About the Project It’s pretty simple to control the brightness of an LED, just give it a PWM signal and change the brightness. But what about a Bulb that runs on AC current? Its brightness won’t be controlled by giving it PWM signals. It will require some additional circuits and, in this article, I’ll be talking all about the AC dimming process and making. Components Required BT136 TRIAC 10KΩ Resistor MOC3021 IC Arduino Board MCT2e IC 2 Pin Terminal 47KΩ 1W Resistor Heat Sink 330Ω Resistor x2 1KΩ Resistor Working Principle In this project, I’m using the Leading-Edge Phase Dimming Method to lower down the output power. In the circuit, we have one zero-cross detector which gives the signal to the Arduino board whenever the signal crosses the zero value. A zero-cross detector is used as a reference to change the phase of the signal. By delivering the power for less than 100%, we cut down the amount of power delivered