Fly-back power circuit

Abstract

The invention discloses a fly-back power circuit which comprises a filter rectifier module, a power conversion module and a constant voltage and constant current feedback module. The filter rectifier module is used for filtering alternate current signals which are input through the input end of a power supply, converting the alternate current signals into direct current signals, and outputting the direct current signals. When a television stands by, the constant voltage and constant current feedback module is used for generating first feedback signals according to the output signals of the power conversion module. When the television is started, the constant voltage and constant current feedback module is used for is used for generating second feedback signals according to the output signals of the power conversion module. By the adoption of the fly-back power circuit, fly-back constant voltage circuits and boost constant current circuits can be integrated, meanwhile, a television mainboard power supply and an LED backlight power supply share a feedback circuit, the fly-back power circuit is simplified, and production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a flyback power supply circuit. Background technique [0002] "Flyback" in the field of power supply technology means that when the switch tube of the switching power supply is turned on, the primary side stores energy in the excitation inductance of the transformer, and when the switch tube is turned off, the excitation inductance releases energy to supply power to the load and output capacitor. The output capacitor maintains the load output when the next switch is turned on. [0003] At present, LED TVs use a three-in-one board, that is, a TV board that integrates power supply, constant current drive, and TV. In order to enhance competitiveness, it is necessary to optimize the power supply line, integrate TV components, and manufacture boards and backlight strips to reduce production costs. Therefore, the TV power supply circuit adopted by some power supply manufacture...

AI Technical Summary

Problems solved by technology

[0005] However, using the above-mentioned front-end flyback output constant voltage and back-end boost constant current circuit requires high-cost materials such as field effect transistors, inductors, diodes, and ICs in the boost constant current part, making the circuit complex and costly

However, the back-end linear step-down constant current circuit requires a larger step-down transistor, which consumes a lot of power, resulting in low circuit efficiency.

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