Single-Stage Single-Switch Four-Output Resonant LED Driver With High Power Factor and Passive Current Balancing

2017 ◽  
Vol 32 (6) ◽  
pp. 4566-4576 ◽  
Author(s):  
Xueshan Liu ◽  
Qi Yang ◽  
Qun Zhou ◽  
Jianping Xu ◽  
Guohua Zhou
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.


2014 ◽  
Vol 610 ◽  
pp. 178-181
Author(s):  
Qing Hua Chen ◽  
Lun Qiang Chen ◽  
Ying Chun Liang ◽  
Ying Jun Chen

This paper proposes a novel single-stage LED driver based on SY5814A for interior-lighting applications with high levels of power factor. High power factor is achieved by constant on-time operation mode, with which the control scheme and the circuit structure are both simple. The proposed driver features cost-effectiveness, high circuit efficiency, high power factor, low input current ripples and a reduced components count. A prototype driver is developed to supply a 15W LED interior-lighting module with a 65V output voltage. Experimental results demonstrate the functionalities of the proposed circuit.


IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Tiancheng Liu ◽  
Xueshan Liu ◽  
Mingzhi He ◽  
Shuhan Zhou ◽  
Xin Meng ◽  
...  

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