These solid-state switches are designed for high voltage high peak current switching applications such as piezo drivers, flash lamp drivers, crowbar circuits and power pulse generators. The switching modules described here are developed an the basis of a new type of thyristor, the so called MCT (MOS Controlled Thyristor) Thyristor switches made of MCTs combine low on-state conduction loss, high surge current capability and a certain capability for active turn-off. The turn-off capability is specified by the Maximum Controllable Turn-off Current rating Ioff(max). Provided this absolute maximum rating is not exceeded, the on-time of MCT switches can be controlled between the Minimum On-Time ton(mjn) and infinity simply by the duration of the control signal.