Investigation of LED Light Output Performance Characteristics Under Different Alternating Current Regulation Modes

摘要

LED performance characteristics under dc regulation modes have been studied extensively. But limited literatures are dedicated to studies of LED performance characteristics under different ac regulation modes. With direct ac powering LEDs for lighting application being available and more attractive in efficiency due to the elimination of ac–dc converter, investigation of the influence of different ac current regulation modes on LED performance characteristics becomes important and essential. This paper presents an experimental investigation of different current regulation modes on LED light output with different LED connection configurations. It is found certain current regulation mode under which a higher light output with the same absolute average current can be obtained. The result is due to facts that the absolute average current is the measurement of electrons and holes recombination rate inside the LED, and second-order nonlinear effect and thermal issue lead to the different light output for different ac regulation modes.