Differences between SCR and TRIAC

by eees.in · April 29, 2025

SCR	TRIAC
It is unidirectional ie, it can conduct current in forward direction only.	It is bidirectional ie, it can conduct current in forward as well as reverse direction.
It is triggered by a narrow positive pulse applied at the gate terminal.	It is triggered by a narrow pulse of either positive or negative polarity applied at the gate terminal.
SCR’s are available with a large current rating.	TRIAC’s are available for lower current rating as compared to the SCR.
It has a fast turn – off and therefore can be used to switch AC supply frequencies upto few KHz.	It has a comparatively longer turn off time than SCR and therefore the use of triac is limited to AC supply frequencies upto 400 Hz.