Abstract: A method for triggering a semiconductor switch with an inductive transformer having a primary side and having a secondary side connected to the semiconductor switch to be triggered includes dissipating magnetic energy that may be stored in the transformer from the transformer with a circuit configuration for demagnetization of the transformer. A switch potential of a given polarity is subsequently applied to the primary side of the transformer for switching the semiconductor switch. An increase of the potential on the primary side of the transformer beyond an allowable value is prevented after the demagnetization of the transformer. A circuit configuration for triggering a semiconductor switch includes an inductive transformer having a primary winding and having a secondary winding connected to the semiconductor switch to be triggered. A control input is connected to a logic circuit.

Abstract: A push-pull series resonant converter switching power supply includes an inductive transformer with a primary winding and at least one secondary winding. Two semiconductor switches are interconnected at a circuit node and connected in a half-bridge circuit between an input potential and an input ground potential. A series-resonant circuit connected between the connecting node and the input ground potential includes a capacitor and an inductor connected in series with the primary winding of the transformer. Diodes are connected between the input potential and the input ground potential for preventing a potential at the capacitor from significantly exceeding the input potential. An output is connected to the secondary winding of the transformer for supplying an output voltage. A control circuit triggers the two semiconductor switches with turn-on pulses for regulating the output voltage to a constant value as a function of a load to be connected to the output by variation of a turn-on pulse repetition rate.