saw myself in exactly the same situation when I started collecting back in 1984. My first repair was successful only because I could see a capacitor with a big split at one end. Replacing the cracked component restored the receiver to working condition and I was indeed pleased with myself. Over the years, I have been confronted with numerous problems , some of which were consigned to the "too hard basket" for quite a considerable time. Eventually, often through sheer determination and cussedness, the problem is usually solved - but not always. As much as I hate to admit it, there have been a few occasions when I have had to seek the services of someone else. How can a hobbyist of a few years standing compete with the knowledge of a radio/TV serviceman who has a lifetime of experience to draw on? I might add, in my defence , that it is damned hard trying to fix a radio that someone else has had a go at beforehand. If there are missing components and lots of disconnected wires, then the hobbyist hasn't much hope unless he really knows what he is doing. Enthusiasm is no substitute for experience. On the other hand, if an old valve receiver is complete and has not been tinkered with , it is not hard to track down a fault. However, what some novice repairers fail to realise is that there is often more th an one fault and a systematic check of the whole receiver is necessary if all the problems are to be isolated. The receiver may require the replacement of many components, not just one. I believe that an extensive knowledge and understanding of radio theory is not necessary to repair vintage radios - but it sure helps. If a collector can correctly identify the individual components and respect the dangers of 240V AC, then there is a good chance of finding and correcting most faults. In this particular article, I hope to discuss various common radio components and their likely problems. Checking through a receiver in a systematic manner will reveal most of the faults that lurk in the maze of wiring that makes a chassis look so imposing to the inexperienced. Switch-on blues This old TRF chassis is nearly 60 years old. It is unreasonable to expect it to work from scratch & it should be thoroughly checked before switching it on. In many cases , particularly in very old receivers , I initially avoid turning them on to see if they will work. Age can do terrible things to ancient electronic parts and I always prefer to OCTOB ER1992 37 a little time checking out the likely trouble spots before switching on. Initial check list These tubular, chassis-mounted electrolytic capacitors dried out ages ago. They will have to be replaced with modern units to restore the set to working order. A good trick is to house the new capacitors in the old cans, in order to maintain an authentic vintage appearance. In the interests of more successful vintage radio repairs , here is my preswitch on check list. Power tr.~nsformer: check power cord from piug to transformer, plus the on/off switch if the set has one. The wiring should be safe and secure. Check the continuity of the transformer primary winding, the centretapped high tension winding and the low tension windings. If all are intact, the transformer will most likely work OK. Replace the transformer if any windings are open. A more difficult transformer fault to check is the shorted turn (or turns). The most obvious symptom is overheating, to the point of self-destruction if allowed to continue. Other corn- Mice can totally wreck old radio components. This particular capacitor would cause a high tension short if power were to be applied and would seriously overload numerous components. Perished 240V power cords can be l'ethal. The dangers of using this one are plain to see but less obvious cord damage can be a trap for the unwary. To avoid problems, it's always a good idea to replace the power cord. check a set out before plugging it in. Of course many old receivers can be plugged in without damage. They may work; they may not. Even if they do not work there is no reason to suspect that the set will totally selfdestruct in 30 seconds. However, in some instances, plugging in a faulty receiver for a prolonged period (which can be as short as a couple of minutes) can overload a particular component to the point of no return. My reluctance to switch on an unknown receiver has b een brought about by a number of bad experiences. 38 SIL/CO,\' Cl/II' I have seen receivers with short circuits in 240V power cords and plugs. I hav e seen rectifier valve anodes glowing red hot, which is something they are not supposed to do. I have also observed boiling wax running out of power transformers and high tension chokes, a hot electrolytic spewing out its overheated contents, internal arcing inside valves and smoke pouring off overloaded resistors and other components. These potentially dangerous and damaging situations can be avoided almost entirely if the restorer spends This 240V power transformer is typical of those used in valve radios. Continuity checks on the primary & high tension windings will give some indication as to whether or not the transformer is in working order. Old capacitors and resistors must be considered suspect until proven otherwise. The radio frequency choke (bottom) would also require checking for continuity. ponent faults can overheat a transformer but, if it overheats with no load across it, then it has a shorted turn. Short of a total rewind, there is no cure. Loudspeaker: assuming that the loudspeaker is an electrodynamic type, check both the field coil and the speaker transformer primary for continuity. The transformer secondary and the speaker voice coil are unlikely to cause trouble. Speakers with open field coils must be replaced or the field coil rewound. Faulty output transformers must be replaced. High tension choke: not all receivers have these as a separate unit, the speaker field coil sometimes doubling in this role. A burnt-out choke or field coil will effectively cut the high tension supply. If a replacement is not immediately available, a resistor of suitable value and rating may be substituted temporarily, at least to get the rest of the set working. However, this will give less effective filtering and usually an unacceptable hum level. The long term solution will depend on what can be salvaged from other sets. Alternatively, a choke and resistor combination may be used, the resistor value being chosen to bring the total resistance to that of the original field coil, typically 1.5kQ. Resistor wattage ratings must be adequate. As an extreme example, a l.5kQ resistor, carrying 80mA, would dissipate 10W. And a safety margin of 50% would be advisable. Intermediate frequency transformers: IF transformers usually have four Power transformers from the early 1930s were large and robust. However, they can still give trouble and should be checked before putting them into service. base connections - two for the primary and two for the secondary. Odd transformers have a centre-tapped _winding or windings with additional connections. Check for continuity. Don't forget that the grid cap connection is one end of the secondary winding. Open windings will stop the receiver and the offending coil will need to be repaired or the transformer replaced with a similar unit. Aerial & oscillator coils: once again, these units usually have two windings and four connections, although some coils have series connected multiple windings with taps. Check for open circuits. Any breaks in the windings will either prevent the set from working or adversely affect its performance. Repairs to broken wires or complete replacement will solve the problem. Resistors: check each resistor for both open circuit and correct value according to its colour code. It is common for old resistors to increase their value with age. Values above 1MQ are particularly susceptible, often increasing in value by two or three times. If they do not exceed 20% tolerance, they are OK. Check all wirewound resistors and the tapped high tension dropping resistor - the voltage divider - if the set has one. Voltage dividers frequently fail at the taps. Volume and tone controls also come under the heading of resistors and these should be checked for smooth operation. An open circuit volume control can stop a receiver from working. Particularly troublesome are the old wirewound potentiomet_ers from the 1930s. Voltage dividers are another troublesome component. Often the taps must be removed and cleaned so as to reestablish a good connection. OCT0BEH 1992 39 SPRING INTO LODESTAR We've g ot it All!! B EAT THESE PRICES!! 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CALL OR FAX US NOW 40 SILICON CHIP Price Output Voltage O· ± 30V with Fine Adjuster: Output Current 0-3A(5A) Adjuster: Load Regulation 0.02% + 3mv; Line Regulation 0 .02 + 3mv: Noise and Ripple 0 .5m Vrms; Over load and short circuit protection All Prices inclusive of Sales Tax Constant Over load and short circuit pro tection Current can be limited from 0-3 A or SA POWER SUPPLY (SINGLE OUTPUT) MOOEL Constant Voltage (CV) Current (CC) RESURRECTION RADIO Vintage Wireless Specialists Repairs - Restoration - Sales Aerial and oscillator coils often fall victims to mice, particularly coils that are wax coated. Checking the base connections with an ohmmeter will quickly establish their serviceability. Capacitors: ageing capacitors cause rriany of the troubles found in old valve radios. Although the mica types are relatively trouble free, the same cannot be said for paper capacitors and electrolytics. For reliable restorations, it is a good idea to make a clean sweep and replace all paper capacitors with modern polyester types. This in itself can solve many receiver problems that would perhaps be difficult for the novice repairman to locate. (The purist may elect to hide the modern types in the cases of the old units, to give the chassis an authentic appearance). Old electrolytics should be checked for shorts, leakage and capacitance to determine whether or not they are serviceable or in need ofreplacement. Since electrolytics are polarised, the This photo shows an old-style wirewound potentiometer, as used for volume controls in early superhets and TRF receivers. An open circuit winding will prevent the set from working. polarity of the ohmmeter test leads is important. It is often opposite to that for the other ranges. And capacitors that test OK on an ohmmeter may break down at higher voltages. The tuning capacitor should also be checked. Scraping plates will cause trouble and objectionable noise. Valves: it is advisable to remove the valves and check the heater pins for continuity. Better still, test the valves in a working receiver (or a valve checker), as this will remove or confirm any doubts as to their condition. Cleaning the base pins and the valve socket connections will also help to minimise valve problems. It only requires one base pin to have a faulty contact and the receiver will not work. Obscure faults If a receiver passes all the checks just described, it can be plugged in with reasonable confidence and there is every chance it will work. If it doesn't, it will be due to some rather obscure fault that could be quite difficult to track down. Some of these faults could be: an internal break in a length of wire (possibly the speaker cord), a dry solder joint, a joint that has never been soldered, a loose blob of solder shorting a connection, a fau lty replacement part, a replacement part that has been wrongly installed, a corroded or loose chassis connection (particularly common on aluminium chassis), or maybe a broken valve socket connection in the socket itself. Our skilled technicians offer QUALITY repairs and restoration. We also have a large stock of bakelite and timber radios fully restored and for SALE. Parts are available for the enthusiast, including over 900 valve types, high voltage capacitors , transformers, dial glasses, knobs, grille cloth etc. Circuit diagrams for most Australian makes and models. Send SAE for our catalog. WANTED: Valves, Radios, etc. Purchased for CASH Call in to our showroom at: 51 Chapel Street (PO Box 1116), Windsor, Vic 3181. Phone: (03) 529 5639; Fax (03) 510 4486 If all the foregoing seems a bit extreme or unnecessary, then consider the following. It is not uncommon to be confronted with a 50-60 year old receiver that has not worked for the past 30 years or more and has been stored in a damp garage for that period of time. A typical check out of such a receiver will often reveal that the loudspeaker field coil and output transformer are open circuit, that the electrolytics are shot, and that the paper capacitors have been chewed by mice. It may also have a burnt-out resistor, a gassy rectifier valve and corroded valve socket connections. In addition, all the rubber insulation on the internal wiring will have perished. There is no easy single cure for these problems. The restoration of most old radios is not a simple process involving the repair of one particular fault. In most cases, there are many faults and all must be found before the restoration can be considered successful. If a systematic fault finding routine is followed, it must ultimately improve the novice repairman's success rate. SC OCT0B ER1992 41 SERVICE 'SLOG Confession is good for the soul Confession is good for the soul, they say. And this story is basically a confession, so let's hope that my (technical) soul will benefit appropriately if I lay bare my sins. No doubt, someone will suggest a suitable penance. The set involved was a Panasonic 68cm colour TV set, model TC-2969 , · and the complaint was a double barrelled one; a "wishy washy" picture and a tendency for the picture to roll. It belonged to one of my regular customers but the call actually came via my antenna installation colleague. He had installed the customer's antenna and the customer had called him in, believing that it was an antenna problem. My colleague quickly cleared the antenna and passed the problem on to me. Because the customer was in an excellent location for TV signals, I realised that it had to be an internal fault. I decided to visit the customer's home, check the performance there, then bring the set back to the workshop. My antenna colleague went FRACARRO DELIVERS..• ... best television antenna performance for less cost. ~ Fracarro 10BL4, 10BL5, 10BL45, 10 element yagrs 1hat <at>filly work Peter C. Lacey Services Pty. Ltd. P.O. Box 678 (74Fulton Rd.) Mount Eliza 3930 Tel:03 787 2077 Fax:(03) 787 3460 ACN006893438 42 SILICON CHIP along to give me hand to load it into the van. Checked in situ, there was no doubt about the rolling problem; it was quite bad and nothing as simple as a hold control setting. The "wishy washy" complaint wasn't quite so clear cut. I had to admit that there was something strange about the picture but I couldn't pinpoint it. The closest description would be that of a weak picture tube but that didn't seem likely, or tie in with the rolling. (With hindsight there may be a better explanation). Its performance was much the same on the workbench and I gave some thought as to how best to tackle the problem. The picture quality was a rather nebulous symptom to work on; I was convinced that it was real enough but without some idea of how it was wrong, it was hard to know what to look for. The rolling problem, on the other hand , was much more tangible. Along with the poor picture quality, it suggested some form of distortion of the video signal, involving the sync pulses. This should be easy to track down. I fished out the manual and started tracing the video path. This proved rather awkward because the circuit is spread over two sheets, each folding out to about 75 x 50cm, and the particular path one wishes to follow often shuttles back and forth between them. This also makes it difficult to illustrate these notes with anything more than a small section. Colleagues who have a circuit should be able to pinpoint the components I nominate. I started at IC101 . This is described as a Phased Locked Loop, Split Vision IF & Sound IF IC. Video comes out on pin 3, goes to emitter follower Q130, then passes through resistors R152 and R150 to pin 3 of IC2501. This is described as a TV/ AV Control IC and is mounted on the B board. I fed in a standard staircase pattern and checked it at pin 3 of IC101, at test point B15 (ie, the emitter ofQ130), and at pin 3 of IC2501. And everything appeared to be normal. As will be evident from the IC2501 diagram (Fig.1), this is basically a switching IC. This type of device is now quite common in video recorders and is also finding increasing use in TV sets as they become more elaborate and offer more features. Switching function In this case, there is a switching function between pin 3 and pin 5, with pin 5 connected to a video-in terminal on the back of the set. But, regardless of the signal source, the switch sends the video signal out on pin 12. I check this point and everything still seemed to be normal. Unfortunately, there are no oscillograms in the manual for this part of the circuit but I was seeing a standard staircase pattern, with no sign of sync pulse compression or other obvious distortion. From pin 12, the signal goes directly to pin 2 of plug/socket combination B2 on the extreme right of the diagram. The signal is then taken across to the E board, where it goes to emitter follower Q302 and then to pin 15 of the Video/Chroma Jungle IC (IC601): Unfortunately, after tracing the signal through this circuitous path, I was no closer to a solution. As far as I could see, the signal pattern held up all the way. So what now? At this point, I came up with what I thought was a smart idea. Why not feed a video signal from the colour bar generator directly into the system ci'..'2'Bll - - - T - - - - - - - - - --- - - - ' ,i,, 1 '- - - - - - - F_=I=.- - - - - - - "j 1 I 02206 UNl212,,.,. UN4212 I 1 AUOI) CX/r-L AIJOD CXlr-F. : I I I I 1 I I I : TJ8ffllG 1 ONLY :-------' I AIJOll IN-I. I 1 FOR CA-2111111 I I I - AIJOll IN-R I i : : ~I I NILL I 1 1 ~-------,--~------, ONLY Fa! CA-21611 - :J20 : 1 I , .✓• L.. - ,1 rJ!OOOT ; -----~ l. lll!O IN 8~ 1. R2511 -T ~; l~~aJARO k1I= 1 J.,l,;;_ _,_, VID!O I I. ·. 'l, •m1 NP ,__j......,;..;._ _ _ _ _e-:,;;;...-----:--"lf/'r--a-""--' C2522 sov I I I I I What did it mean? So what did it all mean? The best construction I could put on it was that it was somewhere on the B board, u~1=t H7~ ; ~u~.1 4 - . , VIDl!ON : ONLY ~OR ONLY F"OR CA-21611 -N21• _____ -~~:~I :__ ~ -=--_-_ ~ __ ~1)STANMY Fig.1: this diagram shows the relevant part of the video chain in the National TC-2969 TV set. The video line comes in at lower left & goes to pin 3 ofIC2501. It then comes out on pin 12 & goes to pin 2 of the B2 socket at right. via the appropriate video-in terminal on the B board and thus into pin 5 of IC2501? Unfortunately, the result of this was inconclusive. On the positive side, it had cured the rolling fault - no doubt about that at all. But the picture quality was another matter. It seemed to be better but it can be very difficult to make a precise subjective assessment in this type of situation. At best, it seemed to be better but it still wasn't right. I decided to try another tack. This time, I decided to take the video signal out of the set via the video output socket (effectively the signal out of pin 12 of IC2501 via Q2504) and feed it into the video-in terminal of another receiver. This time the result was more tangible; it was virtually identical with that of the set in its original condition - except that, if anything, the rolling was marginally worse. r-,-- -- - . around IC2501. But I was all out of bright ideas. It was time to ask for help, so I rang my contact at Panasonic. Having established that I had the circuit in front of me, he directed me immediately to IC2501. He then proceeded to draw my attention to the signal levels at pins 3 and 12, pointing out that the signal at pin 12 should be 6dB up on the level on pin 3. And suddenly I realised how I had slipped up ; the IC diagram contains a small amplifi er symbol , marked 6dB, which I had completely overlooked. And I had made a further mistake by not comparing the two signal patterns closely enough. Thinking in terms of unity gain, I had "assumed" that the pattern at pin 12 was close enough to the one I had seen at pin ·3 - particularly as there was no obvious distortion - and that this was all I should expect. In fact, subsequent measurements showed that it was about 3dB down on the pin 3 level. Again I should have noted this, but 3dB means a voltage ratio of only 1.4 to 1, and I took less notice of it than I should have. CA-216Q A loss of 3dB instead a gain of 6dB meant that the circuitry beyond pin 12 of the IC was being fed with 9dB less than it needed. And, in simple terms, the system didn't like it. In fact, that probably oversimplifies the situation and I'll expand on that in a moment. The cure, of course, was simple. I ordered a replacement IC, fitted it, and everything came good - including the "wishy washy" picture. Significantly, it was only when it did come good that I appreciated just how bad it had been. So what was happening to the picture? I'm still not sure; all I can suggest is that the amplifier failure in the IC involved more than a simple loss of gain. Almost certainly there was also a serious degree of non-linearity, producing an odd scale of video tonal values. This probably involved compression of the highlights, thus robbing the picture of its "sparkle". And another question. Why did my attempt to feed a video signal into pin 5 of IC2501 cure the rolling problem? The answer, I feel, is almost certainly that I fed in a somewhat higher amplitude signal from the generator than was normally available from off-air signals. This lifted the sync pulse amplitude but could do nothing about OCT0 BER1992 43 the picture, looked wise, shook his head, and pronounced the problem as being due to the "poor signal conditions". Nobody was really satisfied with this excuse and after tolerating it for a few more weeks, they called the dealer in again and applied a little more pressure. Only then did he concede that all was not well but he then opted out again on the basis that it wasn't his problem and that they should consult the local serviceman: - ie, yours truly. And so it was that I received a call from the daughter, who outlined the above events, and tried to give me some idea of the problem. This proved difficult initially but, by careful questioning , I gained the impression that there were coloured patches on the screen, a suggestion which she latched onto immediately. She also added that they felt that the fault had been there from day one, at least in some degree. Naturally, it sounded like a classic purity error and I quizzed her about the possibility of any magnetic devices, such as hifi loudspeakers, being located near the screen at any time. But no; she was quite adamant that there was no possibility of this. At this point, I suggested that they bring the set in and, if the fault was as I expected, I could fix it on the spot. And so the set duly turned up in the shop . ~~-- . CONF'~S'SI0N \S GOOD Ft::>~ 11-(~ SOUL-, ·nus:.y SA.Yuo any non-linearity in the IC amplifier. And that's the nearest I can get to explaining what happened and why. But an explanation is not an excuse. The simple fact is I goofed and I've learned a lesson from it. A very rare fault My next story is about another National Panasonic colour set, a model TC-48R60 with a very rare fault. (Incidentally, the "48 " in that type number indicates 48cm , the makers having finally converted to the metric system). The job involved one ofmy regular customers, or at least indirectly, in that the set belonged to her mother. The set was only a few months old and, of course, still under warranty. 44 SILICON CHIP The mother lives alone, a few kilometres from her daughter, and in a rather poor reception area. At this location, TV signals are weak and somewhat ghost ridden. This situation caused some initial confusion, frustration, and delay. The story as told to me was that, shortly after the set had been installed, the owner felt that there was something not quite right about the picture, although she couldn't really pinpoint it. She raised the matter with her daughter and son-in-law and they both agreed that there was something "funny" about it but, similarly, they were at a loss to pin it down. Eventually, they approached the dealer from whom the set had been purchased. He came out, examined Red raster, blue patches I set it up immediately and fed in a blank red raster. Sure enough, it displayed a classic purity error. There was a big patch of blue on the left hand side, about half way up the screen, plus a few lesser patches on the right and along the bottom. All in all, it was quite severe and I wondered how the set had ever been delivered to the customer in that condition. Anyway, I reached for the degaussing wand, plugged it in, and waved it across the face of the tube. This will normally have some effect on even the most serious cases, even iffollowup is needed at the back of the tube. But this time it had no effect whatsoever. Nor did additional passes with the wand around the back of the set. This was a setback but I was not all that worried. I envisaged that I would need to go through a full purity and convergence routine and explained that the set had better be left with me but that I should have it ready later in the day. Ian J. Ttuscott's ELECTRONIC WORLD Problem No.2 30 Lacey Street, Croydon, 3136 Phone (03) 723 3344 Fax: (03) 725 9443 Mail & Credit Card Orders Welcome The daughter accepte d this readily enough but, before she left, she raised another matter; apparently the set also had a nasty h abit of switching itself off, for no apparent reason. Typically, it would do this a couple of times a night but could be turned on again quite readily. I made a mental note to follow this up after the main problem had been fixed . I moved the set from the shop counter to the workbench, pulled the cabinet back off, and switched it on again. And the first thing I noticed was that the pattern of the purity error had changed. The main patch was now a different shape and a slightly different colour. I didn't pay much attention to this. I had turned the set through 90 degrees (ie, from east-west to northsouth) when I moved it and this can sometimes have an effect on purity problems, though seldom on the finished job. TETIA TV TIP Akai CT-K209 TV set Symptom: no picture, no snow; just an even grey screen. Channel selection was normal, as was the sound. The CAO showed that video was going into the video processing chip but nothing was coming out. Cure: R501, the "matrix adjust" trimpot, needed adjustment. This pot adjusts the balance of chroma signals in the delay line and somehow it caused blanking of the luminance part of the video. TETIA TV Tip is supplied by the Tasmanian branch of the Electronic Technician's Institute ofAustralia. Contact Jim Lawler, 16 Adina St, Geilston Bay 7015. **** NOW ALSO AT COLLINGWOOD **** ** 200 Smith St (near PO) ** ** Phone: (03) 419 8208 ** We stock an extensive range of semiconductors, FETs & Mosfets, power & zener diodes, SCRs, Triacs, Linear ICs, 74LS/HC & 4000 series IC's, high-intensity LEDs and displays. Accessories inc. pots, trimpots, RF chokes, voltage regulators, relays, fuses, globes & heatsinks, as well as a comprehensive range of many popular switches, knobs, plugs & sockets. We offer a huge range of resistors & capacitors and popular parts at competitive prices. · More importantly, I have had problems with the metal frame ofmy workbench and make it a point to degauss this before attemting any serious purity or convergence adjustments. I went through this routine again, then attacked the set with the degaussing wand again. Result- no improvement in any shape or form. So it looked like the full treatment. This involves moving the deflection yoke back and resetting it for purity on a green raster (as used for in-line gun tubes , where green is the centre gun) , then going through the full convergence check. All this was a bit of a bind and, although I knew it had to be done, I decided to leave it until after lunch so as to have a clear run at it. When I came back and switched the set on again, I was sure that the purity error had changed yet again. This simply didn't make sense and I was becoming very suspicious. Horizontal streaks And there was another effect; one that I had noticed before but which had then vanished and come back again. This was a series of black horizontal streaks flitting through the raster. It looked for all the world like external electrical interference but this was hardly likely in a bench generated raster pattern. In the light of all this, I decided to have a bit of a poke around the deflection components before going any further. So, armed with my favourite sledge- Rechargeable batteries, both regular, tabbed, rapid charge and back-up types are available ex stock. Ring for a price on our sealed lead-acid, video, cellular phone and watch batteries. We now offer a speedy, courier delivered, mail order service. HI-FI & PA SPEAKERS Huge variety of all common hr-fi replacement speakers, crossovers, speaker cloth & grilles. Call for a price on our great range of speakers, microphones, cables, audio leads & adaptors - we'll send you a catalogue. 2-way crossovers (pair) from $9 3-way crossovers (pair) from $16 SWF12 12" 100 watt RMS woofer $75 SWF8 8" 60 watt RMS woofer $39 Redford PECC 6.5" 60 watt woofer $38 Redford PECC 12" 160 watt woofer $114 DM40 4" 50 watt RMS midrange . $16 DT30 1" 35 watt RMS dome tweeter $11 Ferro Fluid 30 watt (60 max) tweeter $13 Piezo tweeters from $16 Speaker wall mounts from $39 2-W'f,Y speaker switch boxes $18 3-way speaker switch box (impedance matching) $49 Don't forget our disposals store at Sth. Croydon. There's plenty of hard-to-find parts and help you won't get elsewhere! Phone 723 2699 (ask for Mai) OCT0 BER1992 45 SERVICEMAN'S LOG - CTD C )j~•" 1"'\-\6- 0\..-1> SL,.6:96,E.H~W\~6:'R ~ \ \<.., •• hammer (the plastic butt end of a screwdriver), I began tapping any likely components, while watching the purity pattern in a mirror. This had no effect until, more or less in desperation, I gave a light tap - a very light tap - on the back of the picture tube. And bingo! The purity error and the black streaks vanished completely, just like that. I tapped the tube again; and the purity error was back - in a different form - and I had a pattern of black streaks far more prolific than before. I tapped several more times and every time I tapped there was a different purity error. It was sometimes better than before, sometimes worse, and there were similar variations in the black streak pattern. I gave it away then. There was little doubt in my mind what the problem was. The shadow mask was adrift inside the tube, probably because one of the supporting welds had failed . From there on it was largely routine, although there was still a lot to be done. First, the owner's daughter was contacted and the situation explained. She was rather shocked to learn that they had a crook picture tube but I quickly put her mind at rest by explaining that the set was still under warranty and would cost them nothing. I then rang Panasonic and ordered a new picture tube. It arrived in a couple of days and I wasted no time fitting it. This is relatively easy - the single board on the bottom of the cabinet is slipped out; the neck board, convergence yoke, and deflection yoke are removed; and the four corner nuts holding the tube are unscrewed. Fitting the new tube is essentially the reverse procedure, followed by the setting-up routine for purity and convergence. This has been simplified by means of a technical informa- 56mm 29.7mm 26mm Convergence Yoke (TLC2047) 46 SILICON CHIP Fig.2: the convergence yoke assembly for the National TC-48R60 TV set. It shows the suggested spacings for the deflection & convergence yokes for minimum setting-up adjustments. It turned out to be almost spot on. tion sheet setting out typical spacing dimensions for the two yokes. As a precaution, I had supplemented this information by measuring these distances on the old tube with a pair of callipers before I pulled it out. They were within a millimetre or so of the given dimensions. I re-assembled everything, switched on, and was presented with a near perfect picture. Only a few minutes ' work was needed to touch it up. I then let it run for several days, just to make sure. It ran perfectly with no purity problems or black str'e-aks and, significantly, no tendency to spontaneously switch-off. In fact, I am now convinced that all the problems were related. The faulty weld in the tube was allowing two metal surfaces to rub together and, due to the high voltage field around the tube, this caused sparks. This in turn produced the streaks on the screen, along with interference pulses that caused the remote control microprocessor to shut the set down. Crystal frequency To finish off, I'd like to acknowledge a letter from a Mr P. Maljevac, an engineer with OTC in Sydney. He has very kindly supplied the answer to a technical point I raised in these notes for June 1992. While looking for a colour fault, I suspected (correctly) that the reference oscillator crystal had failed and replaced it with one from stock. However, the faulty crystal was marked 8.86MHz instead of the more usual 4.43MHz and I wondered why. Well, Mr Maljevac provides the answer and his letter was reproduced in Mailbag for the August issue (p.5). If you haven't already seen it, I suggest you make a point of referring to it because it gives a very succinct explanation. How had I missed out on that development? Well, it's hard to keep up with every advance these days and, in the service scene, one tends to ignore those parts of a set that don't normally cause problems. It's only when a section fails that one starts asking questions about it. And, unfortunatelv, I don't encounter many Philips sets; they don't seem to break down very often in my area. Anyway, thanks to Mr Maljevac, I now know the answer to my query. We have a limited supply of some 18mm fibre optically coupled 2nd generation image intensifier tubes. These are ex-military and may have some minor blemishes, but all produce full gain. With low light lenses these will produce useful images with as little as starlight illumination. Can also be IR assisted with IR LED's or low power torches, in rare situations where this may be required. The tubes require a 3V battery and a switch to make them operational. The viewer illustrated uses one of these tubes. It was constructed using some low cost plastic tubing and matching fittings for the case, a camera lens, and a low cost eyepiece. Plastic jewellers eyepieces can be used. FOR THE TUBE AND THE SPECIFICATION SHEET $620 Scoop purchase! High quality " Murata" 40kHz ultrasonic transducers. s4 per pair Ring for higher quantity pricing LARGE LCD DISPLAY MODULE ON SPECIAL AT Small PCB assembly ·· based on a ULN2232 IC. This device has a built in light detector, filters, timer, narrow angle lens, and even a siren driver circuit that can drive an external spe aker. Will detect humans crossing a narrow corridor at distances up to 3 metres. Much higher ranges are possible if the detector is illuminated by a remote visible or IR light source. Can be used at very low light levels, and even in total darkness with IR LED. Full information provided. The IC only is worth $16! Our price for the assembly is: $6 You can hear the difference with these premium quality 90 min . pure metal cassettes. These were recorded on once, never played , and then bulk erased. The record tabs have been removed. Brand new large Hitachi LM215XB display, as used in some laptop computers. Ye llow-green LCD reflective type, 480 X 128 dot display, effective display area of 242 X 69 mm, has 14 LSI ICs mounted on the rear of the PCB. Includes four pages of data sheets. Limited stock at a small fraction of their $ real value. ea. Controller kit available for $25 including instructions. 