Microwave transformers again

Hi all

I've been doing some tests on four microwave transformers, basically related to
determine the primary impedance when the secondary is shorted. It turns out that
each transformer has an impedance in this configuration of 20 Ohms.

Thus a single transformer in use as a coil supply will draw 12 amps from a 240V
line, consuming about 2.9kW in the process. I should imagine that this will
get very hot very quickly!

Does anyone else make use of these transformers, and if so, do they have any
problems with them overheating. What sort of shorted secondary impedance do
most TC supply transformers have?

Phil Mason