A Phase Loss Protection Circuit Composed of Voltage Comparators

Abstract

A phase loss protection circuit composed of a voltage comparator relates to a phase loss protection circuit, which is composed of a power supply circuit, a sampling circuit, a voltage comparison circuit and a control output circuit, wherein a rectifier transformer, a single-phase bridge rectifier circuit , filter capacitor a, voltage stabilizing integrated block and filter capacitor b form a power supply circuit; the sampling circuit consists of phase line detection terminal a, phase line detection terminal b, phase line detection terminal c, rectifier diode a, rectifier diode b, rectifier diode c, Composed of rectifying diode d, rectifying diode e, rectifying diode f, voltage dividing resistor a and voltage dividing resistor b; the voltage comparison circuit includes voltage comparator a, bias resistor a, bypass resistor a, voltage comparator b, bias resistor b and bypass resistor b; the control output circuit includes drive resistors, triodes, clamping diodes, relays, chain control terminal a and chain control terminal b. The invention realizes effective phase loss protection and undervoltage protection for the three-phase motor, and the structure of the circuit is simple.

Description

technical field [0001] The invention relates to an electronic circuit, in particular to a phase loss protection circuit. Background technique [0002] If the three-phase motor runs with a lack of phase, it will not work normally, and the motor winding will be burned out soon. Among the damaged three-phase motors, the burnt out motor due to the lack of phase operation accounts for more than half. After the motor burns out, it needs to be replaced. Repairs will not only cause economic losses, but also affect production. [0003] In agricultural production, due to the frequent movement of equipment and the influence of the environment, the probability of three-phase motors running without phase is higher, and a protection circuit that can effectively prevent three-phase motors from running without phase is needed. [0004] The existing phase loss protection device has the disadvantage that it cannot effectively protect the three-phase motor or has the disadvantage that the cir...

AI Technical Summary

Problems solved by technology

[0002] If the three-phase motor runs with a lack of phase, it will not work normally, and the motor winding will be burned out soon. Among the damaged three-phase motors, the burnt out motor due to the lack of phase operation accounts for more than half. After the motor burns out, it needs to be replaced. repairs, not only causing economic losses, but also affecting production

[0004] The existing phase loss protection device has the disadvantage that it cannot effectively protect the three-phase motor or has the disadvantage of complex circuit structure

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