Patent ID: 7750720

Claim:
A circuit arrangement ( 100 ) for galvanically separate triggering of a semiconductor switch ( 400 ), in which the circuit arrangement has a control circuit ( 101 ), that is, a circuit part at trigger potential, a driver circuit ( 102 ), that is, a circuit part at switch potential, a transformer ( 200 ) for galvanically separate transmission of a trigger signal from the control circuit ( 101 ) as a switch signal to the driver circuit ( 102 ), and means ( 301 , 302 ) for rectification of the switch signal, and the semiconductor switch ( 400 ) is embodied with a gate electrode ( 401 ), a source electrode ( 402 ), and a drain electrode ( 403 ) in the driver circuit ( 102 ) and is switchable by a predetermined first voltage between the gate electrode ( 401 ) and the source electrode ( 402 ), so that a predetermined current flows between the drain electrode ( 403 ) and the source electrode ( 402 ), and the switch signal is capable of being applied to the gate electrode ( 401 ) in order to switch the semiconductor switch ( 400 ), and the driver circuit ( 102 ) includes a control transistor ( 320 ) with a base electrode ( 322 ), an emitter electrode ( 322 ), and a collector electrode ( 323 ), and the control transistor ( 320 ) is switchable by a predetermined second voltage between the base electrode ( 321 ) and the emitter electrode ( 322 ), so that, via the emitter electrode ( 322 ) and the collector electrode ( 323 ), the gate electrode ( 401 ) of the semiconductor switch ( 400 ) is capable of being connected to the source electrode ( 402 ) of the semiconductor switch ( 400 ), in order to switch over the semiconductor switch, characterized by voltage generating means ( 350 ) for generating a third voltage, rectified relative to the second voltage, between the base electrode ( 321 ) and the collector electrode ( 323 ) of the control transistor ( 320 ).