Bi-directional power supply self-recovery over-current over-temperature protection device

Abstract

The invention relates to a two-way power supply self-recovery over-current and over-temperature protection device for protecting a low-voltage direct-current motor. Forward rotation and reverse rotation of a motor can be realized through two-way power supply; due to phase discrimination, a comparison amplifier detects the working current of the motor all the time; after the current and the temperature are greater than set values, the circuit of the comparison amplifier is reverse; a high potential is output; a timer is triggered through a logical circuit; level control is driven according to the set delay time; therefore, a corresponding MOSFET is turned off; a corresponding reverse MOSFET is thoroughly turned off by interlocking; locked-rotor, over-current, short-circuiting and temperature rising of the motor are avoided; therefore, the service life of the motor is prolonged; and simultaneously, unnecessary damage on peripheral equipment due to temperature rising of the motor also canbe avoided.

Description

technical field [0001] The invention relates to a safety device for the working current and temperature of a low-voltage DC motor, especially to avoid damage to the motor caused by motor blockage, overcurrent, short circuit and over-temperature, and to realize the recovery of the motor through power supply again after protection. Two-way power supply self-recovery over-current and over-temperature protection device with this protection function. Background technique [0002] At present, the known protection device applied to low-voltage DC motors is PTC, but its protection action time is slow and greatly affected by the ambient temperature. The action time of the same current is longer at low temperature, and the action time is faster at high temperature environment. As the ambient temperature rises, the current resistance of PTC is also decreasing, so it is impossible to achieve a constant current resistance value, the work is unstable, and the number of protection actions ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the slow action time of the existing low-voltage DC motor protection, the influence of the ambient temperature is large, the same current operates for a long time at low temperature, and the action time is fast in a high temperature environment. As the ambient temperature rises, the current resistance decreases, and a constant current resistance value cannot be achieved. The number of protection actions is limited, and as the number of actions increases, the internal resistance of the PTC gradually increases. The present invention provides a two-way power supply self-recovery over-current over-temperature protection device. The internal resistance and current resistance remain unchanged in high and low temperature environments, and the overcurrent, short circuit, temperature protection and action time are precise after the integrated IC, and the number of actions can reach 100,000 times of repeated use. Due to the fast protection action time, the service life of the motor is also extended. Various protection functions of the motor can be restored after the motor is powered again after protection

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