Patent ID: 6853232

Claim:
A power switching device, comprising: a power switching transistor connected in series in a load circuit with an inductive load portion, said transistor having a gate-drain path or a base-collector path; a commutation circuit connected in parallel with said gate-drain path or base-collector path of said transistor, said commutation circuit having; at least one Zener diode determining a commutation clamping voltage for switching on said power switching transistor during a commutation; a normal diode connected in series with and oppositely biased with respect to said Zener diode; control elements for reducing, during a short time, compared with a time period of a commutation cycle, the commutation clamping voltage after an adjustable delay from the beginning of each commutation cycle, said control elements including a control transistor defining the adjustable delay based on a control pulse applied to said control transistor.