re:stepper pwr suplies wasRe: motor/leadscrew/ps recomendations

YES! Replaced my 12v computer supply with a 24v supply I got for $10
on ebay.

Tweeked it to 27.6 volts, and added a .1ohm, 5w resistor between the
10k cap and the PS.

Almost THREE TIMES the speed! Went from a fast jog of 8 ipm to 23
ipm.

Now, if I can just keep the damn thing from flying apart! <BG>

--- In CAD_CAM_EDM_DRO@egroups.com, "Roman Black" <fastvid@e...>
wrote:

> Putting a chopper motor driver on the output
> of most switchers spells disaster. It draws
> nothing but spikes! Your poor switcher was
> probably going into current protect every time
> your chopper drive chopped! :o)
>
> Putting very big caps on the switcher output
> is obvious, this helps a bit. But the caps
> do not *decouple* the supply well enough, so
> as your chopper chops, there are still some
> significant current surges drawn from the
> switcher. You put the resistor BETWEEN the
> switcher and your big caps, this provides
> an impedance to the current surges, so they
> are more likely to be drawn from the big caps
> and not the switcher. You could use an inductor,
> but this gets more complex and I know from
> experience that if you don't mind losing the
> 0.5v (and gaining some extra heat!) this will
> probably be enough to solve it.

> --- In CAD_CAM_EDM_DRO@egroups.com, richard@s... wrote:
> > I don't understand the use of the resistor for the .5v drop.
> >
> > ~+.5v
> > +24v DC---------------[R1, .01ohm]------------[load]
> > |
> > |
> > -[10k cap]-
> > |
> > |
> > GRD ----------------------------------[GRND]
> >