Re: current rating of transformers

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

> turbulatordude wrote:
>
> >Hi,
> >
> >If I have a 24 volt, (12V-0-12) center tap transformer like the

MPJA

> >unit.
> >http://www.mpja.com/productview.asp?product=7846+TR
> >
> >And isolate the center tap I get 24 volts.
> >
> >But when rectified, doesn't the current change also ?
> >
> >There is a note in the catalogue that for this wiring the amps are
> >1.8x
> >
> >The catalogue refers to required ouput amps
> >
> >
> >full wave bridge cap input filter 1.8x to required output amps
> >full wave choke input filter = required output amps
> >full wave, center tap, cap = 1.2x roa
> >full wave, center tap, choke = 0.7x roa
> >
> >
> Using the full winding means current flows in both ends of the

winding

> all the time. So, the current rating must go down. With full-wave
> center tap, each half of the winding gets a rest 50% of the time, so
> current rating goes up. I guess what they are saying here is that

you

> take the load current and multiply by these factors to get the

rating

> of the transformer.
>
> Jon

This is where I'm confused.

If I use the full winding, 24 volts, do I really get 5.8 amps ?
and with center tap, 12 volts, 8 amps
but using a choke at 24 volts, I can get the full 10 amps ?

I wish they would have said secondary output x (factor) = available
ouput.

Dave