A new type of switching power supply short-circuit protection circuit and its protection method

Abstract

The invention relates to a novel switch power supply short-circuit protection circuit and protection method. The novel switch power supply short-circuit protection circuit comprises a fault sampling circuit, a pulse generator circuit and an isolation drive circuit. The fault sampling circuit is used for collecting a fault signal of a switch power supply and opening or closing the pulse generator circuit according to the fault signal. The pulse generator circuit is used for driving the switch power supply to work intermittently according to the fault signal collected from a feedback circuit, so that the circuit has small power, and the long-term short-circuit protection function can be provided. The isolation drive circuit is used for isolation and guiding and preventing other circuits from influencing the frequency of the pulse generator circuit. The structure and the method are simple, the circuit is easy to debug, a sampling point with low power consumption is set, and a pulse generator is used for driving the switch power supply to work intermittently, so that the power consumption is greatly reduced, a long-term protection effect can be realized, and the switch power supply can be automatically restored to normal work in different environments after the fault is eliminated.

Description

technical field [0001] The invention relates to the field of switching power supplies, in particular to a novel switching power supply short-circuit protection circuit and a protection method thereof. Background technique [0002] Switching power supply and DC / DC converter as the secondary power supply of the system are widely used in military and civilian electronic systems such as aerospace, aviation, ships, weapons, electronics, railways, communications, medical electronics, and industrial automation equipment. When the external circuit is overloaded or short-circuited, the short-circuit protection circuit can reduce the input power of the switching power supply or DC / DC converter to provide protection. Under the action of the short-circuit protection circuit, it can avoid further damage to the external circuit, avoid damage to the switching power supply or DC / DC converter due to excessive power consumption or temperature rise, and protect the primary power supply from af...

AI Technical Summary

Problems solved by technology

The existing current reduction protection circuit mainly has the following three deficiencies: first, the short-circuit signal is sampled from the main power circuit, which consumes a lot of power; second, the circuit structure is complicated, there are many components, and debugging is difficult; Sensitive to temperature, the short-circuit power consumption of the switching power supply or DC / DC converter varies greatly at high and low temperatures, and may even cause braking recovery after the high and low temperature short-circuit fault is eliminated

Images