Zero crossing of AC voltage controller

Zero crossing refers to the point where the alternating current (AC) waveform crosses the zero-voltage level

In the context of AC voltage controllers:

• Purpose: Zero crossing is used as a reference for switching devices (like TRIACs or SCRs) to minimize electrical noise and transients.
• Working Principle: The controller waits for the AC signal to cross zero before turning on or off the power device. This reduces sudden changes in current, which helps protect loads and reduces EMI (electromagnetic interference).
• Application: Common in light dimmers, motor speed controllers, and heating control systems where smooth operation and reduced noise are critical.