Re: Power Supplies / Transformers

John Ross wrote:

> From: John Ross <johnr@...>
>
> I need one of you electronics experts to set me strait.
> I've had someone offer me a 110 Pri 24V Sec Transformer at 100 Volt-amps.
> Isn't Amps at 24V allot different than Va? I always thought Va was Source
> voltage + Amperage. Wouldn't a 110 - 24v 1A transformer be 111Va? This guy
> is trying to convince me this or a 20va transformer is what I need. If I
> want 15 amps shouldn't it be like 110+15 or 125Va?
>
> John R

What you are talking about is approx a 4 amp transformer (100 volt/amp / 24volt ) = 4.16amp
The primary current would be (100 volt/amp / 110 volt) = .9 amp
If you want 15 amps at 24 volts, you will need a 360 va transformer.