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Old 01-07-2010, 12:50 PM   #190 (permalink)
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Originally Posted by bennelson View Post
Just one thought on AC motors...

My friend Tom has a Dodge Neon he converted to AC with a stock salvaged AC drive and motor. It is also a 1750 rpm motor on it.

Although his car is clutchless, I notice that he shifts far more than I do on my DC conversion (also clutchless.) I believe that it is because over-volting the DC motor just gives you lots more speed (RPMs), but AC speed is controlled by frequency, therefore, typical AC motors may have a more limited range of speed than many DC motors, at least in what's available for an inexpensive home-build.

On the other hand, a car like a Solectria Force is AC, and is basically just direct-drive. It has no shifting what-so-ever. I believe the difference is in the design of the motor itself (although I don't know how much difference the the controller makes)

So, just throwing it out there that a homebrew AC conversion might be best off keeping the clutch, to make shifting easier - at least on lower RPM motors.
The Solectria's doe have a specially designed motor, 120-156 volts and up to 12,000 RPMs, but it has full torque up to 4,000 RPM and drops off after that. I have a Solectria ACGTX20 that I will be building a controller for. I am hoping to get Solectria controller guts to learn from.
Civic EV
Solectria Force
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