Efficient power supply

Abstract

The invention relates to an efficient power supply. Inductive electric energy on a small inductor and electric energy on primary leakage inductance of a transformer are used as charging electric energy of a follow current circuit, an additional switch tube is adopted for providing a discharge path of the follow current circuit, a main switch tube is a primary providing path of the transformer, and primary electric energy is converted into secondary electric energy along with the switch action of the main switch tube. Two rapid diodes are adopted for providing charging paths for the inductive electric energy of the small inductor and the primary leakage inductance electric energy of the transformer, and simultaneously an input current waveform is corrected. A small capacitor is adopted for improving the current waveform, and simultaneously is used for reducing instant turn-off voltage at two ends of the main switch tube. The power supply is stable, efficient and low in cost.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a high-efficiency power supply. Background technique [0002] Forward power supply and flyback power supply are widely used in various electrical equipment. Their advantages are simple circuit and low cost. The disadvantage is low efficiency. These power supplies are directly connected to a filter capacitor after the rectifier silicon bridge. This structure will generate a large amount of non-linear current and pollute the AC grid. At the same time, it has a low utilization rate of the power transmitted by the grid. [0003] In order to reduce the nonlinear current and meet the international standard ENG1000-3-2, various methods have been proposed to improve the power factor, including passive power factor correction circuits, whose power factor is between 80% and 90%. ; There is also an active power factor correction line, the power factor of this line can reach 99%. Th...

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Problems solved by technology

[0004] The above circuit also has some disadvantages: first, it has a large inrush current when it starts to work; second, it increases the existing voltage, thereby increasing the requirements for subsequent power conversion components (that is, the requirements for the switch tube). The damage of the high power factor power supply mostly belongs to this reason; 3. Due to the increase of the first-order line, the self-loss of the power supply is also increased.

[0005] In addition, many single-stage high power factor power supplies have been proposed. Most of these lines are at the expense of line reliability, which is not advisable.

In order to improve the efficiency, people have proposed the LLC switching power supply circuit, which uses the principle of zero current shutdown, reduces the switching loss, and greatly improves the efficiency of the power supply (the efficiency of the whole machine can reach 92%). However, this circuit is also Increased manufacturing costs, while this did not reduce the loss of the PFC circuit

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