Measuring Unknown Transformers

[Steven-H]

All,
I received a couple of transformers, and I'd like to know the specs on them. I've measured the voltages, etc; but now I'd like to know what sort of amperage I can expect out of the unit. What is the best way to go about this (while staying in the land of the living...) ?

Thanks !
Steve

[Geek]

Hi,

Here's a page with some useful charts:
http://geek.scorpiorising.ca/windingtransformers.html

Find the approximate VA of the core by the size. Then if you can see the wire, at least one winding, you can derive the rest pretty much from math.

Cheers!

[Steven-H]

Very cool - I'll see what I can come up with this evening !

Thanks again,
Steve

PS - On one of my transformers, it is potted - so this solution is not going to work.....Any suggestions then ?

[Wavebourn]

Originally posted by Steven-H

PS - On one of my transformers, it is potted - so this solution is not going to work.....Any suggestions then ?

Usually transformers are optimized either by maximal over-temperature, or by maximal voltage drop.

I usually load all secondaries until voltages on them drop on 10% then calculate.