The heater is on high voltage, so it has its own (small) contactor. To avoid the software glitch that accidentally continues to power the heater, which causes the pre-charge resistor to blow, there are two ways to avoid this fatal flaw: - add a small circuit in the pre-heater contactor coil loop, so that even if the SW accidentally brain-farts and leaves it on, the added circuit has a time-delay after seeing the ignition turned on and will not engage the heater until a couple seconds after the car has actually started. - or cut one of the legs off that pre-charge resistor and wire it outside of the controller to a well-accessible location where a blowing pre-charge resistor might be a nuisance, but a quick swap can be made an be back on your way, instead of the scrapnel destroying the circuit board... Of course, this only works with not-yet-damaged boards. I'd be interested in inspecting the board of a disabled Think City to see if I can get it going again, they seem to be fun little cars.
Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of damon henry via EV Sent: Thursday, December 22, 2016 7:23 AM To: Robert Bruninga; Electric Vehicle Discussion List Subject: Re: [EVDL] Sequence of Events contactors There is no standard way of handling startup, so to say "most" is a bit misleading. What you describe certainly does not fit the sequence of either of my two OEM hybrids, nor does it match my two DIY EVs. There is no definitive answer to the question posted. Perhaps a better question needs to be asked. Something a bit more specific. For instance, I am planning on converting an ICE to an EV. What is a safe startup sequence to power on my 12 volt and traction circuits and what components are required? Even then, more details are better, for instance do you have a DC-DC converter, and what kind of motor controller are you using. Damon ________________________________ From: EV <ev-boun...@lists.evdl.org> on behalf of Robert Bruninga via EV <ev@lists.evdl.org> Sent: Thursday, December 22, 2016 7:10:20 AM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Sequence of Events contactors Most EVs and Hybrids have at least three contactors. The sequence is: * Close One battery lead and check for leakage * Drop that relay and close the other lead with a series resistor and check for leaks * Bring the first one back in to power up still via the series resistor for a few milliseconds to allow the car system to charge all capacitors * If still no smoke, pull in a main contactor to bypass the resistor. You can hear the relay dance in any Prius or most other EV's. There should be NO heavy loads until all of the above are complete. A software glitch in the THINK CITY made the mistake of leaving the 4 kW heater possibly on, so that on the third step above, the 4kW is trying to go through a 5W 47 ohm resistor and it blows up. This kills the car, and all replacement b0oards are gone, most cannot be repaired, and so the company is out of business and there are lots of THINK CITY's just gathering dust. Bob, WB4aPR _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20161222/f0df de3a/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
