Triacs are electronic components that are widely used in AC power control applications. They are able to switch high voltages and high levels of current, and over both parts of an AC waveform. This makes triac circuits ideal for use in a variety of applications where power switching is needed.

Whats the purpose of a triac?

A TRIAC is triggered into conduction in both directions by a gate signal like that of an SCR. TRIACs were designed to provide a means for the development of improved AC power controls. TRIACs are available in a variety of packaging arrangements. They can handle a wide range of current and voltage.

What are the advantages of a triac over an SCR?

Advantages of Triac:

It needs only a single heat sink of a slightly larger size whereas for SCR two heat sinks should be required of smaller size. A safe breakdown in either direction is possible using TRIAC but for SCR protection should be given with parallel diode.