A self-excited push-pull converter capable of realizing short-circuit protection and a short-circuit protection method

Abstract

The invention discloses a self-excited push-pull converter capable of realizing short-circuit protection and a short-circuit protection method. The transformer of the converter includes a ring-shaped magnetic core, an input winding, an output winding and a starting winding, an input winding, an output winding and a starting winding. The windings are all wound on the ring-shaped magnetic core, the input winding and the output winding do not overlap and cross each other, the starting winding overlaps the input winding, and does not overlap and cross the output winding; or, the starting winding is distributed in the input winding Between the input winding and the output winding, neither the input winding nor the starting winding overlaps with the output winding. The invention can reduce the capacitance value of the starting capacitor, improve the capacity of the self-excited push-pull converter with capacitive load, and maintain a lower short-circuit working current under the short-circuit condition, so as to perform short-circuit protection for a long time.

Description

technical field [0001] The invention relates to the field of self-excited push-pull converters, in particular to a self-excited push-pull converter capable of realizing short-circuit protection and a method for realizing short-circuit protection by using the converter, which can reduce the size of a startup capacitor and provide long-term short-circuit protection. , reduce the short-circuit current and improve the capacity of the capacitive load. Background technique [0002] The main forms of circuit structures of existing self-excited push-pull converters are Royer circuits and self-oscillating Jensen circuits. Royer circuit can realize the short-circuit protection of the output load by optimizing the circuit design, as described in the patent document with publication number CN102291001A, but this prior art needs to adjust the leakage inductance of the transformer when short-circuit protection is realized. If the value is too large, the transmission efficiency of the tra...

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Problems solved by technology

[0006] 1. Short-circuit protection cannot be realized, or the short-circuit working current is relatively large, and continuous short-circuit cannot be realized, otherwise it is easy to burn the switch tube;

[0007] 2. In order to reduce the short-circuit working current, increase the capacitance value of the starting capacitor, so that the capacitance value of the starting capacitor is larger, resulting in higher cost of raw materials;

[0008] 3. The capacity with capacitive load is weak. If the capacitive load is forcibly increased, it will cause poor startup and burn the switch tube

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