Charge and discharge protective circuit for battery

Abstract

The invention discloses a charge and discharge protective circuit for a battery. The charge and discharge protective circuit comprises a battery, a charge circuit, a load circuit, an overvoltage protective circuit and an under-voltage protective circuit. The overvoltage protective circuit comprises an overvoltage reference voltage circuit, a first comparison circuit, an NAND gate and a first switch tube. The under-voltage protective circuit comprises an under-voltage reference voltage circuit, a second comparison circuit, an AND gate and a second switch tube. If the battery is overcharged, the voltage of the positive electrode of the battery is higher than the rated voltage of the battery, so the first comparison circuit outputs high level and the NAND gate outputs low level to cut off the first switch tube, the charge circuit stops charging the battery, and then the battery is prevented from being overly charged. If the load circuit excessively consumes electric energy of the battery, the voltage of the positive electrode of the battery is lower than the lowest under-voltage, so the second comparison circuit outputs low level and the AND gate outputs low level to cut off the second switch tube, the load circuit stops consuming the battery, and then an overvoltage and under-voltage effect is achieved.

Description

technical field [0001] The invention belongs to the technical field of circuit design, and in particular relates to a battery charging and discharging protection circuit. Background technique [0002] In the use of the battery, overcharging the battery or excessive use of the battery by the load circuit causes the battery to undervoltage, which will cause harm to the battery and shorten the service life of the battery. [0003] In the prior art, the charge and discharge protection chip or the simulated charge and discharge protection circuit is used to protect the charging and discharging process of the battery, but the price of the charge and discharge protection chip is relatively high, which will increase the manufacturing cost of the product; and the simulated charge and discharge protection circuit The response speed is slow, susceptible to electromagnetic interference, and has low protection performance for the battery. Contents of the invention [0004] The applica...

AI Technical Summary

Problems solved by technology

[0002] In the use of the battery, overcharging the battery or excessive use of the battery by the load circuit causes the battery to undervoltage, which will cause harm to the battery and shorten the service life of the battery.

[0003] In the prior art, the charge and discharge protection chip or the simulated charge and discharge protection circuit is used to protect the charging and discharging process of the battery, but the price of the charge and discharge protection chip is relatively high, which will increase the manufacturing cost of the product; and the simulated charge and discharge protection circuit Slow response, susceptible to electromagnetic interference, and low protection performance for batteries

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