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Mike,
Please ellaborate on how an old UPS will help me produce a variable frequency and amplitude required to run a vehicle (bike, scooter, motorcycle, car, whatever).
Please show me a link to a DC-input 3-phase VFD for under $1000 capable of driving a few kW.
If my idea is totally fruitless i'll drop it. But please, ellaborate when you're telling me it isn't a good idea.
Hummingbird,
The huge inrush can apparently be avoided by driving the amplitude at the same factor as the frequency from the motor rating. Ie, if the motor is expecting 208V @ 60Hz, then when you're starting off at 0.6Hz you push 2.08volts, then when you're moving really slowly at 6.0Hz you push 20.8V, etc. Apparently deviation from this ratio allows you to control your torque for smooth take-offs and reasonable current at low rpm.
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