PulseWidthModulation comments

[Ludis Langens]

< rauscher at icst.com> wrote:
> Was this motor designed specifically for this freq? When I first developed
> this PWM motor controller, I was trying to run it at 20KHz also. But the
> motor was down on power.

The PWM was confined to a "conventional" switching supply - a
transistor, diode, inductor, and capacitor.  The motor saw only a DC
voltage.  It would have been possible to use the motor as the inductor,
but the boss didn't want to experiment on a one-off cu$tom motor.

> Sounds as thou the noise is from the P/S, and not the motor. I've only
> heard a light whine from the motors, and only at lower speeds. So hopefully
> the noise won't be enough to drive folks out of the car <g>.

Yes, this noise came from the power supply, not the motor.  I don't know
what would happen if the motor had high frequency PWM flowing through it.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/