Soft start control device for high-power motor

Abstract

The invention discloses a soft start control device for a high-power motor. The soft start control device comprises a motor, an alternating current power supply, a rectifying circuit, a bidirectional thyristor, a unijunction transistor, a transformer, a sliding rheostat, a voltage-regulator tube, a fifth diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor and a second capacitor. According to the soft start control device, after the rectifying circuit performs rectification, current limitation is performed through the first resistor and after voltage stabilization, the large-capacity capacitors are charged; gradually-increasing (from small to large)of a turn-on angle of the bidirectional thyristor due to trigger pulses can be delayed through the discharge quantity of the sliding rheostat to the unijunction transistor; and even if the resistance value of the sliding rheostat is adjusted to a minimum value, the bidirectional thyristor cannot be connected fully immediately, thereby achieving the purpose of soft start. The speed of the soft start of the motor can be changed through adjusting the sliding rheostat. Through adopting soft start, a surge current of a cold motor can be limited, the motor can be prevented from being burned out, the service life of the motor can be prolonged and inconvenience caused by motor burning in work is reduced.

Description

technical field [0001] The invention relates to a motor controller device, in particular to a soft start control device for a high-power motor. Background technique [0002] For a circuit with a high-power motor as a load, because the motor has a large power and low resistance value, the resistance value in the cold state is lower before it is turned on, and the starting current of the motor is very large. Sudden start may cause the phenomenon of burning out the motor, causing the motor to burn out. reduced service life. Contents of the invention [0003] The object of the present invention is to provide a soft start control device for a high-power motor in order to solve the above problems. [0004] The present invention achieves the above object through the following technical solutions: [0005] The invention includes a motor, an AC power supply, a rectifier circuit, a bidirectional thyristor, a unijunction transistor, a transformer, a sliding rheostat, a voltage ...

AI Technical Summary

Problems solved by technology

[0002] For a circuit with a high-power motor as a load, because the motor has a large power and low resistance value, the resistance value in the cold state is lower before it is turned on, and the starting current of the motor is very large. Sudden start may cause the phenomenon of burning the motor, causing the motor to burn out. reduced service life

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