The TIL3010 is a TRIAC output optocoupler from Texas Instruments, designed to isolate low-voltage control logic from AC mains loads. It switches AC loads via an internal TRIAC triggered by an infrared LED, giving you galvanic isolation between the microcontroller side and the power side.
What the TRIAC output means on the bench
A TRIAC output optocoupler like the TIL3010 handles AC switching natively — no external bridge rectifier needed. The internal TRIAC turns on when the LED current exceeds the trigger threshold and stays latched until the AC load current drops below the holding current (zero-crossing turn-off). That makes it ideal for resistive or lightly inductive AC loads like heaters, solenoid valves, and small motors. For heavily inductive loads (large contactor coils, transformers), you'll want a snubber RC across the TRIAC output to prevent false triggering from dV/dt transients.