Three-phase power supply open-phase detection circuit

• Main Authors: ZENG JINBO, PAN XIANG, DING XINZHONG, HUANG SHIQI, LI XINGLONG, HUANG YUPU
• Format: Patent
• Language: Chinese; English
• Published: 14.10.2022
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The utility model provides a three-phase power supply open-phase detection circuit. The three-phase power supply open-phase detection circuit comprises a rectifier bridge circuit used for being connected with each phase of a power supply; the current-limiting resistor is connected with the rectifier bridge circuit in series, and a light-emitting diode in the optocoupler is connected with the rectifier bridge circuit and the current-limiting resistor in series to form a circuit; the pull-up resistor is connected in series with the photoresistor in the optocoupler, the power supply is used for supplying power to the pull-up resistor, and one end, far away from the pull-up resistor, of the photoresistor is grounded; and the detection line is connected between the pull-up resistor and the photoresistor. According to the technical scheme, the condition of voltage drop in the three-phase circuit is detected through the optocoupler, so that whether the three-phase circuit is open in phase or not is obtained, detecti