Experimental Verification of a Linear AC LED Driver with a Light Flicker Compensating Circuit and High Power Factor Operation by Modulating the Current Regulator

2019 ◽  
Vol 139 (9) ◽  
pp. 814-821
Author(s):  
Yuichi Noge
2015 ◽  
Vol 83 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Dejun Yu ◽  
Ning Ning ◽  
Shuangyi Wu ◽  
Qi Yu ◽  
Wenbin Chen ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1340
Author(s):  
Yih-Her Yan ◽  
Hung-Liang Cheng ◽  
Chun-An Cheng ◽  
Yong-Nong Chang ◽  
Zong-Xun Wu

A novel single-switch single-stage high power factor LED driver is proposed by integrating a flyback converter, a buck–boost converter and a current balance circuit. Only an active switch and a corresponding control circuit are used. The LED power can be adjusted by the control scheme of pulse–width modulation (PWM). The flyback converter performs the function of power factor correction (PFC), which is operated at discontinuous-current mode (DCM) to achieve unity power factor and low total current harmonic distortion (THDi). The buck–boost converter regulates the dc-link voltage to obtain smooth dc voltage for the LED. The current–balance circuit applies the principle of ampere-second balance of capacitors to obtain equal current in each LED string. The steady-state analyses for different operation modes is provided, and the mathematical equations for designing component parameters are conducted. Finally, a 90-W prototype circuit with three LED strings was built and tested. Experimental results show that the current in each LED string is indeed consistent. High power factor and low THDi can be achieved. LED power is regulated from 100% to 25% rated power. Satisfactory performance has proved the feasibility of this circuit.


2019 ◽  
Vol 34 (7) ◽  
pp. 6747-6759 ◽  
Author(s):  
Xueshan Liu ◽  
Xuewen Li ◽  
Qun Zhou ◽  
Jianping Xu

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