A thyristor is a solid-state semiconductor device with four layers of alternating P- and N-type materials. It acts exclusively as a bistable switch, conductor when the gate receives a current trigger, and conducts until the voltage across the device is reversed biased, or until the voltage is removed (by some other means). There are two designs, differing in what triggers in the conducting state. In a three-lead thyristor, a small current on its Gate lead controls the larger current of the Anode to Cathode path. In a two-lead thyristor, conduction begins when the potential difference between the Anode and Cathode is sufficiently large (breakdown voltage).
Some sources define silicon-controlled rectifier (SCR) and thyristor as synonymous. Other sources define thyristors as more complex devices that incorporate at least four layers of alternating N-type and P-type substrate.
Because thyristors can control a relatively large amount of power and voltage with a small device, they find wide application in control of electric power, ranging from light dimmers and electric motor speed control to high-voltage direct-current power transmission. Thyristors may be used in power-switching circuits, relay-replacement circuits, inverter circuits, oscillator circuits, level-detector circuits, chopper circuits, light-dimming circuits, low-cost timer circuits, logic circuits, speed-control circuits, phase-control circuits, etc.
|Breakdown Voltage Vbr||400V|
|Continuous Output Current||800mA|