The TRIAC is a three terminal semiconductor device for controlling current. It gains it's name from the term TRIode for Alternating Current.
It is effectivly a development of the SCR or thyristor, but unlike the thyristor which is only able to conduct in one direction, the TRIAC is a bidirectional device.
|Is it an SCR or a triac||Triac|
|SCR voltage max||400V|
|SCR IG (uA)||50µA|
|SCR VG (V)||2V|
|SCR hold In||50mA|