Re: transformer question

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:

>
> turbulatordude wrote:
>
> >Hi,
> >
> >I have a transformer with a lable of 220/460 primariy and 110/220
> >secondary.
> >
> >1kva.
> >
> >Would I be able to connect it 110 to get 55 volt ?
> >
> Yup, that's right, you'll get 55 VAC from each secondary winding.
> Note than 55 V AC into a rectifier will give 78 V on the capacitor.
>
> > and if so, any idea
> >what current I could pull out of it ?
> >
> >
> Best is to put the secondary in series and use a pair of big diodes (or
> half of a bridge rectifier) with the center tap of the windings
> connected to the
> - of the capacitor. OK, starting with the KVA rating at the design
> voltage of
> 110 V, the current would be I = (KVA * 1000)/V. So, a 1 KVA transformer
> would provide 1000/110 = 9 A. This may be a little optimistic for
> continuous
> duty at full load, but will certainly be fine for most CNC applications.
>
> Jon

I'm also concerned that the secondary wire size would be suitable for
9A @ the 55.

I am hoping that the 55 less the 1v diode drop = 54 times 1.414 to get
the 77 or so volts for the G320 would be a good match. (nothing like
cutting things a little close eh ?)

I guess I will need to look at over voltage and the actual utility
voltage as well.

Dave