Abstract: A circuit providing switch-off relief of controllable semiconductor switches, such as a gate turn-off thyristor. A series connected storage capacitor and diode are placed in parallel across the thyristor. A controllable discharge switch is driven by a control circuit so as to close a discharge current circuit connecting the storage capacitor to the primary winding of a transformer. The discharge switch is responsive to the voltage polarity across the diode to enable a current to flow through the primary winding for discharging the storage capacitor and for interrupting the current flow through the primary winding for discharging the energy stored in the transformer through a secondary winding.