TRIAC Basic Operation

Triode for alternating current,TRIAC, is an electronic component that can control power in two direction in an AC circuit. The figure (a) shows the block construction and schematic symbol of TRIAC. The TRIAC is operated like two SCRs in parallel connection in opposite direction like shown in figure (b). Here is the figure of TRIAC:

A TRIAC can be triggered by either polarity, positve and negative. It has only single gate, even though the figure (b) shows each SCR has a gate. The TRIAC operates in same direction with an SCR in foward direection because the TRIAC is operated in bothe directions, operating and blocking. [Circuit’s schematic diagram source: littlefuse.com]