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Notes & Errata Automatic Starter Circuit For Cars, Circuit Notebook, April 2016: as noted in the Mailbag pages of this month’s issue, if this circuit is added to any car it brings about a dangerous situation whereby the car’s engine could be inadvertently be started in any gear. We cannot recommend that anyone install this circuit on their car. Ask SILICON CHIP . . . continued from page 103 it’s rated for at least 250V DC. Not all 0.25W resistors would necessarily withstand this. If that still isn’t bright enough, maybe try 150kΩ or parallel the existing 220kΩ resistor with a 470kΩ resistor. Deep cycle charger not working correctly I built the Charger for Deep Cycle 12V Batteries from the November & December 2004 issues, mainly because I had a suitable transformer. But it has a problem: when I push the Start button it shows the battery type, as if I had pushed the Set button. I have checked all wiring and the circuit board, especially around the switches and display. Everything else is OK and all voltages measure as correct. When programming the PIC, I initially used pin 4 as VDD, as shown on the circuit. As it did not work, I then connected pins 4 & 14 to +5V and ultimately, after checking the data sheet, I got it right and used pin 14. The chip then programmed OK but I feel as if this is where the fault may lie. Do you think I should get another PIC or could it be something else? (P.C., Balgal Beach, Qld). • It is unlikely the PIC is damaged. Make sure you have the 1nF capacitor connected to ground from the common switch connections. Check that diodes D7-D9 are connected the right way round. If it still doesn’t work properly, you could try a new PIC. Advertising Index Allan Warren Electronics............ 103 Altronics.........................loose insert Decibel HiFi.................................. 73 Digi-Key Electronics....................... 3 DSCAPE.................................... 103 Emona Instruments.................... IBC Using a GPS module with an enable pin Front Panel Express..................... 15 I bought and am installing a VK­ 2828U7G5LF GPS module in the Accurate GPS 1PPS Timebase for Frequency Counters (SILICON CHIP, February 2013). The data sheet link for this model states that the yellow lead is designated as “Power Enable”, a point not mentioned in your original article (and so I assume it is peculiar to this later model unit, which also includes status LEDs and is certainly faster). Can you advise me where to terminate this lead? (P.S., Warwick, Qld.) • As noted in the data sheet PDF with respect to the Power Enable pin: “a high level means that the module works, low level means the modules (sic) is closed”. Therefore, you should connect the Power Enable pin to the +3.3V or +5V supply, depending on what you are using for the circuit. SC Icom Australia.............................. 11 Next Issue The June 2016 issue of SILICON CHIP is due on sale in newsagents by Thursday 26th April. Expect postal delivery of subscription copies in Australia between May 26th and June 3rd. Hare & Forbes.......................... OBC Jaycar .............................. IFC,49-56 KCS Trade............................... 28-31 Keith Rippon Kit Assembly ........ 103 LD Electronics............................ 103 LEDsales.................................... 103 Master Instruments.................... 103 Microchip Technology................... 13 Minitech Engineering..................... 6 Monster Electronics...................... 12 Mouser Electronics......................... 5 Ocean Controls.............................. 8 PCBCART...................................... 7 Rohde & Schwarz.......................... 9 Sesame Electronics................... 103 SC Radio & Hobbies DVD............ 89 SC Online Shop............ 39,45,96-97 Silicon Chip Subscriptions........... 95 Silicon Chip Wallchart.................. 35 Silvertone Electronics.................. 14 Tronixlabs.............................. 59,103 WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. 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. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Competition & Consumer Act 2010 or as subsequently amended and to any governmental regulations which are applicable. 104  Silicon Chip siliconchip.com.au