Transformer with potential isolation protection for mains device or voltage converter has primary coil whose a.c. impedance drops when trigger temp. above operating temp. is reached

摘要

The transformer (1) has a primary coil (3) and a secondary coil (4) and a ferromagnetic core (5) fitted into a coil body. The a.c. impedance of the primary coil drops when a trigger temp. above operating temp. is reached, whereby the trigger temp. is lower than the softening temp. of the coil body and/or the coil winding insulation. An Independent claim is also included for a mains device or a voltage converter with a transformer.