Re: [CAD_CAM_EDM_DRO] transformer for power supply

Thomas Powell wrote:

>With the following speced toroidal transformer what DC power supplies are
>possible?
>
>115/230 Volt, 50/60Hz Output: 20 VAC @ 10 AAC 118 VAC @ 13 AAC
>
>I will be inputting 220.
>
>What will the AAC rating be for DC?
>
>

That information is not clearly indicated in the description. Some
transformers
are rated as "control transformers", and expect a resistive load. So
you'd get
10 Amps only to a resistive load, and maybe somewhere in the neighborhood of
6 A into a capacitor-input filter (that is the official term for a capacitor
immediately following the rectifier). I'm assuming you want to use this
as a
28 V power supply. In that case, you could probably get more wattage, as
the major winding (the 118 V one) would not be used. But, I can't tell,
as the 20 A AC spec is really no spec at all. What is the duty cycle?
10% or continuous? What is the environmental spec? Forced air cooling,
or a sealed box at 50 C? What is the output spec, cap input filter,
resistive
or other?

As for voltage, as I said yesterday, you could get 28 V DC from the 20 VAC
winding, 167 V DC from the 118 V AC, or 139 V DC by using the 20 V
winding to buck part of the 118 V winding.

Again, you don't tell us what you are looking for, so it is very hard
to answer such questions.

Jon