39 EHT GENERA TOR ea or 10 for $50 GEL BATTERIES s10 ea or 10 for $85 or 3 packs for $45 Based on a brand new, very compact modern EHT flyback transformer which includes an EHT diode rectifier. We supply the transformer, a very simple circuit , and the components to suit . All you need to make a very simple EHT or DC or pulsed AC supply. Powered from 12V DC supply. Great for EHT experiments, EHT testing , plasma displays (large light bulbs can be used) etc. Total price for the transformer and the $ components Is only: Stock up on this limited stock surplus item. Brand new, 6-12V (6V/50mA, 12V/150mA). Giveaway at: $6 ssoo BARGAIN MONOCULAR VIEWER ea or 5 for $25 NICAD BATTERY PACK A complete nicad battery power pack that was intended to be used in emergency lighting application . Contains 17 " D" size 1.2V/4 AHr batteries which can be easily separated into individual cells . New packs in their original packing. $75 per pack A very small but complete IR telescope which only needs an EHT power supply, which is provided in kit form. PCB and all on board comp"s only. Limited stock at a reduced special price. s229 Contains mainly 8 modern ferrite transformers which are very easy to disassamble and rewind . Ferrite halves are clipped together and no adhesives are used between them or in coil winding. There are four identical small transformers and four indentical larger transformers. The transformers can be rewound for use in inverters, inductors, filters, etc. s5 These matching components were removed from brand new IR tank viewers. They include a large low light objective lens, a large prefocussed IR image converter tube, a power supply or power supply kit to suit the tube and an adjustable eyepiece assembly. Make a professional infra red night viewer at_a ridiculous price of: For the set . VISIBLE LASER DIODE POINTER-PEN 17 High quality military binocular IA viewer. Self powered, and originally intended to be mounted on a helmet. Focus is adjustable from 1 metre to infinity. Requ ires some IA illumination . Powered by one single 1.5V battery. Original fibreglass carry case provided . Limited stock. ON SPECIAL PROJECTION LENS Brand new large precision projection lenses, which were originally intended for big screen TV projection systems. Will project images at close proximity, onto walls and screens and it has adjustable focussing . Main body has a diameter of 117mm and is 107mm long . The whole assembly can be easily unscrewed to obtain three very large lenses: two plastic and one glass. The basis of the cheapest large magnifier or projection system? Experimenters delight at $28 ONLY (Item No. 0137) $199 Brand new 6 volt 1 watt amorphous solar panels, 150m x 150mm, will deliver one watt whilst charging 6-8V batteries. Two of these in series make a great 12V battery maintainer/charger. Have weather protection, and terminating clips are provided. Incredible pricing: Famous "high-spec" Gates brand dual cell batteries, enclosed in a plastic moulding . 4V-5AHr per pack. Connect 3 packs in series to obtain a 12V/5AHr battery. Brand new, fresh stock, fully charged. Limited stocks at a giveaway price of: $18 INFRA RED NIGHT VIEWER ea. or 5 for $25 METAL CASSETTES $6 S5 $249 Price includes one rifle or pistol mount. MUSIC ON HOLD PCB PCB assembly based on a 7910 CF LSI music generator IC. Plays Greensleeves or Home on the Range, with a sound quality which is hard to believe. Full chords and accompaniment. Also produce two different alarm sounds. Apply 1.5-12V across two of connector pins to obtain music. Copy of E.A. project (Dec. 80) employing this IC is provided. ea. Small black anodised metal body. Removable pressure switch . Vertical and horizontal adjustments. Battery life more than 10 hours continuous. SmW 670nM class IIIA laser. Range is about 150m, some would claim three times more. Shock tested to 2000g . One year warranty. r <.rt :~--·; i~::·: ea Very small tube and inverter to suit; suit long range gunsights, laser pointers. Incredible value at s1so Includes tube, supply and ballast resistor STEPPER MOTORS These are brand new units, main body has a diameter of 58mm and a height of 25mm. Will operate from SV, has 7.5 deg. steps, coil resistance 6.6 ohm and it is a two phase type. Six wires. ONLY $12 ea. (Item No. 0140) \. ..-.·· ...·:_~-··>-:.. MYSTERY LASER Suit teachers, doctors, businessmen, and other professionals. Improve and enhance all your presentations. Not a kit , but a complete commercial pen sized laser pointer at an incredible price! ON SPECIAL AT s1so Small pen sized body. Runs on two small AAA battery. Battery life: 2-10 hours. Visible 5mW red (670nM) laser. Projects a visible red spot at more than 50 metres. As used for medical treatment by doctors and acupuncturists. Brand new, large MILSPEC guages. Overall diameter approx. 130 mm . Pressure guage reads from 0-16 bar. Temperature guage reads from - 20 to 80 deg C and has a remote sensor attached to a 2m lead. We have accumulated a good supply of some new and used tubes and heads with powers in the range of 0.5-2mW. These may have some small beam geometry problems. The lubes and the heads are guaranteed for one year! You can purchase one of these tubes/heads with our Universal 12V laser inverter kits for the price of the inverter only! s79 OFF ~ ON POWER VOL UME Build this mini amplifier for personal stereos Have you ever wanted to use your personal stereo player with speakers instead of those tiny and annoying headphones? This little project allows you to do just that. It uses only one low-cost IC and a few external components. By DARREN YATES Personal stereos have revolutionised the way we listen to our favourite music and radio stations. Not only can we now listen to Beethoven on the train going to work but also while jogging, studying for exams and during those tedious hours at work (oops .. not that it happens here, Boss!) - in fact, just about anywhere we want. If you stop and think about it, you can now buy a sensitive FM stereo receiver with a stereo cassette deck that fits easily into the palm of your hand - and many now come with a 48 SILICON CHIP 3-way graphic equalizer and Dolby noise reduction. Some even feature auto-reverse for the cassette deck as well. About the only thing the personal stereo lacks is a couple of pint-sized speakers that plug in when you've had enough of those tiny earphones poking holes through your noggin. These days, there are a few amplified speakers available but most of these come with an equally amplified price-tag to boot! Of course, many solutions to the problem have been found, including mounting a couple of LM386 audio amplifier !Cs on a board to drive a couple of small loudspeakers. The only problem with this approach is that you have to use two !Cs and these inevitably take up a fair amount of board space. "Well, what about stereo amplifier chips?" I hear some of you ask. There are a few of these around, some of which have already been used in previous projects. In the Portable AM Stereo Radio project published in September 1989, we used a TA7376P chip, which was a single in-line (SIL) package, but it was physically a bit on the fragile side if you weren't careful. The next chip we used was National Semiconductor's LM831 . This time the package was a 16-pin DIL, but it didn't have the same output power as the LM386. Its main prob- OFF 47 16VW L1 + 0 ~: o v I gvoc PLUGPACK TDA2822M 470 16VW l • v ~ R I G HOUTPUT T 10n 0.1 ! L2 INPUT S TEREO, L3 vtErr,1E ~ - - - - - f VR1b 10kLOG -:- 470 alf 10n 0.1 L1, L2 AND L3 • 6T, 0.68mm ENCW, AIR CORED WOUND ON A 5mm DIA. MANDREL i ~ V OUTPUT LEFT I PARTS LIST 1 PC board, code SC01110921, 60x 37mm 1 TDA2822M 1W + 1W stereo amplifier IC 1 plastic utility zippy case, 131 x 68 x 45mm 1 front panel label, 124 x 62mm 1 9V 300mA DC plugpack 1 miniature toggle switch 3 mono 3.5mm sockets 1 3.5mm stereo socket 2 3.5mm stereo plugs 4 rubber feet 2 10Q 0.25W 1% resistors 1 miniature 10kQ logarithmic dual potentiometer 1 knob to suit potentiometer Capacitors MINI STEREO AMPLIFIER Fig.1: the circuit is based on the TDA2822M stereo amplifier chip from SGS. Inductors Ll, L2 & L3 ensure that the RF signal picked up by the input leads is not shunted away by the amplifier inputs, since this signal is used by the tuner. 2 470µF 16VW electrolytics 2 100µF 16VW electrolytics 1 47µF 16VW electrolytics 2 0.1µF 63VW MKT polyester lem is that NS has now discontinued it - strike out one IC. Then we came across a tiny 8-pin DIL device, the same size as the old LM386, but with two amplifiers packed inside, capable of delivering 1W into 8 ohms at 9V. Delving into the specs a bit more revealed that it would also work down to 1.8V - a definite · plus over most other ICs - and that it has only 0.2% distortion, which is pretty good for such a tiny package. The device in question is the TDA2822M. Miscellaneous Circuit diagram Let's take a look at the circuit diagram in Fig.1. As you can see, there's very little to it. The input signal comes direct from your stereo player into the two volume pots VRla and VRlb. Notice that it also comes via three aircore inductors. The reason for these is that if your personal stereo has an AM/FM radio built in, it uses the headphone leads as the antenna. The inductors prevent the RF signal from being shunted away by the amplifier inputs. A dual-ganged potentiometer provides the volume control for both channels and we have omitted a balance control. This saves a little money on a control which is very rarely used on any stereo amplifier. The stereo signal passes into ICla for the right channel and IClb for the left. The gain of both amplifiers is set internally to 100 (40dB), while the low frequency roll-off is set by the lO0µF capacitors at pins 5 & 8. The output is coupled to the speakers by two 470µF capacitors (pins 1 & 3) and each amplifier has a Zobel network consisting of a 0. lµF capacitor and a lOQ resistor, which prevents any high frequency instability from occurring. The supply voltage can be anywhere from 1.8V to 12V, with obvious improvements in sound quality and output power available at the higher voltages. At 3V, the IC will put out Hookup wire, screws, nuts, solder. more than 100 milliwatts per channel into 4Q, which is quite adequate for personal listening. And that's about it as far as the circuit workings are concerned. As we said before, there's very little to it. Construction All of the components for the Mini 9VDC PLUGPACK RIGHT OUTPUT Fig.2: mount the parts on the PC board & install the wiring as shown in this diagram. Inductors Ll, L2 & L3 are made by winding six turns of0.8mm enamelled copper wire on a 5mm former (eg, the shaft of a drill bit). OCT0BER1992 49 Once the coils are in, you can solder in the resistors and the capacitors. Again, follow the wiring diagram carefully to make sure that each part is correctly located and take care with the polarity of the electrolytic capacitors. The last item to be mounted on the board is the TDA2822 IC. Note that pin 1 of this device is adjacent to a notch or dot in one end of the plastic body. Once the board is complete, check it thoroughly for any errors such as solder splashes across tracks or between IC pins. When you're happy with it, you can begin work on the case. Installing the board The PC board is secured to the bottom of the case, using machine screws & nuts, with extra nuts used as spacers. Use rainbow cable or light duty hook-up wire for the wiring connections & take care to ensure that the supply is wired with the correct polarity. Amplifier (except for the volume control, on/off switch and sockets) fit onto a small PC board measuring 60 x 37mm (code SC01110921). Before you begin construction, check the PC board carefully for any shorts or breaks in the copper tracks. If you find any, use a small artwork knife or some wire links as appropriate to fix the problem. Next, you can wind the three coils. This is really quite easy. All you need to do is get a 5mm (or 7/32-inch) drill ~ fl!#- bit and wind on six turns of 0.8mm enamelled copper wire. Make sure that you wind the turns close together and reasonably tightly, but don't make the turns too tight otherwise you won't be able to get them off the drill bit. When you've wound all three coils, scrape the enamel off the ends and solder them to the board. Check the overlay wiring diagram (Fig.2) to make sure you insert them into the right holes. MINI STEREO AMPLIFIER Before iI.1stalling the board into the zippy case, you will have to drill holes for the volume control, the power switch and the four 3.5mm sockets. We suggest that you drill some small guide holes first and then use a tapered reamer to enlarge the holes to suit. When you go to fit the 3.5mm sockets, you will probably find a small problem. The threaded bush of each socket isn't quite long enough to protrude sufficiently through the plastic case and hence you won't be able to secure the nut. The solution is to use an 8mm drill bit and slightly countersink each hole by hand. This will provide more access to the thread and allow you to get the nuts on. Once all the hardware has been mounted, the wiring can be completed using light-duty hook-up wire or rainbow cable - see Fig.2 . Finally, the board can be secured to the bottom of IO SCOl110921 - ~~ ! OFF 0 ON Q MIN POWER MAX VOLUME Fig.3: the front panel & PC board artworks. Check the board for etching defects before installing any of the parts. 50 SILICON CHIP 0 I the case using 3mm machine screws and nuts, with extra nuts used as spacers. Connecting plugs The next step is to wire up the connecting cables. Let's start with the signal cable that connects your personal stereo player to the amplifier. This needs to be a 1-metre length of figure-8 shielded cable fitted at either end with a 3.5mm stereo plug. You can either purchase two stereo plugs and wire them together or you can save time by buying the complete lead; eg, Arista Cat. No. AL161 for $3.95. Next, you can work on the speaker cables. Alternatively, you could buy a pair of small speakers which already have the cables connected. If you're "rolling your own", make sure that you connect the positive and negative speaker terminals to the same terminals on each of the two 3.5mm mono plugs. You should use some light duty (figure-8) speaker cable for this. Here's what the PC board looks like close up. Scrape away the enamel from the leads of the inductors before soldering them to the board & make sure that all polarised parts are correctly oriented. amplifier's current drain by connecting your multimeter (set to the ZOOmA range) in series with the 9VDC supply and one of the supply rails. With no input signal, you should find that the current drain is about lOmA or so. Ifit is any more than this, switch off and check that you have the circuit wired up correctly. When Testing The test procedure is quite simple. First, it's a good idea to check the the speakers are connected, the "no signal" current should still be the same, at about lOmA. Next up, plug in your personal stereo receiver and set the volume control on it to about halfway. Now increase the volume on the stereo amplifier and you should be able to hear the fruits of your labour. SC Electronics Workbench® EmonaLAB4 Four instruments in one package! The electronics lab in a computer! • aocr, .... 66600666 The LAB4 has four full function test instruments: ■ DC POWER SUPPLY Triple output; 5V, 15V, 0-50V ■ with neatly laid out and labelled front panel controls. Also, the LAB4 is compact and only takes up a small space, compared to four bench-top instruments. DIGITAL MULTIMETER Full function, auto-ranging ■ FUNCTION GENERATOR 0.02Hz-2MHz, with SWEEP ■ FREQUENCY COUNTER 1Hz-100MHz input range INDEPENQENTINSTRUMENTS Each instrument in the LAB4 is completely independent and can be switched ON or OFF as required, The LAB4 has only one 240V mains input, saving on multiple power points. Each instrument is clearly defined A simple, intuitive and very powerful teaching tool, Electronics Workbench lets students and hobbyists design and test both analog and digital electronic circuits, without the delays and expense of a laboratory. FEATURES EMONA INSTRUMENTS NSW ......................... (02) 519 3933 VIC ............................ (03) 889 0427 OLD .......................... (07) 397 7427 DISTRIBUTORS Perth Adelaide Hobart ............... (09) 244 2777 ........... (08) 362 7548 (002) 34 2233 • Quick and simple circuit entry • Digital and Analog Modules included, complete with all components • Simulated instruments: dual trace scope, spectrum analyser, function generator, multimeter, digital word generator and logic analyser • Complete control over all component values and parameters • Print: circuit schematics, parts list, instrument readings, macros • Logic conversion - truth table to Boolean formula to logic gates • Customisable hypertext help system 0 M. . 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As well it . an uses a controlled, it WO~ bi ~otor, so though th:~ni~rs the '.backComplete with delu xeg own when the going /peed is components, PCB anlfrle-punched screened f~ont s tough. ush mounted m ains . socket. panel ' f~;~~ f~~ ~r ~~F~ ~ MINI 1.5V TO 9y Q DC CONVERTER Here's 9 volt bant eas · Y way to replace th Th~ ea!/f~ 1~~i:tf~:~efficienf~e5evx61f~!:~se !1A)\li~!P~~6etyape of 1.~~ui!1T (~oAmg~eNnts . What ' more expen • • · , or 17 s more, the PCB me s1ve 9V battery x 43mm and fit . asures Just · battery compartm!it~s1ly insid e a 9V Cat K-3231 $995 AUDIO SWEEPER QQ [z] $4695 Also Available I . . Insulated Triac (BTA~~IV/dua lly As used in K- 3085 -6008) Cat Z-4515 $595 A kit for in buget-priced fact anyone inv I audi.ophiles, sound e abudio test system~~!? or interested in sou~~e~~•. enthusiasts ... ass) of speake yses th e performa · . 1s affordable acoustics. It con~~~ speaker enclosures f~fe~ (f"!11d ,_treble & and a meterin ts _of a sweeping audio c1r_cu1ts and room comes complit::i~~if~e~ ~hich measures \~!t generator instrument case PCB e uxe pre-punched f u s. The kit components. ' . hardware (including d~ont panel, plastic meter) and all ~~~n~I t1tY4 ~~~,~~,~~!ER t1tY4 3½ DIGIT Q monitoring voltage w~ich IS perfect for anything from s, including batteries This ~ower supplies to car can be b~ilt to r!;~ral purpose panel 200V DC or curren voltage up to+/with suitable switc~i~P to ~A _(or both the hobbyist st d g). It s ideal for application ~ he~e ent and any voltage or curren/ou need to monitor precisely. Complet:ccurately and all components, PCBw~~h LCD screen , snap . (Requires 9V b attd a 9V battery ery) Sem TDAicond 1514tor Of The Month! POWER A~~O WATT/RMS HIGH . Cat K-7502 s399s Also Availabl I . . Liquid Crystal Dise l nd1v1dually As used in K-?sof ay with data sheet. 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CatZ-6117 • s1995 Please contact your for availabn~rest store SCANNER BOOKS Register of Government Radio Frequencies NSW & ACT Scanner Fanatics Frequency Register of NSW Scanner Fanatic Frequency Register of Vic Australian Radio Frequency Handbook B-4100 B-4102 B-4104 B-9601 $29.95 $24.95 $24.95 $14.95 DATA & REFERENCE BOOKS Towers International Transistor Selector Resistor Colour Code Chart Philips Linear Databook Philips IC & Semiconductor Reference Guide SGS-Thompson CMOS 4000 Databook SGS-Thompson SCR & TRIACS Databook SGS-Ttiompson DIODES Databook SGS-Thompson Small Signal Transistor Databook Motorola RF Devices Dotobook Motorola RAMs & EEPROMS Dotabook Motorola Thyristors Databook B-4600 B-1000 B-5553 B-5552 B-5560 B-5564 B-5566 B-5568 B-5400 B-5402 B-5404 $49.95 $ 5.95 $49.95 $18.95 $24.95 $24.95 $29.95 $19.95 $29.95 $19.95 $19.95 ELECTRONICS & HOBBY BOOKS Electronics Tips & Techniques Mastering IC Electronics Home Remote Control Projects Basic Electronics Theory l Ol Opto Electronics Projects Encyclopedia of Electroni9 Circuits Vol.3 Introductory Electronics Aviation & Space Science Projects Electronics for Model Railways 14 FM Bugs to Build Data Sheet on PCB Making Guide to NiCad Batteries Wire & Cable for Electronics RF Interference Handbook B-1600 B-1612 B- 1614 B-1 615 B-1617 B-1760 B-3635 B-6 702 B-3642 B-3650 B-6005 B-6040 B-161 8 B-2401 $29.95 $39.95 $29.95 $39.95 $29.95 $54.95 $18.95 $16.95 $ 2.95 $ 3.50 $ 1.25 .95c $49.95 $19.95 SHORTWAVE RADIO BOOKS Shortwave Listening Guidebook Passport to World Band Radio World Radio & TV Handbook Radio In Australia B-2040 B-2050 B-2092 B-2300 $29.95 $34.95 $35.95 $ 4.90 AMATEUR BOOKS Yaesu Amateur Radio Log Book Yaesu Ham Operators World Mop ARRL YAGI Antenna Design ARRL Antenna Handbook 16th Ed. ARRL Radio Handbook, 1992 Ed. Secrets of RF Circuit Design Your Gateway to Pocket Radio AA-25 Pocket Radio Protocol W.IA Into Electronics W.IA Novice Electronics WJA l 000 Questions for Novice Candidates WJA 500 Questions for AOCP Candidates. B-2029 B-2030 B-2105 B-2209 B-2225 B-2311 B-2402 B-2403 B-2313 B-2317 B-23 16 B-2318 $ 9.95 $ 6.95 $29.95 $39.95 $49.95 $39.95 $24.95 $14.95 $ 9.95 $ 9.95 $ 9.95 $ 9.95 SATELLITE TV BOOKS Satellite TV - Pacific Region ARRL Satellite Antology B-2321 B-2400 $29.95 $15.95 CB RADIO BOOKS The Screwdriver Experts Guide CB International PLL Data Book Understanding CB Radio CB EPROM Doto Book B-2324 B-2326 B-2327 B-2329 $19.95 $19.95 $36.95 $14.95 LEARN ELECTRONICS THE FUNWAY Funwoy Into Electronics Vol. l Funway Into Electronics Vol.2 Funway Into Electronics Vol.3 B-2600 B-2605 B-2610 $ 4.95 $ 6.95 $ 6.95 OOKS BOOKS OOKSBOOKS OOKSBOOKS BOOKS BOOKS BOOKS BOOKS BOOKS BOOKS BOOKSBOOKi BOOKSBOOKi BOOKSBOOKi COMPUTER BOOKS The Complete PC Memory Manager RS232 Made Easy. 2nd Ed. PC Architecture & Assembly Language GW BASIC Primer Plus DOS 5.0 Use(s Guide IBM PC Configuration Handbook The 486 Book Quickstart Works For Windows Quickstort Windows 3.1 Quickstart WordPerfect for Windows WordPerfect for Windows By Example WordPerfect 5.1 Quick Reference Microsoft Word 5 Quick Reference MS.DOS 5 Quick Reference Norton Ultilities 6.0 Quick Reference Lotus 1-2-3 Release 3. 1 Quick Reference Hard Disk with DOS 5.0 Quick Reference PC Tool 7.0 Quick Reference Guide To XTREE Quick Reference Windows 3. 1 Quick Reference QUATTRO PRO 4 Quick Reference The Complete DOS 5 with Botch File Disk Atari Portfolio Guidebook A Kid's Guide to Computers B-6097 B-6098 B-6099 B-6100 B-6101 B-6203 B-6205 B-6385 B-6391 B-6397 B-6398 B-6400 B-6402 B-6404 B-6407 B-6408 B-6413 B-6415 B-641 6 B-64 17 B-6418 B-6500 B-8700 B-6700 $39.95 $49.95 $28.95 $59.95 $39.95 $59.95 $69.95 $24.95 $24.95 $29.95 $59.95 $19.95 $19.95 $19.95 $19.95 $19.95 $19.95 $19.95 $19.95 $19.95 $19.95 $69.95 $39.95 $19.95 GAMES BOOKS Leisure Suit Larry Bedside Companion Beyond the Nintendo Masters Mastering Nintendo Video Games Tricks of the Nintendo Masters The Complete Nintendo Video Games Guide Winne(s Guide to GAME BOY Winne(s Guide to SEGA B-6900 B-9800 B-9802 B-9804 B-9806 B-9808 B-9810 $22.95 $19.95 $18.95 $19.95 $19.95 $18.95 $18.95 OCT0HEH '1992 53 FLUKE MULTIMETERS ~'Regarded by industry professionals as the most forgiving multimeters ever made!" Fluke 12 Multimeter Fluke 10 Multimeter With a 3 ¾ digit ( 4000 count) display and a V-check which automatically changes modes. What's more, it has continuity capture which records intermittant opens and shorts as brief as 250mS. In addition, the min/max record and time stamp lets you capture precisely what occurred and when. Hook it up, walk away, then come back and find out what happened ... it's that easy! 1 ~at~~~ ~ARRAN1Y! $159 A tough and dependable multimeter designed for true one-hand operation. It has a 3 3/ 4 digit ( 4000 count) display, as well as auto and manual ranging. With AC/DC voltage measurements (to 600 volts), continuity beeper, Ohms & diode tester, digital display, and overload protection. The Fluke 10, a new generation in speed, versatility and value. CatQ-1611 $109 2 YEAR WARRANTY! Specifications Speciflcaffons DCV 4000mV, 4V, 40V, 400V, 600V ,Accuracy (0.9% +2 for 4000mV & 4V range) (0.9% + 1 for 40V, 400V & 600V ranges) 1¥:,V: 4000mV,4V,40V,400V,600V Resistance: 400 Ohm, 4K Ohm, 40K Ohm, 400K Ohm, 4M Ohm, 40M Ohm Capacitance: 1uf, l Ouf, l OOuf, l OOOuf, 10,000uf DCV: 4000mV, 4V, 40V, 400V 600V ,Accuracy: (1.5% +2 for 4000mV & 4V ranges) ( 1.5% + l for 40V, 400V & 600V ranges) N:,V: 4000mV,4V,40V,400V,600V Resistance: 400 Ohm, 4K Ohm, 40K Ohm, 400K Ohm, 4M Ohm, 40M Ohm LEADS AND CLIPS Industrial Test Lead Set Right-Angle Test Leads. Silicon insulated test leads (63" long). With shrouded right-angle connectors, interchangeable stainless steel test probes and safety $ alligator clips. Shrouded input plugs which will not pull out of meter during use. Single piece construction. l metre long. $ 7995 Cat Q-1652 ; .· • TT I- ::::::: j j Alligator Clips Set of two black and two red slip-on clips for right-angle test leads. $ CatQ-1660 1295 cat Q-1650 1995 Deluxe Test Lead Kit Everything in a handy soft carry pouch. Comes with interchangeable tips - 2 alligator clips, 2 spade lugs, l retractable hook tip & 2 standard pointed tips. Includes shrouded banana plugs. $ Cat Q- 1658 5995 Fluke 10 & 12 Holster Snap your meter into this yellow holster and it wi II absorb shocks and protect it against damage. With tilt stand and a moulded hanger loop which can be used as a probe holder. $ Cat Q- 1614 2495 Fluke 10 & 12 Softcase High Voltage Probe The best way to keep your Fluke series l 0 meter safe and organised. There's room for leads and small accessories as well. Measuring high voltages made easy and safe. Division ratio is l 000: l. Measures up to 40kV or 28kV RMS AC. Has l OOOMohm input resistance. Cat Q-1616 CatQ-1690 $2 495 Also Avalialable!.. .. Fluke 73 Series II 70 SERIES II FLUKE MULTIMETERS Cat Q-1603 The all new Series II Fluke professional quality multimeters give you better value, better performance and more features than ever before. All of the '70 Series' meters now have 'Touch Hold', Diode Test, Continuity beeper, Automatic Self Test, Sleeper Function and exceptionally long battery life as standard features. Fluke 75 Series II $ 199 Cat Q-1605 Fluke 77 Series II Cat Q-1607 MAJOR DICK SMITH ELECTRONICS AUTHORISED STOCKISTS: NSW: ARMIDALE: New Englaoo Electrooics 711655 BALLINA: Ballina Electrooics 867022 BATEMAN'S BAY: Baycity Sight &Souoo 725030 BATHURST: Electronic Frootiers 323933 BOWRAL: Bowral Electrical Supplies 611861 BROKEN HILL: Hobbies & Electronics 884098 COOTAMUNDRA: Cootamuoora Music & Lite 422561 COFFS HARBOUR: Coifs Hartlour Electrooics 525684 OENILIQUIN: Deni Electronics 813672 OUBBO: Chris's Hi R 828711 FORSTER Forster Village Electronics 545006 GOULBOURN: Tunlive 221288 GRAFTON: Repairs & Spares 421911 GRlfflTH: Miatronics 624534 INVERELL: lnverell Electronics 221821 KEMPSEY: P&L Leonard 631134 LEETON: Leeton Audiotrooic 532800 LIGHTNING RIDGE: Lightning Ridge Solar Power291013 LITHGOW: Douroy PhotoQraphics 513173 LISMORE: OeCfo Electronic Services214137MOREE: Moree Electronics 522091 MUOGEE: Headware 723895 MURWILLUMBAH: Strings & Things 723684 NARRABAI : Namoi Computer Service 923274 NELSON SAY: Nelsoo Bay Elect & Hobbies 813685 NOWRA: Nowra Electronics 210722 PARKES: Strad Music Ctr 623366 PORT MACQUARIE: Hastings Computer Service 840255 RICHMOND: Silicoo Crafts 784101 TAREE: Manning Electronics 512233 ULLAOULLA: Coastal Electrooics 553989 WAGGA WAGGA: Phillips Electronics 216508 WALGETT: Walgett Electrooic Centre 281116 WELLINGTON: Wellington Service 452325 WINDSOR: Hawkesbury Electronics 776722 VASS: Warmingtoo Electrical 261116YO\JNG : Keith Donges Electroo,cs 821279 VIC: ARARAT: Jerram Electrooics 522345 BAIRNSDALE: LH & LM Crawford 525677 BENALLA: North East Electronics 622710 CASTLEMAINE: Inspect Electrics 723773 COLAC: Colac Electrooics 312847 ECHUCA: Gilmour Electrooics 822956 Ml LOURA: Pullman Auto Pro 232882 MORWELL: Roylaine Ptv Ltd 339458 SHEPPARTON: Aoorew Guyatt Electronics 219497 SWAN HILL: Nyah District TV Service 329303 ST. ARNAUD St. Arnaud Appliances 951000 WARRAGUL: Roylaine 234255 WARRNAMBOOL: Koroit St Elec Services 627417 WONTHAGGI: South Gippslaoo Photo Service 721411 OLD: AYR: Delta Electrix 831566 BLACKWATER: Cool Trooics 825827 BOWEN: Oelpro Agencies 86 3477 BUNOABERG: Bob Elkin Electronics 521785 CALOUNDRA: Electro-mart 918533 DALBY: Hobby & Electronics 625770 lJYSAAT: Dysart Videotrooixs 582107 GLADSTONE: Electronic Enterprises 726660 INGHAM: Masons Electrooics 763188 l~NISFAIL: lnnisfail Hi-fi 612014 KINGAROY: MO& MM Siegle 624535LONGREACH: LooQreach Souoo & Communications 583307 MACKAY: Stevens Electronics 511723 MARYBOROUGH: Ke.Iler Electronics 214559 MT ISA: Outback Electronics 433331 NAMBOUR: Nambour Electronics 41,1966PIALBA: Keller Electronics 283749 STANTHORPE Granite Belt Communications 813333 TAS: BURNIE: Electrooic City314760 DEVONPORT: Al Electrooics 248322 SA: MT GAMBIER: Hutchesson's Communication 250400 PORT LINCOLN: Basshams TV & Comp World 830075 WHYALLA: Eyre Electronics 454764 WA: ALBANY: Micro Electronics 412077 BUNBURY: Micro Electronics 216222 GERALDTON : Batavia Lighting & Electrical 211278 KALGOORLIE: Today's Electrooics 215212 KAFflATHA: Pllbara OOice Stwies 854836MANOUAAH: MandurahHi R 5812206PORT HEIJLMO: Ivan Tomek Electrooics 732531 54 SILI CON C H IP SAN&&AN With Cassette Player! All-Band World Receiver Open your ears to the world with the stunning Sangean ATS-8 l 8CS. This fantastic receiver covers Longwave and continuous shortwave frequencies from l .62 to 30MHz and local AM/FM stations (FM stereo with optional headphones) What's more, with an inbuilt BFO (beat frequency oscillator) it can receive many HF SSB transmissions including marine, aircraft, amateur and commercial broadcasts. An inbuilt tape deck even allows you to play your favourite tapes and preset it to record broadcasts. Top features include five-way tuning, 45 station memories, a full function digital display, dual time and alarm clock. A dual conversion receiver design offers switchable filters and an adjustable RF gain control to provide optimum reception. It's simply brilliant! Cal D-2842 EXCLUSIVE Shortwave Listeners Guidebook Harry Helms Learn how to top into the exciting and 'live' the world of shortwave! This valuable book tells you how to get the best programs, news and broadcasts from around the world. As well, there's tips on choosing the right antenna, conditions affecting reception, international & domestic broadcasting and more. Cat B-2040 $ Passport To World Band Radio 1992 World Radio TV Handbook 1992 A valuable guide on how to get started with your shortwave receiver. It's packed with useful information, with everything from what's on, to the best (& worst) SW radios. If you've just discovered shortwove radio, are just starting out, or want to keep up with the latest world changes, this book is a definite must-have1 2995 One of the most sought after books among shortwave enthusiasts. With up to date and complete listings of international radio and TV stations. Provides frequencies, addresses, call signs, ID's ... you name it. B-2092 $35 95 Cat B-2050 Easy To Use Easy Etch Engraver Aquick and effective way to make sure your tools don't get mixed up with others. This reliable engraver lets you quickly mark tools, stereo equipment and household valuables with a permanent identification or serial number. It's easy to handle and has steel bits so you can engrave on metal, plastic, wood and most materials. Complete with 12V plug pack and long cord. Cat T-4753 s399s Quick and Easy! Heat 'n Strip Gun Cut your work time by half! This handy tool is ideal for heatshrink work, -removing old paint, removing vinyl tiles, loosening rusted or over-tightened nuts, drying .. and hundreds of other uses. It's lightweight, mains operated and hos a dual temperature range (400 & 600°C) Cat T-4845 •- Ideal for PCB work! Super Tool A must for any hobbyist or enthusiast! This extremely high quality tool is perfect for PCB and other precise work. It sands, polishes, drills engraves, and mills. What's more, it comes with o wire brush, milling cutters,grinding wheel, high speed drills, chuck collets, eraser sticks and mains adaptor_ Complete with handy, go-anywhere plastic case. CatT-4754 $7995 DS XPRESS PHONE & MAILORDER SERVICE Outside Sydney (FREE Call) 008 22 6610 Sydney And Enquiries - 888 2105 FAX: (02) 805 1986 or write to OS XPRESS, PO BOX 321 N/RYDE NSW 2113 All Major Credit Cards Accepted. 