I am having some trouble understanding the behaviour of my toroidal transformer. Currently, I am using a 400V to 12V transformer in reverse, meaning I supply 12V and around 1.5 A to the secondary side of the transformator and try to get 400V output voltage.
My problem is, when I connect anything to the primary side, my voltage breaks down, meaning I only get around 2V of input voltage and 60V of output voltage.
I am supplying the secondary side with a OPA548, which should be able to easily supply my 12V 1.5A, but no matter how and if I limit the current, the voltage always breaks down.
Can someone please help me understand what I am missing about my circuit?
EDIT: Could it be that because of the low input impedance of the secondary windings, I nearly short my circuit and therefore the voltage drops?