This circuit is similar with our previous dimmer circuit, but the gate control is full-wave rectified using diode bridge. This circuit can be used to replace electric switch for your incandescent lamp, brushed motor, soldering iron or heater. Here is the schematic diagram of the dimmer switch:

dimmer switch circuit schematic

Please note that his dimmer switch can only work on AC voltage, it’s not a DC dimmer. Many devices can be controlled by this dimmer circuit, especially every device that is not require a perfect a sine wave voltage fro the power, and doesn’t  internally regulate the  power  supply to give a constant power.