Triac & SCR Output PhotoCouplers

Triac and SCR output photocouplers can be used with both AC and DC signals with optocouplers utilizing a SCR (thyristor) or triac as the photo-detecting device. They are primarily designed for AC power-control applications, and are semiconductor devices that combine the functionality of an opto-triac or an opto-SCR with a power triac. They provide electrical isolation between a low voltage input and a high voltage output, thus being able to switch the high voltage output. This type of optocoupler configuration forms the basis of a very simple solid state relay application which can be used to control AC mains powered load, such as with lamps and motors.