What is the primary purpose of a DIAC?

The primary purpose of a DIAC (Diode for Alternating Current) is to act as a triggering device for a TRIAC (Triode for Alternating Current). When the voltage across the DIAC reaches a certain threshold, it conducts in either direction, thus allowing current to flow through it. This sudden change in conduction can be used to trigger a TRIAC, which can then control power in AC circuits.

This triggering function is key for applications such as dimmers, motor speed controls, and similar electronic devices where phase control techniques are utilized. The DIAC itself does not regulate power directly or amplify voltage, nor does it stabilize gain; rather, its role is to facilitate the control of other components like TRIACs, thereby indirectly impacting power regulation and control within a circuit.