Re: Production EVs

[XURQ03A@prodigy.com ( LEE A HART)]

Tom Shay wrote:
> Brakes on my Ranger pickup are strong enough to stall the motor in 1st
> or reverse gears.

That's because your controller's current limit is still working. If the
transistors fail shorted, it's not. Then your motor gets all the current the
batteries can supply. That will easily be 1000+ amps!

My ComutaVan has a little GE 12 HP motor, only 72v, and a contactor controller
(no current limit). Once I got a flat tire. I don't carry a spare and was only
a mile from home, and was going to replace the 15-year old tires anyway, so I
kept going. Wobble, wobble, flop, flop, slap, slap, WHAM, WHAM... then silence
(though it got pretty slow). The tire had disintegrated to the point where it
had flopped over and snagged on a suspension mount, locking that wheel.

The car still dragged itself the last couple blocks home. With one rear wheel
locked, the other wheel turns 2:1 faster, so the car was effectively in 3rd
gear. Still the spinning series spun!

Lee Hart                     If you would not be forgotten
4209 France Ave. N.          Soon as you are dead and rotten
Robbinsdale, MN 55422 USA    Either write things worth the reading
phone (612) 533-3226         Or do things worthy of the writing
e-mail XURQ03A@prodigy.com   (Ben Franklin, Poor Richard's Almanac)