AC load start-stop control circuit

Abstract

The invention discloses an AC load start-stop control circuit, which comprises a main circuit and a control circuit, wherein the main circuit comprises a voltage zero crossing point starting circuit and a current zero crossing point stopping circuit, a starting switch is cascaded in the voltage zero crossing point starting circuit, a stopping switch is cascaded in the current zero crossing point stopping circuit, a normally open contact of a relay in the voltage zero crossing point starting circuit and a normally closed contact of a relay in the current zero crossing point stopping circuit are connected to the control circuit. By using chances of AC voltage and current periodic zero crossing points, the voltage zero crossing point starting control and the current zero crossing point stopping control of an AC load circuit are realized, overvoltage and overcurrnet generated from starting and stopping instantly are eliminated, and impaction caused to a power grid can be relieved to ensure that the whole power grid is greatly reduced. The AC load start-stop control circuit has the advantages of stable work and high reliability.

Description

technical field [0001] The invention relates to the field of AC load control, in particular to an AC load start-stop control circuit. Background technique [0002] At present, the moment when AC loads are most impacted by voltage and current is when the switch is on and off, that is, the moment of starting and stopping, especially for high-voltage and high-current load circuits. The traditional start-stop control circuit such as figure 1 As shown, the main circuit composed of fuses FU1, FU2, contactor main contacts CJ-2, CJ-3 and fuses RD, RD1, start jog button HA, stop jog button TA, contactor coil CJ and Its other main contact CJ-1 constitutes the control circuit. The overvoltage and overcurrent generated at the moment of starting and stopping of this circuit not only cause impact on the circuit work, but also cause fluctuations to the power grid, which seriously affects the life of electrical equipment and affects The surrounding working circuits generate strong electro...

AI Technical Summary

Problems solved by technology

The traditional start-stop control circuit such as figure 1 As shown, the main circuit composed of fuses FU1, FU2, contactor main contacts CJ-2, CJ-3 and fuses RD, RD1, start jog button HA, stop jog button TA, contactor coil CJ and Its other main contact CJ-1 constitutes the control circuit. The overvoltage and overcurrent generated at the moment of starting and stopping of this circuit not only cause impact on the circuit work, but also cause fluctuations to the power grid, which seriously affects the life of electrical equipment and affects The surrounding working circuits generate strong electromagnetic interference

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