A TRAIC is similar to two thyristors connected in anti-parallel. With no signal to the gate, the TRIAC will block both half cycles of applied ac voltage provided its peak value is lower than break over voltage (V) of the device. The turning ON of the TRIAC can be controlled by applying the gate trigger pulse at the desired instance.
Mode-1 triggering is used in the first quadrant and Mode-3 triggering is used in 3rd quadrant. Most of the thyristor characteristics apply to the TRAIC. In a TRIAC, the two conducting paths from MT, to MT2 or from MT2to MT1, interact with each other in the structure of the TRAIC. Voltage, current and frequency ratings of TRAICS are lower than thyristors. The Voltage and current rating are 1200V and 300A
