We all know what an AC dimmer is; for those who don’t, it’s a kind of a circuit which can control the amount of AC voltage to be given to any device. You can see them in a fan regulator or a light dimmer switch. But have you ever wondered of applying the same concept of regulators/dimmers using a microcontroller? If you haven’t, don’t worry, this project deals with the same stuff.First of all we need to understand the importance of a triac in such circuits. A triac is a 3 terminal device which can control the amount of AC current passing through it. This can be achieved by applying variable AC potential at its Gate pin.