On 6/29/05, Harold Hallikainen <harold@hallikainen.com> wrote:
> 
> >
> > Right.  I used a simple resistor+zener supply in my application.  (15V
> > zener, 15k resistor, 0.1 uF across the zener. rectified 117 VAC, 20kHz
> > PWM, IRF740)
> >
> 
> OK, I see that as a possibility. Did you use a single device and a bridge
> rectifier, or two devices with steering diodes?
> 
> Harold

Actually, I was driving a universal motor, so I used a bridge
rectifier and a single device in series with the motor inside the
bridge.  This gave me a 160VDC supply.  (there was no filter capacitor
on this supply, so it was 120 Hz pulsed "DC".)

Unless your load can take DC, this arrangement is not gonna work for
you.  I don't think it would be too hard to modify it to move the load
outside the bridge.  I think you'd just need to add a diode to the
resistor+zener.

Regards,
Mark
markrages@gmail
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