Power supply driving circuit

Abstract

The invention relates to a power supply driving circuit, comprising a pulse transformation circuit, an LC resonance circuit, a synchroguide and a direct sampling and partial voltage sampling circuit.The synchroguide is used for controlling a switching tube to switch on and switch off at the same frequency when the resonance of the LC resonance circuit happens and comprises a single chip, a PWM signal generation circuit and an AND gate circuit, wherein the PWM signal generation circuit and the LC resonance circuit are connected in parallel to generate a PWM signal having the same oscillation frequency with the LC resonance circuit; and the PWM signal controls the switching tube to repeatedly switch on at the zero voltage time of a positive half-wave rising edge of a sine wave in an oscillation waveform of the LC resonance circuit and to switch off at the zero time at the zero voltage time of a positive half-wave failing edge of the sine wave, thus the switching tube works at a switching-on state or a switching-off state close to zero voltage, the switching loss and the heat generation of the switching tube are largely reduced, the electrical energy is saved and the switching characteristic and the service life of the switching tube are ensured.

Description

technical field [0001] The invention relates to a power drive circuit, in particular to a voltage resonance method to generate a controllable drive current and voltage, which can be used as a power drive circuit for battery charging, DC-driven lamps and the like. Background technique [0002] Chinese patent ZL200610087237.3 discloses a battery charger, which drives the VMOS switch tube to switch on and off through a single-chip microcomputer, converts the DC high voltage output by the rectifier circuit into a pulse voltage, and the secondary of the transformer obtains a lower pulse voltage, which is rectified After filtering, charge the battery. [0003] The disadvantages of the above-mentioned prior art are: the on-off of the VMOS switch tube is directly controlled by the rectangular wave output by the single-chip microcomputer, so that the turn-on voltage or the turn-off voltage of the switch tube when it is turned on or off is often high, resulting in switching loss and m...

AI Technical Summary

Problems solved by technology

[0003] The disadvantages of the above-mentioned prior art are: the on-off of the VMOS switch tube is directly controlled by the rectangular wave output by the single-chip microcomputer, so that the turn-on voltage or the turn-off voltage of the switch tube when it is turned on or off is often high, resulting in switching loss and making the switch The heat of the tube is serious, which not only wastes electric energy, but also affects its switching characteristics and service life, which in turn affects the service life of the entire charger

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