分析脉冲宽度调制(PWM)双通道输出白光LED的混合调光方法, 建立PWM与混合光源输出的光通量和色温之间变化关系的非线性数学模型。基于ZigBee无线通信模块CC2530作为双路PWM输出, 控制以SN3350为核心的LED恒流驱动电源, 完成占空比可调的暖白和冷白两路白光LED的色温和光通量混合调光控制系统设计, 并通过高精度快速光谱辐射计HAAS-2000测试系统进行测试。实验结果表明, 双路PWM能够较好地实现对LED色温和光通量的输出大小进行控制, 混合光源相关色温在3 250~15 000 K范围内连续可调。理论计算与系统控制的光通量和色温存在的相对误差分别小于1.70%和8.50%。

A nonlinear mathematical model of the relationship between the luminous flux and the color temperature of the hybrid light source is established by analyzing the hybrid dimming method of pulse width modulation (PWM) dual channel output white LED. The system uses ZigBee wireless communication module CC2530 as a dual PWM output control to SN3350 as the core of the LED constant current drive power. It achieves a duty cycle adjustable warm white and cool white two white LED color temperature and luminous flux mixed dimming control. Experiments were carried out using a high-precision, fast spectroradiometer (HAAS-2000) test system. Experimental results show that the dual PWM can achieve better control of LED color temperature and luminous flux, and the correlated color temperature of the mixed light source can be continuously adjusted in the range of 3 250 K to 15 000 K. The relative errors of theoretical calculation and system control are less than 1.70% and 8.50%, respectively, corresponding to the luminous flux and color temperature.