A Completely Capacitor-less, LED-switching Offline Lighting System

抄録

Recently LED lighting apparatus are becoming more popular and well received by users. An offline LED apparatus needs to have electrolytic capacitors inside to supply LEDs with a regulated DC voltage. Although LEDs are characterized by longevity, the shorter lifetime of the constituent electrolytic capacitors limit the lifetime of the LED lighting apparatus. That means that actual LED lifetime is being wasted, consequently wasting the manufacturing cost. This paper proposes a new LED drive circuit topology, which does not need any electrolytic capacitors and shows the simulation results of the circuit. Also described are simulation results of its efficiency, the power factor, and EMC characteristics without any reactance at the line interface. From the simulation results, it is shown that the circuit topology has the potential for practical use.