How to estimate the output power

[Gale William]

Hello, I have a Power supply without label. Anybody can help me to estimate the regulated output power? No-load power is about 6W. Thanks!

[budm]

Re: How to estimate the output power

So it is 220VAC to 13VAC step-down transformer. What is the wire gauge being used in the secondary side? That will give you a clue as to how much current you can draw from the secondary winding. It is not easy or possible to get the exact VA rating of the unknown transformer (you need to know the core material, core loss, core cross section, etc.). may be some one that design transformer for living can explain.

[Gale William]

Re: How to estimate the output power

So it is 220VAC to 13VAC step-down transformer. What is the wire gauge being used in the secondary side? That will give you a clue as to how much current you can draw from the secondary winding. It is not easy or possible to get the exact VA rating of the unknown transformer (you need to know the core material, core loss, core cross section, etc.). may be some one that design transformer for living can explain.

Thanks for your information budm! Any idea of an estimated VA rating not calculated. More than 500VA?

[mariushm]

Re: How to estimate the output power

That's not a power supply, it's just a toroidal transformer.

It's probably 12v AC, but your multimeter shows 13v AC because it's unloaded. As you connect devices to the output of the transformer, the output voltage will probably go down closer to 12v AC.

It looks capable enough to do 500VA but i can't be sure.. how heavy is it?

[budm]

Re: How to estimate the output power

Based on your dimensions, 400~500VA is the estimated value.
I.E.
http://www.antekinc.com/as-4212-400va-12v-transformer/

[jiroy]

Re: How to estimate the output power

Most cheap Chinese gadgets use such Toroidal Trans to cut expenses . Cheap designs and not reliable .