Power Transformer

[Mandoman]

Is there a way to calculate the amperage of a power transformer? I tried doing some calculations myself, but it always comes out fubared.

Thanks!

[Ronsonic]

Lots of ways. What info do you have to work with and what do you need to know?

[Mandoman]

I have the input voltage, output voltage,and input impedance. I'm just wondering how to find the output milliamps so I know what type of power tube it will be able to handle.

[celeste]

Originally Posted by Mandoman

I have the input voltage, output voltage,and input impedance. I'm just wondering how to find the output milliamps so I know what type of power tube it will be able to handle.

The easiest thing to do is to assume that it is designed for 10% regulation, so load it down till the voltage drops by 10%. What ever current it takes to load it down that far is your number

[DGDGBD]

Where did you get the power transformer from?

[Mandoman]

Out of My champ 600 that died, I can't find any specs on its, I was gonna use it for a 5F1 build.

[ThermionicScott]

If it helps, the schematic gives 280VAC for the secondary (I assume when the amp is on and the tubes are drawing current), and the signal tubes are drawing about 49mA total. I would use Celeste's procedure -- hook up the PT to exactly 120VAC input (do you have a variac?), measure the unloaded voltage on the secondary, then load it down until you get a 10% drop.

- Scott