為提高LED照明電路的使用性能和適用范圍，提出了一種基于恒流驅動電路LM3402的調光電路控制系統。由1個LM3402電路驅動一串高亮度白光二極管，根據設定的亮度需求，微處理器P89LPC932通過脈寬調制（PWM）進行調節。實踐證明:該系統能夠滿足多種場合照明的各項要求，工作穩定可靠，在同等照度下功耗較白熾燈降低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.