Energy-saving zero crossing detection circuit and apparatus thereof

The invention, which is suitable for the electronic circuit field, provides an energy-saving zero crossing detection circuit and an apparatus thereof. The zero crossing detection circuit comprises an optical coupler U1, a divider resistor R3, a diode D1, a resistor R2, and a capacitor C1. Pins 1 and 2 of the optical coupler U1 are respectively connected to an output terminal and an input terminal of the diode D1; the pin 1 of the optical coupler U1 is connected with one end of the divider resistor R3; and the pin 2 of the optical coupler U1 is connected with one end of the capacitor C1. And the other ends of the divider resistor R3 and the capacitor C1 are respectively connected to an anode and a cathode of a power input. Besides, a pin 4 of the optical coupler U1 is connected with one end of the resistor R2 and the other end of the resistor R2 is connected with a reference voltage VCC; and a pin 3 of the optical coupler U1 is earthed to ground (GND). According to the invention, a capacitor C1 is in tandem wi