Circuit arrangement for preventing the application of AC voltages to isolated primary inputs

摘要

A circuit arrangement is provided which prevents feedback of AC voltage from a secondary AC voltage network supplied via a plurality of magnetic voltage regulators to the primary side of a voltage regulator (SK) no longer supplied on the primary side. The circuit arrangement detects the phase relationship between current and voltage on the secondary side of the voltage regulator and switches off its secondary winding when the voltage regulator behaves as a capacitive or a mixed resistive/capacitive load. IMAGE