EV List Lackey via EV wrote:
Intriguing! This seems to be the story's origin:
https://www.thedrive.com/culture/we-found-motorolas-secret-chevy-corvette-ev-
prototype-from-the-1990s
or https://v.gd/NbYpwY
One wonders why an organization with presumably deep pockets had to start
with a used glider.
I agree that the author seems a bit clueless about EVs and their
history. I sent him an email with additional details.
The article's author calls this an "EV prototype"
Yes, it was a test bed. Motorola was a big semiconductor supplier to the
auto industry. They routinely wrote application notes to encourage
automotive engineers to use their parts. Of course they had to test
their circuits, to be sure they really worked. The Corvette was a good
(and fun) way for the engineers to do it!
They didn't make it public because auto company executives would be
outraged if (for example) Ford knew that "their" circuits were designed
and tested in a (gasp choke) GM vehicle!
So a little possibly irresponsible speculation: maybe Motorola management
looked at GM's 1990 Impact prototype and the Hughes AC "Vector Drive," and
wondered whether Motorola might catch some of the potential EV market.
Many of Motorola's industrial and automotive EV application notes were
collected and published in the "Motor Control Electronics Handbook" by
Richard Valentine (c) 1998. The authors and references are almost all
Motorola Semiconductor employees and application notes. There you'll
find the 'Vette's motor controller, charger, power steering (and more),
all laid out completely enough that one could actually build them.
The article... suggests that it's a series DC motor.
But... it sounds more like an AC induction drive of the time.
Yes; it was an AC induction motor. But there were probably DC motors in
the vehicle as well, for things like the power steering pump and A/C
compressor.
BTW, the Valentine book also describes a DC traction motor drive system
in a Ford pickup truck. Maybe another test bed of the Motorola group?
The Impact, Hughes, and AC Propulsion drives all ran in the 300-400 volt
range, though not at 1000 amps.
Not 1000 amps continuous; the batteries weren't up to it. But remember
that the motor controller steps the voltage down and the current up. It
could well have delivered 1000 amps peak to the motor.
Bummer that the article's author wasn't more knowledgeable about EVs. One
of us might have figured out a LOT more, given the same opportunity to nose
around it. Does anyone here live close to Gurnee, Illinois?
It would indeed be interesting to hear an expert's opinion on the vehicle!
For one thing, I expect that the (few) batteries in it weren't original,
but added by someone attempting to see if the vehicle still worked.
Lee Hart
--
"#3 pencils and quadrille pads." -- Seymour Cray, when asked
what CAD tools he used to design the Cray I supercomputer
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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