Re: Power needed to drive 3 nema 42 motors?

Hi,
After some ribbing and empirical observations on motor heating,
I've decided to reduce my power supplies to around 65volts for my
nema42's. I used a variac to test the different voltages and didnt
notice any benefit in running above 70volts. Everything just ran
cooler at the lower voltages, and modern steppers work well there.
I'll rewind my master autoformer to bring the mains down
some more. Currently it has 20 turns, which I'll increase until I get
the desired output from the secondaries of the power transformers.
All gauges being used are oversized for safety. ( Warning :Dont wind
your own until you know what you're doing ;-)
-Lee

--- In CAD_CAM_EDM_DRO@y..., <MIKEC@W...> wrote:
> not necessarily if a sepoerate secondary is used as implied
> ----- Original Message -----
> From: "Raymond Heckert" <jnr@a...>
> To: <CAD_CAM_EDM_DRO@y...>
> Sent: Tuesday, September 10, 2002 6:28 PM
> Subject: Re: [CAD_CAM_EDM_DRO] Re: Power needed to drive 3 nema 42
motors?
>
>
> > See my ******* comment ******* below
> > RayHex
> >
> > ----------
> > > From: caudlet <tom@t...>
> > SNIP
> > >
> > > Don't use a variable transformer. Most of them are
Autotransformers
> > > (one winding) and provide no isolation (that's a bad thing).
Either
> > > order a transformer of the voltage and current range you want
or get
> > > creative and find a surplus unit that has several secondaries
you can
> >
> > > use to get the voltage you want. A multi-winding transformer
is a
> > > versatile thing. Depending on how you phase the windings you
can add
> >
> > > or subtract AC voltages.
> > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - -
> > - - - - - - - - - - - -
> > You can even take a secondary winding and
> > > put it in series with a primary winding and use it to lower the
high
> > > current secondary.
> >
> > ******* THIS THEN BECOMES AN AUTOFORMER! *******
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> >
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reach it if
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> >
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