This universal triac controller circuit with optocoupler solves the problem that triacs have when functioning at low temperatures (triac needs higher gate current) by adding a transistor at the output ...

Check out this link for On Semiconductor’s datasheet for a line of “Zero-Cross Optocoupled Triac Drivers.” The ability to zero-cross when turning on AC line voltage to some loads may be advantageous.

Fairchild Semiconductor introduced the FL7730 single-stage primary side regulation (PSR) controller with power factor correction (PFC) for use with triac and analog dimming compatibility. Fairchild ...