Re: [CAD_CAM_EDM_DRO] 48V 10A! Mauch 2A board?

Right Jon,

That's why I mentioned going DIRECTLY across the filter cap. Ignore the
regulation! Another way to lower the UNREGULATED output voltage is to
connect a small filament transformer in SERIES with the primary to BUCK
the primary voltage by 5, 6, or 12v (would also work if one wanted to
raise the voltage a little, but watch the caps!).

I've also acquired "the lot" of new, unused 28v 6A transformers. Dual
primaries, each with additional tap. If anyone is interested, contact
me off line.


Alan KM6VV


Jon Elson wrote:

>
> Alan Marconett KM6VV wrote:
>
> > Hi Randy,
> >
> > Nice find! If you find another one, give me a call! I've come across a
> > source of 28v, 6A transformers; I'm going to run them in parallel, and
> > maybe even series-parallel. Now to find a bigger cap, I have a 40K, 50v
> > cap, but would need a higher voltage for for series, and more C for
> > parallel.
> >
> > Your supply sounds like too much for the L298's, IMO. You might examine
> > the primary taps, I assume it's regulated, you could lower the taps, and
> > pull off voltage directly across the filter cap. That might possibly
> > lower your voltage to an acceptable value.
>
> If it is regulated (sounds like it) changing transformer taps won't
> do anything until it drops out of regulation. There should be a voltage
> adjust pot on the circuit board, but it probably only has a +/- 5%
> range. You might need to modify the circuit a bit to drop the regulated
> voltage. Or, you could turn the voltage down with a variac, and live
> without regulation.
>
> Jon