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Old 09-22-2010, 04:57 PM   #367 (permalink)
MPaulHolmes
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Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
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I fixed 2 problems. One software and one hardware. lets say you have a register that has some of its bits unused, or read only... Don't write to those. hahaha. It causes lots of problems.

OK, now for hardware... Fran put together a hardware overcurrent shutdown circuit, which worked perfectly for 2 pwm outputs (SR). It uses a zvp4105a P-mosfet. I am overloading the sucker with 6 pwm channels. I need smaller resistance across it. It's 10 ohms. Digikey has some 5 ohm ones, so I ordered 2 of those and will parallel them. 2.5 ohm should be good. For now I just bypassed the hardware over-current circuit and all 6 channels are pwming from 0 to 15v. By the way, I'll be able to test everything properly in a couple days because LUKE ORDERED AN OSCILLOSCOPE FOR ME!!!!!! (ELECTRICZX2)

EDIT: Oops, actually I think the hardware problem is a little different than I thought. IT's still the overcurrent circuit, but I'm homing in on it. Holy cow this is fun. Too bad I have a job.

EDIT EDIT: OK, the overcurrent circuit is mostly working. I think I need to add a pulldown resistor to help HCPL_POWER to go all the way to 0v when it's off. One reason it was in continual disable mode is because the regen overcurrent point was set to 0 amps. haha And I had zero amps going through it. There's still more to check out, but I think the whole control board is going to work as planned, with maybe only a single resistor needing to be added! The next board is going to require only very very minor changes. That's a first!
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Last edited by MPaulHolmes; 09-23-2010 at 02:21 AM..
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