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amino · 11-28-2011, 11:53 PM

Hi Paul,

I built the 500 amp controller from the kit last Month and after testing it a couple of weeks ago at 16 volts (2x8 volt batteries) with just the motor connected, all seemed well. I decided to install it in the car and test it at the pack voltage which is currently 80 volts, as I needed to test the precharge time, using a small 7 watt bulb through a solid state relay setup which I already had for the old Kelly controller.

When I switched the circuit on to activate the relay, the bulb did not light up. Instead there was a small puff of smoke from inside the controller, at the rear (M-) end , so I took it all apart and looked for the source of the smoke, but did not see any sign of damage anywhere! No burnt smell, no charred components.

I measured the Gate-to-Source resistance on all the Mosfets and they seem fine (infinity), although the one at the back (Q1) at first seemed shorted, but when I measured it again a little later, it also showed infinity between Gate and Source. Any suggestions while I have it apart?

Thanks,

Amin

11-28-2011, 11:53 PM	#5220 (permalink)
amino EV DIYer Join Date: Jun 2009 Location: Vancouver, BC Posts: 28 Thanks: 8 Thanked 6 Times in 5 Posts	A puff of smoke.... Hi Paul, I built the 500 amp controller from the kit last Month and after testing it a couple of weeks ago at 16 volts (2x8 volt batteries) with just the motor connected, all seemed well. I decided to install it in the car and test it at the pack voltage which is currently 80 volts, as I needed to test the precharge time, using a small 7 watt bulb through a solid state relay setup which I already had for the old Kelly controller. When I switched the circuit on to activate the relay, the bulb did not light up. Instead there was a small puff of smoke from inside the controller, at the rear (M-) end , so I took it all apart and looked for the source of the smoke, but did not see any sign of damage anywhere! No burnt smell, no charred components. I measured the Gate-to-Source resistance on all the Mosfets and they seem fine (infinity), although the one at the back (Q1) at first seemed shorted, but when I measured it again a little later, it also showed infinity between Gate and Source. Any suggestions while I have it apart? Thanks, Amin Attached Thumbnails