Open-phase protection circuit composed of voltage comparators

Abstract

The invention discloses an open-phase protection circuit composed of voltage comparators, and relates to an open-phase protection circuit which includes a power supply circuit, a sampling circuit, a voltage comparator circuit and a control output circuit, wherein the power supply circuit includes a rectifier transformer, a single phase bridge type rectifier circuit, a filter capacitor a, a stabilizing integrated block and a filter capacitor b; the sampling circuit includes a phase line detecting element a, a phase line detecting element b, a phase line detecting element c, a rectifier diode a, a rectifier diode b, a rectifier diode c, a rectifier diode d, a rectifier diode e, a rectifier diode f, a voltage dividing resistor a and a voltage dividing resistor b; the voltage comparator circuit includes a voltage comparator a, a bias resistor a, a bypass resistor a, a voltage comparator b, a bias resistor b and a bypass resistor b; the control output circuit includes a driving resistor, a triode, a clamping diode, a relay, an interlocking control end a and an interlocking control end b. The open-phase protection circuit provides open-phase protection and low-voltage protection effectively for a three-phase motor, and is simple in structure.

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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