Overvoltage protection circuit for linear constant current driving of LED

Abstract

The invention belongs to the technical field of electronic circuits, and relates to an overvoltage protection circuit for the linear constant current driving of an LED. The circuit comprises a series LED lamp group module and a constant current module, and is characterized in that the circuit also comprises a voltage sampling module and a light modulation module; the positive electrode of a series LED lamp group is connected with an input power supply, and the negative electrode of the series LED lamp group is connected with the input end of the constant current module and the input end of the voltage sampling module; the constant current module is used for enabling a current passing through the series LED lamp group module to be constant; the voltage sampling module samples the voltage of the output end of the series LED lamp group module, and the output end of the voltage sampling module is connected with the input end of the light modulation module; the output end of the light modulation module is connected with an enabling end of the constant current module, and the light modulation module is used for controlling the on / off of the constant current module. The beneficial effects of the invention are that the circuit can effectively reduce the power consumption and temperature of a chip, protects the LED lamp beads and devices, and enlarges the adaptive range of the chip to the voltage fluctuation.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits and relates to an overvoltage protection circuit for linear constant current driving LEDs. Background technique [0002] Light-emitting diodes (LEDs) are now widely used in various fields, and their main advantages are small size, low power consumption, and low cost. As a new light source, it needs to be specially designed for electric drive. At present, the main drive methods are linear drive and switching power supply drive. The linear drive method is relatively simple, has the advantages of low electromagnetic interference EMI and low cost, and occupies a large share in the market. However, when the power supply voltage fluctuates, the input voltage of the chip will increase, which will increase the power consumption of the driver chip, causing the chip to heat up or even burn out. Therefore, for LEDs driven by constant current, having an overvoltage protection circuit can well re...

AI Technical Summary

Problems solved by technology

However, when the power supply voltage fluctuates, the input voltage of the chip will increase, resulting in increased power consumption of the driver chip, causing problems such as heating or even burning of the chip.

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