Remote On-Off Switch through Small Transformer

This is a remote on-off switch circuit. With this circuit, we can take the benefit of using small switch to control larger AC current from high power devices. Safer operation is the other benefit, since this circuit is control the power without running line-voltage switch leads, only low voltage exposure for human operator. Here is theĀ  schematic diagram of the circuit:

This circuit usesĀ  small transformer, a 6volt filament transformer, which is connected between one of the main terminals of a Triac and the gate. The remote switch is connected with secondary of transformer. When the switch is closed, the transformer will saturate and trigger the Triac because of short-circuits on the secondary. When the switch open, there is no gate current because blocked by transformer, so the equipment does not receive power from Triac.