Three-phase power supply phase sequence dedicated circuit

Working principle of the circuit: When the red, white and blue wires of the phase sequence table are connected to the three-phase
power and all three phases are powered, the three yellow LEDs will light up. When the phases are correct (red,
white and blue are connected correspondingly ) (L1, L2, L3 of three-phase power), the green LED lights up and the buzzer
emits an intermittent alarm sound; when the phase is incorrect, the red LED lights up and the buzzer
emits a continuous alarm sound. If a phase loss occurs, the yellow LED corresponding to the open circuit
will go out, the red and green LEDs will not light up, and the buzzer will sound a continuous alarm.