基于LED光源隧道照明调光系统的研究与设计

Research and Design of the Tunnel Lighting Dimming System Based on LED Light Source

针对隧道照明调光的要求,设计了一种基于PWM驱动大功率LED的调光系统。该系统采用恒流可控电路,主电路采用BUCK拓扑结构,控制电路采用自带PWM功能的单片机。通过对负载电流的采样,控制输出PWM脉冲的频率和占空比,以达到负载电流恒定的目的。该方法解决了LED在不同环境及时间内的亮度调节问题,且可在不改变其他电路参数的情况下增加或减少一定数量的LED,节约了成本,同时也给施工带来了极大的便利。试验表明,系统的各项性能指标均达到要求,抗干扰能力强。

In accordance with the requirement of turmel hghting dimmer, the dimming system using PWM to drive large power LED is designed. In this system, constant current controllable circuit is adopted, and the BUCK topology structure is used as the main circuit. The control circuit is the single chip computer equipped with built-in PWM function. Through sampling the load current, the frequency and duty factor of the output PWM pulses are controlled to achieve the goal for constant load current. The method solves the problem of the dimming for LED under different environment and at different time, and is able to increase or decrease certain quantity of LED without changing other circuit parameters; this reduces the cost and brings great convenience in construction. The experiments show that the performance indexes meet requirement, and the system features strong anti-interference capability.