光电工程, 2012, 39 (7): 132, 网络出版: 2012-08-02
基于两通道 PWM的 LED调光调色方法
A Dimming Method for LED Based on Two Channels’ PWM
摘要
针对 LED动态照明的实现问题,本文提出一种基于两通道 PWM的调光调色方法。该方法通过分析 PWM混光技术下的几何、光度、色度与电力约束条件,论证了两通道 PWM实现调光调色的确定性和局限性,建立了混合光的期望光度量、色度量与两通道占空比之间的定量计算模型。利用该方法对高、低色温两种白光 LED进行混光实验,模拟了自然光的照度和色温变化,实测值与理论值之间的平均误差分别是 15 lx和 23 K。实验结果表明,此方法可以较好地实现预期光度、色度要求的光谱。
Abstract
To realize dynamic lighting of LED, a dimming method based on two channels’ Pulse Width Modulation (PWM) and light-mixing technology was presented. According to the analysis on geometrical, photometric, colorimetric and electrodynamic constraints, the determinacy and limitation of two channels’ PWM dimming for realizing Expected Photometric and Colorimetric Quantities (EPCQ) were demonstrated, and a quantitative model was established, which mapped the EPCQ into duty cycles. To examine the model, a light-mixing experiment with two kinds of white LED simulated variations of illuminance and correlation color temperature from dawn to midday. Mean deviations between theoretical values and measured values were obtained, which were 15 lx and 23 K respectively. Result shows that this method can effectively realize the light spectrum which has a specific requirement of EPCQ.
王纪永, 王建平. 基于两通道 PWM的 LED调光调色方法[J]. 光电工程, 2012, 39(7): 132. WANG Ji-yong, WANG Jian-ping. A Dimming Method for LED Based on Two Channels’ PWM[J]. Opto-Electronic Engineering, 2012, 39(7): 132.