Self-oscillation hiccup-type short circuit protection circuit and design method therefor

Abstract

The invention discloses a self-oscillation hiccup-type short circuit protection circuit and a design method therefor. The circuit comprises a power switching circuit, a current detection circuit, an overcurrent and short circuit discrimination circuit, a power switching drive circuit, a reference voltage circuit, and an oscillation time delay recovery circuit. The method comprises the steps: 1, selecting proper parameters forming the current detection circuit; 2, selecting proper parameters forming the overcurrent and short circuit discrimination circuit; 3, selecting the formed overcurrent and short circuit discrimination circuit to be connected with the current detection circuit; 4, selecting proper parameters forming the reference voltage circuit; 5, forming the reference voltage circuit, and enabling the reference voltage circuit to be connected with the overcurrent and short circuit discrimination circuit; 6, selecting proper parameters forming the oscillation time delay recovery circuit; 7, forming the oscillation time delay recovery circuit, and enabling the oscillation time delay recovery circuit to be connected with the reference voltage circuit; 8, connecting the self-oscillation hiccup-type short circuit protection circuit. According to the invention, the self-oscillation hiccup-type short circuit protection circuit achieves the overcurrent and short circuit protection, and can set the automatic recovery time of the power switching circuit.

Description

technical field [0001] The invention belongs to the technical field of overcurrent and short circuit protection, and in particular relates to a self-oscillating hiccup type short circuit protection circuit and a design method thereof. Background technique [0002] With the continuous improvement of my country's industrial production safety indicators, the requirements for protection functions such as overvoltage, overcurrent, and short circuit of the power supply are also increased. Among them, the overcurrent protection function is very important for the power supply. It not only protects the power supply itself, prevents the power supply from being burned out due to excessive current caused by short circuit, but also meets the requirements for use in special environments. With the rapid development of the coal industry, more and more electrical equipment is used in coal mines, and at the same time, higher requirements are placed on the safe use of electricity for electrica...

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Problems solved by technology

[0003] The Chinese patent with the application number 201110451994.5 discloses a self-recovery cut-off protection circuit for a low-voltage high-power safety barrier, which better solves the problem of turning off the power switch circuit when the low-voltage high-power safety barrier is over-current or short-circuited, making the input circuit Stop outputting electric energy to the load to realize over-current or short-circuit protection of the low-voltage high-power safety barrier, and an oscillation circuit is set in the power switch drive circuit, which can drive the power switch circuit to be automatically restored after the power switch circuit is turned off, so that the input circuit outputs The electric energy is supplied to the load, which realizes the self-recovery of the circuit, and can suppress the output of the fault spark energy to a certain extent; however, the automatic recovery time of the power switch circuit cannot be set through the oscillating circuit, so that the power switch circuit is turned off and shut down irregularly. When the oscillating circuit oscillates too fast, the enhanced PMOS tube in the power switch circuit may appear to be turned on again without being completely cut off, which will cause the problem that the fault spark energy is not completely limited; in addition, the self-recovery time of the circuit is limited by The influence of the input circuit voltage cannot be set according to the requirements of the protection circuit, so that the application range of the short circuit circuit is small

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