Experimental investigation on the performance characteristics of white LEDs used in illumination application

The LEDs lamps´ high efficiency, long life time and energy saving potential have made them emerge as a new illumination lighting source. The temperature in the p-n junction can be considered to have a linear relationship with the forward current. Therefore, a proper current regulation strategy is important to alleviate the light output degradation and to maximize the useful life of high power LEDs. This paper presents an extensive experimental investigation on the influence of different current regulation modes on the light output degradation and lifetime of LEDs. It has been found that pulsed current regulation mode may be the optimal regulation mode for maximizing the useful lifetime of power LEDs.