Diac Symbol Diagram. It is the symbol for a reverse conducting thyristor. From the diagram a diac unlike a diode resembles a bipolar junction transistor bjt but with the following exceptions.
The diac can be performing for both the direction. It is a simple scr with a diode connected in antiparallel for conduction in reverse bias. Then the symbol of the diac looks like a transistor.
The basic construction and symbol of diac is shown in above diagram.
A diac is a p n p n structured four layer two terminal semicon ductor device as shown in figure a. In some way this demonstrates the structure of the device which can be considered also as two junctions the two terminals of the device are normally designated either anode 1 and anode 2 or main terminals 1 and 2 i e. The layers closer to the terminals are the combination of both positive and negative layers. The diac has four layers pnpn and two terminals anode a1 and a2.
