In article , Andre Majorel wrote:
On 2008-09-24, Arfa Daily wrote:
"Andre Majorel" wrote in message
...

Think I might as well increase the load until the transformer
becomes "too hot"...

Increasing load and watching voltage droop is much more effective and safe,
but burning it out is another method.

I didn't even read where the transformer came from, but it doesn't matter.



If you do that, it might be the only time that you do, as it
may well have a thermal fuse embedded in the primary winding,
which will likely fail. Open circuit. Forever ...

Oh. My "too hot" threshold is probably at least 20°C below the
manufacturer's, though. g

What exactly is the issue with knowing the rating of this
transformer ?

Partly desire to learn what rules of thumb might exist, partly
that I'm going to reuse the transformer to power a few dual
supply circuits and want to know how much I can count on.

Apparently, it is working, as you are able to measure
voltages. Worst case, you could just measure the primary
current with it running the tuner. If it's a 'typical' little
red transformer that is normally to be found in such items,

It does have red adhesive tape around the windings.

then just multiply the power consumption calculated from
measuring the input current, by about 1.5 to get a ballpark
figure for the transformer rating. When I say "ballpark", I
actually mean in the same county, but maybe not the same town
...

Thanks.