LED dimming circuit, device and method

Abstract

The invention discloses an LED dimming circuit, device and method. The LED dimming circuit comprises a reference voltage source, a line voltage compensation module, a dimming module and a constant current source module; the line voltage compensation module outputs compensation information to the reference voltage source according to a current line voltage; the reference voltage source modulates areference voltage according to the compensation information and outputs the reference voltage with the compensation information to the dimming module; the dimming module outputs a corresponding dimming voltage to the constant current source module according to the reference voltage with the compensation information and a dimming signal input by outside; and the constant-current source module is used for controlling a working current of an LED lamp string according to the dimming voltage. The reference voltage with the compensation information is input to the dimming module for dimming, so thatthe line voltage compensation depth can be correspondingly adjusted synchronously under different dimming depths; and the requirements of constant power can be met under each dimming depth, and the dimming linearity is not influenced, so that the working stability of the LED dimming circuit is improved.

Description

technical field [0001] The invention relates to the technical field of LEDs, in particular to an LED dimming circuit, a dimming device and a dimming method. Background technique [0002] Linear constant current drives LED lights, the fluctuation of mains voltage will cause the lamp beads to flicker, so the linear dimming driver chip needs to achieve constant power to improve the overall lighting effect. However, in the existing dimming circuit, since the line voltage compensation coefficient cannot be adjusted, it is impossible to achieve constant power at all levels of dimming depth. For example, when the dimming depth is 100%, constant power can be achieved by adjusting the line voltage compensation coefficient , when the dimming depth is 10%, since the line voltage compensation coefficient remains unchanged, the line compensation is too deep at this time, which may cause the output voltage to be 0, which seriously affects the dimming depth. In addition, a single line volt...

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Problems solved by technology

However, in the existing dimming circuit, since the line voltage compensation coefficient cannot be adjusted, it is impossible to achieve constant power at all levels of dimming depth. For example, when the dimming depth is 100%, constant power can be achieved by adjusting the line voltage compensation coefficient , when the dimming depth is 10%, since the line voltage compensation coefficient remains unchanged, the line compensation is too deep at this time, which may cause the output voltage to be 0, which seriously affects the dimming depth. In addition, a single line voltage compensation coefficient will cause Constant power cannot be achieved in some dimming depths, and it will also affect the linearity of dimming

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