Design and Implementation of Single-stage High Power Factor Converter for Dimmable LED Bulb Power

• Main Authors: Hsiu-Pin Tsai, 蔡銹斌
• Other Authors: Rong-Seng Chang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/10482342345066751597

碩士 === 國立中央大學 === 光電科學與工程學系 === 101 === This thesis aims to research and propose a single-stage high power converter with dimmable LED driver.The circuit is a primary feedback control for the Quasi-Resonant without secondary feedback signal. With the auxiliary winding of the transformer , it feedbacks output voltage to the detecting pin of controlling component for detecting the switching drain-source voltage of the valley to achieve valley-switching and reduces the switching losses. For dynamic dimming ,with the instruction, the dimming information through digital / analog converter into an analog signal,can be transmitted to the pulse width modulation circuit, thereby changes the output current value ,to achieve 5~100% dimming and stabilizes the LED light source without flicker under low dimming condition.The circuit has the strengths with high power , few components, small size, simple design. The component of Triodes AC switch (TRIAC) is not required. To the end , the implementation of LED bulb has verified the feasibility of the designed circuit.