A pwm dimming method for led

Abstract

The invention relates to a PWM dimming method of an LED, which is used for adjusting the PWM wave output by a single-chip microcomputer. The LED is connected to the PWM wave output end of the single-chip microcomputer. The collection device is connected with the single chip microcomputer, when the value collected by the light collection device is S max There is no need to turn on the LED light at this time, that is, the duty cycle of the PWM wave output by the single-chip microcomputer is 0, when the value collected by the light collection device is 0, the duty cycle of the PWM wave output by the single-chip microcomputer is 100%, and the LED light is the brightest at this time In addition, the PWM wave comparator array M is pre-saved in the microcontroller C [n,l], the method provided by the present invention conforms to the physiological characteristics of the human eye, adaptively adjusts the brightness of the LED light according to the ambient light conditions, keeps the overall ambient light intensity constant, greatly reduces the non-linear feeling of people when adjusting the LED, and makes the light adjustment more uniform.

Description

technical field [0001] The invention relates to a PWM dimming method of an LED. Background technique [0002] With the development of LED lighting technology, its advantages over traditional lighting are prominent, and LED lights are gradually replacing traditional lighting in society. It has the following advantages: the manufacturing materials are environmentally friendly; the particle layout of the LED lamps causes less scattering and greatly reduces light pollution; it directly converts electrical energy into light and has high energy efficiency; the manufacturing materials are stable and not easily damaged. [0003] The optical parameters of LED lights mainly include: light intensity, luminous flux, illuminance, luminous efficiency, etc., and the electrical parameters of LED lights mainly include: current, voltage, power, power factor, etc. Generally speaking, because a small change in the forward voltage drop of the LED can cause a large change in the forward current ...

AI Technical Summary

Problems solved by technology

In the PWM dimming mode, if you simply change the duty cycle to adjust the brightness of the LED without any processing, then the step feeling of the lamp is more obvious when it changes color, and it is accompanied by a slight jitter phenomenon. Therefore, for the human eye, The PWM dimming method has the disadvantages of uneven dimming, non-linear perception by the human eye, and insufficient dimming levels.

Images