Over-current protector for motor

Abstract

The invention discloses an over-current protector for a motor, belongs to the technical filed of motor protection, and overcomes the defects of the conventional over-current protector including low sensitivity and high power consumption. The over-current protector is fixed on the outer surface of the casing of the motor and comprises a comparator circuit, a sampling circuit and a control circuit, wherein the sampling circuit is used for sampling a required current value and generating a sampling voltage; the comparator circuit is provided with a pre-set reference voltage and used for comparing a sampling voltage value with a reference voltage value; the comparator circuit outputs a lower level signal to the control circuit when the sampling voltage value is greater than the reference voltage value, and the comparator circuit outputs a high level signal to the control circuit when the sampling voltage value is less than the reference voltage value; and the control circuit disconnects or connects the power supply of the motor according to the low level signal and the high level signal. Owing to the special circuit design, the over-current protector provided by the invention has the advantages of sensitive response, short response time and low power consumption.

Description

technical field [0001] The invention relates to an overcurrent protection device, in particular to an overcurrent protection device for a motor. Background technique [0002] A motor is a device that converts electrical energy into mechanical energy through a drive shaft. The drive shaft drives the external mechanical device to operate to achieve the various functions required. When the motor lubrication fails or the external mechanical device is stuck, causing the drive shaft speed to drop or stop, the electric energy of the motor cannot be effectively converted into mechanical energy, which will cause the internal current of the motor to increase rapidly, which will increase the internal temperature of the motor and cause the motor to burn out Even cause a fire. [0003] The motor in the prior art avoids the above situation by setting the motor protector to cut off the electric energy source of the motor when the motor is locked. The commonly used motor protector is gene...

AI Technical Summary

Problems solved by technology

However, in the motor circuit, the output current is relatively large, and if the method of voltage drop is used to judge the current overcurrent, there will be a large loss of power consumption, which is a waste of cost.

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