Power Factor Corrected LED Direct AC Driver with Self-Adaptive Control

Abstract:
This article presents a novel LED Direct AC Driver (DACD) technology. The basics of the conventional DACD are presented and its merits and flaws are addressed. The proposed novel DACD is made up of very few components. It is intended for making cost-effective, compact design with high performance. The driver’s input current is self-adaptively controlled to follow a half sinusoidal waveform to achieve low THD, high PF, and to improve the output luminance regulation accuracy over whole AC input voltage range. Furthermore, under the worst operation scenario, its self adaptive control circuit dramatically reduces the conventional DACD Max power loss; therefore greatly enhancing the LED light system reliability. The simulation result is presented and validates the operation of the proposed circuit.