Re: toroid transformer

Probably the best idea would be to combine both your ideas. Use 110v
into the 220v input to get half the voltage, and go with Jons idea
of running them out of phase to get about 69-70VDC. This is
certainly ok for geckos.

Mark




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> Correct me if I'm wrong, but it seems that if you connect the 110

on

> the 220 input you'll have half the voltage.
>
> that puts the 118 at 59vac.
>
> 59 less 1.4 for the drctifier drop = 57.6 VAC, with the filer cap,
> you jump to 81.4V not too bad.
>
> the... a couple of diodes to drop you to 79 volts and you're in

Gecko

> Heaven.
>
> 13 amps on the line, dropping around 2 volts is only about 26

watts

> so the diodes will not be blisetering hot but would need to heat

sink

> them.
>
> Of course I'm not sure if you get the full amps with the lower
> voltage on the 220 input.
>
> Dave
>
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...>

wrote:

> >
> >
> > Thomas Powell wrote:
> >
> > >What DC voltage and amperage would I be able to get from a

toroid

> > >transformer with these specs? Running with 220 input.
> > >
> > >115/230 Volt, 50/60Hz Output: 20 VAC @ 10 AAC 118 VAC @ 13 AAC
> > >
> > >
> > >
> > Well, this is probably a bad choice, as most of the transformer

is

> > devoted to the 118 VAC winding. The 118 V winding produces
> > 118*13 = 1534 W, the 20 VAC winding produces 200 W. The
> > 118 V winding is 94% of the transformer's output, the 20 V
> > winding is only 6%. But, using a full wave bridge on the 20 V
> > winding, you would get 28 VDC, with the 118 V winding you'd
> > get 167 V DC. Using the 20 V winding counter to the 118
> > V winding you'd get 98 VAC, rectified you'd have 139V DC.
> > I don't know if any of these voltages are close to what you
> > are looking for.
> >
> > Jon