Circuit structure for realizing stepless dimming function

Abstract

The invention relates to a circuit structure for realizing a stepless dimming function, and the circuit structure comprises: a first current generation circuit module which is used for achieving the continuous linear change output of a first current; a second current generation circuit module which is used for realizing continuous linear change output of second current; a first switch module which is used for controlling the charging and discharging time of the capacitor; a second switch module which is used for controlling the charging and discharging time of the capacitor; a frequency modulation module which is used for performing frequency modulation on the first current and the second current; and a LED driving module which is used for dimming the LED light source. By the adoption of the circuit structure for achieving the stepless dimming function, a dimming circuit based on a PFM mode and an implementation mode are provided, the working frequency of the circuit is modulated, the switch-off time of a switch tube is increased to change the duty ratio of the switch-on time of the switch tube, and finally LED dimming is achieved; and the LED output current can change linearly along with the dimming control signal, and a stepless dimming scheme can be realized.

Description

technical field [0001] The invention relates to the field of smart home, in particular to the field of LED dimming, and specifically refers to a circuit structure for realizing stepless dimming. Background technique [0002] With the development and promotion of the Internet of Things and smart homes, there are more and more demands for light source dimming, and the quality requirements for dimming are also getting higher and higher. Therefore, LED dimming technology needs to be continuously improved in order to give full play to its own advantages and follow the development trend of smart home. [0003] At present, the commonly used dimming technologies include linear dimming, PWM dimming and thyristor dimming, among which the linear dimming circuit is relatively simple, which changes the peak current of the inductor by changing the voltage or resistance to change the LED drive current. The disadvantage is The smaller peak current will increase the operating frequency of t...

AI Technical Summary

Problems solved by technology

When the PWM frequency is low, the LED light source will flicker and emit noises that can be perceived by the human ear. When the frequency is high, it is difficult to achieve high dimming accuracy and depth

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