A control device includes a triac and a first diode that is series-connected between the triac and a first terminal of the device that is configured to be connected to a cathode gate of a thyristor. A second terminal of the control device is configured to be connected to an anode of the thyristor. The triac has a gate connected to a third terminal of the device that is configured to receive a control signal. The thyristor is a component part of one or more of a rectifying bridge circuit, an in-rush current limiting circuit or a solid-state relay circuit.