0/Nite Courier Available. 24 HOUR DESPATCH OF ALL ORDERS NSW • Albury 21 8399 • Bankstown Square 707 4888 • Blacktown 671 7722 • Brookvale 905 0441 • Bondi 3871444 • Campbelltown 27 2199 • Chatswood Chase 411 1955 • Chullora 642 8922 • Gore Hill 439 5311 • Gosford 25 0235 • Hornsby 477 8633 • Hurstville 580 8622 • Kotara 56 2092 • Liverpool 800 9888 • Maitland 33 7866 • Miranda 525 2722 • Newcastle 811896 • North Ryde 878 3855 • Orange 818 400 • Parramatta 689 2188 • Penrith 32 3400 • Railway Square 211 3777 • Sydney City 267 9111 • Tamworth 86 1711 • Wollongong 28 3800 ACT• Belconnen (06) 2531785 • Fyshwick 280 4944 VIC• Ballarat 31 5433 • Bendigo 43 0388 • Box Hill 890 0699 • Coburg 383 4455 • Dandenong 794 9377 • East Brighton 592 2386 • Essendon 379 7444 • Footscray889 2055 • Frankston 783 9144 • Geelong 232 711 • Melbourne City 399 Elizabeth St 326 6088 & 246 Bourke St 639 0396 • Richmond 4281614 • Ringwood 879 5338 • Springvale 547 0522 QLD • Booval 282 6200 • Brisbane City 229 9377 • Buranda 391 6233 • Cairns 311 515 • Capalaba 245 2870 • Chermside 359 6255 • Rockhampton 27 9644 • Southport 32 9033 • Toowoomba 38 4300 • Townsville 72 5722 • Underwood 341 0844 • SA • Adelaide City 2321200 • Beverley 347 1900 • Elizabeth 255 6099 • Enfield 260 6088 • St Marys 277 8977 WA • Cannington 451 8866 • Fremantle 335 9733 • Perth City 481 3261 • Midland 250 1480 • Northbridge 328 6944 TAS • Hobart 31 0800 • Launceston 344 555 NT • Stuart Park 811977 81374 OCT0IJE/l 1992 55 The Thunderbird Battery Charger This charger has automatic voltage selection for 6V, 12V & 24V lead-acid batteries & is electronically regulated to deliver just the right amount of current. It features output short-circuit & reverse battery protection & has LEDs to indicate the state of the battery. By HERMAN NACINO,VICH 56 SILICON CHIP . Most of us have experienced, at some time, the frustration of trying to start a car only to find that the battery was flat. Apart from the annoyance of this situation, Murphy's Law practically guarantees that when it does happen, it will do so at the worst possible time. The best way to avoid this kind of situation is to have a good battery charger on hand and to use it regularly, not just for charging a battery after it has gone flat but to keep the battery fully charged during periods when it is not in use. Of course, lead-acid batteries are used not only in cars but in a wide range of other applications as well, such as ride-on mowers, emergency lighting systems and portable transceivers. Battery maintenance is just as important in these applications as it is for the battery in your car. In some cases, the battery is used on an infrequent basis and requires regular recharging to keep it in good condition. Regardless of the application, a good charger, correctly used, will ensure maximum performance from your battery (or batteries) when needed. It may also save money by ensuring maximum battery life. Lead-acid batteries are not cheap, so it makes sense to take care of them by investing in a good charger. Unfortunately, many battery chargers on the market are built to a price. They are relatively cheap but lack features that ideally should be included in any charger worthy of the name. One of the worst aspects of some cheap battery chargers is that, incorrectly used, they can damage a battery and shorten its life expectancy. Most battery chargers provide a "fast" charge rate, typically 4-6 amps. Some chargers also provide a much lower "trickle" charge rate which is selected by a switch. The idea is that the "fast" charge rate is selected when charging a flat battery and the "trickle" charge rate is selected to keep the battery topped up once it has become fully charged. The main problem with this type of charger occurs if it is inadvertently left on the "fast" charge setting for prolonged periods after the battery has fully charged. In this situation, the battery will be overcharged, resulting in gassing and drying out of the electrolyte inside the battery. Permanent damage to the battery can result with consequential shortening of battery life. There could also be a serious safety hazard due to the highly explosive gases generated when a battery has been overcharged. The solution to this problem is a battery charger which monitors the battery voltage and automatically reduces the charging current as the battery approaches full charge. This is the principle behind a regulated battery charger and is the basis for this project. Commercially-built regulated battery chargers are hard to find and are The two power transformers used in the unit are mounted on an L-shaped aluminium bracket which also serves as a heatsink. The remaining electronic circuitry performs voltage, current & temperature regulation. expensive because of the extra circuitry that's involved compared to conventional (unregulated) battery chargers. This project, however, uses low-cost, readily available components to minimise the overall cost but without compromising on performance. In addition, it offers a combination of features that are difficult to find in commercial chargers. Main features This charger will charge 6V, 12V and 24V automotive type lead-acid batteries. However, it is not intended Specifications • Automatically charges 6V, 12V & 24V lead-acid batteries. • LED indicators show high, medium or low battery charge. • Electronic regulation of voltage & charging current. • Features temperature, shortcircuit & reverse battery protection. • 1OA maximum output current; 8A continuous output current at 12V. for charging sealed (gel) type leadacid batteries which have different charging requirements. Its main features include electronic output voltage regulation, output current limiting, output short circuit protection and protection against reversed battery connections. A LED display on the front panel indicates the level of battery charge either LOW, MEDIUM or HIGH. This eliminates the need for a more expensive, and mechanically more fragile, moving coil ammeter or voltmeter. The heart of the battery charger is the electronic regulator circuit. This uses an SCR which operates in a switching mode to control the output current. This type of regulator circuit is much more efficient than the linear regulator circuits used in some battery charger designs. In practical terms, this higher efficiency translates into a higher output current capability for a given size of input transformer and a smaller heatsink for the output regulating element (SCR). And, in case the heatsink gets too hot, the circuit also incorporates thermal shut-down to protect the SCR from damage. Unlike conventional battery chargers, this unit does not require a bat. O CTOBEH 1992 57 Cl CXl ~ Cl'.) i:=1 ~ R ~ F1 A~ 2 1.5A 1 7 0 T1 ' . ... SCR1 MCR264-4 ~ + t i ! A~ i ~ r 0--o-~r 15A i T ' 1'.. 240VAC .,. NO J , D3 !1N4002- .,. RB ! 10k' 02 BC546 .., R13 82k E El, BATTERY VCC R7 100k VCC 6/12V SENSE ADJUST 6V VR1 20k r-1 +5V I B -:- ,ffio E1LJc I I RTH1 +5V R14 100k 1ii .J.: 12/24V SENS ADJUST 24V R19 100k VIEWED FROM BELOW fNv-- I I +5V +5V ~ ~ R2l 150!.1 5W I I I ECB' .,. TEMPERATURE SENSE +5V c1.i: 10! .015!.1 COPPER TRACK ON BOARD .,. R12 8.2k A I R16 22k I :--•--~ .,. 35VWJ A~K .....J! C5..,,; R17} 47k R20f 47k ........... ~ b-+5V 1+ +5V R22· 2.2k t. VCC B R18' 1.8k .,. +5V .,.- OPTIONAL RELAY BATTERY SELECT RELAY CONTROLLER REGULATED BATTERY CHARGER C6.i: 10J R29 56Dn .,. tery selector switch. Instead, it automatically sets the output voltage to suit the battery being charged. This feature makes this charger more convenient to use than ordinary battery' chargers - all you have to do is connect the leads to the battery. It also prevents the possibility of damage to the charger or to a battery that might otherwise result if a switch was set to the wrong voltage. How it works VB VREF__/ /1 [/ /1 [/ /1 L VB VREF VOUTLJLJLJl VOUTU7Jlf1 Fig.2: this diagram shows how the sampled battery voltage (V 8 ) on pin 4 ofICla interacts with a reference voltage (VREF) on pin 5 at intermediate battery voltages. As the battery voltage rises, ICla's output (VouT) goes high later during each mains half cycle and thus the SCR turns on for shorter periods of time. The circuit for the battery charger is shown in Fig, 1. Let's see how it battery voltage is compared with a reference voltage to derive an error works. Power for the circuit is obtained signal. This error signal is then used from the mains via a pair of trans- to control the SCR. When the battery formers, Tl and TZ. Each transformer voltage is low, SCR1 turns on early in has a pair of tapped 15V secondary each half-cycle of the mains AC wavewindings which can be connected in form, so that a large current flows into various configurations for different the battery (see Fig.7). At the end of output voltages. Relay RLY1 connects each AC half-cycle, the unfiltered DC the secondary windings of Tl and TZ voltage to the SCR drops to zero, alin a parallel configuration for charg- lowing the SCR to turn off in readiing 6V and 12V. batteries, and in a ness for the next half cycle. As the battery voltage approaches series configuration for charging 24 V batteries. The transformers are each the value set by the reference voltage, rated at lO0VA, giving a total input SCR1 is progressively turned on later in each half-cycle so that the average rating of Z00VA. current is reduced. When the battery For those who may be wondering, the main reason for using two trans- . voltage reaches the set value, SCRl is formers instead of one is that' high off for most of each half-cycle so that only sufficient current flows into the power transformers are quite expensive. It was cheaper to use two smaller battery to maintain its charge. A voltage divider (R13 & R34) betransformers than a single transformer tween the positive and negative terwith the same total VA rating. Diode bridge BR1 converts the AC minals is used to sample the battery output voltage from the transformers voltage and is adjustable by means of to an unfiltered DC voltage which is VRl. Op amp ICZa acts as a voltage follower and buffer but, due to the applied to the anode of SCRl. This DC voltage is also fed to a voltage effect ofC4, ignores the ripple voltages divider and filtered by capacitor Cl to generated across the battery terminals derive a supply rail (Vee) for the regu- by the battery charging current. This lator circuit. Diode Dl isolates the ensures a smooth regulating characfiltered DC voltage from the unfiltered teristic and avoids some of the adverse affects that can occur with more DC voltage ar.plied to SCRl. conventional circuits. During operation, a sample of the Voltage regulation is accomplished by ICla which is part of an LM339 quad comparator IC with open collector outputs. In this type of comparator, a pull-up resistor must be fitted to Fig.1 (left): the circuit uses op amp get a high output. comparators ICla, IClb & IClc to ICla compares the sampled battery phase control SCRl to provide voltage voltage on its pin 4 input with a refer& current regulation. ICla generates ence voltage applied to its pin 5 inthe voltage control signal; IClb the put. This reference voltage is derived temperature control signal; & IClc the from 5V regulator IC4 (via a voltage current control signal. IC2b & IC2c divider consisting ofR12, R17 & R18) provide the automatic voltage and carries a superimposed ramp selection feature (6V, 12V or 24V), waveform voltage which is generated while IC3b, IC3c & IC3d drive the three indicator LEDs. by ICld and capacitor C5. This ramp waveform is synchronised to the half cycles of the AC mains waveform. When the battery voltage is low, the voltage at pin 4 ofICla is less than the reference voltage at pin 5. ICla's output is therefore high and this turns on QZ, Ql and SCRl so that current is supplied to the battery. Conversely, when the sampled battery voltage exceeds the reference voltage, ICla's output goes low and QZ, Ql and SCR 1 turn off. At intermediate battery voltages, the voltage on pin 4 intersects the ramp waveform on pin 5 to give a pulsed waveform at the output of ICla - see Fig.2. As the battery voltage rises, the output of IC la goes high later in each half cycle and SCRl is turned on for a proportionately smaller fraction of the time. Current limiting Current limiting is achieved using current sense comparator IClc. During operation, the charging current flows through a resistance of 0.015Q (formed by a copper track on the PC board). This resistance is in series between the negative battery terminal and ground and so the voltage across it will be proportional to the charging current. The resulting voltage is then filtered by R19 and C7 and applied to pin 6 of IClc for comparison with a reference voltage on pin 7. This reference voltage is derived from the bottom tapping of voltage divider R12, R17 & R18 and again carries _a superimposed ramp waveform which is derived from ICld. As the voltage across the 0.015Q resistor rises, it interacts with the ramp voltage and IClc narrows its output pulses. This proportionately reduces the on-time of SCRl during each mains half-cycle, thus limiting the average current into the battery. Temperature limiting is achieved · OCT0in·: ll 1992 59 a 6V or 12V battery, the normally closed (NC) relay contacts connect the transformer secondary windings in parallel. If a 24V battery is connected, the output of IC3a goes high and turns on Q3. This, in turn, activates the relay, which then connects the transformer secondary windings in series. LED indicators Use plastic cable ties to keep the wiring tidy & check all wiring before applying power. The relay on the regulator board switches the transformer secondary windings·in parallel for 6V/12V batteries & in series for 24V batteries. using IC1b and this works in a similar manner to IC1c. In this case, however, the sensing device is a thermistor (RTH1) which is mounted next to SCR1 on a heatsink. It forms part of a voltage divider network (along with R24) and varies its resistance according to the temperature. The resulting voltage developed across R24 is then applied to pin 8 of IC1b and compared with a ramp voltage on pin 9. At low temperatures, the voltage on pin 8 will always be below the ramp voltage and so IC1b has no effect on the output current. If, however, the heatsink temperature rises, IC1 b progressively increases the phase angle of SCRl to reduce the output current. This means that the current is reduced smoothly rather than abruptly as the heatsink temperature approaches the set limit. Voltage selection Comparators IC2b & IC2c provide the automatic voltage selection feature. As previously stated, IC2a generates an output voltage that's proportional to the battery voltage. Its output at pin 2 is then connected directly to pin 10 of IC2b and to pin 8 of IC2c via a voltage divider consisting ofR14 & R15. 60 SILICON CHIP The resulting voltages on pins 10 & 8 are then compared with a +5V reference on pins 11 & 9. If a 6V battery is connected, the outputs of IC2b & IC2c will both be off and the output of IC2a is fed directly to pin 4 of the voltage sense comparator (IC1a) via R7. However, if a 12V battery is connected, the output ofIC2b will go low. This effectively connects one end of R10 to ground and so R7, VR2 and R10 now form a voltage divider on pin 4 of IC1a to set the correct charging voltage for a 12V battery. If a 24V battery is connected, the output of. IC2c also switches low and pulls Rl 1 to ground, thus setting the correct voltage divider ratio for charging a 24 V battery. Comparator IC2d sets the output current limit when charging 24V batteries. When a 24V battery is connected, the output of IC2d goes low. This pulls resistor R9 to ground and thus halves the reference voltage on pin 7 of IClc. This, in turn, reduces the current limit to half that used for 6V/12V batteries. Comparator IC3a controls relay RLYl and this, in turn, switches the secondary windings of the mains transformers in series or in parallel, depending on the battery voltage. For Comparators IC3b-IC3d control th e LED indicators. The inputs of IC3b are in parallel with the inputs ofICla. For low and high battery voltages, the output ofIC3b swings close to OV and +5V, respectively. For intermediate battery voltages, the output of IC3b is a pulse waveform with a duty cycle that increases with battery voltage. This waveform is smoothed by R28 and C6 and applied to the non-inverting inputs of IC3c and IC3d. IC3c and IC3d form a window comparator. When the battery voltage is high, the output of comparator IC3c turns off and Q4 turns on (via R31) and lights LED 2. At the same time, the current through LED 1 is bypassed since there is insufficient forward bias to turn the LED on due to the presence of D5. Similarly, when the battery ·voltage is low, the output of IC3d turns off and Q5 turns on and lights LED 3. For intermediate battery voltages, both comparator outputs are low and LEDs 2 and 3 are off. LED 1 is now no longer bypassed by either of the other two LEDs and consequently turns on. Construction This project is housed iri a moulded plastic case which consists of a base and cover. The transformers and 240V wiring components are mounted on an aluminium L-shaped plate which also serves as a heatsink for the SCR and bridge rectifier. Most of the remaining parts are mounted on two PC boards. The larger board is used for the regulator circuitry _and relay, while the smaller board carries the LEDs. Before commencing the assembly, use a piece of wet-and-dry sandpaper to smooth the mounting areas for the rectifier bridge and SCR on the vertical face of the aluminium plate. This is especially important in the case of the SCR because it must be insulated from the metal plate with a thin insulating washer. If there are metal burrs, ON HEATSINK- + BR1 ~ Fig.3: install the parts on the PC board & run the wiring as shown in this diagram. The external wiring connections to the board are made using quickconnect spade terminals. Be sure to use heavy-duty (10A) cable for all wiring connections on the secondary side of the transformer. they may cut through the insulating washer and cause a short circuit between the SCR and the plate. Fig.3 shows the wiring details. Start the assembly by mounting the 240V fuseholder and terminal block on the base of the aluminium plate. This done, solder a length of 240V 2-core flex to the fuseholder and cover the solder joints with a plastic or rubber sleeve. The fuseholder terminals, incidentally, have holes through which the wire ends should be looped be- fore they are soldered. This way, if the solder joints come loose for any reason, the wire ends will not come away from the terminals. Now bolt the two transformers and the earthing connector lug to the aluminium plate. Run the wires from the fuseholder and the primary windings of the transformers together and slip a 75mm length of 10mm diameter plastic sleeving over these wires. The free ends of these wires are now fitted with quick-connect spade terminals using a suitable crimping tool. Important: all the quick-connect spade terminals used for the 240VAC connections should have plastic insulating sleeves, to minimise the possibility of human contact with live terminals. For the sake of your own safety, do not use non-insulated terminals. Connect the primary leads of the transformers to the terminal block as follows: blue wire to blue wire and brown wire to brown wire. Now connect one of the wires from the fuse holder to the terminal for the brown wires, then connect the other wire from the fuseholder to a separate terOCT0BER 1992 61 - Power Supplies Bench-Top Instruments FUNCTION GENERATORS GW GFG 2 MHz SERIES] GFG SERIES COMMON FEATURES Frequency Range 0.2 Hz to 2 MHz, continuously variable. Output Waveforms sine, triangle, square, TTL pulse and ramp Output Level > 20 Vp-p open circuit, 10 Vp-p into 50 ohms VCF Oto 10V input for 1000:1 output frequency variation DC offset of± 10 VDC GFG-8016G ► Frequency Counter & 2 MHz Function Generator Special Functions Frequency Counter • Internal or External operation • Frequency range 0.1 Hz to 10 MHz • Sensitivity s; 20 mV rms 10 MHz • 6 digit LED display GFG-8017G ► Sweep Function, 2 MHz Function Generator Special Function Sweep Generator Operation • Auto or Manual sweeping • Sweep width is 1000:1 ratio • Sweep time is variable from 0.5s to 30s • Sweep modes LIN, LOG (.HULo) - FUNCTION GENERATORS GFC-F SERIES l ► Competitively Priced ► Professional Quality GFC-8010F/8010G 120 MHz Frequency Range: 1 Hz to 120 MHz Sensitivity: S20 mV 10 Hz to 100 MHz s;30 mV 100 MHz to 120 MHz Display 8 digit display and Gate Time 0.1 s, 1s, 10s GFC-8055F/8055G 550 MHz Frequency Range: 1 Hz to 550 MHz Sensitivity: Input A s;2Q mV <at> 100 MHz Input B S150 mV<at> 550 MHz 8 di! LED and Gate Time 0.1 s. 1s and 10s 11, I ii !!MM!NT COUNTERS 1• GFC-G SERIES 1 ► Frequency, Period and RPM Ranges The GFC-8131G is an economically priced 1.31 GHz counter. Additional features include a continuously variable Gate Time control as well as adjustable variable Level/Sensitivity. Front panel switches include AC/DC input coupling. LPF and attenuator controls. GFG-8019G Multifunction 2 MHz Function Generator Special Functions 3 units in 1 • Inbuilt Frequency Counter, same as GFG-8016G • Inbuilt Sweep Generator, same as GFG-8017G • AM and FM Modulation, internal or external ► GFG-80200 Digital Readout 2 MHz Function Generator Special functions large 0.5 inch, 4 digit LED display for frequency indication ► AUDIO SIGNAL GENERATOR ► Low Distortion Oscillator The GAG-808G is GW Instruments' latest general purpose audio oscillator. Being an RC type oscillator ensures a pure, low distortion sinewave output over the entire frequency range. A switchable output attenuator, calibrated in steps of 10 dB, makes the GAG-808G ideal in teaching as well as service applications. Both the sinewave and square wave outputs can also be varied by a continuous ampl~ude control. GAG-808G Frequency Range: 10 Hz to 1 MHz, in 5 ranges Sinewave Output: >20 V pk-pk; Distortion < 0.1 % Squarewave Output: >10 V pk-pk; Rise time< 200 ns Output Impedance: 600 ohm Stepped Attenuator 0 to -50 dB in 10 dB steps GFC-8131F 1.3 GHz Frequency Range: 0.01 Hz to 1.3 GHz, AC or DC coupling Period Range: 0.6 rpm to 7,200 rpm Sensitivity: Input A 10 mV<at> 80 MHz I utB50 mV<at> 1.3GHz 11 AA ;t-f ■ 1 ): IN Escort GW POWER SUPPLY BASIC FUNCTIONS Continuously variable voltage and current from zero to rated limit with FINE and COARSE controls. Outputs are electronically protected against short circuit or overload conditions. The input is fuse protected, with a true 240V AC input. Automatic Constant Voltage - Constant crossover with LEDs 1• GPG-8018 Frequency Range: 0.5 Hz to 5 MHz Pulse width and spacing independenUy variable 100 ns to 0.1 s Functions Run, Trigger, Gate, One shot, Square, invert Outputs TTL (Fanout 40) Variable Output (0,5 to 10V) for CMOS Synchronisation Output (Fanout 10) CAT. No. MODEL PRICE CAT. No. MODEL PRICE 10003 10004 10005 10006 10009 GW-GFG-8020G GW-GFG-8017G GW-GFG-8016G GW-GFG-8019G GW-GAG-808G 398.50 408.50 485.50 552.50 269.50 10011 10012 10013 10015 10016 GW-GPG-8018G GW-GFC-80100 GW-GFC-8055G GW-GFC-8131G GW-ESC-2200 369.50 276.50 405.50 558.00 553.50 GPS & GPR-DIGITAL SERIES 1 1• GPC-DIGITAL SERIES SINGLE output DC Supplies 2 Analogue Panel Meters, V and A The GPR-Series includes Floating Output, allowing either side to be linked to ground. FINE and COARSE voltage and current control. Clearly marked analogue panel meters, CLASS 2.5 1• Low ripple noise components, typically 0.5 mV rms to 1 mV rms. Excellent line and load regulation, typically 0.01 %. Dual and Quad output supplies with SERIES and PARALLEL functions. Guaranteed for 12 months, with 9 years experience in Australia 1 1• GPC-SERIES 1 ► ► SINGLE Output, DC Supplies ► Two 3'/, Digit LCD Panel Meter, V or A The GPR-D Series includes Floating Output, allowing either side to be linked to ground. FINE and COARSE voltage control. An inbuilt, autoranging 200V DC Digital Voltmeter (100VA models). 1 ► TRIPLE Output DC Supplies ► TRIPLE Output DC Supplies ► Two 3'/, Digit LED Panel Meters ► 4 Analogue Panel Meters Dual Variable Outputs Dual Variable OU1puts Switch selectable configurations Switch selectable configurations Independent both outputs controlled separately Independent both outputs controlled separately Dual Tracking provides Master/Slave control voltages Duel Tracking provides Master/Slave control voltages Parallel doubles output current range Parallel doubles output current range Series doubles output voltage range Serles doubles output voltage range Single Fixed OU1put Single Fixed OU1put Each output has an overload indication LED. Both Variable and Fixed outputs are floating. SPACE SAVER SERIES Inbuilt Logic Probe 5V DC Power Supply Output GPS & GPR-SERIES ► il!t•X•l: ii AA ;t-W EUC-2200175 MHz Frequency Range: 5 Hz to 175 MHz (CH A), 5 Hz to 2 MHz (CH B) Period Range: 0.5 µs to 0.2s, 5 Hz to 2 MHz (CH A) Frequency Ratio Measurement: 11 (CH B)/f2 (CH A) Totalise Range o to 99999999 (CH A) Time Interval Measurement Range 0.5 µs to 0.2s Sensitivity: Input A <150 mV <at> 175 MHz Input B <30 mV <at> 2 MHz Di a 8 . HED ► ► ECONOMICAL LABORATORY DC POWER SUPPLIES Iskra MODEL RANGE CAT No. PRICE GPS-1830 GPR-1810H GPS-2020 GPR-3060 GPR-6030 GPS-3030D GPR-6030D GPC-1850D GPC-3030D GPC-1850 GPC-3030 0-18V 0-3A 0-18V 0-10A 0-30V0-3A 0-30V 0-SA 0-60V 0-3A 0-30V 0-3A 0-60V 0-3A 2x0-18V 5A, 1x5V 3A 2x0-30V 3A, 1x5V 3A 2x0-18V 5A, 1x5V 3A 2x0-30V 3A, 1x5V 3A 10201 I0202 10203 10204 10205 10206 10207 10208 10209 10210 10211 282.50 723.50 395.50 479.50 535.50 489.50 654.50 742.50 742.50 714.00 714.00 HSG-SERIES, 1 phase Single Phase, Panel Mount The HSG-Series are open frame type variable transformers, designed to be incorporated in control panels and other dedicated equipment. They can all be mounted vertically or horizontally, except for the high power HSG-0602 which must be installed vertically. Front panel includes dearly labelled scale and control dial. A screw type terminal block is used to connect input and output leads. Input voltage is 240V Ac, 50 to 60 Hz. W·i;J,., :j! Ii ;H: M:(•) ;1f'ii3;t-i I ,i1'l ~K HSG 0022, 0052, 0102, 0202 and 0602 ELECTRONIC KITS & MODULES BI-FET PRE-AMP WITH 3 WAY TONE CONTROL $72.00 This super low distortion stereo pre-amplttier uses high slew rate wide bandwidth TL-074 op-amps for 0.005% total harmonic distortion. RIM curve deviation is 0.2 dB. Tone controls can be switched in and out. Fully regulated power supply. Low, High and Mid tone controls. SPECIFICATIONS Frequency response: 10 Hz to 100 KHz, ±0.5 dB CAT No. S0307 Total harmonic distortion: ±0.005% at rated output Intermodulation distortion: 0.005% at fated output Sensitivity: · 2.5mV<at> 47K Phono: 100mV<at>100K Aux· and tape: RIM deviation: ±0.2 dB, 20 Hz to 20 KHz Signal to noise ratio: Phono: 75dB Tuner, aux and tape: 90dB Output: Tone controls: ±10 dB at 50 Hz Bass: Mid: ±5dBat 1 KHz Treble: ±10 dB at 15 KHz Dimensions: 8"x4.13"x 1.38" 15 V DC<at> 0.5to 1 amp. Power requirements: 36W PURE CLASS A MONO POWER AMPLIFIER $64.00 Audiophiles will instantly recognise the unchallenged superiority of pure class A operation. The circuit uses full complementary driver stages and a quasi-complementary darlington transistor output stage. If you desire extraordinarily dean sound this amplifier is for you! CAT No. SPECIRCATIONS Power Output: 36 watts into 8 ohms Frequency response: 10 Hz to 20 KHz Less than 0.01% Total harmonic distortion: Voltage gain: 30dB 22 VAC x 2, 3 amps Power requirements: 5¾"x3"x1'/a" P.C.B. Dimensions: 51/a" X 25/e°' X 3" Heat sink: 250W (BTL 320W) ALL FET, DUAL DIFFERENTIAL, SYMMETRICAL STEREO DC FINAL AMPLIFIER CHARACTERIsTIcs: CAT No. S0314 $199.00 • Equipping loudspeaker protector, ensuring speaker safety. • Equipping a rectifier section for power supply, with 2 powerlul filter capacitors, maintaining powerfully supply voltage during high output • DC circuit design without input and negative feedback blocking capacitor, the lowest frequency response • reaching DC (0 Hz), making the bass more sonorous and powerful and the treble clearer. ' • FET and MOSFET integrated design. incorporating the advantages of both vacuum tubes and transistors. • 12 inches black and big heatsink without leads for exterior connection. • 6 pairs of 120W N. channel and P. channel MOSFET with class AB power outputs, extra low transient distortion, new circuit design. MAIL ORDERS WELCOME: CHEQUE, MONEY ORDER, BANKCARD, MASTERCARD, VISA OR AMERICAN EXPRESS PHONE OR WRITE TO US FOR A COPY OF PRICE LISTS SHOP HOURS: Mon-Fri: 9.00-5.00. Sat: 9.00-1.00 All prices include Sales Tax STATE OF THE ART FULLY COMPLEMENTARY SYMMETRICAL FET STEREO PRE-AMPLIFIER $159.00 Significant features of this outstanding stereo preamplttier are the use of fully complementary and symmetrical FET transistor stages. Employs 1% metal film resistors. Power supply is fully regulated. Has a time delay circuit which prevents turn-on thumps. Power supply components are on board so that It requires only an external transformer. SPECIFICATIONS Frequency response: RIAA curve deviation: Total harmonic distortion: Intermodulation distortion: Channel separation at 1 KHz: Hum and noise: Phone: Aux: Phono sensttivity: Output: Record output: Maximum output at 0.1% distortion: Power requirements: Power consumption: 10 Hz to 100 KHz ,0.2 dB, 30 to 15,000 Hz Less than 0.007% at rated output Less than 0.005% at rated output Better than 70 dB Better than 70 dB Better than 90 dB 2mV<at>47K 1.5V (0.01% T.H.D.) 150mV 15V External transformer, 30V x 2 12W <at> 400 0-SOV 6A HIGH EFFICIENCY, CUT-OFF AND AUTO-RESET, ELECTRONIC-PROTECTED, REGULATED POWER SUPPLY CHARACTERISTICS: Employs professional regulator IC ()IA723) for high stability, reliability and low ripple. Auto input regulator decreases the dissipation at about one-fourth the other. Efficiency is increased and the wasted heat is decreased. Sophisticated protector device is a cut-off type protection. The reaction is faster than fuses. Do not damage the loaded device or regulator tt..W. Built-in testing circuit. No need to press reset button. All-purpose identifying sound indicator uses sound and LED to indicate varied operating status. Over-load indicator, voltage adjuster and current-protector selector switch. Has current adjustable circuit. High power output transistor is mounted on a larger U-pit heat sink. Output is sufficient and cooling effect good. Rectifier circuity also has larger heat sink. Only needs to connect a power transformer. 