Can a toroidal former become permanently magnetised and cause excessive
current draw. ? This one does not attract a small piece of iron. I don't
know what the main
secondaries are supposed to provide, but can give 300 watts into 4 ohms.
I've wound off the primaries to try and
understand what is going on with this transfornmer. Applying 70 volt ac ,
from a variac, across series secondaries is ok but increase to 75 volt and
the current draw goes up to 1/4 amp. Should be able to take twice that
voltage. Absolutely no visible problem , to the wiring or the coating of the
toroid and both secondaries measure DMM the same DC. Tomorrow will apply
something a bit over 70 volt with temperature sensitive labels fitted
around. I will even try a TV degaussing coil.