基于LM3402的LED调光电路设计

为提高LED照明电路的使用性能和适用范围，提出了一种基于恒流驱动电路LM3402的调光电路控制系统。由1个LM3402电路驱动一串高亮度白光二极管，根据设定的亮度需求，微处理器P89LPC932通过脉宽调制（PWM）进行调节。实践证明:该系统能够满足多种场合照明的各项要求，工作稳定可靠，在同等照度下功耗较白炽灯降低90%以上。

Abstract:

 To improve the usability and application scope of the LED lighting circuit， a new LED dimmer circuit system based on the constant current drive circuit LM3402 was presented in this paper. A LM3402 controlled a string of high brightness lighting emitting diodes. Basing on the need of illumination， microcontroller P89LPC932 sent out pulse width modulation to adjust the brightness. The application indicates that this system can meet multiple lighting requirements on many occasions， it works stably and reliably， and it could reduce the power consumption above 90% compared with the incandescent bulb in the same illumination.