A BJT-type multi-segmented LED driver suitable for wide input voltage range

Author(s):  
Yi Chen ◽  
Yugang Bao ◽  
Yiping Yang
2012 ◽  
Vol 542-543 ◽  
pp. 997-1000 ◽  
Author(s):  
Jin Jian Zhang ◽  
Xian Song Fu ◽  
Ping Juan Niu ◽  
Yi Li Liu

A steady output single-ended flyback switching power supply using L6561 current mode PWM controller designed in this paper. The designed circuit consists of single-ended flyback topology and based on the peak current PWM technology. The circuit has input voltage range from 85V AC to 265V AC and about output drive capability of 12V/2A. Based on the specific chip L6561, the novel single-ended flyback AC/DC converting circuit is adapted for mobile or office equipment, off-line battery chargers. The low-power Switched-Mode Power Supply (SMPS) are the most noticeable examples of application that this configuration can fit. The testing results show that the design of this method can reduce the switching power supply ripple, and ensure stable voltage output.


Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 575
Author(s):  
Mei Yu Soh ◽  
S. Lawrence Selvaraj ◽  
Lulu Peng ◽  
Kiat Seng Yeo

LEDs are highly energy efficient and have substantially longer lifetimes compared to other existing lighting technologies. In order to facilitate the new generation of LED devices, approaches to improve power efficiency with increased integration level for lighting device should be analysed. This paper proposes a fully on-chip integrated LED driver design implemented using heterogeneous integration of gallium nitride (GaN) devices atop BCD circuits. The performance of the proposed design is then compared with the conventional fully on-board integration of power devices with the LED driver integrated circuit (IC). The experimental results confirm that the fully on-chip integrated LED driver achieves a consistently higher power efficiency value compared with the fully on-board design within the input voltage range of 4.5–5.5 V. The maximal percentage improvement in the efficiency of the on-chip solution compared with the on-board solution is 18%.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7844
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Yao-De Tsai

A buck-type light-emitting diode (LED) driver is proposed herein. The proposed LED driver automatically possesses current sharing and high step-down voltage gain. Without complex control, the proposed LED driver, with a single input and multiple outputs, can achieve automatic current sharing of four-channel LED strings, even under the different number of LEDs of each LED string. Furthermore, as compared with the traditional four-phase interleaved buck converter with a single input and a single output having current sharing required, the proposed circuit has the duty cycle up to 0.5, not 0.25, meaning that under the same input voltage the latter has a wider output voltage range than that of the former. Above all, if the proposed circuit with N outputs, then it still has the duty cycle up to 0.5, not one over N as shown traditionally. Moreover, as compared with the current sharing based on the differential-mode transformer, the proposed circuit has no magnetic resetting loop required. In this paper, the operating principles and design considerations of the proposed converter are discussed. Finally, the theoretical analyses and performances of the proposed LED driver are verified by simulation and experiment.


2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.


2018 ◽  
Vol 2 (1) ◽  
pp. 30
Author(s):  
Hisatsugu Kato ◽  
Yoichi Ishizuka ◽  
Kohei Ueda ◽  
Shotaro Karasuyama ◽  
Atsushi Ogasahara

This paper proposes a design technique of high power efficiency LLC DC-DC Converters for Photovoltaic Cells. The secondary side circuit and transformer fabrication of proposed circuit are optimized for overcoming the disadvantage of limited input voltage range and, realizing high power efficiency over a wide load range of LLC DC-DC converters. The optimized technique is described with theoretically and with simulation results. Some experimental results have been obtained with the prototype circuit designed for the 80 - 400 V input voltage range. The maximum power efficiency is 98 %.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2536
Author(s):  
Bor-Ren Lin ◽  
Yi-Kuan Lin

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.


Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 88
Author(s):  
Kosala Gunawardane ◽  
Nalin Bandara ◽  
Kasun Subasinghage ◽  
Nihal Kularatna

Cleaner and greener energy sources have proliferated on a worldwide basis, creating distributed energy systems. Given the unreliable nature of the renewable sources such as solar and wind, they are traditionally based on inverters interfaced with legacy AC grid systems. While efficiency, output waveform quality and other technical specifications of inverters keep improving gradually, only limited attention is given to widening the input range of inverters. This paper presents a new supercapacitor assisted (SCA) technique to widen the input range of an inverter without modifying the inverter itself. Developing a prototype version of a 24 V DC input capable supercapacitor-assisted wide input (SCASWI) inverter using a supercapacitor circulation front end and a commercial 12 V DC line frequency inverter is detailed in the article, explaining how the SCASWI inverter technique doubles the input voltage while maintaining the useful characteristics of the commercial inverter. The new technique has the added advantage of DC-UPS capability based on a long-life supercapacitor module.


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