0-30V 10A PROFESSIONAL HEAVY-DUTY REGULATED POWER SUPPLY WITH PROTECTOR CIRCUIT CAT No. S0008 $89.00 CAT No. S0009 $84.00 CHARACTERISTICS Employs professional regulator IC ()IA 723) for high stability, reliability and low ripple. Multi-Purpose IC protector is equipped with cut-off protection and current limited protection and is selected by a switch. It is suitable for all kinds of conditions. The protector circuit employs fully IC and the design is elaborated. It operates at very high speed and is faster than fuse and conventional transistor protector circuits. Do not damage any load or regulator itself. It is durable and reliable. IC protector circuit is a new design. (The protector circus is completed and tested). IC protector besides protects from overload, it recovers automatically after the overloading is gone. Don't need to reset. The operating status of the protector is displayed by an indicator. Equipped with output rejustor, protecting-current selector (divided into 2.5A, 5A, 7.5A and 10A) and status selector. The design is made whole. It includes rectifier, filter and noise suppression circuits. The rectifier circuit is equipped with heat sink that keeps the operator in safely. Only need to connect power supply. Four high•current power transistors are mounted on a professional heat sink, cooling effect is good and output is stable. · RESISTOR COLOUR CODES 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 No. Value 4-Band Code 1% 5-Band Code 1% 5 1 2 1 4 3 2 1 1 6 2 2 1 1 100kO 91kn 82kO 56kO 47kn 22kO 10kO 8.2kO 5.6kO 2.2kO 1.8kO 5600 150O5W 1200 1000 10W 560 brown black yellow brown wt,ite brown orange brown grey red orange brown green blue orange brown yellow violet orange gold red red orange brown brown black orange brown grey red red brown green blue red brown red red red brown brown grey red brown green blue brown brown not applicable brown red brown brown not applicable green blue black brown brown black black orange brown white brown black red brown grey red black red brown green blue black red brown yellow violet black red brown red red black red brown brown black black red brown grey red black brown brown green blue black brown brown red red black brown brown brown grey black brown brown green blue black black brown not applicable brown red black black brown not applicable green blue black gold brown minal on the terminal block. The aluminium plate and the parts mounted on it may now be fixed to the plastic base using two self-tapping screws. These are installed from the outside of the case and are adjacent to the bend in the bracket. When that is done, attach the four rubber feet to the underside of the plastic base with four 12mm-long self-tapping screws installed from the top of the base. Note that two of these screw_s pass through the corners of the aluminium bracket. grommet into the hole in the aluminium plate. Note: this cordgrip grommet is installed from the underside of the case. The next step is to use short lengths of heavy-duty hookup wire to connect the secondary windings of one of the transformers in parallel. Make sure that the terminal marked "OV" on one winding is connected to the terminal marked "OV" on the other winding. Similarly, check that the two 15V terminals on opposite sides of the transformer are connected together. Fig.3 shows the details. Mains cable The mains cable can now be installed by running it through a 12mmdiameter hole in the aluminium plate. Run this cable between the transformers and under the wires from the primary windings of the transformers. Crimp quick-connect terminals to the wire ends and connect them as follows: Active (brown) to fuse terminal on connector block; Neutral (blue) to transformer primary (blue) terminal on connector block; and Earth (green) to the earth lug bolted to the aluminium plate. Note that all the crimp connectors must be fitted with insulating sleeves. At this stage, you should also connect a 3-pin plug to the opposite end of the cable if one is not already fitted. S_ecure the cable by pushing a cordgri p 64 SILICON CHIP WARNING! Hydrogen gas is generated by batteries under charge. For this reason, always charge batteries in a well-ventilated area and do not generate sparks by connecting high-current loads directly to the battery terminals. When using the battery charger, always connect its output leads to the battery before switching on the mains power. Any failure to observe this simple precaution can lead to dangerous arcing at the battery terminals when the charger is connected and, in extreme cases, could even cause the battery to explode. When this job is completed, connect the two secondary windings of the other transformer in parallel (ie, connect the two OV terminals together and the two 15V terminals together). The terminals marked "12V" are left unconnected. Voltage checks Check all wiring thoroughly, then use the "ohms" range on your DMM to verify that there is good electrical continuity between the Earth pin on the mains plug and the aluminium plate. Check also that there are no shorts between any of the plug pins. You can now do a quick test by plugging the unit into a power point and switching on. Measure the voltages across the secondary windings of the transformers using an AC voltmeter to confirm that all is correct. You should get a reading of around 16-17VAC. If any of the voltages are incorrect or if the fuse blows, recheck the mains wiring and the transformer secondary connections. · Main board assembly No particular order need be followed when installing the parts on the main PC board, although it's best to leave the larger components until last. Make sure that all polarised components, such as the ICs, transistors, diodes and electrolytic capacitors, are with plastic tubing before connecting them to the header, socket. Heatsink assembly This close-up view shows the bridge rectifier & the heatsink bracket that's used to secure the SCR & thermistor. Tighten the bracket mounting screw firmly but don't overtighten it, otherwise you risk damaging the SCR. The 4-pin header strip on the PC board (in front of the fuse) connects to a matching socket & 4-way cable that runs to the LED indicator board. Be sure to plug the socket in with the correct polarity, otherwise the LEDs won't work. ALUMINIUM PLATE -----(HEATSINK) ---ALUMINIUM BRACKET ALUMINIUM BRACKET SELF-TAPPING SCREW ~~~1', 'scR---- o~'J~:i\i:• \ (~~THERMISTOR .):f'....,._'J I RUBBER WASHER C~UIT BOARD / . . _ __ _ _ _ _ _ _ ____. APPLY HEATSINK COMPOUND TO BOTH SIDES OF RUBBER WASHER Fig.4: this diagram shows the mounting details for the SCR & the thermistor. Install the thermistor so that it lines up with the midpoint of the SCR body & smear all mating surfaces with heatsink compound before attaching the bracket. correctly oriented. The SCR is mounted at full lead length, while the thermistor must be mounted so that its body lines up with the centre of the SCR. A 4-pin header strip is also mounted on the board and this mates with a complementary socket that's wired back to the LED board. These headers come supplied in strips of eight (or more) pins and it's simply a matter of snapping off the number of pins required. External wiring connections to the board are made using quick-connect spade terminals. There are six such wiring points and you should solder a male spade lug to the board at each location. The three indicator LEDs can now be installed on the small board. Use a yellow LED for LED 1, a green LED for LED 2 and a red LED for LED 3. Make sure that all the LEDs are correctly oriented - the anode lead is always the longer of the two (see Fig.1). The four wiring leads between the LED board and the header socket are run using 200mm lengths of lightduty hookup wire. Begin by soldering these four leads to the board, then bundle them together and sleeve them The PC board is supported on the base of the case by four plastic mounting posts. The mounting posts used here each have a clip-in end which locks automatically when pushed 1nto the mounting hole. When these posts have been fitted, clip the board into position and slide the thin rectangular thermal washer supplied with the kit behind the SCR. Position the thermal washer behind the SCR exactly as shown in Fig.4, then trace around its outline with a pencil. This done, remove the PC board and apply heatsink compound to the back of the thermal washer. The thermal washer should now be mounted on the metal bracket by using the heatsink compound to hold it in position. Next, clip the main board back onto the mounting posts. Adjust the position of the rubber washer if necessary and position the thermistor as close to the SCR as possible. Apply generous amounts of heatsink compound between the rubber washer and the thermistor and the SCR, then stick a piece of foam rubber to the back of the SCR mounting bracket - see Fig.4. Finally, attach the metal bracket to the aluminium plate using a self-tapping screw to secure the assembly. Be careful not to overtighten the screw, otherwise you could damage the SCR. The bridge rectifier can now be installed on the metal plate, to the left of the SCR assembly. Smear its mounting surface with heatsink compound, then attach it to the metal plate using a 4 x 10mm bolt. · The wiring from the transformer secondaries to the diode bridge and to the main board must be run using heavy-duty (10A) hook-up wire. Solder the four leads to their respective transformer secondary terminals, then bundle them together and slip a 50mm-length of 10mm plastic tubing over them. The two leads that go to the bridge rectifier are now soldered to the AC terminals (see Fig.3), while the two remaining leads are fitted with quick-connect spade lugs and connected to the main PC board. The remainder of the wiring from the bridge rectifier can now be completed. As before, use 10A cable for OCT0 BER1992 65 PARTS LIST 1 PC board, code SC14110921, 177 x 72mm · 1 PC board, code SC14110922, 34 x 15mm 2 M-2170 30V CT mains transformers (Altronics) 1 3AG 1.5A 240V fuse (F1) 1 3AG 15A fuse (F2) 4 PCB fuseclips 1 3AG fuseholder 1 12V 10A DPDT relay 4 plastic PCB mounting posts 2 cordgrip grommets 4 plastic feet 6 plastic cable ties 1 200mm-length of 10mm-dia. heatshrink tubing 1 200mm length of 4-core light duty cable 1 plastic case 6 plastic rivets 1 aluminium baseplate 1 aluminium heatsink bracket 1 piece of foam rubber, selfadhesive, 10 x 8mm 1 packet of heatsink compound 1 mains lead with plug 1 4-pin header 1 4-pin socket 1 insulating washer, 30 x 20mm 8 PC mounting spade lugs 16 female spade lugs 1 5-way 240V terminal block with spade lug connectors 1 1.5m-length of heavy-duty hookup wire 1 1-metre length of heavy-duty (1 0A) figure-8 cable with battery clamps 1 front-panel label 4 self-tapping 4 x 12mm screws (to secure rubber feet) 3 self-tapping 4 x 6mm screws 5 4 x 10mm bolts (to secure transformers & earth lug) 3 4 x 15mm bolts (to secure the mains terminal strip & bridge rectifier) 8 4mm nuts 8 4mm washers 1 Philips 6.8kQ NTC thermistor (RTH1) 3 20kQ trimpots (VR1 ,VR2,VR3) Semiconductors 3 LM339 quad comparator ICs (IC1-IC3) 1 78L05 3-terminal regulator (IC4) 66 SILICON CHIP 1 35A bridge rectifier (BR1) 1 MCR264-4 40A SCR (SCR1) 1 BC556 PNP transistor (01) 1 BC546 NPN transistor (Q2) 1 BD679 Darlington transistor (Q3) 2 BC548 NPN transistors (Q4,Q5) 5 1N4002 silicon diodes (D1-D5) 1 1N4751 30V 1W zener diode (ZD1) 1 5mm yellow LED (LED1) 1 5mm green LED (LED2) 1 5mm red LED (LED3) Capacitors 2 100µF 35VW electrolytic 1 100µF 16VW electrolytic 2 10µF 16VW electrolytic 1 1µF 50VW electrolytic 1 .01µF monolithic Resistors (0.25W, 1%) 5 100kQ 1 91kQ 2 82kQ 1 56kQ 4 47kQ 3 22kQ 2 10kQ 1 8.2kQ 1 5.6kQ 6 2.2kQ 2 1.8kQ 2 560Q 1 150Q 5W 1 120Q 1 56Q Calibration circuit 1 1N5404 3A diode 1 10µF 50VW electrolytic capacitor 1 100Q 1OW resistor Where to buy the kit A short-form kit of parts for this project is available from the author for $65 plus $15 p&p. This kit includes a predrilled case, the metal baseplate & heatsink bracket, a front panel label, \ he PC boards, all the semiconductors, the thermistor, the PC mounting spade lugs, the thermal washer, the mains terminal block, mounting posts for the regulator board, & the battery cable & clamps. It does not include the power transformers, the mains cord, minor hardware items, the relay or minor PC board components (note: other parts available on request). Payment should be made by cheque or money order to: H. Nacinovich, Beryl Rd, Gulgong, NSW 2852. Phone (063) 74 1486. Note: copyright of the PC artwork associated with this project is retained by the author. these leads and fit them with spade lugs to make the connections to the board. Check all these wiring connections very carefully; it's all too easy to make a mistake here. Finally, feed the heavy-duty (10A) 2-core battery cable through a hole in the plastic base, fit the leads with quick connect terminals and connect them to their corresponding terminals on the PC board. Use a cordgrip grommet to secure the cable to the plastic base and fit the far ends of the cable with large battery clips. Calibration To calibrate the battery charger, you will need a voltmeter (preferably a digital multimeter) and a 0-30V DC variable power supply. You also need a 100Q 10W resistor, a lOµF 50VW capacitor, a 3A diode and some hookup cable (note: the power supply, resistor and capacitor are used to simulate the battery). The step-by-step calibration procedure is as follows: (1). Connect the lOOQ resistor, diode and capacitor across the output of the variable power supply as shown in Fig.5. Do not connect the charger at this stage. (2). Switch on and adjust the variable supply for 6.8V across the lOOQ resistor. (3). Connect the battery charger output leads across the resistor, as shown in Fig. 5. Switch on the battery charger and adjust VR1 so that the LED display just changes from "MEDIUM" to "HIGH". (4). Switch off the battery charger and adjust the power supply output to give 13.6V across the lOOQ resistor. Switch on the charger again and adjust VR2 so that the LED display just changes from "MEDIUM" to "HIGH" as in step 3. (5). Switch off the battery charger and adjust the power supply output to give 27.2V across the lOOQ resistor. Switch on the charger again and adjust VR3 so that the LED display again just changes from "MEDIUM" to "HIGH". That completes the calibration procedure. By the way, if your variable power supply only goes to 20V or so, you can obtain the extra voltage required for step 5 by connecting a 12V battery in series with it. Testing Before placing the unit into general service, it's a good idea to check that PCB and SCHEMATIC CAD 3A OIODE COVER REMOVEO +t - - - ~- -- - - - - - - + - IM-+-1+ 100n 10W BATTERY CHARGER 10 50VW + _ VARIABLE POWER SUPPLY (0·30V) :·· ,__ r .. _ Fig.5: this circuit is used to calibrate the unit, so that it charges the battery to the correct voltage on each of the three ranges (6V, 12V & 24V). Just follow the step-by-step instructions in the text. --- - - ·::t = UQlJID!I. I ~ ..... : - : TV IFAMPLIFJE •.:: , '" I ' \. F -~- ,,, '1'\lli':6",---ti . ~ !"'"'~ ! .:: i _--------------- '------------_______ 1-10A AMNIETER .J BATTERY CHARGER LEAD-ACID BATTERY Fig.6: this test circuit is used to ensure that the current & temperature limiting circuits are working correctly. The 12A load can be made up by connecting several high-power automotive lamps in parallel. SCR1 INPUT VOLTAGE EASY-PC • Runs on PC/XT/AT/286/386 with Hercules, CGA, EGA or VGA. VOLTAGE PIN 13, IC1d • Design Single sided, Double sided and Multilayer boards • Provides Surface Mount support SCR1 CURRENT, FLAT BATTERY • Standard output includes Dot Matrix/Laser/Inkjet printers, Pen Plotters, Photo-plotters and NC Drill SCR1 CURRENT, BATTERY NEAR FULL CHARGE Fig.7: if you have an oscilloscope, you can compare the voltage waveforms on the input of the SCR & on pin 13 ofICld against those shown here. The bottom two waveforms show the SCR current for a flat battery & an almost fully-charged battery respectively. Notice how the SCR turns on later in each half-cycle as the battery nears full charge. • Award winning EASY-PC is in use in over 12,000 installations in 70 Countries World-Wide • Superbly Easy to use • Not Copy Protected Options: • 1000 piece Schematic symbol library the current and temperature limiting circuits are working correctly. To do this, you will need a 12V lead-acid battery in reasonable condition, a 0lOA ammeter (ie, a digital multimeter), and a resistive load which draws at least 12A. A suitable load can be made up by connecting several high-power 12V automotive lamps in parallel. If you don't already have the lamps in your workshop, try scrounging a couple of old sealed headlamp units for a few · dollars from a wrecker's yard. The required load can then be made up by connecting the high and low-beam circuits in parallel to give a total load of about 160-170W. Of course, you can also use eight 20W globes in parallel if you have them on hand. You can easily calculate the load current using the formula I= P/V, where I is the current, P is the total wattage of the globes, and V is the battery voltage. To test the charger, connect it to the battery with the 10A ammeter in series with the positive lead as shown • Surface Mount symbol library • Gerber Import facility For full info 'phone, fax or write: BTC PO BOX432 GARBUTT 4814 QLD. PH (077) 21 5299 FAX (077) 21 5930 OCT0HEH1992 67 The mains cord is installed from the underside of the base & is clamped using a cordgrip grommet. Be sure to fit insulating sleeves to all the quick-connect spade lugs that clip on to the mains terminal block, to protect yourself from accidental contact with the mains. TABLE 1: OUTPUT CURRENT VS. BATTERY VOLT AGE Battery Voltage Nominal Actual Charger Output Current (measured at actual battery voltage) 6V 10A (+/-1A) 6.9V* 200mA (max). 11 V 9A (+/-1A) 13.8V* 100mA (max) . 22V · 5.5A (+/·0.5A) 27.6V* 100mA (max). 6V 12V 24V An entry marked with an asterisk (*) indicates the voltage across the battery when it is fully charged. in Fig.6, but don't connect the resistive load at this stage. Switch on and check the current reading. This will depend on the state of charge of the battery but should be not exceed the limit specified in Table 1 (ie, 9A ±1A). If the battery is flat, the output current will probably be very close to the specified 9A limit, due to the current limiting action of th(l regulator circuit. If, however, the current exceeds the specified limit by an appreciable amount, switch the charger off immediately and check the main board for wiring errors and incorrect component values. In particular, check the 68 SILICON CHIP values of Rl 7 and R18. Assuming everything is OK, connect the load across the battery as shown in Fig.6 and note the ammeter reading. This should approach the specified 10A limit although, if the battery is fully charged, it may be necessary to wait a while for the battery voltage to drop sufficiently for the current limiting action to come into effect. In other words, a fully charged battery will initially supply part of the load current, thus giving a lower than expected current reading until the battery partially discharges. Do not disconnect the battery for this test; its presence is necessary to ensure that the charger switches to the correct output voltage. As before, switch off immediately and check the regulator circuit if the charging current exceeds the specified limit by a significant amount. Finally, check the voltage at pin 8 of IClb. At a heatsink temperature of 25°C, this voltage should be approximately 1. 2V. During normal operation, the heatsink temperature will rise above the ambient level and the voltage on pin 8 of IClb should rise accordingly. At high charging current levels, the heatsink temperature may rise to 65°C or thereabouts, at which point the voltage on pin 8 of IClb should be about 3.6V. IClb should now act to reduce the charging current to prevent additional temperature rise, as described previously. If, at any temperature, the measured voltage on pin 8 of IClb is significantly outside the range expected or does not increase with heatsink temperature, check the circuitry around thermistor RTH1 and R24. Note that, ideally, the charger should also be tested with 6V and 24 V batteries. However, this will not usually be practicable and it's generally safe to assume that everything is OK if the circuit checks out with a 12V battery. Final assembly The display board can now be mounted on the cover. Enlarge the holes if necessary until the LEDs are a snug fit and note that the green LED (HIGH) goes towards the top. A dab of adhesive can be applied to the sides of the LEDs to secure the assembly in position. This done, fit the label to the cover, plug the LED wiring connector into the main board, and fit the cover to the base. Finally, secure the cover using the plastic rivets supplied. These rivets come in two parts: a bush and a pin. The bushes are pushed through holes in the sides of the cover and matching holes in the .b ase flanges. The pins are then pushed into the centres of the bushes to prevent the rivet assemblies from coming apart. To remove the cover, use a punch to push the plastic pins out of the bushes. The bushes can then be removed by pulling them out of the cover. SC S/1,ICO/li -CBIP • J ~· ♦ o. ~ } . ~'. . , . The Philips PM3394 digital/analog scope While more than half the world wide sales of oscilloscopes are now of digital storage models, there is still a big demand for analog performance. Recognising this, Philips has recently released a new range of analog/digital scopes which combine the best of both worlds. By LEO SIMPSON We had the chance to review the top model of the range, the Philips PM3394. This is a 200MHz 4 channel scope with a digital sampling rate of 200 megasamples/second. It also was fitted with the "Math+" option and the GPIB/IEEE488.2 option, making it a very powerful measurement instrument, as we shall see. In the last 12 months or so, there has been an accelerating trend towards digital-only oscilloscopes with raster scanned cathode ray tubes; ie, borrowing from the technology of computer video monitors. These have the advantage oflarge bright displays and compact size. On the debit side, there are some signal measurement situa- tions where the analog scope is definitely preferred and this is mainly to do with low signal levels and those where waveform fidelity is all important. Clearly, a raster scanned digital scope cannot provide true waveform fidelity - the good old vector scanned cathode ray tube can, can't it? Well , in fact, that statement is not quite true and it is only when you see the combination of the two different scope types that you fully realise that both digital and analog displays can reveal or conceal details of a signal waveform. In effect, there is a very good argument in favour of this type of combination instrument. The Philips PM3394 uses a conventional PDA (post deflection acceleration) tube with an acceleration voltage of 16.5kV. The tube viewing area .0CTOflEH 1992 73 is 8 x 10cm and all settings can be displayed on screen. To the right of the screen is a column of six blue buttons which are softkeys - their function changes depending on which control menu is displayed on the righthand side of the screen. On the lower half of the control panel are buttons which provide the normal control features which you would expect to associate with each of the four vertical inputs; ie, sensitivity, coupling (AC, DC or GND) and triggering (positive or negative slope). For each input channel, there are two buttons to control the sensitivity. Pressing the down or up button causes the sensitivity to change in a 1-2-5 sequence from 20mV/div to 50V/div if a 10:1 probe is connected or from 2mV/div to 5V/div if a 1:1 probe is connected. The type of probe connected is automatically compensated for if Philips 9000 series probes are used or it can be switched, via the probe menu, if a non-Philips probe is used. In addition, if you push both the up and down buttons simultaneously for a moment, you can then vary the sensitivity continuously from 20mV/div to 125V/div, with 3-digit resolution, if a 10:1 probe is connected. The facility of a calibrated continuously variable input attenuator is very useful and the ability to go to 125V/divmeans that AC mains voltages can easily be measured and displayed. Interestingly, if you are in the digital mode, you can have a vertical input sensitivity of much more than 20mV/div. By calling up the Display menu on the screen, you can call for vertical magnification of up to 32 times. This equates to a vertical input sensitivity of 625 microvolts per division. Of course, measuring signals at these low levels means that quantising noise becomes an appreciable part of the displayed signal. However, you can then get around part of that problem by using an averaging (AVG) mode for the signal display. But we are getting ahead of ourselves in presenting this review. On the upper half of the control panel are the controls for the main timebase, delayed timebase and trigger selection. The timebase can be varied in 1-2-5 steps from 500 milliseconds per division up to 20ns per division and this can be increased by a factor of 10 to 2ns/div. In the digital 74 SIUCO .\' CIIIP The Philips "Touch Hold & Measure" probes supplied with the PM3394 scope are a useful innovation. When the scope is in digital mode, pressing the Command button on the probe freezes the waveform on the screen together with the principal measurements. By the way, the "T" symbol on the other probe button is an earth symbol. Pushing that button grounds the probe. mode, on the other hand, the time base can run much slower, down to 200 seconds per division. At this minimum rate, it would take 2000 seconds, or 33 minutes to scan the screen once! Triggering facilities The triggering facilities are especially comprehensive. Pressing the Trigger button brings up a menu on the screen which allows you to select between "edge", logic and TV modes. The "edge" mode is conventional triggering and you are able to select AC or DC coupling, low frequency or high frequency reject and positive or negative edge triggering. In TV mode, you can select field 1 or field 2 or lines and then you can go on to select the actual line number to be displayed. Video systems supported are HDTV (1050, 1125 or 1250 lines), NTSC, PAL and SECAM. While the PM3394 is a combination digital/analog scope, all the controls mentioned have been associated with the analog mode of operation although clearly, they have the same function when the unit is in digital mode. Autoset button Perhaps the most useful button of all is on the top lefthand corner of the control panel and it is the Autoset button. When all else fails and you can't make any sense of a test setup you are doing, you can always restore sanity by pressing the Autoset button. This causes the scope to measure the signals present at the four inputs and then select timebase and vertical attenuator settings which give a useable display. From that point you can then alter settings to proceed to the measurement you want. Digital control facilities All the digital scope facilities are brought into play by the row of buttons along the top of the control panel . and the "soft" buttons down the righthand side of the screen. In general, the buttons along the top call up function menus on the lefthand side of screen and these can then be selected and varied using the soft buttons. For example, say you have a square wave on the screen and you wap.t to measure its principal parameters such as voltage and frequency. The first step is to push the "measure" button which brings up the first "MEASURE" menu on the screen. Pushing one of two soft buttons brings up "MEASl" or "MEAS2" menus on the screen. These a-llow you to display readings of voltage such as DC, RMS, MIN, MAX, PKPK (peak to peak), Low, High, overshoot, and preshoot. You can also display time parameters such as frequency, period, pulse duration, rise and fall times and duty cycle. All of these measurements are scrolled through by rotating the track knob These two scope photos show the same signal displayed in analog (left) & digital (right) modes (although with slightly different attenuator settings). Note that the analog trace is slightly blurred due to noise superimposed on the signal. Again, these two shots show the differe_nces between the analog (left) and digital displays. The analog trace shows the blurring effect of noise while the digital trace shows glitches which are otherwise invisible. By the way, the PM3394 has the facility for inserting user text comments on the screen, as seen here. This is very useful when taking scope photos as a permanent record. which doubles as one of the cursor controls at other times. Touch hold probes This brings us to the alternative method of making measurements which is unique to the Philips PM3300 series of scopes when teamed with the PM9000 series of probes. These probes provide two facilities whkh can be very useful and these are accessed via the UTILities button. One is "Autoset" which enables the appropriate vertical input sensitivity to be set for the signal being displayed. The other is "Touch, Hold & Measure" which allows the signal being displayed to be frozen on screen together with readings for DC level, RMS value, peak to peak value and frequency. This is done by pushing the "Command" button on the probe once. Pushing it once again reverts the scope to the previous display mode. Also on the probe is another small button with a "T" marking which you might think was meant for the "touch and hold" facility. That's what we thought but it is actually a grounding button and the "T" is the European symbol for earth. That threw us for quite a while until a Philips sales representative put us right. Regardless of that, the touch and hold facility is a really good idea and particularly useful where you have difficulty making connection to an instrument but wish to store and measure the signal. Of course, you can do the same thing by saving and storing a waveform so that its parameters can be measured and analysed but the touch and hold probe is such a convenient idea. We think it is sure to catch on with other scope makers. Picture quality The major difference between analog scopes and digital storage scopes is the way in which they present signal waveforms on the screen. With analog scopes, the signal waveform is repeatedly scanned across the screen so that what you see depends on the sweep speed. At low sweep speeds it is safe to say that the waveform displayed on the screen is essentially very close to the waveform being measured, after allowing for non-linearities in the CRT's deflection system. At higher sweep frequencies, the waveform displayed on the _screen is also close to that being measured except that any high-frequency noise superimposed on the signal will tend to show up as a slight blurring or thickening of the trace. By contrast, on digital scopes, the same waveform is subject to a one-off sampling process each time the screen waveform is updated. This means that the waveform is likely to have a spikier appearance than if it was displayed on an analog scope. The spikes will partly be due to the discrete quantising steps but also partly due to the superimposed noise on the waveform. On a raster scanned digital scope you also have the problem that the display is made up of discrete dots and depending on the nature of the signal (and the keenness of your eyesight), these fine dots will be more or less evident. In the case of the Philips PM3394 scope though, the display process is essentially the same in digital or analog mode. You may wonder how this can be but remember that this scope uses a conventional vector scanned cathode ray tube (CRT) - ie, the electron beam is moved across the screen by the signals applied to the horizontal and vertical deflection plates. In the digital mode, signals pass through the input attenuators and are then processed by the analog to digital conversion circuitry.. The result-. ing digital signals are either stored to memory and further processed or are fed to the digital to analog conversion circuitry where they are converted back to analog signals to be displayed on the screen. Because of this additional conversion process, the screen display is not made up of dots. (Although, just to confuse the issue, one of the display menu options is a dot waveform). Not only is the display a continuous waveform but the very high sampling rate of 200 megasamples per second means that waveform fidelity in the digital mode is very good. In most measurement situations, the only real difference between waveforms displayed in analog and digital modes is that in digital mode the trace will . O CTOBER 1992 75 be brighter, sharper and will show more hash. And as noted above, the hash will partly be due to noise and spikes on the signal and partly due to the quantising process. If you then switch to the "Acquire" m enu and select averaging, anywhere between 2 and 4096 samples, you can clean up the waveform as much as you want. However, the more samples you select, the slower will be the response of the displayed waveform to changes in the signal. In practice, we found that selecting an average of 8 samples was a good compromise, giving excellent waveform fidelity and quick response to signal changes. In fact, for most of the work done in the SILICON CHIP lab, we think this digital + average would be the preferred mode. One reason why the waveform fidelity is so good in this mode is that it increases the effective vertical resolution from 8 bits to 16 bits. And even if you do stay in the digital mode most of the time, it is always possible to flick back to the analog mode. at any time just by pressing the digital button; pressing it again flicks you back to digital mode. In this way you can check the differences in the display and check for the presence of glitches. Math+ option An overview of the comprehensive autofitatic measurement functions was given above but these tend to pale when you consider th e power of the "Math+" option. This involves a separate card with its own processor and a great deal of ancillary circuitry. In effect, it turns the PM3394 into a powerful signal analyser. And this is on top of the standard mathematical functions in all the PM3300 series. These comprise Add, Subtract, Multiply and Digital Filter. Typically, the Add function can be used to add a displayed signal to that of another input channel or a stored signal. The same applies to the Subtract and Multiply functions. For example, you could use the Multiply function to compute the product of voltage and current signals and hence display the power waveform. The Digital Filt er provides a selectable low pass filter in which the lowest corner frequency is inversely proportional to th e timebase fre- quency. This function allows you to display a signal and then show its shape after the signal has passed through the filter. The filter corner frequency (-3dB point) is displayed on the screen at the same time. The additional functions provided by the Math+ option are Integrate, Differentiate, FFT (Fast Fourier Transform) and HST (Histogram). The first two are more or less self-explanatory and can be easily demonstrated using a square wave signal; integration of a square w ave gives a triangular waveform while differentiation gives rise to an impulse waveform with positive and negative spikes corresponding to the positive and negative going edges of the square wave. For those not familiar with FFTs, this function effectively turns the scope into a spectrum analyser with a signal dynamic range of 50dB. In the FFT mode, the signal is processed into its fundamental and harmonics and these are displayed in the frequency domain; ie, amplitude versus frequency. One of the photos accompanying this review shows the classic FFT of a square wave with the odd harmonics displayed with decreasing A unique family of full function pocket-sized digital rnultirneters. ■ LARGE LCD DIGITS SAFETY TESTER ■ SAFETY TEST LEADS ■ FUSED 10A CURRENT JACK ■ INPUT WARNING BEEPER ■ DM5XL DM10XL DM15XL $71.00 $98.00 $120.00 Al l prices plus 20 % sales tax. JE ST LUCIA ELECTRONICS 24 Campbell St. Bowen Hills Q 4006. Tel: (07) 252 7466 Fax (07) 252 2862 ECONOMIC ELECTRON/CS: 22 Campbell St. Bowen Hills Q 4006. P.O. Box 481, Fortitude Valley 4006. Tel: (07) 252 3762. Fax (07) 252 5778. SOUTHPORT ELECTRONIC SHOP: Shop 1, 10 Welch St. Southport Q 4215. Tel: (075) 32 3632. Fax: (075) 51 0543. 