Circuit for preventing power source protection caused by overlarge motor starting surge currents

Abstract

A circuit for preventing power source protection caused by overlarge motor starting surge currents comprises a current sensor, a voltage follow circuit, a rectifying circuit, a comparator, an IGBT and an MCU. The voltage follow circuit is connected to the current sensor through a resistor A, the rectifying circuit is connected to the output end of the voltage follow circuit, and the IGBT and the MCU are connected to the output end of the comparator. The current sensor transmits a current signal of the IGBT to the voltage follow circuit to perform impedance conversion to avoid wave form distortion, and then the signal enters the rectifying circuit to be rectified so that the comparator can perform peak detection. The comparator compares the rectified current signal and reference voltage output by a voltage stabilizing tube, if a current peak value reaches a protection threshold value of the IGBT, a turn-off signal is output through the output end of the comparator, so that the IGBT is turned off temporarily, the turn-off signal is transmitted to the MCU, and therefore the situation that power source protection is performed to stop a motor from being smoothly started because the currents at the instant of starting a motor are overlarge to exceed the protection threshold value of the output currents of the IGBT is prevented.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a power supply protection circuit. Background technique [0002] The protection circuit of the existing power supply will directly protect and stop the output when the IGBT output current reaches the protection threshold, but the current of the motor is very large when starting, so it is easy to exceed the protection threshold of the IGBT output current, so the motor has not started yet , the power supply is protected and cannot be used normally. If the replacement of high-power IGBT will increase the cost. Contents of the invention [0003] In order to overcome the deficiencies of the above technologies, the present invention provides a circuit for preventing power supply protection caused by motor start-up inrush current. [0004] The technical scheme that the present invention overcomes its technical problem adopts is: [0005] The circuit for preventing the power ...

AI Technical Summary

Problems solved by technology

[0002] The protection circuit of the existing power supply will directly protect and stop the output when the IGBT output current reaches the protection threshold, but the current of the motor is very large when starting, so it is easy to exceed the protection threshold of the IGBT output current, so the motor has not started yet , the power supply is protected and cannot be used normally

If the replacement of high-power IGBT will increase the cost

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