Re: [CAD_CAM_EDM_DRO] Re: LARGE DC MOTOR speed control question

"Derek B." wrote:

>
> STAN MCDONALD wrote:
> >
> > I measured the 240 rectified and got 280
> > I measured the 120 rectified and got 130.
> > What gives one would think that if 240 = 280 an increase of 40 volts
> then why
> > would you not get 140-155 when 120 was converted to dc. Since my
> motor needs 180

If you put a capacitor (large) across the DC output of the rectifier,
you will get 1.414
times the RMS voltage reading, which will be around 170 V DC for a 120 V
input.
Without the capacitor, you will be feeding a rectified sine wave into
your meter,
and it will indicate strange things, depending on whether it is a true
RMS meter
or not. It sounds like your meter might be a true RMS one.

Jon