76 SILICO N CHIP STOCK SALE!! FANS 80 x 80 x 25mm 240VAC .. ... $15.00 120 x 120 x 38mm 240VAC . $15.00 MISCELLANEOUS The interior of the Philips PM3394 is quite different from units we have seen in the past. It has a large moulded plastic chassis and large double-sided printed circuit boards which are packed with surface mount components. The CRT is fully screened and the outer case of the unit is vinyl coated aluminium. The large coils at the rear of the tube are the delay lines for the vertical amplifiers. amplitude against increas ing fre quency (ie, 1F + 1/3F3 + 1/5F5 + ). To identify the frequency, you just move a vertical cursor along the signal trace and you get a readout of the frequency and its amplitude, down to -50dB. FFT analysis can be applied to input signals and to stored signals alike and is particularly useful for analysing one-shot signals. When you consider that the FFT covers the whole frequency range of the instrument (ie, up to 200MHz in the case of the PM3394), this is a very powerful and cost-effective option indeed. HST (Histogram) is an unusual feature which displays the voltage distribution of a signal against time. For example, a perfect square wave will have a histogram which indicates that the signal is high 50% of the time and low 50% of the time. Real world signals have a much more complicated voltage distribution and the HST facility can reveal a lot of information which has previously been unavailable from normal scopes. Although this has been a relatively long review of the PM3394, it cannot hope to cover the instrument's full range of features. We were very impressed with this oscilloscope and predict that it will sell well in the years to come. It has a good range of features encompassed in its digital and analog display modes and its Math+ option is very worthwhile; in fact, some buyers are likely to purchase the PM3394 almost for this option alone. The prices of the four models in the PM3300 series are as follows. Top of the range is the PM3394 with 4 input channels, 200MHz bandwidth and 200MS/s sample rate and priced at $10,919. Next down is the PM3392 with the same bandwidth and sample rate and 2 plus 2 in put channels ( ie, 2 channels with full attenuators and two with switched sensitivity) and priced at $10,079. Then there is the PM3384 with 100MHz bandwidth, 200MS/s sample rate, four input channels and priced at $9239. The PM3382 variant has the same ban dwidth and sample rate and 2 plus 2 channels and is · priced at $8399. Three options are applicable to the whole range. The Math+ option is $840 while th e GPIB/IEEE488 .2 card and the 32Kb memory card are also $840 each. These prices do not include sales tax. For further information, contact Philips Test & Measurement Division, 25-27 Paul St North, North Ryde, NSW 2113. Phone (02) 888 8222. SC EA frequency cou nter (1 only) ... .. .. .............. .... .... ... .... $200 Mains power lead with plug 10A .... ... ........ ... ..... :. $4.00 Mains power plug ..... ...... ........ $2.00 Cable ties 94 x 2.4mm ... .. .. ... ....... ... .. ... .. ... ... . $4.00 per 100 FM stereo transmitter ..... .... .. $49.95 Cera mic resonator 3.58MHz .. $1 .00 ALKALINE BATTERIES AA size ........ ... ..... ... ... .... $1 .40 each C size .. ....... ...... ..... ........ $2.25 each 9U PP3 size ... .... ........ ... $4.30 each D s ize ..... ...... ....... .......... $3.00 each SEMICONDUCTORS 1N4004 .... .... .... ..... ..... ...... ... ... $0.05 1N4007 .... ... .. .... .... .. ... .. ... ..... .. $0,08 1N4148 .... .... .............. ........ .. .. $0.04 MJ1 5003 .. ........... ....... ....... .. ... $6.50 MJ 15004 .... ..... ........ ...... .... ..... $6.50 MJ15024 ..... ...... ......... ..... .. ..... $8.60 MJ 15025 ... ..... ... .... :.. ..... ... ..... . $8.60 TOA 1023 .... .. .... ...... ... ..... ..... ... $4.30 TDA1085 ...... ... .... ................. $18.00 TC9142 ..... .. .... ........ ... ... ......... $5.50 MC14514 .. .... .... .... ........ ... ..... . $3.00 NE555 ......... .. .. .. ......... ......... ... $0.40 MJ E13007 ... .... .. .. .... .. .... .:.... .. . $4.00 ALL ITEMS 10 PlUS 10% OFF HVCAL ELECTRONICS Unit 4, 62 Gt. Western Hwy, Parramatta, NSW 2150. Phone (02) 633 5477 Fax (02) 891 ·5540 Credit Cards Welcome OCT0BER1992 77 AMATEUR RADIO BY GARRY CRATT, VK2YBX How to make transmitter measurements Amateur radio operators have a responsibility to ensure that the power, frequency & harmonics of their transinitters are maintained within specified limits. This requires the use of some specialised test equipment to make accurate measurements~ gains to be had in the surplus test equipment market. For instance, a Hewlett Packard HP5245 frequency counter, which has an accuracy of three parts in 109 (ie, 3Hz per 1GHz!), can readily be obtained for a few hundred dollars. These counters offer far Watts To dBm Conversion Chart Perhaps the most obvious transmitter parameters that must be monitored are power output and frequency. Fortunately,transmitter frequency is relatively easy to check, if not with an inexpensive frequency counter, then with a receiver covering the particular band of operation. Some VHF and UHF repeaters even have a system whereby an audio tone is transmitted by the repeater, dependent upon the frequency error of the incoming signal. If we assume that a frequency error of 0.005% is accept- able on the VHF amateur bands, this equates at worst case, to an actual frequency error ofless than lkHz. Most kit frequency counters, have similar accuracy. However, professional test laboratories use frequency counters having an accuracy of five parts in SILICON CHIP +3OdBm +36.98dBm 10W +4OdBm 15W +41.76dBm 2OW +43.O1dBm 25W +43.979dBm 1010_ 3OW +44.77dNm Look for bargains 35W +45.44dBm Although a frequency counter kit having reasonable accuracy can be obtained for several hundred dollars, there are also some exceptional bar- 4OW +46.O2dBm 45W +46.53dBm Surplus test equipment can often be picked up on the secondhand market at bargain prices. This HP5245 frequency counter only costs a few hundred dollars & has an accuracy of three parts in 109 , making it ideal for frequency checks. 78 1W 5W SOW +46.98dBm 55W +47.4OdBm 6OW +47.78dBm 65W +48.13dBm ?OW +48.45dBm 75W +48.75dBm BOW +49.O3dBm 85W +49.3.dBm 9OW +49.54dBm 95W +49.77dBm 1OOW +5OdBm 1O5W +5O.21dBm 11OW +5O.41dBm 115W +5O.6OdBm 12OW +5O.8OdBm 12sw +5O.97dBm 13OW +51.14dBm 135W +51.3OdBm 14OW +51.46dBm 145W +51.61dBm 15OW +51.76dBm L2 OUTPUT ~ L1, L2 AND L3 : 2T, 1mm ENCW WOUND ON 8mm DIA FOAMER Fig.I: this simple notch filter circuit provides 30-40dB of attenuation in the 144-148MHz amateur band. The notch filter can be built on a small piece of blank PCB material & housed in a metal diecast case. superior value for money. A range of plug-in modules for these counters can extend the range of the instrument up to 12GHz. (HP-432A, etc) offer an accuracy of 0.2%, at a cost of $500-$700. Output power Amateur operators must also be able to measure transmitter output power. This is perhaps the easiest measurement to make, considering the range of low-cost HF/VHF/UHF power meters that are now -available. However, care should be taken to ensure that the rating of the power meter is not exceeded. When measuring the output power of an SSB transceiver, a "PEP" (peak envelope power) meter should be used. The "industry standard" power meter is the Bird model 43. This is an insertion type power meter, requiring plug-ins for different frequency bands. This can add significantly to the cost. Also it can only claim an accuracy of 5 % . More accurate measurements can be achieved using a thermistor mount and power meter. These instruments must be used in conjunction with an in-line attenuator. By taking the displayed power level (usually in dBm) and adding the value of the series attenuator, the transmitter's power output can be calculated. These instruments are broadband, usually offering a frequency coverage from 10MHz to 40GHz or so, and covering power levels from as low as l0µW to 10mW, when used without external attenuators. The accompanying table shows the relationship between watts and dBm. Hewlett Packard produced a series of these power meters during the late 1970s and early 80s. Models HP-43 lA/ B/C can be found at surplus test equipment stores for as low as $300 or so. Such an instrument offers a measurement accuracy of 3%. Later models Transmitter harmonics The amateur bands are harmonically related to ensure that interference from maladjusted transmitters falls within other amateur bands. Even so, good operating practice dictates that amateurs should be capable of measuring harmonic radiation levels at the transmitter output. Transmitter harmonics are most easily measured using a spectrum analyser. However, some precautions are necessary before connecting a transmitter to a spectrum analyser. A typical spectrum analyser such as the Hewlett Packard model 141, available to amateurs at a reasonable price, has a dynamic range of 50dB or so, and clearly, the transmitter cannot be con- nected directly to the analyser. So an attenuator or "pad" must be inserted between the two pieces of equipment. The value of this attenuator must be such that the spectrum analyser is not driven into overload (compression). A typical 25W transmitter (+44dBm) must be connected via 70dB of attenuation to reduce the signal level at the analyser input to -25dBm (around 220mV into a 50Q. load). Such attenuation can be achieved by connecting several discrete attenuators in series. The first must be capable of handling the transmitter output power, while the remaining attenuators can have a lower rating (dependent on the value of the first pad). In most cases, a fixed attenuator is directly connected to the transmitter and variable attenuators are used to optimise the input to the spectrum analyser. However, this approach has one serious drawback. By attenuating all signals by 70dB or so, the spectrum analyser would need a display range of over 80dB to readily observe a transmitter harmonic having a power level of -30dBm (ie, -74dB with respect to the fundamental). What is really needed is a selective attenuator, or filter. By notching the fundamental frequency by 25-40dB, without affecting the level of the harmonics, a reduced amount of additional attenuation is necessary, enabling those harmonics to be more easily observed on the spectrum analyser. Fig. l shows the circuit diagram and layout of a suitable filter. This has a notch attenuation of 30-40dB in the 144-148MHz band and only 0.ZdB attenuation at the second and third harmonics. The unit is easily constructed in a diecast aluminium box and the filter components can be mounted on a piece of blank PCB material. By drilling holes in the lid of the box, access can be obtained to the trimmer capacitors, thus making the filter adjustable. SC Hamfest 92 The "industry standard" Bird model 43 is an insertion-type power meter with plug-in modules for different frequency bands. The Northern Corridor Radio Group (VK6ANC) has advised us that their annual event "Hamfest 92" will be held on Sunday, 1st November at the usual venue of Carine College of Tafe, in Perth, WA. All are welcome. OCT0BEH 1992 79 Phone Your Order To Us Toll Free We guarantee our Jetservice Courier will deliver to your door faster than any other Australian supplier (including that local supplier just up the road). If we fail, I'll give you your money back plus $5.00 for your inconvenience. 2 Sector Ararm System Kit Here's a simple project that monitors the power drawn from a 'master' socket and automatically switches on a 'slave' socket. It will monitor one or several appliances plugged into the 'master' and switch on one or several devices pi ugged into the 'slave'. Ideal fo r Hi-Fi's or computers with peripheral hardware. K 6070 $59.95 Solar Generator Kit (EA March/ April '89) Features: • Includes 12V 1.2 Amp hour Easy to build, assembles on a single PCB • Two sectors delayed and instant inputs • Entry and exit delay • Panic alarm ~~t~~~~:i~;e 4 Channel Guitar Mi xer & p reamp K"t I :::dn:a~~nia~~sl:~r acid car battery via the sun. Ideal for boats, caravans and remote data acquisition stations etc. (SC Jan 1992) This project takes advantage ~~:row suitab le solar panel. noise, K1680 $13.95 low cost _B_a_b_y __R_o_o_m _..,M ,..,,..o_n..,i-to - r----1 ;~~~~~~ "tter features separate bass, midrange and trebel controls, very low noise and Transml & KitFM distortion, separate input level controls 0 il:~ BABY AOOM This Baby Room t.tONffOR Monitor allows you to Iisten to your baby from a remote location using a conventional FM receiver . It runs from a single 1.SV AA battery and includes a muting faci lity so that it only transmits sounds above a certain level. $24 K1180 .95 Ni-cad Battery Discharger Kit Designed to rid your ni-cad batteries of the 'memory effect' and regain full re-charge potential. It discharges your nicad batteries correctly to enable a full and proper re-charge. Suit most battery packs. Great for mobile phones, rechargeable drills, remote controlled toys etc. K1640 $24.95 New 4-Channel Lighting Desk input • Line monitoring • Soft prealarm • Lamp tell-tale output • Auxilliary relay for external siren etc • Key switch operation • Operates on virtually any type of sensor From The Sun. The Solar Generator charges Must be used in conjunction with a (SC Dec '90) This 4 Digit Combination Lock is bound to prove useful in many applications. Such as accessing alarm systems, electronic doors, ignition killers or just about anything that comes to mind. Momentry or latched relay output. inbuilt sealed leadacid backup battery • K1910 $89.oo (ETI Dec '87) Four Digit Combination Lock Kit K1925 $44.50 ~i~~ ~n0 ~1u~~~i~e;e;'n;fr~t~o~~:~~~b~r use keyboards to guitars to tape decks. In fact, you can feed it with just about any audio signal - it's not just limited to guitar outputs. K5535 $49.95 Transistor Tester Kit (EA Aug '83) Checks transistor in circuit. "No need to unsolder suspect transistors". Have you ever de-soldered a suspect transistor, only to find that it checks out OK? Features: • Tests both · NPN and PNP transistors in circu it at the touch of a switch • Tests Diodes and SCRs as well • No need to switch between NPN and PNP - it's automatic • LED indication to show condition of device. K253o$17.5o Adjustable 0-45V, 8 Amp Bench Power Supply (SC Jan/ Feb '92) K3360 $375 .00 Using state of the art circuitry this supply will be a great asset to the enthusiast and professional alike. It uses switch mode principles which allows for smaller transformers, and heatsinking wh ich means greater efficiency, less heat and lighter weight. Featurea: • Variable output • Variable current limit • Separate Earth Terminal • Individual Volt .and Amp Meters• Constant 13.BV setting • Short circuit proof Speclflcatlona: • Output voltage 0-45V • Output current BA <at> 35V, 6A .<at>. 40V • Load regulation 1% • Ripple and Noise 40mVp-p at BA 35V • Current limit 800mA8.6A • Over current limit 9A • Foldback current less than 2A (SC June/July '91) Make your atag• production a profeNlonal lhow with thla new Lighting Mixer. Ideal for 1m1teur thHtre groupa band• etc. This 4-channel lighting desk is intended for theatre, disco and music group applications. It has heavy duty circuitry and is able to cope with spotlights rated up to 1000 watts or more. It has been designed and built for the rigours of commercial use. You can flash each channel up to any brightness as set by the 'Flash Master' fader. Similarly, the 'Channel Master' control fades all lights up or down, to or from their individual fade settings. Two chaser faders control the rate and lamp brilliance when the unit is operated in chaser mode. The lights can be flashed to full brilliance or to an intermediate s,•tting as set by the 'Chaser Master' fa~~ K5815 Normally $3 .00 This Month $299 .00 Mini Home PABX Telephone Exchange Kit (SC Aug/Sept '92) This great unit allows you to place calls on hold, intercom other extensions, answer cal Is from any extension and transfer calls. It is expandable up to 10 extensions, and is compatible with all DTMF (touch tone) telephones. ! Operation is as simple as •· pressing '*' to place a call on hold, press the . extension number (0-9) - .- - -•• -_ -_ ,- .-- •- .~ and the respective station rings. Once answered, you have a two way intercom , with which you can announce a call. To pick up the incoming call from hold press '#'. A neat feature is that all extensions will ring when an incoming call is. placed on hold for 30 seconds so that it won't be forgotten. Basic kit rs comp lete with power supply, case and facilities for 3 extensions. Extra extension boards allow expansion in multiples of 3. Simple operation, fantastic for home or small office. No more shouting from room to room. NB: Not Telecom I cm•nH<at>I K1430 Basif Kit $189.oo K1435 -- -- -~"------ . .J Expansion Board Digital Voice Recorder Kit $79.95 Approved (SC Dec '89) This Digital Recorder delivers astonishing reproduction of voice and/or music without any moving parts. It can store 4 different 38 second messages or 1 recording up to 2 minutes. Typical applications include• Alarm system messages • Sales messages for customers put on 'hold' • Talking Displays for shops • Emergency wa rning messages • And countless other applications where voice or music is required • K 9550 PCB alone version • K 9555 Includes fully punched & screen printed instrument case. K 9550 PCB Format $129.95 K9555 With Instrument Case Laboratory Power Supply Kit $149.95 K330o$195.oo (EA May '85) 3-50 Voll ■ at up to 5 Amp• This supply has been one of our most popular. lt inc ludes the latest refinements and is now housed in a tough 'ABS' instrument case. This compact version uses a . . . high efficiency toroidal transformer resulltng in less heat and weight. • Exclualve to Altronlcs • Deluxe instrumerit case • Attractive silk screened front panel • Pre-drilled and punched chassis - No holes to drill • Front panel drilled for K3302 option. Specifications: • Output Voltage: 3 to 50V • Output Current: 5 Amps Max • Floating Output • Ripple: less than 5mV • Dual Meters 1O Turn Pot For Precision Voltage Control Option K3301 $4.50 Fixed +/ -12V Rails lndependant of Main Output K3302 $14.50 Get 240V AC from your car, truck or boat battery. The Altronics range These kits use quality Vila speakers made in Denmark and spec.ially engineered enclosures for includes an inverter for nearl y ev ery application . Fantastic for camping, boating, farms and anywhere else 240V AC isn 't available . Each size inverter optimal performance. Black wood grain veneer make them ideal for any decor and situation. These two way models include high grade crossovers, speaker terminals and removable front grille. Simpl~ construction with only basic tools and skill is available in kit form or fully built and tested. The 300 and 600 Watt Inverters now feature new improved circuitry using multiple mosfet outputs making them even more reliable with a genuine 300 or 600 watt continuous power rating. Our latest model, the 1200 Watt Powerhouse offers excellent value for money and performance. It features crystal locked circuitry and a massive 2400 watt power surge making it ideal for small fridges , vacuum cleaners, power tools etc. Any model an absolU1e necessity where 240V isn't available. Call Altronlc1 today for more information on freecall required . These kits are complete and include speaker cloth, damping material, grille ci1ps, speaker te r minals , screws and parts. Outstanding performan ce for the fra ction of the cost of commercial equivalents. 008 999 007. VI FA SA-50 2 Way Bookshelf System, 50 Watts RMS 300 Watt 6750 Kit Version $279 K 6755 Built-up $379 K Famous Vlfa 5" Woofer H~Jtto'lo We have a huge surplus Vila C13WG-08-08 woofe These quality drivers offe high performance in both ported and sealed enclosures. Exceptionally s useable up to SkHz. Careful d construction using rubber surr it possible to obtain an amazin RMS power calabicity. Fantast replacement or new constructi 3110 Normally ~ 0 0 Now 6.5" Carbon Flbr C Woofer A fine driver using only high quality components and technology. For example fl1&-P-Q~l!"110 sl! 11 -:,, 600 Watt $499 K 6770 Kit Version K Built- up 12v Input K " . '. : -_, l___ . .. ._, C!Oow•lloc/4 -=-'Z , , ''"•,,,., barium ferrite magnets, revolutionary Kapton voice coil and unique c arbon fibre cones . 6774 Built-up 24V Input $62._ -------- ....__ All Models ' ''I ntery elude rieavY 6775 Leads 5 outy Ba1 Because of the high water Normally 1200 Watt K K K 6790 Kit Version $799 6792 12V Input $9 6793 Built-up Built-up 24V Input 99 Now Only $7aa-:'50 -,., $699.oo pr ~"'-----------------1 Stereo Extension Celling Speaker Kit Want a set of high grade extension speakers for the back patio, games room , den, workshop, kitchen? Well here at Altronics we have put together this great kit which includes speakers, grilles, cable , screws and even a wall mounted volume controller. The speakers are our high quality 4" C 0626 dual cone drivers, with stylish white grilles - ideal for mounting in the ceiling . Volume c ontrol mounts in standard electrical wall box and includes 6 volume settings as well as off . Includes 2 x 20m cable. 00 Watt Economy Inverter 12V 240V C Turn DC to AC. This fantastic inverter will power lights, TV's tools, electric shavers and a whole host of other appliances. Great for camping , out in t he bush and any place where 240V is not available. Featureo: • Complete with over current circuit breaker• Fused 240V output• Built in 0988 Normally $9~o, Now Only $69.oo speakers, nciudes control 8 ill••· volu~able' & Even . ,,_ ..-, voltage • Strong steel case and M a120 $249.oo c 3032 $169.oo ea mounting hole centres . Specifications available on request. Simply wires in parallel to your woofer. No crossover or capacitor required. As it presents almost no load to your amp it doesn't effect the overall speaker system's impedance. Fantastic for hi-fi or disco speakers. 30 Watt Monitor Serles C 60 Watt Column Serles C C 0938 100 Volt Line White C 0937 100 Volt Line Black Audio Frequency Generator 1540 Normally $3~ .oo Now $25O.oo bass speaker. Massive 2.5kg nett weight. See Altronics '92 catalogue for full details. !,1.1' \ !J,S\ Normally ~ o o ,io '/'11'1.-rs p, KSN 1165A. Features Altronics today for a free colour brochure. Q response down to 30Hz these drivers make an ideal sub-woofer o r replacement 400 watt maximum these speakers are made easy by employing the new " Wacki " bracket system. Call Waveform ■ : maximum power rating of 200 watts or 120 watts continuous and a frequency power capability frequency response 1.BkHz to 30kHz and SPL at 93dB (2.83v/ 1m). 91 x 91mm Two sizes available, 30 and 60 watts RMS , in a black or white powder coat finish . Moun ting Sine/ Square Output Level: Sine: 8V rms Square: 10V P-P Output Attenuator: -20dB, -40dB and fine adjust 15" PECC Woofer These Poly Emulsion Coated Cone (PECC) woofers offer excellent quality and performance. Wit11 a This new bullet tweeter looks and tweeter. Ported design makes bass response incredibly smooth and deep. Specification 1: Frequency: 10Hz - 1MHz Accuracy: +/ -3% + 2 Hz Output 59.95 sounds great. Genuine Motorola This fantastic new range of monitors and columns just have to be heard to be believed. Designed by the Altronics engineer team with extensive consultation from audiophiles and architects, these speakers are absolutely ideal for hi-fi ex'tensions and P.A. Constructed from rugged extruded aluminium and UV resistant plastic makes these units both weatherproof and built to last. The drivers used are 4" carbon fibre with an inbuilt cox ial 0924 White !149 0925 88 Ohm Ohm Black ,00 ea 0927 100 Volt Line hite $160 ' C 0928 100 Volt Line Black .00 ea $ This Month Only Motorola Plezo Tweeter Weather Proof Monitor and Sound Column Speakers C or 30 watts RMS. Resonant frequency 65Hz. See Altronics '92 catalogue for full details. C 3034 Normally $ 8 ~ This Month panel meter to monitor output voltage • panel meter to monitor output chassis. resistant structure of carbon fibre these speakers are ideal for boats and automoti ve use . Max input power 70 watts $2 4 5 .00 ea C RF Signal Generator With provision for internal and external modulation . Specifications: Frequency Range: 100kHz - 150MHz 1n 6 ran ges RF Output Level: 100m V rms Accuracy: +/ -3% Modulation: • Internal Universal Wacki Brac:ket Yet another Altronics innovation , proudly designed and made in Australia. These great new speaker mount brackets simply screw onto the wall and speaker allowing a universal 50° angle of adjustment. Suitable for speakers up to 5kg. No special tools (30% depth ): 1kHz • Externa l: 50Hz-20kHz • Crystal Locked Oscillator Q 1550 Normally $ ~.00 Now 6160 $39.95 required . Available in white or black. A must for any extension speaker. $225.oo H H 8010 White 8012 Black $39.9s pair As a result of a bulk scoop purchase, we are able to offer to you these fantastic universal Ni-C42d battery chargers at a more than ridiculous price! It will charge any combination of up to 4 of AAA, AA, C or D size batteries at one time plus a 9V. High quality comp uter fans ideal for power supplies, amplifiers, computers etc. Reliable Sun non brand. Full range available for almost any application. Features a LED indication to show each battery has made an electrical contact. Also has an added bonus of a battery tester function. Hurry. Stocks limited. Definately $19.95 24V DC Model F 1020 80mm' $22 .25 F 1040 120mm' $23.90 F 1030 120 mm' $24.25 12V DC Model no back orders. 5 This Month Only 240V Model• LI D NOT SHOWN F Passive Infra-Red Flood Light Control Just arrived, this new model PIA floodlight activates when it detects movement of a person or car approaching. Great to we lcome visitors, ward off intruders or even to find the keys in the dark! Features daylig ht sensing circuit which means unit will not activate during daylight hours (save on your power b il l). Inc ludes manual override fac ili ty to turn lig hts on co nt in uous ly or automatica ll y. Features movement sensitivity adjustment, and turn on period. Great for the driveway or backyard . Complete with two screw in type sockets for standard 150W floodlight globes (not _in_c_i_ud_e_d_)_._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _-1 1050 80mm' $17.so Finger Guard• F 1022 80mm $2 F 1032 120mm .45 Sturdy Spotlight Relay ~ Includes two separate 30 Amp relays with ind 1vIdual fuses G reat for car headlights, spotlights etc. S 4335 Normally ,I I , 1111 Th is UHF system contains one receiver an d 3 w ireless reed switches for doors and w indows etc. Th e main contro ller simply pl ugs into 240V, the remote, reed switches are attached to your door/ window frames and presto, the alarm is instal led' Simple push button operation, 4 digit user selectable on/ off code , built-in siren makes this unit a pleasure to use. Includes 12V 1.2Ah ba ck up ba ttery and 9V batteri es fo r remote reed switches . Because t here is Cen tra no need to drill holes in the wall or wi th Built-i n Sire cei ling, making this unit j ust great for rented flats or units, or for those who SB 5260 !\Jormall don't want the trouble and hassle of a wired system . Also ideal fo r boats , Now only ca ravans, the shed, garage or granny flat. Take the uni t wit h you if you move - no wasted time and money. $2 Remote Car Alarm With Wlreleu Remote Control Audible warning with a 125 decibel loud siren and visible warning of flashing headlights when the alarm system is triggered. Keyring remote contro l allows arming with 'beep' sound and disarm ing wi t h head li ghts flashing sign al. The alarm system wi ll be triggered by unauthorised entrance through the car doors. boot. bonnet or removal of the car sound unit. The siren will sound and the headlights flash for 60 seconds. Easy to ln1tall. S 5220 $99 .00 ALTilOnlCl 174 Roe St. Perth W.A. 6000 Phone (09) 328 1599 PHONE TOLL FREE 008 999 007 MAIL ORDERS Cl- P.O. Box 8350 Stirling Street PERTH W.A. 6849 STANDARD DELIVERY & PACKING CHARGE $3.50 to 500gms, $5.50 500gms - 1Kg, $8 1 Kg-5Kg AUSTRALIA WIDE - We process your order the day received and despatch via. Australia Post. Allow approx 9 days from day you post order to when you receive goods. OVERNIGHT JETSERVICE Up to 3Kg is $10.00. 3Kg to 5Kg is $23.00- We process your order the day received and despatch via . Overnight JetMrvlce Courier for delivery next day Country areas please allow additional 24-48 hours. This Month On ly RCA Sockets PA 0235 Normall y $3.,M6 $1.50 Universal Re Control ;ii ~' M 1" These term inal blocks are ideal for 240V, speaker or DC vo ltage termination. Can be cut into shorter strips. Raised base for extra voltage protection . PX 2110 Normally Now Only $3.50 or 10 up $3.oo Stationmaster CB Base Antenna Extra wide bandwidth base antenna without ungainly size . Suppl ied with a fully pre-tuned and assembled DC grounded matchi ng system and all mounting hardware. Waterproofed and useable at any height above the ground, earthed or unearthed. • 50 Ohm impedance• V.S.W.R. 1.3:1 • Height 5.6m • Power 1kW Th is uni ver sal infra -red remote con trol makes all other rem ote units superfluous. Wi ll control CD playe rs, videos, TV's and stereos etc. Controls up to 6 d iffere nt applia nces. Easy to use and program me from an existing fun ctio nal rem ote. A 1000 .. ' ,M, ,1~. $~ 3 rows of stereo (left and rig ht) socket s. Hig h quality. Barg ain price . This Month Only JI' $1~o $9 .95 1----------------Chassis Mount Amazing Value on Deleted UHF Alarm Way WireProduct Terminal Blocks 12 L 3215 Normally~ $69.es This Month Only $99.oo Blank Rack ,., Panels Top quality blank pa nel c earout . I stock must go at these crazy prices. Stock is limited with definately no back orders at these prices. 