Direct-current voltage switching circuit and liquid crystal display device

Abstract

The invention provides a direct-current voltage switching circuit and a liquid crystal display device. The direct-current voltage switching circuit comprises a voltage doubling circuit and a protective circuit, wherein the voltage doubling circuit comprises a voltage doubling input end and a voltage doubling output end, the voltage doubling input end receives first voltage, the first voltage is converted into second voltage through the voltage doubling circuit, and the second voltage is output to a VGH line in the liquid crystal display device through the voltage doubling output end; the protective circuit comprises a detection unit, a current and voltage converting unit, a comparing unit and a control unit, the detection unit detects currents between the VGH line and transmission lines to obtain detection currents, the current and voltage converting unit obtains detection voltage according to the detection currents, the comparing unit compares the detection unit with reference voltage, when the detection voltage is higher than the reference voltage, and the control unit sends out a control signal to switch off the voltage switching circuit. The transmission lines comprise a VGL line or VCOM line in the in the liquid crystal display device.

Description

technical field [0001] The invention relates to the display field, in particular to a DC voltage conversion circuit and a liquid crystal display device. Background technique [0002] With the development of display technology, liquid crystal display devices are favored by a large number of users due to their advantages of small size and low power consumption. A liquid crystal display device generally includes a circuit board, a backlight module and a liquid crystal display panel. The circuit board is used to drive the backlight module and the liquid crystal display panel. The backlight module is used to provide light for the liquid crystal display panel, and the liquid crystal display panel is used to display text, images and other information. The circuit board typically includes circuitry for DC voltage conversion. The DC voltage conversion circuit usually converts the first voltage into a second voltage, and outputs the second voltage to the VGH line of WOA (Wire On Ar...

AI Technical Summary

Problems solved by technology

Due to various reasons (for example, conductive particles in the liquid crystal display), the VGH line and the VGL line in the WOA or the VGH line and the VCOM line are short-circuited

When the VGH line and the VGL line in the WOA or the VGH line and the VCOM line are short-circuited, the current in the VGH line increases, causing the wiring in the WOA or other components in the LCD device to be burned

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