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MARKET CENTRE Cash in your surplus gear. Advertise it here in SILICON CHIP FOR SALE PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone 0434 781 191. sesame<at>sesame.com.au www.sesame.com.au tronixlabs.com - Australia’s best value for hobbyist and enthusiast electronics from adafruit, DFRobot, Freetronics, Raspberry Pi, Seeedstudio and more, with same-day shipping. LEDs, BRAND NAME and generic LEDs. Heatsinks, fans, LED drivers, power supplies, LED ribbon, kits, components, hardware, EL wire. www.ledsales.com.au PCB MANUFACTURE: single to multi­ layer. Bare board tested. One-offs to any quantity. 48 hour service. Artwork design. Excellent prices. Check out our specials: www.ldelectronics.com.au PCBs & Micros: SILICON CHIP can supply PCBs and programmed microcontrollers and other specialist parts for recent projects and some not so recent projects: www.siliconchip.com.au or phone (02) 9939 3295. KIT ASSEMBLY & REPAIR KEITH RIPPON KIT ASSEMBLY & REPAIR: * Australia & New Zealand; * Small production runs. Phone Keith 0409 662 794. keith.rippon<at>gmail.com VINTAGE RADIO REPAIRS: electrical mechanical fitter with 36 years ex­ perience and extensive knowledge of valve and transistor radios. Professional and reliable repairs. All workmanship guaranteed. $10 inspection fee plus charges for parts and labour as required. Labour fees $35 p/h. Pensioner discounts available on application. Contact Alan on 0425 122 415 or email bigal radioshack<at>gmail.com DAVE THOMPSON (the Serviceman from SILICON CHIP) is available to help you with kit assembly, project troubleshooting, general electronics and custom design work. No job too small. Based in Christchurch, NZ but service available Australia/NZ wide. Phone NZ (+64 3) 366 6588 or email dave<at> davethompson.co.nz WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Tannoy, Goodmans, Wharfe­ dale, radio and wireless. Collector/ Hobbyist will pay cash. (07) 5471 1062. johnmurt<at>highprofile.com.au ADVERTISING IN MARKET CENTRE Classified Ad Rates: $32.00 for up to 20 words plus 95 cents for each additional word. Display ads in Market Centre (minimum 2cm deep, maximum 10cm deep): $82.50 per column centimetre per insertion. All prices include GST. Closing date: 5 weeks prior to month of sale. To book, email the text to silicon<at>siliconchip.com.au and include your name, address & credit card details, or phone Glyn (02) 9939 3295 or 0431 792 293. Ask SILICON CHIP . . . continued from page 94 motor and is controlled by a boost sensor which has a cut-in adjustable between 6 and 30 psi and a maximum output adjustable between 10 and 100 psi. My problem is that in reality it doesn’t engage until 8 psi, leaving me to have to push the vehicle harder to get the effect of the system. I was hoping to be able to wire this motor speed controller in parallel with the boost controller to enable siliconchip.com.au me to override the system and dial in a desired amount of methanol/water when conditions require it, while still allowing the boost switch to take over on steep climbs. I have assembled the kit and installed it after performing the tests described in the instructions. It returned pretty much the figures quoted and gives me a range of almost zero to 12V when I turn the potentiometer (Jaycar supplied me with a potentiometer with the same value as the trimpot). The result when I flick my switch on however is full pressure which does not alter as I adjust the control and when I drive the vehicle at boost level the boost controller fails to take over. I initially installed D2 and C3 at the motor and thought maybe this was affecting the boost controller so I tried moving them closer to the circuit board, leaving two separate parallel circuits to the motor, but this seems to make no difference. I have retested the output voltage at the circuit board while installed in the car and get the correct results. Is what I’m trying to do not possible or do I . . . continued on page 104 December 2015  103