2 unit - All $8.00 3 Unit - H 0422 Natural Aluminium H 0432 Grey H 0435 Black H 0423 Natural Aluminium H 0433 Grey Ail $12.95 • HEAVY HEAVY SERVICE - A ll orders of 10Kgs or more must trave l Express Road Please allow 7 days for delivery. $12.00 to 10Kgs. $15.00 over 10Kgs. INSURANCE - As with virtually every other Australian supplier, we send goods at consignees risk. Should you require comprehensive insurance cover against loss or damage please add $1.00 per $100 of order value (minimum charge $1 ). When phone ordering please request "Insurance". TOLL FREE PHONE ORDER - Bankcard, Visa, Mastercard Holders can phone order toll free up to 6pm Eastern Standard Time. Remember with our Overnight Jet1ervlce we deliver next day. AL TRONICS RESELLERS Chances are there is an Altronic Reseller right near check this list or phone us for details of the nearest dealer. a ■ These dealers generally carry a comprehensive range of Altronic products and kits or will order any required item for you . you - Blue Ribbon Dealero are high lighted with WA COUNTRY ALBANY BP El ect ronics ■ (098) 412681 Micro Electronics (098) 412077 BUNBURY Micro Electronics (097) 216222 ESPERANCE Esperance Communications (090) 713344 MANDURAH Lance Rock Retravision (09) 535 1246 PORT HEDLAND Ivan T omek Electronics (09 1) 73253 1 ROCKINGHAM TV Joe's (09) 5271806NT ALICE SPRINGS Farmer Elect ro nics (089) 522388 DARWIN Ventronics (089) 853 622 VIC A ll Electron ic Components (03) 6623506. TECS (03) 6706474 BORONIA Ray Cross Elect ron ics ■ (03) 7622422 CHELTENHAM Ta lking Electronics (03) 5842386 COLLINGWOOD Truscot! Electronics (03) 4198208 CROYDON Truscott E l ectronics ■ (03) 7233860 FOOTSCRAY G.B. Telespares (03) 3179100 PRESTON Preston Electronics ■ (03) 4840191 COUNTRY BAIRNSDALE LH & LM Crawford (051) 525677 BALLAR AT Ballarat Electronics (053) 311947QLD Del sound PL ■ (07) 8396155 WEST END B.A.S. Audiotronics (07) 8447566 WOODRIDGE David Hall Electronics ■ (07) 8082777 COUNTRY GLADSTONE G ladstone Electronic Services (079) 724459. Electronic Enterprises (079) 726660 MAROOCHYDORE MALS Electronics ■ (074) 436119 MARYBOROUGH Keller Electronics (071) 214559 NAM BOUR Nambour Electronics (074) 411966 PIALBA Keller Electronics (071) 283749 ROCK HAMPTON Access Electronics (East St.) (079) 221058 TOWNS VILLE Super Solex ■ (077) 724466 SA Force Electronics ■ (08) 2125505 BRIGHTON Force Electron i cs ■ (08) 3770512 CHRISTIES BEACH Force E l ectronics ■ (08) 3823366 FINDON Force Electronics ■ (08) 3471188 HOLDEN HILL Force El ec troni cs ■ (08) 2617088 LONSDALE Force E l ectronics ■ (08) 3260901 ENFIELD Aztron ics ■ (08) 3496340 COUNTRY WHYALLA Eyre Electro nics (086) 454764TAS HOBART Geo rge H arvey ■ (002) 342233 LAUNCESTON George Harvey ■ (003) 316533 NSW David Reid Electronics ■ (02) 2671385 REVESBY Revesby Electron ics (02) 7922295 SMITHFIELD Chant ronics (02) 6097218 COUNTRY COFFS HARBOUR Coifs Habour Electronics (066) 525684 NEWCASTLE Novocastrian Elect.Supplies (049) 621358 WARNER& BAY Vilec Distributors (049) 489405 WINDSOR M & E Elect. and Communications (045) 775935 WOLLONGONG Newtek Electronics ■ (042) 271620. Vimcom Electronics (042) 284400 WOY WOY Alphatran Electronics (043) 434919 I PRODUCT SHOWCASE I Beckman digital multimeters Beckman Industrial is a w ell respected test instrument brand name that has been around for a long time. Their multimeters have usually been priced at a premium and so the release of these three new lower priced meters is a change. All three multimeters have a 3½digit liquid crystal display with 18mm high digits and a count of 1999. Dimensions are 150 x 32 x 69mm. All units have deeply recessed input sockets and are supplied with safety test leads with shrouded jacks and insulated prods with only the tips exposed. The meters have a safety beeper which sounds if you have a lead plug inserted in the wrong input socket for the range selected. The beeper also functions on the continuity range. Battery life is an important consideration for a multimeter. For the three meters in the range, battery life is quoted as 300 hours for an alkaline 9V battery and 200 hours for a carbon zinc type. To replace the battery it is necessary to remove two screws and then prise the case apart. Inside, the meters appear to be well made and based on the Intersil 7106 family of chips. Each of three models has a large range selector switch but the measurement facilities vary between models. The DM5XL is the base model and has DC voltage ranges from 200mV to 1000V, AC voltage ranges of 200V and 750V, DC current ranges of 200uA GPS satellite timing generator card The Model GPS-PC timing generator card occupies one slot in any IBM XT or AT (or compatible) and can be synchronised to UTC by the GPS satellite system, or can operate as a stand-alone generator. The internal timing is synchronised to UTC to better than 5µs. The synchronisation process alsg to 200mA , resistan ce ranges from 200Q to 2MQ, as well as diode and continuity ranges. Interestingly, its input impedance for voltage ranges is 1MQ rather than the conventional lOMQ Its DC accuracy is quoted as ±0.8% . The median model is the DMl0XL which has the same AC and DC voltage and current ranges as above, plus a 10 amp DC range , resistance ranges from 200Q to 20MQ and a LED safety tester facility w ith indication for 6V, 12V, 24V, 50V, 110V and 240V. This facility can be used even if the meter's battery is fl at. Its DC accuracy is ±0.7% . Top of th e range model is the DM15XL which has the same DC voltage and current ranges as the DMl0XL measures the frequency difference between the interna] oscillail:or and the input code. If the GPS input code should fail, this information is used to correct the oscillator and maintain aceura~e timing across periods of input failure. When the user wishes to read the time, a "fFeeze" command is sent and the time is saved in RAM. The time remains static until the user clears the freeze command. but without the LED safety tester. Its AC voltage ranges are from 200mV to 750V and it has the widest resistance coverage for the lot with ranges from 200Q to 2000MQ Its DC accuracy is ±0.5%. A 1-year warranty applies to all three models. Recommended prices for the new Beckman pocket sized digital multimeters are $71 for the DM5XL, $98 for the DMlOXL and $120 for the DM15XL. Sales tax at 20% should be added to these prices where applicable. Beckman digital multimeters are available from Economic Electronics, 22 Campbell Street, Bowen Hills Qld 4006, phone (07) 252 3762, or from Southport Electronic Shop, Shop 1, 10 Welch Street, Southport, Qld 4125. Phone (075) 51 0543. Programming switches control the output fo11mat (BCD or ASCII) , as well as the address of the board. Incluqed is a 5¼-inch, 360Kb disc with a TIME.DOC file to assist in set-up and operation, as well as a sampl0 program in Basic fOF time retrieval (TIME.BAS) . For further information, contact Rohde & Schwarz (Australia) Pty Ltd, 63 Parramatta Rd , Silverwater, NSW 2141. Phone (02) 748 0155 . O CT0BER 1992 83 Circuit software from Number One Systems Breakthrough Computers of Queensland are Australian distributors for Number One Systems Ltd, a company well known in Europe for coming up with the CAD package EASY-PC, which is currently in use in over 50 countries around the world. We recently received review copies of a couple of circuit analysis programs from the same stable as EASY-PC, so we were eager to try them out. ANALYSER III allows you to load in a net list of an analog circuit diagram and it will then give you a Bode plot of both phase and gain with respect to frequency over an incredible range of 0.001Hz (that's lmHz) to 999GHz. You can set the frequency range of the plot to suit your circuit and once completed, send it to a dot matrix or HP LaserJet II compatible printer. Installation is a breeze. ANALYSER III uses its own intelligent installation program to decompress the files it needs to meet your system requirements. This is a great idea and means that you don't have to load in files that aren't relevant to your machine; ie, CGA files are not wanted if you have a VGA monitor. Once the software is loaded, all you do is type "AN3" and <return> and you're away. It's now that you're most likely to look up the manual, if you're anything like most computer users! And this is one of the great joys of the package - the manuals actually match the software they're written for. In fact, ANALYSER III is one of the few packages we've seen that has manuals which exactly match how the software works. You don't have to wade through a stack of info before you get into using the software. ANALYSER provides Portable hard disc is a breakthrough It had to happen eventually. With hard disc drives becoming smaller all the time, it was only a matter of time before someone came up with a fully portable unit. And now it has arrived. The PHd which stands for Pocket Hard Disc, is available in four models with formatted capacities of 40MB, 60MB, 80MB and 120 megabytes. It weighs just 350 grams and meas- 84 SILICON CHIP about 20 example circuits ready for analysis, and the manual follows every step, including loading in the net list and setting up the parameters. It also shows what the screen should look like at various times. It also shows how to write your own net lists for your own circuits and how to load your own components into the library. The first example is AMP.NET which is a LF351 FET-input op amp configured as a non-inverting amplifier with a gain of 100. As soon as you load it in, the program begins analysis from the BEGIN frequency to the END frequency. The gain scaling can be changed from a linear ratio to dBs and you can set the maximum gain shown on the graph. Numerical results of a circuit analysis are also available by selecting the "list numeric results" from the analyser operations menu. Finally, the plot can be printed out on either a 9 or 24-pin dot matrix or a LaserJet II compatible printer. Overall, ANALYSER III is a must for any engineering lab. It's ability to include many of the "real world" effects make it well worth the investment. ANALYSER III retails for $540 and is available direct from the Australian distributors, Breakthrough Computers. Contact them on (077) 21 5299 or fax them on (077) 21 5930. ures 148 x 28 x 75mm. Average seek time is just 16 milliseconds and the unit has been ruggedised to withstand shock up to 150G. In use, the PHd is designated as "Drive D" and is connected to the computer's parallel port. Power is normally supplied from a:n adaptor plug which fits into the standard keyboard DIN socket. While it is just a little heavy to be comfortably carried in your pocket, the PHd takes up very little room in your briefcase and provides a neat solution for those who need to have access to or carry large amounts of data to different locations. For further information, contact the manufacturers, KT Technology, Building 7, Central Boulevard, Portside Business Park, Port Melbourne, Vic 3207. Phone (03) 646 5755. Digital scope from Dick Smith Electronics Dick Smith Electronics has announced the release of four new oscilloscopes under the Digitor brand name. The new models include a lowcost 20MHz base model analog unit, fully featured 20MHz and 60MHz analog instruments, and an advanced 20MHz analog/digital model. All models are housed in an attractive, low profile enclosure featuring a robust carry handle/tilt bail, and are supplied with two probes and accessories. The fully featured 20MHz and 60MHz models offer component test, beam find and dual timebase facilities, as well as the usual functions. The 20MHz digital/analog storage model is the first really low-priced unit. As well as being a very capable analog scope, the unit features dual 2K x 8 trace buffers with trace roll, save and plot facilities. Prices for the four models range from $699 to $1599 for the digital storage model. They are available at all Dick Smith Electronics stores. New AC/DC single phase power meter current and power, the 2534 can also measure and display apparent power, reactive power, power factor, phase angle, Watt hours and frequency from 4Hz to 22kHz. A memory card interface is provided as standard with the Model 2534, allowing readings to be saved and later plotted on a Yokogawa chart recorder, or loaded into a PC via Yokogawa's model 3781 PC Memory Card Reader for subsequent analysis. RS232 and GPIB interfaces are also available as options. For further information, contact Tony Richardson, Yokogawa Australia Pty Ltd, Centrecourt D3, 2 5-2 7 Paul St North, North Ryde, NSW 2113. Phone (02) 805 0699. duced into the work environment. Charged objects need only be brought near a field-sensitive electronic device to cause damage or degradation. Items such as circuit board substrates, insulative tapes and plastic objects cannot be grounded, which means that traditional static control techniques are ineffective. A neutralising air ioniser is the only effective way to control their static charge. A compact new product from 3M, Yokogawa has released a new single phase high-accuracy AC/DC power meter intended for measurement of appliance power consumption and · single phase power distribution. Known as the 2534, the new power meter is capable of measuring AC and DC power at levels of up to 600V and Static control fan 20A, to an accuracy of 0.5%. The from 3M measuring range may be selected automatically or manually. Effective grounding is an essential An AC bandwidth of 10Hz to 20kHz part of any static control system. Wrist allows accurate power measurement, and heel straps, table mats and workeven in the presence of complex curstations should all form part of a sysrent waveforms such as caused by tem for removing static charges from PCs, facsimile machines and TV re- · personnel and conductive objects. ceivers. However problems can arise when In addition to measuring voltage, non-conductive materials are intro- EXTENSIVE RANGE OF PRINTER SWITCHES AND CABLES AVAILABLE. COMPUTER CABLE ASSEMBLY • SPECIALLY CABLE ASSEMBLY • POWER CENTRE AND POWER STRIP • GENDER CHANGER • COVER AND CONNECTOR • SMART SWITCH PARALLEL • CONVERTER & BOOSTER • SPECIAL INTERFACE DATA SWITCH BOX. .. A ST LUCIA ELECTRONICS . . 24 Campbell St. Bowen Hills Q 4006. Tel: (07) 252 7466 Fax (07) 252 2862. ECONOMIC ELECTRON/CS: 22 Campbell St. Bowen Hills Q 4006. PO. Box 481, Fortitude Valley 4006. Tel: (07) 252 3762. Fax (07) 252 5778. SOUTHPORT ELECTRONIC SHOP: Shop 1, 10 Welch St. Southport Q 4215. Tel: (075) 32 3632. Fax: (075) 51 0543. OCT0RER1992 85 TENCON'92 "TECHNOLOGY ENABLING TOMORROW" IEEE The Institute of Electrical and Electronics Engineers. Inc II MELBOURNE 1992 IEEE REGION 10 INTERNATIONAL CONFERENCE ON Computers, Communications and Automation Towards the 21st Century 9th - 13th November 1992 MELBOURNE WINS INTERNATIONAL ENGINEERING CONFERENCE Melbourne has been chosen over Beijing and Seoul to host one of the Asia/Pacific region's most prestigious conferences. The world-wide Institute of Electrical and Electronics Engineers will hold TENCON '92 at the World Congress Centre this November. The Conference theme is Computers, Communications and Automation Towards the 21 st Century. A wide range of topics including artificial intelligence, optical communications and manufacturing automation are included in the programme. International experts from many parts of the world are expected to attend TEN CON '92 to present the latest developments in fields of vital importance to tomorrow's technology. The conference will also feature a specialised exhibition, a day for secondary school students and teachers, and tutorial presentations on data, security, computer vision, software reliability and multimedia services. More information is available from Marg Scarlett at the address below, or to receive further information complete the attached slip and return it to: TENCON '92 c/- Convention Network, 224 Rouse Street, Port Melbourne 3207, Victoria, Australia. Telephone: +61 3 646 4122 Facsimile: +61 3 646 7737 -------------------------------------Please Send Me A Copy Of The TEN CON '92 Main Announcement And Registration Brochure Name: _ __ _ _ _ _ __ _ __ _ __ _ _ __ _ _ _ _ _ __ _ __ _ _ _ __ Address: _ _ __ _ _ _ __ __ _ _ _ _ __ _ _ _ _ __ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ __ _ _ __ __ _ _ __ _ _ __ _ __ _ _ _ _Postcode_ _ _ _ __ Country: _ _ _ _ _ _ _ __ __ __ _ __ __ _ __ __ _ __ _ __ _ _ _ __ i- I ·--------....---._..a-~--------~ ---.. . . . . . . _. -----------· PROUD SUPPORTERS OFTENCON '92 86 S ILICON CHIP the 3M Brand 961E Ionised Air Blower, is a self-contained, intrinsically balanced, bipolar ioniser. An equal proportion of both positive and negative ions are produced and gently fanned across the work area. This is claimed to neutralise all electrostatic charges and ensure a totally static free environment. For further information, contact 3M Australia Pty Ltd, 950 Pacific Highway, Pymble, NSW 2073. Phone (02) 498 9333. New projector has LCD light valves Barco has introduced the Barcodata 5000, its first super high brightness, full colour light valve projector which is intended for sports events and outdoor venues. Designed to operate in full ambient light, the projector can be used for front or rear screen projection, and table or ceiling mounted configurations are possible. The single lens Barcodata 5000 video and data projector uses three active matrix liquid crystal display (LCD) panels, each with a resolution of over 755 x 550 pixels, and a 575W metal halide lamp to produce highly luminous images on screens up to 10 metres wide. An overall resolution of more than 1.3 million pixels with an equivalent CRT light output of more than 5000 lumens is a feature of the projector. Barco's advanced digital architecture enables simple installation and set up by an infrared remote control. Precise adjustments are made through an easy to follow menu driven onscreen display. It can project video sources in NTSC, PAL and SECAM colour standards, as well as the most common computer graphics formats (VGA and Macintosh). For further information, contact Peter Della Tolla, Trace Technology Pty Ltd, Unit 4, 265-289 Williamstown Rd, Port Melbourne 3207. Phone (03) 646 5833 or (008) 331 554. OTP and flash memory cards from TI Texas Instruments has adopted Personal Computer Memory Card InternationiJ.l Association (PCMCIA) standards for its new one-time-programmable (OTP) and flash memory cards. The new OTP cards are available in 256Kb, 512Kb and 1Mb versions, while the flash cards are available in versions from 256Kb to 2Mb. The OTP memory card is a user-replaceable module designed for program storage. Typical applications include font storage for printers and program storage for equipment ranging from PCs and facsimile machines to musical instruments, electronic cash registers and machine controllers. They can be electrically erased and rewritten by users in the system, much like files can be added, changed or deleted on a floppy disc. For this rea- son, flash memory cards are well suited for laptop and palmtop computers, as well as for other data storage applications where ruggedness, small size, fast access and low power are concerns. TI memory cards are user insertable and feature fast read and write capability, with access times of 200ns. The new cards support both 8-bit and 16-bit processors. For further information, contact Rita Wong, Texas In.s truments, 6 Talavera Rd, North Ryde 2113. Phone (02) 878 9000. Fully protected power MOSFET Philips Semiconductors has introduced the world's first 3-pin power MOSFET to include integrated shortcircuit, over-temperature and overvoltage protection. Encapsulated in a standard TO-220 package, the BUK101-50 TOPFET (Temperature and Overload Protected Field Effect Transistor) requires no additional protection components, and can be driven directly from conventional logic circuitry. This allows TOPFETs to be used as replacement MOSFETs in existing equipment, as well as for new designs. They are particularly suited to switching of lamps, motors and solenoids in automotive electronics. The BUK101-50 is an N-channel, enhancement-mode DMOS FET with an Ros [ON] of 60mn and a continuous current rating of 26A (100A peak). Its protection circuitry automatically switches the BUK101-50 into the off state if the junction temperature exceeds a safe value (typically 180°C) as a result of inadequate heatsinking or short circuit load currents. The over- temperature and short circuit protection circuits incorporate a latch which maintains the BUKlOl-50 in the off state until its control input is driven low. In addition, on-chip avalanche diodes, coupled with a controlled turnon of the BUK101-50's powerMOSFET, provide dynamic clamping of Vos voltages which exceed 50V - fully protecting the device from transients caused by the switching of inductive loads. For further information, contact Philips Components, 32 Waterloo Rd, North Ryde , NSW 2113. Phone (02) 805 4455. SC OCT0HEH 1992 87 REMOTE CONTROL BY BOB YOUNG Internal combustion motors for R/C models; Pt.3 This month, we continue our discussion on the use of lubricating oil in fuel mixtures. Castor oil has the advantage of being good as an upper cylinder lubricant but its residue after the fuel is burnt is a real problem to clean off models. Here let me state, knowing that once again I am about to bring down the wrath of the gods, that there is still no substitute for castor oil. It is still one of the best upper cylinder (high temperature) lubricants available. It has been said that castor oil runs towards the heat, whereas all other oils run away; a trifle poetic perhaps but it does sum up the position rather nicely. There are other benefits of synthetic oils which are mainly to do with less drag on moving components, ageing Modern wisdom has it that synthetic oils and castor oil can be mixed and the fuel mixtures quoted range from 5% Gloglide and 95% methanol (9 .5:0.5) to 10% synthetic, 10% castor oil and 80% methanol (80:10:10). The key factor always, it seems, is to use as little castor oil as possible because of the undesirable side effects of this substance. Personally, I do not recommend oil mixtures as low as these and they are quoted as a guide to popular opinion only. "The basic problem in choosing a lubricant & ratio arises from the fact that every model calls for a different mix" of residues and a lower glazing factor, but to delete castor oil from the fuel completely, to my mind at least, leaves the motor vulnerable to seizing under some extreme conditions. It can be done but the modeller must know exactly what he is about. The two most common synthetic oils used, in Sydney at least, are Gloglide and Synlube. Klotz is another popular oil, particularly for 4stroke engines, as it does not gum up the valve gear as badly as castor oil. 88 SILICON CHIP The basic problem in choosing a lubricant and ratio arises from the fact that every model calls for a different mix. Take for example, a 60 2stroke Schnurle ported motor, one of the work horses of the model aircraft movement. In the good old days, before noise pollution laws prohibited behaviour such as I am about to describe, I used to run an O.S. 60 in a very sleek aerobatic aircraft with a very slender nose. This model was very fast which meant that the revs had to be high to maintain forward speed. This suited the Schnurle ported motor well, as they tend to prefer high rev (14,000 rpm plus), low torque applications. Thus, I found that a 10x7 prop was ideal for this model. The cylinder head was fully exposed to the slipstream for maximum cooling, while the muffler used was a low back pressure, flowthrough model which placed the minimum of thermal stress on the motor. (It also placed a minimum of emphasis on noise reduction). Thus· we have an application in which the piston has a minimum of dwell time at TDC (top dead centre), efficient exhaust gas extraction and a high volume of cooling air passing over the fins on the cylinder head and muffler. This application was one in which I could have used a minimum of oil had I wished. I never did and always stuck with 4:1 methanol/castor oil. I also used to run my motors towards the lean side for maximum revs, a potentially dangerous situation as we shall see, but I always used a fuel pump and a fuel tank on the centre of gravity in this particular model. I flew with the same motor for many years and never replaced the piston or cylinder. Cowled engine bay If we now take that same motor and place it inside a fully cowled engine bay on a scale model of the same weight, we will suddenly be confronted with a vastly different situation. Assuming that the model is of a radial engined aircraft, the prop will need to be larger to compensate for Protect _your valuable issues Silicon Chip Binders This shot from the Bob Young archives shows a Silvertone Weightlifter, held here by Wing Commander Alan Turton. This model was designed for extended operating times and featured a completely exposed cylinder head for cooling. Its all up weight was around 10 kilograms. (Photo taken in 1976). the shrouding effect of the larger cowling and to allow sufficient air mass flow to provide some thrust from the prop. Thus the prop will blow out to say a 12x6 or even a 13x5. This will immediately drop the revs and raise the operating head temperature. Worse still, the muffler may be enclosed inside the cowling for the sake of appearance The muffler will also more than likely be a simple box type with no airflow passing through for cooling or extraction of the hot exhaust gases. Even worse, if the modeller tries to use scale exhausting and channels the exhaust gases out via the scale exhaust openings, there is a distinct risk of the motor re-breathing burnt, hot exhaust gases instead of fuel-rich, cool air. Here we have a potentially ·lethal combination. A slower flying aircraft, a motor swinging a larger load, hotter exhaust gases, possible ingestion of hot exhaust gases into the carburettor and very little cooling air over the cylinder head and muffler all combining to raise the head temperature to beyond the safe limits. The result can be a seized motor and a very expensive repair. Here the need for maximum oil is of paramount importance. Different types of motors also have their own lubrication needs. Motors with piston rings have vastly different characteristics to the lapped piston/cylinder or even the ABC (aluminium/brass/chrome) piston/cylinder liners. There are other factors which confuse the issue even further. Often you will hear a modeller say, "but I have been using the same motor, same fuel and model for years, so why has the motor seized now?" The answer is that the airflow patterns inside a cowling are very complex and even the type of manoeuvres being practised on any one day can alter the flow patterns enough to raise the temperature inside the cowling. Add to this a continual build up of cylinder and cooling fin glaze from old burnt oil, a hotter than usual day and a needle setting that's just a little leaner than usual, and bang goes an engine. The problem of successfully cowling scale models is one that has plagued the modelling fraternity ever since scale modelling began. The basic problem in the above scenario is of course the wrong choice of motor to begin with. A Schnurle ported motor should not be used in this situation. A 4-stroke motor which will swing a much larger prop at much lower cylinder head temperatures would be a bE)tter choice. But model- These beautifully-made binders will protect your copies of SILICON CHIP. They feature heavy-board covers & are made from a distinctive 2-tone green vinyl. They hold up to 14 issues & will look great on your bookshelf. * High quality * Hold up to 14 issues * 80mm internal width * SILICON CHIP logo printed in gold-coloured lettering on spine & cover Price: $A 11 .95 plus $3 p&p each (NZ $6 p&p). Send your order to: Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 979 6503; or ring (02) 979 5644 & quote your credit card number. Use this handy form l ----------Enclosed is my cheque/money order for $_ _ _ or please debit my O Bankcard 0 Visa O Mastercard I Card No: Card Expiry Date __/__ Signature _ _ _ _ _ _ _ _ __ I Name _ _ __ __ _ _ _ __ I Address_ _ _ _ _ _ _ _ __ . __________ _ - - - - - . , . . - - P/code_ __ Q CTOllE/l 1992 89 Engines for remote controlled models - ctd lers will insist on using what they have at hand or they just simply cannot afford to buy a new motor. Whatever the reasons, the above scenario arises time after time on model flying fields. Model boats The problem of engine overheating in model boats is virtually non-existent for a more than adequate supply of cooling water is always at hand. In fact, the reverse is often the case, where too much water is pumped through the water scoop and the motor is over-cooled to the detriment of performance. Some care must be exercised in starting before the model is placed in the water but, by and large, the minimum oil ratios may be used in a boat. On the other hand, model cars present a formidable challenge as an adequate supply of air or water is seldom· available. In this case, oversize heatsinks are used on the motor and the maximum airflow available is piped inside the car body. Oil ratios are of the utmost importance in these models. Some land models, such as tanks, use closed circuit water cool- battery, is reliable and is quite powerful. It still has its adherents in control line and free flight. The fuel is typically 30% ether, 30% kerosene and 40% castor oil. It can be a little tricky to start for beginners as there are two running controls to adjust, both of which interact: (1) the regular needle valve, used to adjust the fuel/air mixture; and (2) the sub piston or contra piston, which is adjusted by the compression screw on the top of the cylinder. For a twiddler, this situation is dynamite and I have seen them land themselves in all sorts of bother because they are constantly twisting the compression screw and the needle valve. The basic rule with diesels is once the compression screw is set at the running position, never change it more than one half of one turn in the reduced compression direction and never adjust the needle valve. If weather changes or some out of the ordinary change forces an adjustment, never move the needle more than one turn. If the correct settings are lost, they can be difficult to find. This also applies to the first start of a new engine. "A good bright spark cures many ills in a model engine and these motors perform reliably & are quite long lasting" ing systems complete with radiator, but they are rare. Thus the answer to the question, "how much oil?", is just simply another question, "in what application?". Types of motor Turning now to the common types of motors in use in models, let's begin with the diesel. This type of motor has largely fallen by the wayside in the field of R/C modelling. This is largely due to the fact that it is difficult to provide a throttle control and if a throttle is fitted, the idle is not reliable. Model diesels are almost invariably 2-stroke. The diesel is cheap to run, does not require a starting 90 SILICON CHIP Once set up correctly, however, the diesel can be a most reliable starter and the ·old Mills 0. 75cc diesel is the most reliable motor I have ever had the pleasure of flying with. First flick starts are almost guaranteed and for this reason the Mills 0. 75 is still first choice for the power scramble, a freeflight event in which the winner is the flyer logging the most minutes of flight time in a 1-hour period, most of which can be spent scrambling after the model. This event is great fun for kids and mature age kids as well. It's a pity more R/C flyers do not indulge in this event. It certainly deflates much of the pomposity found on some R/C flying fields. It brings us back to the original concept of an outdoor activity in a country setting, providing physical and mental exercise, companionship, low cost and straight out fun! The only event to top it is the night scramble. The sight of 10 or 20 little fireflies buzzing around under a full moon, pursued by sometimes inebriated and usually overweight torch bearers, can be quite entertaining. The continual drift of conversation from out of the darkness, expletives and the odd splash, followed by "who put that #<at>&! river there?", all added to the sense of mischief and drama. Those were the good old days! Spark ignition motors The spark ignition motor is for enthusiasts and has a good following amongst those who know exactly what they want from a motor. As stated last month, a good spark cures many ills in a model engine and these motors perform reliably and cheaply, and are long lasting. The fuel is usually petrol/mineral oil but methanol/castor oil may also be used. Efficiency is better on petrol and fuel mixes of 40:1 (40 parts of petrol to 1 part of oil) are quite common. Methanol fuels for spark ignition usually run around 6:1 to 10:1 (10 parts methanol to one part castor oil). As a general guide, the smaller the engine the higher the oil content. These motors find their way into a lot of large models and capacities of up to 160cc are quite common. Modified chain saw motors provide a very cheap source for these large motors. The low cost of the fuel, combined with the very low oil residues on the model, are two of the favourite · virtues quoted by the enthusiast. Spark ignition motors throttle well but the throttle arrangement is a little more cumbersome, as timing retardation must be provided in addition to the normal carburettor control. Modern spark ignition motors are routinely run with electronic ignition and the timing can be provided from a variety of sensors - Hall Effect and light beam sensors being the two most popular. The throttle control moves the position of the pick-up head in relation to the timing disk. Because model engines run at very high revs, magnetic pick-ups are not particularly successful. The sensor is usually mounted on the prop driver, close to the hub of the prop or fly- wheel. The electronic ignitions usually run on 4.5-6V and most modellers seem to use the same coils that were fitted to the original spark interrupter systems. As stated last month, great care must be exercised when using petrol-based fuels. Spark ignition may be applied to 2stroke or 4-stroke motors. However, there is a major advantage with petrol fuels in 4-strokes because the very small clearances used in these motors can be badly fouled by burnt castor oil, particularly if the motor has not been run for some time. Burnt castor oil ages into a rubbery compound which can melt under heat into a very hard glaze. This is difficult to remove and, for this reason, after-run cleaning is important with 4-stroke motors. The low content of mineral oil in petrol-based fuels means that any residue is much easier to remove and does not age as badly. But there is one saving grace for castor oil and that is, it is still one of th~ best upper cylinder (high temperature) lubricants available and you delete castor oil from your fuel at your own peril. The typical fuel mix for methanol based 4strokes is 10% nitromethane, 10-12% castor oil and the rest methanol. Glowplug motors By far the most popular motor for R/C work is the glowplug motor, either 2-stroke or 4-stroke. The 4-stroke has gained greatly in popularity over the past few years as reliability and performance have gradually improved. They are very popular with the scale fraternity due to the more realistic exhaust note and lower noise levels. The mufflers are also much smaller and thus easier to fit into scale models, while the lower head temperatures are a boon for operation inside fully enclosed cowlings. They also swing larger props at lower revs, thereby further reducing noise levels due to the lower tip speed of the propeller. They do, however, suffer from several drawbacks. These drawbacks include higher cost, greater complexity, increased maintenance and lower output power when compared to the modern highly-developed 2-stroke engine. However, to those modellers who know exactly what they want from a model, the foregoing inconveniences are easily outweighed by One in a Thousand... speaker that performs with equal excellence on both classical and A rock music is a rare speaker indeed. While this is probably the ideal loudspeaker, the sad fact is that most speakers are leaning towards either one or the other type of music. So when a speaker comes along which truly performs equally well with such different types of music, it's no wonder the critics sit up. This is what Stereo Buyers Guide had to say about the new DALi 400: "The soundstage was large, very large, but unlike most speakers which give a large stage, the 400s didn't fluff the imaging inside it. The detail was surprising in its clarity and placement- surprising because our reference speakers didn't deliver as much on the same tracks. This doesn't happen very often! The bass was simply stunning-as clean as we 've heard in a long time, yet so controlled and strong, especially in the lowest octave. No wool here; the 400s shook the foundations. The highest frequencies glistened.... the stage showed lots of air; there was plenty of room in the image for all the musicians. The 400s won us over completely without any trouble at all. These speakers are great value in build quality, aesthetic appeal, and especially in musical temperament. We 're recommending them without reservation". Audition the new DALi 400 at your nearest DALi dealer today, DALi 400 SPECIFICATIONS: Cabinet type .. ... ........ ... ............. Bass reflex Woofers ............. 2 x 170mm Polypropylene Tweeter ............. ......... ..... 25mm soft dome Freq 'cy response(+/- 3dB) ..... 35-18, 000Hz Sensitivity ... ..... ............... 93dB (2.83V/1m) X-over frq 'cy ............ 250GHz (Lin.Directivity) Long Term Power Handling ....... .... 140 Watt Timber finishes ...... ........ Black or mahogany R.R.P...... ....... ... .... ......... .. $2500 per pair For a free information kit on the full range of DALi speakers, please contact Australian Distributor: SCAN AUDIO, 52 Crown Str, Richmond VIC 3121. the benefits obtained and there are many fine models now powered by these little engineering masterpieces. The workhorse of the model movement is still the 2-stroke glowplug engine, developed these days to give staggering performance. Light in weight, simple in construction and . easy to start, they are extremely powerful, very easy to throttle and give reliable operation at low revs. With all that, the modern glowplug motor is a far cry from the old Frog 160, my first glowplug motor purchased in the early 1950s. Ph: (03)429 2199. Fax (03)429 9309 I only ever got that motor running once and then I got such a shock after weeks of futile flicking that I forgot to remove my thumb from the propeller disc and it went through that thumb like a bacon slicer. It was a lesson I never forgot and I have treated all motors with great respect from that point on. Keep in mind that the Frog 160 was 1.6cc in capacity, a tiny motor by modern standards. Motors of 160cc are commonplace these days and are capable of inflicting serious injury. They must always be treated with great respect. SC Ocrn!l1-:n 1992 91 COMPUTER BITS BY BYRON MILLER The inside story on hard disc standards Confused about hard disc drives? Here we sort out the differences between today's competing disc drive standards. There is a battle raging. It is a battle to assume the role of standard bearer for the PC hard-disc drive interface. The venerable ST-506 served the PC industry well during its first decade, but as we move off into the 90s with increasing reliance on high-performance 386, 486 and 586 systems, users are demanding ever-greater speed, capacity and ease-of-use. Three technologies - ESDI, IDE and SCSI - are vying to become the next standard. But how does the prospective buyer choose from these? In this article, we will examine the basic ideas and history behind each, compare and contrast their strengths and weaknesses, and point out situations where each would be useful. Reprinted with permission from RadioElectronics magazine, June 1992 issue. Copyright©Gernsback Publications, Inc., 1992. Because each of the three new driveinterface standards represents, in some way, a response to the ST-506, let's begin with a little history and Background background on the development of that standard. Properly speaking, the ST-506 was the model number of a hard-disc drive that Seagate Technology introduced in 1980. The capacity of that drive was a whopping five megabytes (5Mb)! Several years later, Seagate introduced a 10Mb monster (the ST-412) with a similar electrical interface, and a new feature called buffered seeking. This feature allowed the drive to "collect" sequential seek commands and then move the read/write head across the surface of the disc in one quick, smooth motion. These drives recorded data on the .disc platters using modified frequency modulation (MFM). The combination of recording method and electrical interface limited the maximum rate at which data could be transferred to and from the drive to five megabits per second (5 Mbps). By encoding the data on the drive in the run-length.limited (RLL) format, designers could increase the data transfer rate by 50% to 7.5 Mbps. The capacity also increased by 50%. Early standards This 85Mb hard disc drive from Western Digital has an IDE interface. It also features 960 cylinders, 10 heads & 17 sectors per track. 92 SILICO N CHIP The market continued to demand greater performance and so, in early 1983, an ad hoe committee formed and produced the first draft of a specification for a new drive interface. This later became known as the Enhanced Small Device Interface (ESDI). By 1986, ESDI became a proposed ANSI standard and early in 1990, it became officially recognised·as ANSI X3.1701990. Development of the Intelligent Drive Electronics (IDE) interface began in 1984 when Compaq got together with Western Digital to develop an ST-506 controller that mounted directly on a hard-disc drive. The following year, Compaq worked with Imprimis (now a part of Seagate) to integrate Western Digital circuitry onto a Wren disc drive. Compaq subsequently shipped the first PC with an IDE drive and other manufacturers followed suit shortly thereafter. The appeal of IDE is that it eliminates one PC board and most of the interface electronics required between a system bus and a hard disc, thereby significantly lowering cost. Today, IDE has pretty much displaced ST-506 as the standard drive interface for desktop PCs. The Small Computer System Interface (SCSI) can be traced back to the Shugart Associates System Interface (SASI), which was developed by the same company (Shugart Associates) and the same designer (Al Shugart) that developed the ST-506. In fact Shugart developed SASI around the same time as the original ST-506. From the beginning, the SASI interface was designed to be more general than the specialise9- interfaces previously developed for personal computer peripherals. Rather than using specialised signals to control various lowlevel hardware functions, SASI/SCSI included from the beginning a general-purpose 8-bit parallel bus and several control signals. The hope was (and still is) that a general-purpose bus would attract designers of various types of peripherals. SASI supported several important features, including daisy-chaining drives and issuing high-level commands via a command block. Vendors quickly adopted SASI and began to add features and functionality; eg, support for Write Once Read Many (WORM) drives and other types of devices. Similarly, vendors increasE)d the maximum number of devices from two to seven. They also added the ability to service several devices at once. After some evolution, the SASI interface became so popular that in 1986 the X3T9 .2 ANSI working group adopted it as standard ANSI X3.1311986, or SCSl-1 for short. An enhanced version, SCSI-2, was finalised in 1990; it provides for wider bus widths and other performance-enhancing features. With that background in mind, let's now look at each type of interface in more detail. ESDI basics ESDI is a disc-controller interface TABLE 1: ESDI AND ST-506 SIGNALS ESDI Signal ST-506 Signal Pin No. Head select Reserved 2 Head select Write gate Head select Write gate 4 6 Config/status data Seek complete 8 Xfer Ack Track 0 Attention Write fault Head select Head select Sector Pin 7 on data cable Head select 10 12 14 16 18 20 22 24 26 28 30 32 34 Head select Index Index Ready Ready Xfer request Step Drive select Drive select Drive select Drive select Drive select Drive select Read gauge Command data Drive select ' Direction in that is like an enhanced ST-506. For starters, ESDI uses a similar cable and connector scheme - a 34-conductor control cable that is daisy-chained from drive to drive, and a separate 20conductor data cable for each drive. ESDI controllers typically support only two drives, even though the specification allows a maximum of seven. The signals on ESDI and ST-506 cables are similar but by no means identical, so you cannot run an ESDI drive on an ST-506 controller, nor an ST-506 drive on an ESDI controller. Electrically, all signals are TTL compatible; the maximum length of an ESDI drive cable is about three metres . Table 1 compares signals from both of those systems. Another similarity between ESDI and ST-506 is that ESDI is a devicelevel interface. In other words, its control signals ·direct low-level actions such as selecting a drive head and moving it to a desired track on the disc. As we'll see, SCSI and IDE devices contain high-level interfaces in which the operating system issues commands like: "Give me a block of data, as quickly as you can, and don't bother me with the details!" The biggest difference between ESDI and ST-506 drives is the data transfer rate, which for basic ESDI drives runs at twice the ST-506 rate (10 Mbps) , -- and which reaches its maximum at 24 Mbps. As for disc format, ESDI drives typically put about 34 sectors on a track (versus 17 for a standard ST-506 drive), and they run with a 1:1 interleave. In operation on a PC, most ESDI controllers emulate standard ST-506 controllers (eg, the ubiquitous WD1003), so no additional software drivers are required. IDE drives also emulate the WD1003 but SCSI drives always require external software drivers. IDE The IDE interface strongly resembles the AT I/O expansion bus , as shown in Table 2. There are some important differences and there is also some inconsistency in the way different manufacturers use some signals. For example, IOREADY can appear on pin 21 , pin 27 or on both, depending on the disc drive manufacturer. Many new system boards contain a built-in IDE interface, so there's no need to waste an expansion slot on a disc controller. Inexpensive IDE adapter cards are also available for older systems. If you're not buying a preconfigured system, you must check to ensure compatibility between your intended controller and hard disc drive(s). Electrically, an IDE drive connects to the O C /'Olll-:H -1992 93 TABLE 2: I0E AT 1/0 BUS SIGNALS AT 1/0 Signal IDE Signal Description CS1FX- N/A Chip select for ST-506 compatible 1/0 CS3FX N/A Chip select for ST-506 compatible 1/0 DA0-DA2 SA0-SA2 Drive address bus lines DASP N/A Drive active I Drive one percent 000-0015 SD0-S015 Drive data bus DIOR- -IOR Drive 1/Q read DIOW- -IOW Drive 1/Q write DMACK- -DACKx DMAWQ acknowledge DMARQ DRQx OMA request INTRO IRQ14 Drive interrupt IOCS16- -I/OCS16 Drive 16-bit 1/0 IORDY IOCHRDY 1/0 channel ready PDIAG- N/A Passed diagnostics RESED- RESET Reset; on AT bus is opposite polarity SPSYNC N/A Spindle sync. Produces clock for slave drives . controller with a 40-conductor ribbon cable. Like ESDI, the IDE interface emulates a standard IBM hard-disc controller, and an IDE drive masquerades as one with a corresponding value in the host system's BIOS drive table. Internally, an IDE drive typically has 34 sectors per track, although translation can make it appear to have 17, to match a BIOS table value. In addition, IDE drives usually operate at a 1:1 interleave. You cannot change interleave, perform a low-level format, or run low-level disc utilities. The controller electronics reside at standard disc-drive I/O port addresses (IF0-IF7 and 3F0-3F7) and respond to all standard commands (format track, read sector, write sector, etc), as well as enhanced commands that allow for more efficient operation. For example, commands C4 and C5 allow the system to read and write multiple sectors, respectively. However, most AT BIOS's do not yet support the enhanced disc-drive commands. The IDE interface has evolved rapidly since 1984, occasionally with different vendors creating incompatible enhancements. Hence, in 1988 a Common Access Method (CAM) commit94 SILICO N CI-IJP tee formed to define standards. By early 1989, the committee had produced a draft of an AT Attachment (ATA) interface standard. That document has evolved quite a bit over the years and is now well on its way to becoming an ANSI standard, by way of the X3T9 .2 working group. Like the ST-506, the IDE standard allows a maximum of two devices on its shared bus. Drive 0 functions as the master and drive 1 as the slave. Maximum cable length is only 45cm, so the drives must be situated close together, SCSI SCSI is an intelligent system-level interface that, in theory, can connect a variety of devices through a common parallel 8-bit bus, including disc drives, optical scanners, printers, tape drives, network adapters , and various types of optical drives . It is an unfortunate fact of life that, in practice, you'd probably end up installing a different SCSI host adapter for each type of device in your system. And it is difficult if not impossible to use a SCSI device intended for one system (eg, a DOS-based PC) on another (eg, a Macintosh) system. The SCSI bus consists of eight data bits, a parity bit, nine control lines, and a line for terminator power, as shown in Table 3. The bus can be driven with either single-ended or differential line drivers. In both cases, the bus has a total of 50 lines. A single-ended system alternates grounds with signals; in a differential system, even and odd pins form differential signal pairs. Maximum cable length is six metres for single-ended systems and 25 metres for differential systems. SCSI devices on PCs and Macintoshes usually follow the single-ended standard. A host device issues a command to a SCSI device via a 6-byte command descriptor block, which specifies an op code, a logical unit number and block address, a length control byte, and a control byte. The control byte has a feature that allows multiple SCSI commands to be sent in a single block. Every SCSI command returns a status byte, each bit of which has a specific meaning (good, busy, etc). Most devices currently on the market adhere to the SCSI-1 standards. However, many new devices conform to SCSI-2, which offers much greater potential performance. Whereas SCSI1 allows a maximum of four million transfers per second, SCSI-2 allows 10. In addition, SCSI-2 increases maximum bus width from the 8-bit SCSI-1 standard to an optional 16 or 32 bits. The X3T9.2 committee completed the SCSI-2 specification in August 1990; after editorial polishing, it should be published some time this year. SCSI can communicate with several different devices simultaneously. For example, a SCSI host can disconnect from a target device after issuing a command, connect to a different target device , give it a command, disconnect from it, and then reconnect back to the original device. By contrast, IDE operates in a master/slave mode in which the interface can issue only a single command at a time. BIOS-level software drivers are re• quired to use a SCSI device in a PC, typically added through an adapterbased EPROM or a device driver loaded at boot time. The Macintosh has a built-in SCSI manager. SCSI compatibility is still a problem. Although electrically identical, SCSI peripherals from different vendors may be dissimilar. In other words, a SCSI drive from vendor A may work TABLE 3: SCSI BUS SIGNALS Slgnal(s} 080-7 8-bit bidirectional parallel data bus Data bus parity line (optional) ATN Attention. Used to send message to target when it has control of the bus BSY Busy. Indicates that the bus is unavailable for use ACK Acknowledge; used by initiator for handshaking RST Reset. Used to initiate a bus free phase MSG Driven by target to indicate that current transfer is a message CID REQ 1/0 NEW Explanation DBP SEL whets Used by initiator to select target before command execution. Also used by target to reconnect when the re-selection phase is implemented Control/Data. Used during information transfer phases to transfer commands, status, messages and data over the bus Request by target during information transfer phases. Handshakes with ACK to envelop data Input/Output. Determines direction of transfer during information transfer phases in Speaker Design ? " "i) . ~~:~k~r $149* ~~ Designer Australia 's latest complete speaker design environment, includes, enclosure, crossover & optimisers, zobel, room placement & much more ! CALSOD l .20H - $119*# Australian and powerful LEAP - modular trom $449# LEAP - evaluation $149# LMS Ver 3.0 - update $195*# Pnces based an AUSSl=USS0.75 fine with a given SCSI adapter, while a SCSI drive from vendor B does not. This is due to variations in the interpretation and implementation of the SCSI command set. Hundreds of commands are available, some of which work differently with different types of devices. For example, one form of the write command can be used for writing to a Direct Access Device (DAD) and another for a Sequential Access Device (SAD). One vendor can interpret a disc drive as a DAD where another would interpret it as a SAD. Sending a SAD write command to a DAD device will not work. In response to that dilemma, the CAM committee has defined a standard subset of SCSI commands that performs basic functions (read, write, etc). The resulting eleven commands are known as the Common Command Set (CCS) and are part of the SCSI-2 standard. Compare & contrast Like ST-506, ESDI is an unintelligent device-level interface that transfers data serially from drive to controller, which compiles serial bits into 8-, 16- or 32-bit chunks of data and presents them to the host. IDE and SCSI devices, by contrast, build up data bytes on the drive and present them to the system in 8-, 16or 32-bit chunks. The advantages are several: less-expensive controllers and adapters, less cabling, improved reliability, and higher performance. IDE drives (even with an adapter, if required) typically cost less than SCSI and ESDI drives of comparable capacity and performance. However, a given system can hold a maximum of two IDE drives , whereas seven SCSI devices can be handled directly, and theoretically thousands indirectly. ESDI controllers typically allow only two drives and there is no pretence of supporting other types of devices. Both IDE and SCSI drives suffer from various types of compatibility problems that make system integration trickier than it should be. * demo disk available # comprehensive data available ME Technologies ( an ME Sound Pty Ltd subsidiary ) P.O. box 50, Dyers Crossing NSW 2429 '!I' 065 50 2254, fax 065 50 2341 Silicon Chip Binders Recommendations Selecting a drive interface depends on your performance needs, capacity needs, budget, and future system plans. If cost is the main determinant, you'll probably want to go with IDE. If performance is paramount, ESDI or SCSI will be your choice. Remember that performance you don't need right now may become necessary in the future. Sometimes a little added expense turns out to be a good investment. If you need a really large drive, ESDI or SCSI will also be required. If you hope to share a single interface card among multiple peripherals. SCSI may eventually help you realise that goal. SC These beautifu lly-made binders will protect your copies of SILICON CHIP. They are made from a distinctive 2-tone green vinyl & will look great on your bookshelf. Price: $A 11.95 plus $3 p&p each (NZ $6 p&p). Send your order to: Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 979 6503; or ring (02) 979 5644 & quote your credit card number. Qcromrn 1992 95 Silicon Chip Ironies For Everyone: What You Need to Know About Capacitors; Telephone Bell Monitor/Transmitter; 32-Band Graphic Equaliser, Pt.2; LED Message Board, Pt.2. BACK ISSUES May 1989: Electronic Pools/Lotto Selector; Synthesised Tom-Tom; Biofeedback Monitor For Your PC; Simple Stub Fi lter For Suppressing TV Interference; LED Message Board, Pt.3; Electronics For Everyone - All About Electrolytic Capacitors. July 1988: Stereo Control Preamplifier, Pt.2; Fitting A Fuel Cut-Off Solenoid To Your Car; Booster For TV & FM Signals; The Discolight Light Show, Pt.1; Tone Burst Source For Amplifier Headroom Testing; What Is Negative Feedback, Pt.3; Amplifier Headroom - Is It A Con? August 1988: Building A Plasma Display; Universal Power Supply Board; Remote Chime/Doorbell; High Performance AC Millivoltmeter, Pt.1; Discolight Light Show, Pt.2; Getting The Most Out Of Nicad Batteries; Data On Insulated Tab Triacs. September 1988: Hands-Free Speakerphone; Electronic Fish Bite Detector; High Performance AC Millivoltmeter, Pt.2; Build The Vader Voice; Motorola MC34018 Speakerphone IC Data; What Is Negative Feedback, Pt.4. October 1988: Stereo FM Transmitter (Uses Rohm BA1404); High Performance FM Antenna; Matchbox Crystal Set; Electronic House Number; Converting A CB Radio To The 28MHz Band; Queensland's Powerful Electric Locomotives. November 1988: 120W PA Amplifier Module (Uses Mosfets); Poor Man's Plasma Display; Automotive Night Safety Light; Adding A Headset To The Speakerphone; How To Quieten The Fan In Your Computer; Screws & Screwdrivers, What You Need To Know; Diesel Electric Locomotives. December 1988: 120W PA Amplifier (With Balanced Inputs), Pt.1; Diesel Sound Generator; Car Antenna/Demister Adaptor; SSB Adaptor For Shortwave Receivers; Why Diesel Electrics Killed Off Steam; Index to Volume 1. January 1989: Line Filter For Computers; Ultrasonic Proximity Detector For Cars; 120W PA Amplifier (With Balanced Inputs) Pt.1; How To Service Car Cassette Players; Massive Diesel Electrics In The USA; Marantz LD50 Loudspeakers. February 1989: Transistor Beta Tester; Minstrel 2-30 Loudspeaker System; LED Flasher For Model Railways; Build A Simple VHF FM Monitor (uses MC3362), Pt.1; Lightning & Electronic Appliances ; Using Comparators to Detect & Measure. March 1989: LED Message Board, Pt.1; 32-Band Graphic Equaliser, Pt.1; Stereo Compressor For CD Players; Amateur VHF FM Monitor, Pt.2; Signetics NE572 Compandor IC Data; Map reader For Trip Calculations; Electronics For Everyone Resistors. April 1989: Auxiliary Brake Light Flasher; Elec- June 1989: Touch-Lamp Dimmer (uses Siemens SLB0586); Passive Loop Antenna For AM Radios; Build A Universal Temperature Controller; Understanding CRO Probes; LED Message Board, Pt.3. July 1989: Exhaust Gas Monitor (Uses TGS812 Gas Sensor); Extension For The Touch-Lamp Dimmer; Experimental Mains Hum Sniffers; Compact Ultrasonic Car Alarm ; NSW 86 Class Electric Locomotives. September 1989: 2-Chip Portable AM Stereo Radio (Uses MC 13024 and TX7376P) Pt.1 ; AlarmTriggered Telephone Dialler; High Or Low Fluid Level Detector; Simple DTMF Encoder; Studio Series 20-Band Stereo Equaliser, Pt.2; Auto-Zero Module for Audio Amplifiers (Uses LMC669). October 1989: Introducing Remote Control; FM Radio Intercom For Motorbikes (Uses BA 1404 & TDA7000) Pt.1; GaAsFet Preamplilier For Amateur TV; 1Mb Printer Buffer; 2-Chip Portable AM Stereo Radio, Pt.2; Installing A Hard Disc In The PC. November 1989: Radfax Decoder For Your PC (Displays Fax, RTTY & Morse); Sensitive FM Wireless Microphone; FM Radio Intercom For Motorbikes, Pt.2; 2-Chip Portable AM Stereo Radio, l ----------------------------------- ---, Use this handy form to order your back issues Please send me a back issue for: o October 1988 O March 1989 O September 1989 o February 1990 o July 1990 o December 1990 0 May 1991 o October 1991 o March 1992 o August 1992 O November 1988 □ April 1989 O October 1989 □ March 1990 □ August 1990 O January 1991 0 June 1991 0 November 1991 o April 1992 0 September 1992 0 O 0 O 0 0 0 .0 July 1988 December 1988 May 1989 November 1989 April 1990 September 1990 February 1991 July 1991 □ December 1991 0 May 1992 Enclosed is my cheque/money order for $___or please debit my: O O O O 0 O 0 O O O August 1988 January 1989 June 1989 December 1989 May 1990 October 1990 March 1991 August 1991 January 1992 June 1992 O Bankcard Card No. Signature _ _ _ _ _ _ _ _ _ _ _ _ Card expiry date_ _ /_ _ O Visa Card O September 1988 O February 1989 0 July 1989 o January 1990 O June 1990 O November 1990 0 April 1991 o September 1991 O February 1992 0 July 1992 o Master Card $5.00 each (includes p&p). Overseas orders add $1 each fo,r postage. NZ orders are sent air mail. Detach and mail to: Street _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ SILICON CHIP PUBLICATIONS PO BOX 139 COLLAROY BEACH NSW 2097 Suburb/town ______________ Postcode _ _ _ _ __ Or call (02) 979 5644 & quote your credit card details. Fax (02) 979 6503. Name __________________________ L----- · - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 96 SILICON CHIP Pt.3 ; Floppy Disc Drive Formats & Options; The Pilbara Iron Ore Railways. December 1989: Digital Voice Board (Records Up To Four Separate Messages); UHF Remote Switch; Balanced Input & Output Stages; Data For The LM831 Low Voltage Amplifier IC; Install A Clock Card In Your PC; Index to Volume 2. January 1990: High Quality Sine/Square Oscillator; Service Tips For Your VCR ; Speeding Up Your PC; Phone Patch For Radio Amateurs ; Active Antenna Kit; Speed Controller For Ceiling Fans; Designing UHF Transmitter Stages. February 1990: 16-Channel Mixing Desk; High Quality Audio Oscillator, Pt.2; The Incredible Hot Canaries; Random Wire Antenna Tuner For 6 Metres; Phone Patch For Radio Amateurs, Pt.2; PC Program Calculates Great Circle Bearings. March 1990: 6/12V Charger For Sealed LeadAcid Batteries ; Delay Unit For Automatic Antennas; Workout Timer For Aerobics Classes; 16Channel Mixing Desk, Pt.2; Using The UC3906 SLA Battery Charger IC. April 1990: Dual Tracking ±50V Power Supply; VOX With Delayed Audio ; Relative Field Strength Meter; 16-Channel Mixing Desk, Pt.3 ; Active CW Filter For Weak Signal Reception ; How To Find Vintage Radio Receivers From The 1920s. May 1990: Build A 4-Digit Capacitance Meter; High Energy Ignition For Cars With Reluctor Distributors ; The Mazzie CW Transceiver; Waveform Generation Using A PC, Pt.3; 16-Channel Mixing Desk, Pt.4; What To Do When Your Computer Goes Bung, Pt.1 . June 1990: Multi-Sector Home Burglar Alarm; Low-Noise Universal Stereo Preamplifier; Load Protection Switch For Power Supplies; A Speed Alarm For Your Car; Design Factors For Model Aircraft; Fitting A Fax Card To A Computer; What To Do When Your Computer Goes Bung, Pt.2. July 1990: Digital Sine/Square Generator, Pt.1 (Covers 0-500kHz); Burglar Alarm Keypad & Combination Lock; Simple Electronic Die; Low-Cost Dual Power Supply; Inside A Coal Burning Power Station ; What To Do When Your Computer Goes Bung, Pt.3; Weather Fax Frequencies. August 1990: High Stability UHF Remote Transmitter; Universal Safety Timer For Mains Appliances (9 Minutes) ; Horace The Electronic Cricket; Digital Sine/Square Wave Generator, Pt.2; What To Do When Your Computer Goes Bung, Pt.4. September 1990: Music On Hold For Your Telephone ; Remote Control Extender For VCRs ; Power Supply For Burglar Alarms ; Low-Cost 3Digit Counter Module; Simple Shortwave Converter For The 2-Metre Band. October 1990 : Low-Cost Siren For Burglar Alarms ; Dimming Controls For The Discolight; Surfsound Simulator; DC Offset For DMMs; The Dangers of Polychlorinated Biphenyls; Using The NE602 In Home-Brew Converter Circuits. November 1990: How To Connect Two TV Sets To One VCR; A Really Snazzy Egg Timer; LowCost Model Train Controller; Battery Powered Laser Pointer; 1.5V To 9V DC Converter; Introduction To Digital Electronics ; Simple 6-Metre Amateur Transmitter. December 1990: DC-DC Converter For Car Amplifiers; The Big Escape -A Game Of Skill; Wiper Pulser For Rear Windows; Versatile 4-Digit Combination Lock; 5W Power Amplifier For The 6Metre Amateur Transmitter; Index To Volume 3. UHF Modulators; Build An lnfrared Light Beam Relay; Compact Solid-State Laser Pointer; Colour TV Pattern Generator, Pt.2; Windows 3 & The Dreaded Unrecoverable Application Error; Index To Volume Volume 4. January 1991 : Fast Charger For Nicad Batteries, Pt.1 ; The Fruit Machine; Two-Tone Alarm Module; Laser Power Supply; LCD Readout For The Capacitance Meter; How Quartz Crystals Work; The Dangers When Servicing Microwave Ovens. January 1992: 4-Channel Guitar Mixer; Adjustable 0-45V SA Power Supply, Pt.1 ; Baby Room Monitor/FM Transmitter; Automatic Controller Fo r Car Headlights; Experiments For Your Games Card; The GPS Satellite Navigation System ; Restoring An AWA Radiolette Receiver. February 1991 : Synthesised Stereo AM Tuner, Pt. 1; Three Inverters For Fluorescent Lights; LowCost Sinewave Oscillator; Fast Charger For Nicad Batteries, Pt.2; How To Design Amplifier Output Stages; Tasmania's Hydroelectric Power System. March 1991: Remote Controller For Garage Doors, Pt.1; Transistor Beta Tester Mk.2; Synthesised AM Stereo Tuner, Pt.2; Multi-Purpose 1/0 Board For PC-Compatibles; Universal Wideband RF Preamplifier For Amateurs & TV ; A Look At The Config.Sys & Ansi .Sys Files. April 1991: Steam Sound Simulator For Model Railroads; Remote Controller For Garage Doors, Pt.2; Simple 12/24V Light Chaser; Synthesised AM Stereo Tuner, Pt.3; A Practical Approach To Amplifier Design, Pt.2; Playing With The Ansi.Sys File; FSK Indicator For HF Transmissions. May 1991: Build A DTMF Decoder; 13.5V 25A Power Supply For Transceivers ; Stereo Audio Expander; Fluorescent Light Simulator For Model Railways; How To.Install Multiple TV Outlets, Pt.1 ; Setting Screen Colours On Your PC. June 1991: A Corner Reflector Antenna For UHF TV ; 4-Channel Lighting Desk, Pt.1; 13.5V 25A Power Supply For Transceivers ; Active Filter For CW Reception ; Electric Vehicle Transmission Options; Tuning In To Satellite TV, Pt.1. July 1991 : Battery Discharge Pacer For Electric Vehicles; CD Error Analyser, Pt.1; Loudspeaker Protector For Stereo Amplifiers ; 4-Channel Lighting Desk, Pt.2; How To Install Multiple TV Outlets, Pt.2; Tuning In To Satellite TV, Pt.2; PEP Monitor For Transceivers August 1991: Build A Digital Tachometer; Masthead Amplifier For TV & FM; PC Voice Recorder; Error Analyser For CD Players, Pt.2 ; Tuning In To Satellite TV, Pt. 3; Installing Windows On Your PC ; Step-By-Step Vintage Radio Repairs. September 1991: Studio 3-55L 3-Way Loudspeaker System ; Digital Altimeter For Gliders & Ultralights, Pt.1 ; Build A Fax/Modem For Your Computer; The Basics Of AID & D/A Conversion; Windows 3 Swapfiles, Program Groups & Icons; How Glass-Mount Antennas Work. October 1991 : Build A Talking Voltmeter For Your PC, Pt.1 ; SteamSound Simulator Mk.11; Magnetic Field Strength Meter; Digital Altimeter For Gliders & Ultralights, Pt.2; Getting To Know The Windows PIF Editor. November 1991: Colour TV Pattern Generator, Pt.1; Battery Charger For Solar Panels; Flashing Alarm Light For Cars; Digital Altimeter For Gliders & Ultralights, Pt.3 ; Build A Talking Voltmeter For Your PC, Pt.2; Error Analyser For CD Players Pt.3 ; Modifying The Windows !NI Files. December 1991: TV Transmitter For VCRs With February 1992: Compact Digital Voice Recorder; 50-Watt/Channel Stereo Power Amplifier; 12VDC/ 240VAC 40-Watt Inverter; Adjustable 0-45V SA Power Supply, Pt.2; The Mobile Telephone Revolution ; Designing A Speed Controller For Electric Models. March 1992: TV Transmitter For VHF VCRs ; Stu dio Twin Fifty Stereo Amplifier, Pt.1 ; Thermostatic Switch For Car Radiator Fans ; Telephone Call Timer; Updating The Resistor/Capacitor Scene; Coping With Damaged Computer Directori es; Valve Substitution In Vintage Radios. April 1992: lnfrared Remote Control For Model Railroads ; Differential Input Buffer For CROs; Studio Twin Fifty Stereo Amplifier, Pt. 2; Understanding Computer Memory; Switching Frequencies in Model Speed Controllers; Aligning Vintage Radio Receivers, Pt.1. May 1992: Build A Telephone Intercom ; LowCost Electronic Doorbell; Battery Eliminator For Personal Players; lnfrared Remote Control For Model Railroads, Pt.2; A Look At Large Scree n High Resolution Monitors; OS2 Is Really Here; Aligning Vintage Radio Receivers, Pt.2. June 1992: Multi -Station Headset Intercom, Pt. 1; Video Switcher For Camcorders & VCRs ; lnfrared Remote Control For Model Railroads , Pt.3; 15Watt 12-240V Inverter; What's New In Oscilloscopes?; A Look At Hard Disc Drives; Video Editing On The Small Screen. July 1992: Build A Nicad Battery Discharger; 8Station Automatic Sprinkler Timer; Portable 12V SLA Battery Charger: Off-Hook Timer For Telephones; Multi-Station Headset Intercom, Pt.2; Understanding The World Of CB Radio; Electronics Workbench For Home Or Lab. August 1992: Build An Automatic SLA Battery Charger; Miniature 1.5V To 9V DC Converter; The lnterphone Digital Telephone Exchange , Pt.1; Dummy Load Box For Large Audio Amplifiers; Internal Combustion Engines For Model Aircraft ; Troubleshooting Vintage Radio Receivers. September 1992: Multi-Sector Home Burglar Alarm; The lnterphone Digital Telephone Exchange , Pt.2 ; General-Purpose 3½-Digit LCD Panel Meter; Track Tester For Model Railroads; Build A Relative Field Strength Meter; Internal Combustior,:i Engines For Model Aircraft, Pt.2. PLEASE NOTE: All issues from November 1987 to June 1988 plus the August 1989 issue are now sold out. All other issues are presently in stock. For readers wanting articles from sold-out issues, we can supply photostat copies (or tearsheets) at $5.00 per article, including postage. When supplying photostat articles or back copies, we automatically supply any relevant Notes & Errata at no extra charge. O CTOBER 1992 97 ASK SILICON CHIP Got a technical problem? Can't under~tand a piece of jargon or some technical principle? Drop us a line and we'll answer your question. Write to: Ask Silicon Chip, PO Box 139, Collaroy Beach, NSW 2097. Solar cells for the sprinkler controller In the July issue of SILICON CHIP, you described an 8-station automatic sprinkler controller, this being operated via a 24VAC plugpack. Would it be possible to operate this controller via a solar cell, either directly or to charge up a battery (then to use the battery to operate the controller)? (J.P., Reservoir, Vic). • It would be possible to run the circuit from a 12V battery which could be charged with a suitable panel. However, you would be wise to discuss this idea further with the author of the article before deciding to purchase the kit. When the pigeons come home to roost My Dad flies racing pigeons and has asked me to build him a remote control sensor device for use around the yard and inside the house, to detect when a bird lands and goes through the trap. I am only new to electronics but would like your help. Perhaps SILICON CHIP might even produce a kit for this as there are thousands of pigeon Wants to discharge 4.8V nicad packs I intend building the Nicad Battery Discharger as described on page 22 of the July 1992 issue. However, as I am into radio controlled model aircraft, I need to discharge 4-cell 4.8V receiver battery packs. Can you supply a quick sketch/ description of the required modification to swap the 6.0V setting to 4.8V. I believe that this will only require replacement of the 5. lkQ and 750Q resistors on either side of the 6.0V setting with new val98 SILICON CHIP flyers out there who would buy one as they all would have the same problem. At the moment they use assorted pivoted boards and wires leading to a bell, but most have to sit out in the cold for hours waiting and watching to see them land. I also would like to keep it simple and at a reasonable price so that the average person can afford it and put it together themselves. Most pigeon fanciers would have 240V AC in their pigeon lofts for lights, so the sensor device could run off a 12V plugpack supply. (D. P. , Port Pirie, SA). • We suggest you build the Infrared Light Beam Relay featured in our December 1991 issue. It's as light as a feather, easy to perch in some precarious position and will sound a buzzard - sorry, buzzer - when the pigeon lands. Alternatively, you can use the on-board relay to sound a bell or siren. Video enhancer for tape dubbing I wish to enquire if you have ever published or intend to publish a video enhancer or booster for boosting the signal when dubbing video from a ues. (A. S., Port Hedland, WA). 