In our previous lessons, I examined the working principle of Thyristor and TRIAC. In this video, I will basically explain the working principle of the DIAC, which is one of the power electronics circuit elements used in AC timer, also known as dimmer circuits and motor speed control circuits, together with the TRIAC. The abbreviation DIAC is used as an abbreviation of the English Diode for Alternating Current. It is understood from its English name that this two-pin power electronics circuit element is used in alternating current.