Re: QUESTION ABOUT SERIES OR PARALLEL ON STEPPER MOTORS - ref post 52721

That's it. you got it.


There is a small voltage drop from the diodes when converting to DC,
so you might see a little less than that exact value.

also, check your wall power. we had a guy on here last month that
was running pretty high and was just over 80 Volts.

Dave



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Jeff Goldberg" <jeff@w...>
wrote:

> I thought I was understanding this and all of a sudden I'm confused

again.

> I thought that the ratio of DC voltage across the bridge rectifier

(across

> the cap) was 1.414 times the secondary AC voltage of the

transformer. For

> example,
>
> My two tap combinations assuming my line voltage is 115 volts:
>
> Primary Tap Secondary tap Measured secondary voltage X 1.414
>
> 115 volt AC 44 volt AC 44 volts AC X 1.414 = 62

volts DC

>
> or
>
> 105 volt AC 44 volt AC 48 volts AC X 1.414 = 68

volts DC

>
>
> Am I wrong in the above?
>
> Thanks for checking my figures.
>
> Regards,
> Jeff
>
> -----Original Message-----
> From: turbulatordude <davemucha@j...> [mailto:davemucha@j...]
> Sent: Thursday, February 13, 2003 8:36 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Re: QUESTION ABOUT SERIES OR PARALLEL ON

STEPPER

> MOTORS - ref post 52721
>
> I can't recomend anything about the capacitors, but you are correct
> in that voltage it the key. if they worked at higher, you did

verify

> they did work actually at those high voltage right ?
>
> regarding power, if you plan on the geckos, 80 volts is the max.
> divide by 1.414 to determine DC voltage bofore the caps. the caps
> will increase the DC to near peak values and not RMS so you pick up
> the 1.414 times raw DC.
>
> If you can cut the DC to 56 volts, you will be good. if you want a
> little more, you can put a terminal connection on 56 volts, then

wrap

> a few turns and add another termianl. it would let you get closer

to

> the 79.999 people shoot for. and it would allow you to correct for
> losses from the diodes/rectifier.
>
> Dave
>
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Jeff Goldberg" <jeff@w...>
> wrote:
> > OK. Sounds like a reasonable thing to do.
> >
> > Back to one of my original questions:
> >
> > Since I can modify the power supply somewhat, and since the max
> drive
> > voltage is 80 volts, should I supply 62 volts, 68 volts (or some
> other
> > voltage which would mean I'd have to scrap the power supply and

use

> > something else). Also, I've seen calculations on how to properly
> size a
> > capacitor for a DC power supply. There is a capacitor (unmarked

of

> course)
> > about the size of a beer can with a 1K ohm resistor across it on
> the DC side
> > of the power supply. Can I assume that if it worked OK at 130
> volts DC, it
> > will be OK at about 1/2 the voltage?
> >
> <snip>