Improvement study on thermal decay effect of LED by using driving technique

• Main Authors: Chih-Hsing Lin, 林志興
• Other Authors: Chung-Ping Liu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/99778528432964573997

碩士 === 元智大學 === 電機工程學系 === 99 === Because the emitting efficiency of light emitting diode (LED) can heavily affected by thermal loss, this problem must be solved to improve the performance of LEDs. In this thesis, an energy-reduction driving technique was proposed to increase and to keep the emitting efficiency of LED at a high level during thermal damping occurred. In this research, properties of a high intensity LED operated at different constant pulse currents were firstly measured and analyzed when thermal damping occurred. In order to design an energy-reduction driving circuit, a waveform generator, a diagnostic circuit, and a light control circuit are thus assembled together to construct a required driving circuit for experiments. Through numerous measurements, we found that the performance of a LED impacted by thermal damping was obviously improved when it was driven by an energy-reduction circuit. Experiment data show that the emitting efficiency of a high intensity LED can be increased by a factor of 50%.