PWM light-modulation method of LED

Abstract

The invention relates to a PWM light-modulation method of an LED, wherein the method is used for adjusting a PWM wave outputted by a single-chip microcomputer. The method comprises: step one, a totallight modulation level number is determined to be N*L, total time of light modulation is determined to be TC, and a register value generated by a single-chip microcomputer PWM wave is determined to beM, wherein the M is a constant value and the n is assigned with 0; step two, time TC / (N*L) of the PWM wave at each light modulation level is calculated; step three, I is assigned with 0; step four, the I is equal to the sum of I and 1, the duty ratio of the PWM wave outputted actually by the single-chip microcomputer is set to be one shown by a formula, wherein [X] indicates the processing of rounding up to an integer on a real number x; step five, whether the I is larger than or equal to L is determined; if so, step six is carried out; if not, the step four is carried out; step six, n is equal to a sum of n and 1; and step seven, whether the n is larger than or equal to N is determined; if so, the program is ended; and if not, the step three is carried out. With the method provided by the invention, the light modulation level is increased substantially and the modulated light becomes soft; and the non-linear feeling of the user is reduced substantially during LED adjustment, so thatthe light is modulated uniformly.

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.

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