Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

That's awesome joe!!!

[jackbauer]

Sounds like a peak detector circuit. Should work well. I must do something similar.

[jyanof]

Originally Posted by MPaulHolmes

OK, First I made the awesome little circuit. Then I precharged the caps and watched on the dedicated volt meter what the max voltage was from Drain to Source.

.....


If 7 is the spikes above max voltage, then it's officially safe to drive around at 193v. hahahaha. Just kidding.

Ok, so I got off my butt and did it too and got something similar. Pack started off at 154V according to the test meter while my voltmeter in the car showed 152. In 3rd gear from a stop, it's easy to hit 500A with little voltage sag. The most I got from the test meter was 161V while the pack sagged to 148V on my car meter. So, I guess to be conservative, we could say that's 13V above pack voltage when considering voltage sag. A pack of lithiums won't sag as much (supposedly).

[MPaulHolmes]

That's so wonderful I can hardly stand it! Thank you Joe!!! Not bad. 13v isn't toooo much. I feel so much better now. The voltage spike magnitude is a linear function of di/dt. dt is the same each time, so I think a 700v controller would have a spike of 18.2v to be conservative. So, with a lithium pack with no sag, assuming the starting voltage was 154v, it should get up to 172.2v, still safe. PHEW!!!

[MPaulHolmes]

I wrote an updated help file for the DIYer that wants to make their own controller. It's based on the kit, but it would be pretty easy to adapt the process to something else I think. I lost a lot of all the good changes that Fred Good made, since the process has changed so much. Let me know if there is anything unclear.
Motor Controller directions

[jackbauer]

Little more progress today getting the parts in the box for a trial fit.

[MPaulHolmes]

OK. that's awesome. I'm not going to lie...

[bennelson]

And just because this is Paul's thread...

I haven't heard any Oprah jokes in a while, but I think there is some kind of method to the madness.

Dr. Phil just became the leader on Jay Leno's Green Car Challenge.

I believe we have reached ONE DEGREE OF SEPERATION between Oprah and electric cars!

[MPaulHolmes]

hahahaha! Go Dr. Phil!!! Go!!!!!

[jackbauer]

Just running a few bench tests with the starter with the scope across M- and B- i'm getting some fast voltage spikes at turn off. Waveform looks quite clean apart from that. Thinking of putting a snubber on the igbt. Any thoughts?