A self-locking circuit and its matched fast unlocking circuit after self-locking occurs

Abstract

The invention discloses a self-locking circuit and a matching fast unlocking circuit after self-locking, including a self-locking circuit and a fast unlocking circuit, the self-locking circuit is connected with the fast unlocking circuit, and the Vcc pin of the self-locking circuit The fifth resistor is connected to the negative electrode of the second zener diode, the anode of the second zener diode is connected to the emitter of the second switching transistor, and the second capacitor and the second capacitor are connected in parallel between the base and the emitter of the second switching transistor. Six resistors, the collector of the third switching transistor is connected to the base of the second switching transistor, the third capacitor and the seventh resistor are connected in parallel between the emitter and the base of the third switching transistor, and the base of the third switching transistor is also It is connected to the PROTECT pin, and the emitter of the third switching transistor is also connected to the GND pin; the invention not only retains the self-locking characteristic of the self-locking circuit, but also solves the problem caused by the long unlocking time of the self-locking circuit after the input power is cut off.

Description

technical field [0001] The invention relates to the technical field of electronic product protection circuits, in particular to a self-locking circuit and a matching fast unlocking circuit after self-locking occurs. Background technique [0002] Almost all electronic products are designed with protection circuits. Many protection circuits use self-locking circuits. However, after the protection circuit is protected, it takes too long for the self-locking circuit to unlock itself. After the input power is turned off, it takes a long time to input again. Otherwise, the circuit is still in the protection state after the power is input, it is difficult to apply to many special usage scenarios, and the production efficiency is low (when testing the protection characteristics during the production process, waiting time or manual discharge is required). Electronic products currently on the market generally use Vcc to add a discharge resistor to quickly unlock the protection state, ...

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Problems solved by technology

[0004] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a self-locking circuit and its matching fast unlocking circuit after self-locking, which not only retains the self-locking characteristics of the self-locking circuit, but also solves the problem of input disconnection. Insufficiency caused by too long unlocking time of the self-locking circuit after power on

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