A primary side control Scheme for Triac dimmable LED driver based on indirect output current sensing
This paper proposes a primary side control scheme for triac dimmer compatlble LED driver based on Fiyback topology.By seining the average primary side switch current and transformer auxiliary winding voltage signal,the output current can be derived using the proposed calculation method,which can be adopted is say operation mode with variable frequency and constant frequeacy control.Based on this indirect sensed output current signal,the output current cau be regulated precisely without conventional isolated feedback circuit.For TRIAC dimming application,it is better to force the input current follow the input voltage to eliminate the dummy load for fire angle detection ud achieve high power factor at no dimming condition.With critical conduction mode or discontinuous current mode operation,the proposed method can achieve all the desired functions as well as a linear dimming characteristic.The detailed operation principles are presented and the experimental results from a 15W prototype verify the theoretical analysis.
Primary side control Triac dimmer LED driver Flyback
Hulong Zeng Ting Jiang Junming Zhang
College of Electrical Engineering ZheJiang University Hangzhou,China
国际会议
9th China International Forum on Solid State Lighting(第九届中国国际半导体照明论坛)
广州
英文
262-269
2012-11-05（万方平台首次上网日期，不代表论文的发表时间）