3.9k • The required modification to 1.2k provide a 4.8V S1 setting is shown at right. You will 1son have to remove the 5. lkQ resistor and substitute 3.9kQ and 1.2kQ resistors instead. However, we cannot guarantee that the circuit will work with only 4.4V on the supply line, since the LM324 may not operate correctly. camera or from a VCR to a second VCR. This is to avoid, as much as possible, degradation of the signal when editing our video masterpieces from the original to a more viewable format. I have built up such a project from one of the other magazines, but that was published in 1983, and I am sure much progress has been made in this field since then. As the video camera has found such widespread acceptance, I feel that this would be a project with wide appeal. (J. L., Biggenden, Qld). • We are reluctant to publish a video enhancer since today's VHS HQ VCRs already have enhancement built in. Further enhancement tends to emphasise noise or grain in the picture. Running a refrigeration plant in the bush We have a power supply problem on our remote property where we have neither mains nor generator power available. The former are too far away to even consider the cost of lines, while the latter is now being looked at since finance may be available. Because we must have an installation of about 15kVA for our refrigeration plant, we think that we may find a solution through either or both of the following propositions. Please tell us what the prospects are from your point of view, when taking the following into account. All enclosed refrigeration compressor units of this size are only available for 3-phase supply. Another aspect of our choice is that the demand needs to be met for part daytime only. If necessary, we could install a rectifier and include a small capacity of storage batteries for the relatively small night-time demands, reconverting DC to AC by one of the newer smallcapacity static devices. We have heard that running 3-phase motors from single-phase 240V AC supplied by a diesel generator is possible with reasonable efficiency. The loss through running an intermediate single motor essential for such a scheme is apparently small. We would thus provide for the required 3-phase demand as well as retaining singlephase running for all normal home appliances and avoid the intermediate battery storage link. Some years back, I saw this "rope trick" performed in a dairy plant operation. There was only one proviso and that was that the intermediate rotary device had to be rotation-started by a hand winder to gain the required starting momentum. We understand that by running a 3phase diesel generator, we are up for higher capital as well as running costs because of the much lower demand utilisation during leisure time. Partial load running of a single-phase generator of adequate capacity is stated to be less inefficient than that of a 3-phase plant. We have also seen that solar voltaic cells have now come down to near $20 per watt. For a no-fuel cost installation but with slightly higher capital outlay, we could generate three single supplies of adequate power. By using some electronic device we should be able to turn this source into an adequate 3-phase power supply. (P. L., Forster, NSW). • With regard to your first question on running 3-phase motors from a single-phase supply, we don't think it is possible at all. Single-phase motors have a starter winding which is switched out of circuit when the motor comes up to speed. 3-phase motors do not have this and since only one of their three windings could be powered, the whole scheme appears to be unworkable. Nor is the · concept of running a 15kVA refrigeration plant from solar power a practical proposition. At your suggested cost of $20 per watt, the solar cells alone would add up to at least $30,000 and then you would need a battery bank which would probably cost a few thousand at least. Add in the cost of the heavy duty electronics needed to convert DC to 3phase AC and you probably would not have much change out of $50,000 in total. Compared with that, a diesel powered 3-phase generator would be a real bargain. However, a solar powered 240VAC facility capable of say 2kW is quite a practical proposition in remote areas Mosfets for the 40W inverter I am a regular reader of your magazine which has produced quite a remarkable range of interesting and practical projects. Since I would like to build the 40W inverter, I was shopping for the Nchannel Mosfets specified by you as MTP3055E. Unfortunately, I can get only type MTP3055A. Can I substitute type A for type E and what's the difference? Also would the efficiency markedly suffer or the output voltage drop too much if the 18V CT transformer was changed to a 12.6V type? Could you please publish an educational series showing how to "design your own" circuits and describing some of the "simple building blocks" in electronics. I and the first article on a suitable 2kW 24VDC to 240VAC sinewave inverter is in this month 's issue. Interference in the TV pattern generator I have built the Colour TV Pattern Generator described in the November and December 1992 issues and I have encountered two problems. The first is suspected RF interference from the modulator causing vertical bars like fish scales moving randomly up and down the screen. This can be varied by putting a hand or test leads on various parts of the circuit. I have tried decoupling the supply to the modulator but it made no difference. When colour bars are selected, there are vertical oscillations running vertically and moving up and down between all the bars. They can be altered in frequency by changing the setting of VCl but the oscillations are still present. They disappear when the generator is switched to grey scale. What do you suggest? (R. B., Broken Hill, NSW). • The RF interference you are.encountering is due to direct radiation from the pattern generator ICs into your TV set. You can minimise this by keeping the pattern generator as far away as possible from the TV set, by using a long lead from the modulator. If you would like to know how to interface these to custom made projects, especially using CMOS ICs. I would also like to see more circuits in your "Circuit Notebook" column, including artworks for copying. Thanks for an otherwise excellent magazine. (M. S., Edgewater, WA). • Unfortunately, you can not use MTP3055As instead of MTP3055Es in the inverter. As pointed out in Notes & Errata this month, the MTP3055A is a completely different device from the MTP3055E. If you use MTP3055As in this circuit instead of the specified "E" devices, they will "blow up". And do not substitute a 12.6V CT transformer for the 18V CT transformer specified - you will get a drastically reduced output voltage if you do. still find the interference troublesome, then you could try adding a groundplane beneath the PC board. The small vertical oscillations between colour bars are normal and are an artefact of the colour generator IC. In practice, this should not present a problem when testing TV sets or monitors. Remote control for model trains My train club intends to build five IR Train Controllers as described in the April, May & June 1992 issues, for use on our NTRAK layout at public displays. As we can only code three units on the 615kHz resonators, we have sourced some 500kHz resonators. Assuming that these will work, would the lO0pF capacitors at pins 16 and 17 ofICl be correct for 500kHz? If not, what is the formula to come up with the correct value? If we place the receivers at one end of the layout and a VCR IR extender (as described the September 1992 issue) at the other end (about 14.5 metres), would the extender handle signal from all five units or would the signals be unsuitable for the receiver section of the extender? The idea is to control the trains when a direct line to the controllers is not clear (people in the way, etc). Also the distance OCT0BEH1992 99 Cordless phone frequencies I have some queries regarding cordless telephones. (1) What frequency do they transmit/receive on? - I have heard it is 30MHz. (2) Do they all use the same frequency? (3) Do they all utilise the maximum power legally permissible? (4) If not, do you have any idea which one does? (5) Although I realise that it would be illegal to attempt, and I would not consider doing it, is it theoretically possible to increase the range of these telephones? I have also heard that under good conditions, they can be effective up to 11cm away. I had thought that by using a 27MHz CB antenna (trimmed to match the wavelength using an SWR meter) and low loss coaxial may be too great for the transmitters ' range. To tie in with the throttles and IR remote controls, could you also come up with the circuits for a digital voltmeter (0-15V or thereabouts) and a digital current meter, both using FND500 7-segment displays or similar as the readouts? The voltmeter may also be popular with car owners. A design which fits into cutouts in the plastic face of a small zippy-box with the circuit board behind would be good. The unit could be kept in the box or the face of the box could be mounted (screwed) on existing panels or dash boards. Another thought , regarding the IR extender: could it handle a number of signals, from five transmitters simultaneously, or would the signals become mixed if transmitted at the same time, even though on different frequencies? (A. M., Browns Plains, Qld). • It should not be necessary to change the 100pF capacitors to suit different resonators; the circuit is universal. We would not recommend the use of the VCR IR extender to increase the range as it should be sufficient by itself. Our prototype had a range of at least 10 metres and this should be enough if you place the receivers centrally on the layout. On the other hand, 100 SIL/CO,\ ' CIIII' cable, it would be possible to produce a gain over the standard telescopic antenna used by these telephones. I hope that you will be able to answer these questions and look forward to your reply. (P.A., Bunnan, NSW). • Cordless phones are duplex devices operating on 30MHz and 39MHz. They all use the same frequencies and they all use the maximum power legally permissible. The base stations are rated for a 300mW DC input while the handheld transceivers are rated for a specified field strength. The only way that it would be possible to increase the range of these phones would be to modify the antenna but this would be difficult since you would have to tune it to suit the two operating frequencies. It would also, as you suggest, be illegal. while we have not tried the VCR IR extender with this circuit, there is no reason why it should not work. In theory, the IR extender should be able to handle a number of signals simultaneously since they are coded differently and each would employ a different ceramic resonator. In practice, though, we think you would be asking for trouble and it is possible that, if two or more transmitters were activated simultaneously, nothing at all would happen or perhaps, at worst, the wrong response may occur. That is probably a good argument for placing the receivers away from each other so that the transmitters are not aimed at exactly the same point. We have produced an LCD circuit which can measure voltage or current and this was published in the September 1992 issue. It should be ideal for your purpose. Questions on the SLA battery charger I wish to build the 6/12V SLA Battery Charger featured in the August 1992 issue of SILICON CHIP but, looking at the price of the UC3906 IC, I don't want to rely on an IC to trickle charge my batterie.s 365 days a year and just hope and pray that it doesn't blow up. I would like to know several things. (1) Can you charge two 6V 10A.h batteries connected in series? (2) Can you leave the charger on permanently? (3) Can you have it on charge and also run it as a UPS and drain about 5A continuously without anything going up in smoke? (4) Can you modify the kit so that it . will drain current from the charger and the battery but still charge the battery, and if so can you publish the updated version? I would also like a charger with short-circuit protection so that if you short it out, it cuts out but turns back on after the short is connected. (J. E., Blackburn South, Vic). • The circuit can be used with batteries on permanent float charge. In this way, the charger and/ or batteries can power the load permanently. It is possible to charge two 6V batteries connected in series and you can leave the charger on permanently. In other words, there is no need to modify the kit to perform the functions listed in your first four questions, although it would only be able to supply about 3A continuously. It is not possible to provide short circuit protection for a battery charger which is permanently connected across a battery. If you short out the output device then, naturally, the battery will supply a very heavy current - there is no avoiding this. On the other hand, if you inadvertently connected the battery around the wrong way, then fuse F2 and diode D2 will automatically protect the charger against the heavy current that would otherwise flow. Also, if you shorted the output of the charger before it was connected to the battery, then again fuse F2 would protect the charger. Notes & errata 40W Inverter, February 1992: at least one retailer has supplied kits that included MTP3055A Mosfets instead of the specified MTP3055E devices. Unfortunately, these are not equivalent devices , as the "A" version includes an internal fast reverse recovery diode whereas the "E" version has a controlled avalanche diode. If you use the MTP3055A device in this circuit, it will "blow up". Do not substitute for the specified MTP3055E devices. -::::::::·::"-:::::•:/>:}:/::?>•.·<:/: :.. :·: ::: :: -; .. .-.·.· ...... -. . . .. ·.•.·.·.. .. ·-·.·.·.. ·.. ·.·.·-·.·.·.·.. · illlillli!II I IIlf1llilill I ~J!!l!I !:~:l~: .:.i~: .: ~~I!I: Rllll l,I IA,1111\: :.~: :\: ~~: A look at some of the best Model Railways in Australia - ·-~ ~~* lnc!~des Au~tralian, European, U.S. and U.K. layouts in all scales .. * Comp~r~ prototype locations in Australia with the Model layout * Vfsit all the recent exhibitions around Australia * All technical detail explained This is a high quality Broadcast Production featuring: We'll show you everything from notebook computers to software solutions at the biggest computer exhibition in Queensland. At Computer Expo you 'll see new and exciting technology from Australia and overseas under one huge roof at the RNA Showgrounds, Brisbane. Everything from PC's and laptops through to printers and software will be on display - so make sure you get there. Available from: CHOO-CHOO-CAM ACTIVE MEDIA IMAGES A Micro Camera mounted atop locos as they move around the layout PO Box 90, Riverwood, N.S.W. 2210 Phone: (02) 580 8525 60 minutes Running Time Cheque. Money Order, Bankcard, MasterCard or Visa ■:=- -~ -~~- 0 ■ EXHIBIDON ~:==::■ BUIIDING RNA ....-0 SEPT. 30 - OCT. 3 September 30: October 1: October 2: October} 10am 10am 10am 10arn - 8pm 8pm 9pm 6prn ■0-..SHOWGROUNDS QUEENSLAND GREGORY TCE ADMISSION:s6 COMPUTER BRISBANE EXP01992 Fur more• iJ~fi ,rmatioll co11/t1cl./tmH•s C11 rlt1i11 al ~lfee11slt111d /~\·b ihitioll .\<'rl'ices JJh: f0 7 ) 8 ·i (, .1 --: 77 Fax: f0 7 ) 8-UJ 181 I JJ() Uux J.:!j.! Suutb Hris/J({ll(' .\l.-1C." <.Jhl ·i I O I OCT0BEH 1992 101 .......TCENTRE Cash in your surplus·gear. Advertise it here in Silicon Chip. sal. Please ring Mogens Hansen (03) 386 8357. ANTIQUE RADIO ANTIQUE RADIO restorations. Your one-stop radio repair shop. Specialising in restoring vintage radios, including chassis rewiring, re-condensing, quality new parts, valves, valve sockets, speakers, power & audio transformers. Secondhand radio dials & parts for most brands & models. About 400 radios in stock for sale, restoration & parts. Every restored w ireless is covered by a 2year warranty on parts & labour. We restore damaged woodwork & cabinets & French polish (approx. 40 coats). Vintage car radios available for sale or restoration. Repairs done on tape decks. Open Sat. 10am-5pm; Sun. 12.30-5pm. 109 Cann St, Bass Hill, NSW 2197. Phone (02) 645 3173 BH or (02) 726 1613AH. FOR SALE WEATHER FAX programs for IBM XT/ ATs *** "RADFAX2" $35 is a high resolution, shortwave fax, Morse & RTTY receiving program. Suitable for CGA, EGA, VGA and Hercules cards (state which). Needs SSB HF radio & Radfax decoder. *** "SATFAX" $45 is a NOAA, Meteor & GMS weather satellite picture receiving program. Needs EGA or VGA plus "WEATHER FAX" PC card. *** "MAXISAT" $75 is similar to SATFAX but needs 2Mb expanded memory (EMS 3.6 or 4.0) and 1024 x 768 SVGA card. All programs are on 5.25-inch or 3.5-inch disks (state which) & include documentation. Add $3 postage. Only from M. Delahunty, 42 Villiers St, New Farm, Old 4005. Phone (07) 358 2785. WANTED WANTED: Manual and disc for EPROM prog rammer - JMC Promac2 Univer- MS-DOS PC PRINTER port driven Z80 development system. Includes Fast Z80 Cross Assembler, Z8TBasic and lots of r-- -----------------------, CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $10.00 for up to 15 words plus 40 cents for each additional word. Display ads (casual rate): $20 per column centimetre (Max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly on a separate sheet of paper & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy Beach, NSW 2097. Or fax the details to (02) 979 6503. Enclosed is my cheque/money order for $_ _ _ _ or please debit my O Bankcard O Visa Card 0 Master Card I I I I I I I I I i I I I Signature_ _ _ _ _ _ _ _ _ _ _ Card expiry date_ _~/_ __ I I Name I I Street _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ I I Suburb/town _ _ _ _ __ _ _ __ _ Postcode_ _ _ _ __ I L _____ ____________________ J Card No. 102 SILICON CHIP source code. Once only initial outlay for the short form kit $76. Additional CPU blank boards $35. For more information, send a 45c stamp to Don McKenzie, 29 Ellesmere Crescent, Tullamarine 3043. Phone (03) 338 6286. KIT REPAIRS: fixed price servicing for all kits, no job too small, only quality components used. Ph (02) 649 2134 after 5pm. SIMPLE IBM PC DATA ACQUISITION & control: C001 - plans & software for a 1-chip a-channel analog to digital converter that plugs into the printer port. Suitable for laptops or desktops, $25. • C002 - a small 15° per step, unipolar stepper motor plus plans for a 1-chip printer port interface & software source code showing how to drive the motor in wave, full-step & half-step modes, $25. • C003 - plans & software for a remote 4-button keypad . Uses the serial port, no external power required , $25. All prices include post & packing within Australia. To order, send cheque or money order to Lambda Systems, PO Box 259, Unanderra, NSW 2526, or send SSAE for more info. SECURITY ALARM COMPONENTS: commercial quality alarm panels, detectors, cable, everything for complete alarm system. DIY kits. Discounted prices. 4-core alarm cable $35 per 100m. 2-core alarm cable (figu re-8) $15 per 100m. PIA detectors pulse count $59 ea. Horn speakers $12.50 ea. Mail order service send SAE for free price list to Security Distributors, 141 Todds Rd, Lawnton, Old 4501 . Phone (07) 882,0002. SURPLUS COMPONENTS: 747CJ OIL ceramic $1 ea or 25 for $20; 150Q 1OW resistors $1 ea or 1o for $8; Bourns 3386 trim pots 5kQ or 10kQ, 50c ea or 10.for $4; Eska 3AG 10A ceramic fuse, packet of 10 $1.50; ex-computer EPROMs, erased and blank tested, 2732, 2764, 27128, $2 ea or 10 for $15; Valves, ex-government, new 12AT7 $8 ea, 5Y3GT $6 ea, KT66 $25 ea, 6AN8A $9 ea, 6BL8 $8 ea. Many other valves MEMORY EXPANSION PRICES AT SEPT 9TH, 1992 I SIMM 1Mb x 5 ?Ons 1Mb x 3 ?Ons 1Mbx8 100ns 4Mb x 9 sons 4Mb x 8 80ns (For SIP add $1.00) LOOKING FOR SEMI'S? We stock both Japanese & European types for TV , VCR and Audio applications. Translstors2SA 2SB 2SC 2SD 2SK BC BD MJ 2N etc. t:::; AN ~~~:1~f E:~~ ~M M 1 11 <~ MB STK TA TDA UPC UPD etc. ' i-d Phone or fax for a price list . Wagner Electronlc ServlcH Ply Ltd. 305 Liverpool Road Ashfield, NSW 2131 Ph: (02) 7118 9233 Fax: (02) 7118 001? DRAM DIP 1 x 1Mb ?Ons 256 x 4 ?Ons 41256 sons 1Mb x 4 (stat) $46 $42 $37 $164 $152 $5 $5 $2 $23 DRIVES SEAG 130Mb 19M SEAG 44Mb 28M C'NER 200/12 C'NER 80/19 $438 $260 $750 $335 IBM PS.2 50/55/70 2Mb 70/35 4Mb $115 $1130 TOSHIBA T3200SX 2Mb T44/6400 4Mb T5200 2Mb $135 $350 $135 MAC 16MbQUADRA 2MbSI & LC 4Mb P'Book $780 $83 $260 BOARDS $232 8Mb AT W2MB 8Mb PS2W2MB $234 4Mb HP Laser W2MB $155 8Mb PANAS W2MB $1 70 1Mb TIW1MB $80 Sales tax 20%. Overnight delivery. Credit cards welcome. Ring for Latest Prices Plans Kits and PCBs 1OOW Valve Amp PCB ........ $30 Valve Amp PSU PCB ..................... ........ .................. $25 Universal PSU (±5/±12V) Dual Supply .. ...... ............ $1 0 Digi 125 1OOW amp/pair ............... ........ .................. $1O ETI 1623 PIA for PCs .... .................... $40 Max 1/0 Board .. .. .. ... ................. .... .......... $40 Max Kit ............................................ ..................... $169 LM380 3.5 amp PCB ........... ................... $7 AEM 35W amp kit ...................................... ............. .. $20 ETI Audio Toolkit PCB .. ............ ..................... $10 AGC Amp PCB ............... ... ........ ......... $7 Z-80 Miniprocessor PCB ............................. $50 6502 Miniprocessor PCB ................. ......................... $50 6809 Miniprocessor PCB ...... ....... $50 8048/8049 Developers board complete B&T ......... $1 99 IBM PC Prototype PCB ······························· ............ $50 EPROM Programmer .............................................. $299 ESL-1 Electrostatic speaker kiVpair inc manual ...... $899 ESL-1 Assembly Manual ............................... $50 P.C. Computers (08) 332 6513 36 Regent St, Kensington SA. PELHAM Tel: (D2) 9BD 6988 Fax: (02) 980 6991 1st Floor, 100 Yarrara Rd, PO Box 382, Pennant Hills, NSW 2120. FIX-A-KIT KIT REPAIR & CONSTRUCTION and components available. Send SAE for list. Open Thursday, Friday 4pm8pm, Sat 9am-4pm. 143 Grays Rd, Enoggera Old . Ph (07) 355 1314 or (07) 855 1880 AH, Fax (07) 855 1014. Visa, Bankcard , Mastercard available for fax or phone orders over $20. Secontronics, PO Box 2215, Brookside Old 4053. HARD DRIVE: Maxtor voice coil IDEAT. Factory warranty. Great bargain. New 120Mb $560, 200Mb $860. Mail order welcome. Altec Pacific. BH (03) 800 2007. Fax (03) 800 3363. AH (03) 801 4391 Wantirna. FOR SALE: Oscilloscope, Thandar, low TRANSFORMER REWINDS 3 MONTHS WARRANTY ON REPAIRS 12 MONTHS WARRANTY ON CONSTRUCTION TECHNICAL ASSISTANCE ALL TYPES OF TRANSFORMER REWINDS HVCAL ELECTRONICS TRANSFORMER REWINDS Design. Manufacture & Repair of Electronic Equipment Reply Paid No.2, PO Box 438, Singleton, NSW 2330. Ph: (065) 76 1291 . Fax: (065) 76 1003. power lightweight portable, operates from disposable or rechargeable cells. Includes AC adaptor/cell charger, carry case and probe. 10MHz bandwidth, 10mV sensitivity per/div. As new $550. Tom (02) 630 1434AH. VISIBLE LASER DIODE BARGAIN: brand new 5mW 670nm laser diode, plus a collimating lens, plus a driver kit, (02) 633 5477 plus instructions. Special introductory price $85. * CRYSTAL OSCILLATOR MODULES: small 4-terminal metal encased crystal controlled oscillator modules similar to the ones used on computer cards, four frequencies: 1, 20, 10 & 50MHz, $7 ea or 5 for $25. * GAS LASER: a brand new 1mW visible red Helium-Neon laser tube (632.8nm) plus a 12V kit supply to power it. $11 0 for the LOCAL TRADES & SERVICES Transfonner Rewinds T.A. Mowles .- \II types or transformer rewinds. Printed circuit boards for the hobbyist. For senice & enquiries contact: (02) 4011393 Fax (02) 7741154 (065) 761291 Fax (065) 761003 (08) 3265590 Ian .J Truscott 's Electronic World EEM Electronics Silicon Chip To ad\'crtise your 1>roducts or scniccs, please call Sharon on Mail or credit card facilities Printed circuit hoard assemhl). switchmode power supplies repaired. Design work from start to finish. Ring an)timc 9am-9pm \lon-Sun. (03) 7233344 Fax (03) 4192808 (03) 401 1393 (02)9795644(018)285532 JV Tuners - Repairs • • • • Shorted Turns Tester High Voltage Probe Degaussing Wand Remote Control Tester For senice & repair work OCT0BER 1992 103 r-------------------------, SILICON CHIP BINDERS l These beautifully-made binders will protect your copies of SILICON CHIP. They feature heavy-board covers and are made from a distinctive 2tone green vinyl that will look great on your bookshelf. * High quality. * Hold up to 14 issues * 80mm internal width. * SILICON CHIP logo printed in goldcoloured lettering on spine & cover. Yes! Please send me _ _ _ SILICON CHIP binder(s) at $A11.95 plus $A3 p&p each (NZ $A6 p&p). Enclosed is my cheque/money order for $_ _ _ _ or please debit my o Bankcard Card No. O Visa Card O Master Card ~~II~~~I I'--'--'--~I I'--'--'--~ Signature_ _ _ _ _ _ _ _ _ _ _ Card expiry date_ _~/_ __ Name _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ __ _ __ Street _ _ _ _ _ _ _ _ _ _ __ __ _ _ _ _ _ _ _ __ Suburb/town _ __ _ __ _ __ _ _ Postcode._ _ __ __ SILICON CHIP PUBLICATIONS PO Box 139, Collaroy Beach, NSW 2097, Australia. Phone (02) 979 5644 Fax: (02) 979 6503. L _________________________ J pair. * SWITCHED MODE POWER SUPPLIES: compact enclosed exTelecom supplies. Dimensions 300 x 90 x 180mm. Unregulated input 3050V, regulated output of 12V <at> 6A or 12V<at> 8A or 5V<at> 40A. Three different units. Limited stocks<at> $28 ea. P+P $7 (heavy!). Specify type when ordering (item No. 0145) . * STEREO HEADPHONES: similar to ones used for stereo "Walkmans". Clearance<at> $2 a pair. * TV ANTENNA: dual telescopic TV antenna similar to ones used on many portable TVs. Clearance <at> $3 ea. * KIT SPECIAL - ELECTRONIC -KEY: use it to activate door strikers for entering buildings, car alarms, central locking - the most secure key ever (see EA July 92). Two keys and one decoder kit for a total of $49.90. Major cards accepted with phone and fax orders. 104 SILICON CHIP Certified p&p Australia $5, NZ (airmail) $10. Oatley Electronics, PO Box 89, Oatley, NSW 2223. Phone (02) 579 4985. Fax: (02) 570 7910. Advertising Index Active Media Images ............... 101 Altronics ............. .... ............... 80-82 Antique Radio Restorations ..... 102 A-One Electronics ................ 62-63 Breakthrough Computers ....... ... 67 David Reid Electronics .. .. .... ...... .. 3 Dick Smith Electronics .......... 52-55 Economic Electronics ................ 76 EEM Electronics .... .......... .. .... .. 103 Electronic Toy services ..... ... .. .. 103 Electronic World ................. 45,103 Emona Instruments ...... ... .. ........ 51 Geoff Wood Electronics ....... .. .. .. .. 7 Hewlett Packard .... .. ...... ... ....... IFC Hycal Instruments ............... 77,103 Jayear Electronics .. ... 33-36,69-72 JV Tuners ......... .... ......... ... ....... 103 KT Technology ......................... IBC Macservice .......... ... ................... 40 M.E. Technologies .. ................... 95 Oatley Electronics ..... ... ...... 47,103 PC Computers ... ...................... 103 Pelham .................................... 103 Peter C. Lacey Services ... ..... .... 42 Philips Test & Measurement ...... 21 Old Exhibition Services ........... 101 RCS Radio .. ... ... .... .................. 104 Reserve Electronics .... ... ... ...... 101 Resurrection Radio ............... ..... 41 Rod Irving Electronics .......... 10-15 Sanyo Australia .................... 28-29 Scan Audio ......... .... ...... ............. 91 Silicon Chip Binders .... .. ..... 89,104 St Lucia Electronics ............. .. .... 85 Tecnico Electronics ................ OBC Tencom 92 .... ............................. 86 Tees Electronics & Computers .... 5 Tektronix ... ................................. 27 Transformer Rewinds ...... .... .... 103 Wagner Electronic Services .... 103 RC§ RADilO PTY LTD ~i~1,~ :::=i ' °ifl!....o I Ill [!OI RCS Radio Pty Ltd is the only company that manufactures and sells every PC board and front panel published in SILICON CHIP, ETI and EA. RCS Radio Pty Ltd, 651 Forest Rd, Bexley 2207. Phone (02) 587 3491 PC Boards Printed circuit boards for SILICON CHI_P projects are made by: • Jemal Products, 5 Forge St, Welshpool, WA 6106. Phone (09) 350 5555. • Marday Services, PO Box 19-189, Avondale, Auckland, NZ. Phone 88 5730. • RCS Radio Pty Ltd, 651 Forest Rd, Bexley, NSW 2207. Phone (02) 587 3491 . DEALERS BOOK NOW Starring KT ·QAT KT 386SX-20 KT 386-25 KT 386-33 KT 486-33 KT 386 NOTEBOOK * * * * • New Costumes • All Australian Support Cast Our Promoter is seeking Dealers wishing to present this talented new range of PC Performers to the Australian Public. Don't miss your opportunity to book your place in this ever expanding dealer network. ,. KT TECHNOLOGY "' ~~~~m~ iu~1~~rsa~~~~~evard, Port Meloourne 3207 Tel: (03) 646 5755 Fax: (03) 646 7997