Power supply device

Abstract

The invention provides a power supply device. A front feed module is arranged between a power factor correction (PFC) module and a main power switching converter. The front feed module acquires the output voltage of the PFC module, extracts power frequency ripples from the output voltage of the PFC module, generates a front feed control signal representing the power frequency ripples and feeds the front feed control signal back to the main power switching converter. The main power switching converter controls the change direction of an output gain to be reverse to the fluctuation direction ofthe front feed control signal. Therefore, the problems of power loss and electromagnetic interference caused when an auxiliary load is powered by an auxiliary power supply converter are solved, and the voltage output by the main power switching converter can directly power the auxiliary load. The circuit in the main power switching converter is a soft switching circuit, so that the electromagnetic interference can be reduced and the working efficiency of the whole machine can be improved.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a power supply device. Background technique [0002] see figure 1 , which is a structural diagram of a power supply device in the prior art. [0003] The power supply device includes a power factor correction (PFC, Power Factor Correction) module 101 , a main power switching converter 102 , a backlight control and voltage conversion module 103 , a feedback module 104 and an auxiliary power converter 105 . [0004] The PFC module 101 performs power factor correction on the input AC power. The output terminal of the PFC module 101 is connected to the input terminals of the main power switching converter 102 and the auxiliary power converter 105 . The main power switching converter 102 is used to adjust the output voltage of the PFC module 101 and output it to the backlight control and voltage conversion module 103 . The backlight control and voltage conversion module 103...

AI Technical Summary

Problems solved by technology

[0007] Since LCD TVs and plasma TVs require switching power supplies to have high efficiency and smooth electromagnetic interference signals, figure 2 The power supply device shown has the following problems: the internal control circuit and speakers in the auxiliary load generally have an output power of tens of watts, and the efficiency of the flyback converter-type auxiliary power converter is low, which will lead to poor overall system efficiency. high

And the flyback converter is a hard switching circuit, if the transmission power is too large, it will cause too much electromagnetic interference

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