A triac is a three-terminal electronic component that acts as a bidirectional semiconductor switch. It is primarily used in power control applications, such as light dimmers and motor speed controllers. Triacs are also commonly used in solid-state relays and uninterruptible power supplies (UPS).
Checking a triac is a simple process that can be performed with a multimeter. The first step is to set the multimeter to the diode test setting. Once the multimeter is set to the correct setting, you can test the triac by connecting the positive probe of the multimeter to the gate terminal of the triac and the negative probe of the multimeter to the anode terminal of the triac. If the triac is functioning properly, the multimeter will display a forward voltage drop of approximately 0.7 volts.
