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Old 01-06-2009, 01:10 AM   #123 (permalink)
MPaulHolmes's Avatar
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
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Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
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It was a nearly complete re-organization of the code, so I would call it a major revision. Also, the philosophy of the program changed. Now, the slow changing stuff (temperature of aluminum heat spreader and throttle position) are checked only like 100 times a second, whereas the current monitoring is happening about 2,000,000 times a second. I am determined not to allow a single current spike to sneak through!

I moved the oscilloscope to the garage, and monitored M- relative to B-. It was pretty interesting! You could see the normal PWM wave, but there was a small amount of "ringing" on the peak (small damped waves on the high times). It's hard to explain. I'll get pictures of it later. It's going to be fun. This will help me with paralleling them too.

The car's version will need 5 to run the car at 250amp max. Maybe I should do a small version like that before the full 400 or 500 amp version. It's not hard to add more mosfets later! At 144v, I don't think it would be hard to stay under 200amp anyway. I almost never get to 200amp at 72v! 160v is usually my max when I'm careful. Heck, that would only be maybe 3 or 4 mosfets! That would be way cheaper! 144v 200amp controller would cost more like $200 and something!
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