The colourful light emitting diode (LED) strings require the corresponding driver to achieve independent control of each output current in the applications of RGB mixed colour LED lighting, LED projection etc. For this purpose, a multi-channel constant current LED driver based on DC current bus distributed power system structure is proposed and analysed here, which is composed of a source converter and several load converters as needed. The source converter adopts the flyback converter to realise power factor correction, electrical isolation, and the load converter adopts the current-type buck converter to realise independent control of the corresponding output current. A 60 W experimental prototype for 42.8 V/0.35 A, 40 V/0.5 A, 35.7 V/0.7 A three outputs with the universal input voltages 90–264 V is designed and implemented, and the experimental results are presented to verify the correctness of the theory analysis.

中文翻译：

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基于直流电流总线分布式电源系统结构的多通道恒流LED驱动器的分析与设计

在RGB混合色LED照明，LED投影等应用中，彩色发光二极管（LED）串需要相应的驱动器来实现对每个输出电流的独立控制。为此，基于DC的多通道恒流LED驱动器本文提出并分析了当前的总线分布式电源系统结构，该结构由一个源转换器和多个需要的负载转换器组成。源转换器采用反激转换器来实现功率因数校正，电气隔离，而负载转换器则采用电流型降压转换器来实现对相应输出电流的独立控制。设计并实现了60 W实验原型，分别用于42.8 V / 0.35 A，40 V / 0.5 A，35.7 V / 0.7 A的通用输入电压90-264 V的三个输出，