Re: UPS to VFD hardware hack

>the output voltage needs to be varied proportional to the output

frequency.

This is the kicker. you must vary the voltage proportional to the
frequency. you could get away with 10-20% off the nameplate, but
your motor would overheat when fed the unexpected power.

if you think of a motor as a device that spins 1700 times per minute
or 30 times a second, or 1 revolution for every 2 cycles of AC wave,
you should be able to envision that the motor does not know what time
it is. (does anybody really know what time it is?) so if you fed it
the same mix twice as fast or half as fast, it would still spin 1
time for every 2 cycles.

It's kinda like steppers that spin just so fast on a voltge, give em
more and they can spin faster.

The truth is that a brand new VSD is so cheap in comparison to the
amount of work involved that there are much better things to hack.

imho

Dave