Electric power circuit and LCD

Abstract

The invention relates to a power circuit and a liquid crystal display; the power circuit comprises a first rectifier filter circuit, a power factor correction circuit, a switch control circuit and a second rectifier filter circuit; the power factor correction circuit comprises a first transformer, a first LED and a first energy storage capacitor; the switch control circuit comprises a transistor and a second transformer; the first rectifier filter circuit converts an AC voltage into a DC voltage; when the transistor is conducted, the first rectifier filter circuit provides the DC voltage for the second transformer through the primary coil of the first transformer, the first LED and the secondary coil of the first transformer; the first energy storage capacitor keeps the DC voltage supplied to the second transformer; when the transistor is intercepted, the second transformer provides voltage for the load through the second rectifier filter circuit. The power circuit has small noise.

Description

technical field [0001] The invention relates to a power supply circuit and a liquid crystal display. Background technique [0002] A liquid crystal display generally includes a liquid crystal panel, a power circuit and a power supply. The power supply supplies power to the liquid crystal panel through the power circuit. [0003] see figure 1 , is a schematic diagram of a prior art power supply circuit for a liquid crystal display. The power circuit 10 includes a first rectifying and filtering circuit 11 , a power factor correction (Power Factor Correction, PFC) circuit 12 , a protection circuit 13 , a switch control circuit 14 and a second rectifying and filtering circuit 15 . [0004] The first rectification and filtering circuit 11 includes a full bridge rectification circuit 111 , a first filter capacitor 112 , two input terminals 113 , 114 , a positive output terminal 116 and a negative output terminal 115 . The two input terminals 113, 114 are used to receive an AC ...

AI Technical Summary

Problems solved by technology

[0014] In order to solve the problem of high noise in the prior art power supply circuit, it is necessary to provide a power supply circuit with low noise

[0015] In order to solve the problem of high noise in the power supply circuit of the prior art liquid crystal display, it is necessary to provide a liquid crystal display with low noise in the power supply circuit

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