Wide Range Dimmable LED Lighting System with Fault Compensation Protocol

Light emitting diodes (LEDs) are more widely acceptable as the light source in many applications due to its high life expectancy and high energy efficiency. They can also be operated by switching circuit to produce desirable dimming effect. This paper describes the development of a wide range dimmable LED lighting system with two- stage PWM multiplexing control to dim the output luminance between 18% and 100% without flickering. Furthermore, the proposed system also incorporates fault diagnosis and compensation protocol to allow the system to continue functioning even with a faulty LED string. The laboratory hardware prototype demonstrates the abilities of the proposed system.