A thyristor is a four-layer semiconductor device with alternating P-type and N-type materials. A Thyristor usually consists of three electrodes: an anode (positive terminal), Cathode (negative terminal) and a gate. The gate is the main control terminal while the main current flows between the anode and cathode.

It acts exclusively as a switch, conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reversed, or until the voltage is completely removed.

Shop Express Electronics range of thyristor switch (silicon controlled rectifier) semiconductors below.