• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.426-427
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• 2010

커패시터 소자와 브릿지 다이오드만을 사용한 교류전원 LED 구동회로를 분석하여, 초저손실 고효율 특성과 더불어 입력전류의 고조파 및 역률특성이 양호해지는 동작점을 찾아내었다. 커패시터 소자는 교류전원에 직렬로 연결되어 전력손실 없이 LED 전류를 제한하는 역할을 하게 되며, 브릿지 다이오드 정류회로는 LED 어레이를 교류전원의 2배 주파수로 구동시키게 한다. 분석결과, 제안된 LED 구동회로는 LED 어레이의 전압강하가 입력 교류전압 최대치의 절반이 될 때 역률특성과 효율이 최고가 되며, 동작온도 변화에 따른 LED 어레이 전압 변동에 대해 출력이 변하지 않는 특징을 갖는다. 이러한 LED 구동회로는 스윗칭 레귤레이터나 IC 등이 없이 단순 수동소자만을 사용함으로써 제품원가 최소화와 효율향상을 동시에 달성할 수 있으며, 실험을 통해 특성이 확인되었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.555-558
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• 2017

In this paper, we designed a power supply AC LED driving device which can display uniform power consumption and light efficiency even when AC power of different size is applied. By setting input voltages and deviations of different sizes, it is confirmed that the electric light characteristics are the same at two input voltages. In addition, according to peak voltage of AC power, improper lighting caused in specific LED section is improved, and LED lighting of all sections is implemented in all commercial AC input voltage.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.504-513
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• 2009

This paper proposes the new type LED driver modularization for illumination LED driver. The proposed LED driver circuit insulates a hot GND of AC input power and a cold GND of LED driver part by using a fly-back converter. In order to control easily the current of the LED, the fly-back converter is operated in the discontinuous mode with excellent dynamic characteristics, and the characteristics of the LED are verified after the closed loop control is performed using a KIA2431. The LED driver module allows the wide AC power input ranges and realizes the burst dimming function which directly regulates a PWM control IC. This paper describes the operation principle of the LED driver module and it is proved the usefulness through the real model with experimentation. Besides, this paper proposes the multi-channel LED driver which the miniaturized and modularized LED driver module are connected by parallel, and verified its propriety by experiments.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1025-1025
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• 2015

본 논문에는 Flyback컨버터의 PWM방식과 조명용 LED 구동장치의 디밍에 의한 조명제어를 제안한다. 제안된 LED 구동회로는 Flyback 컨버터를 이용하여 교류 입력 전원을 직류 출력전원으로 변환되는 과정을 이해한다. 포터커플러의 역할과 그 Feedback원리 그리고 PWM방식으로 IC를 직접 제어하여 버스트 디밍을 구현하고 LED의 밝기 밝기 조절 및 불필요한 전력낭비를 예방하는데 목적을 두었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.275-283
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• 2021

In this study, a driver IC for an AC-powered LED that can be manufactured with a low voltage semiconductor process is designed and the performances of the driver IC were simulated. In order to manufacture a driver IC that operates directly at AC 220V, a semiconductor manufacturing process that satisfies a breakdown voltage of 500V or higher is required. A semiconductor manufacturing process for a high-voltage device requires a much higher manufacturing cost than a general semiconductor process for a low-voltage device. Therefore, the LED driver IC is designed in series so that it can be manufactured with semiconductor process technology that implements a low-voltage device. This makes it possible to divide and apply the voltage to each LED block even if the input voltage is high. The LED lighting circuit shows a power factor of 96% at 220V. In the pnp transistor circuit, a very high power factor of 99.7% can be obtained, and it shows a very stable operation regardless of the fluctuation of the input voltage.

• KOREAN POULTRY JOURNAL
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• v.48 no.1
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• pp.146-149
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• 2016

캐패시터 마이크로폰용 소자반도체 분야에서 세계 일류 기업으로 성장한 (주)알에프세미(대표 이사 이진효)는 꾸준한 연구개발을 통해 혁신적인 교류직결형구동장치(AC Direct LED Drive IC)를 개발하여 LED 조명의 고품질 저가격 실현을 이루고 있다. 일반 가정용, 주차장, 공장 등에 공급한 교류직결형 LED 조명을 양계장에서 사용할 수 있게 방진 방습 기능을 업그레이드 시켜 작년부터 양계장에 본격적으로 공급하고 있다. 이번호에는 수명보증, 차별적인 AS 등으로 양계장 LED 전구 시장에 거침없이 도전장을 내민 (주)알에프세미를 소개코자 한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.485-490
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• 2012

In this paper, driver circuit of LED lights for ships is designed and implemented to replace conventional lights with filament which have short life time due to vibration of ships. The driver of LED module is switching circuit without transformer to reduce volume and cost. As switch circuit controls input 220 VAC with PWM, LED module is reliably driven. Power factor is improved by using valley-fill PFC compensation circuit which is handled to pulse current of switching circuit. Serial-parallel LED circuit is applied to reduce change period of lights of long-term navigation ships. Array of serial-parallel can operate even if some of LEDs is damaged. It is suitable for ships that power consumption and power factor of lights including developed drive circuit have 39Watt and 0.925 respectively.

• Journal of IKEEE
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• v.18 no.3
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• pp.335-340
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• 2014

Recently, LED (Light Emitting Diode) becomes to be useful to apply for the lightening sources in electric systems and the lightening equipment since the power is less consumed with high efficiency, and the size and the weight of LED are small and light, respectively. The LED is controlled with constant current and SMPS (Switching Mode Power Supply). It is necessary for the LED manufacturer to secure the fundamental technology of designing LED chip, and to study the methodology to improve the power factor (PF) and to design the operational circuit for the development of LED to reduce the power loss in the application of LED lightening. The direct AC (Alternating Current) LED driving circuit, HV9910, is widely used in the industry field. In this paper, it is to evaluate the improved methodology for the power factor and efficiency through simulations when PFC (Power Factor Correction) and Noise Filter are added to HV9910.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.643-648
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• 2011

In this study, SMPS driven LED traffic signal light for Large-scale traffic such as railroad and airport was designed and its electrical and EMI characteristics were measured. The output current of the LED module driven by SMPS was 1.67A for AC and DC input voltage over 10V. The conducted emission measured over 0.15~30MHz frequency range was lower than the allowed quasi-peak and average level, and the radiated noise measured over 30~1000MHz frequency range showed $23.96dB{\mu}V/m$ at 59.96MHz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4177-4185
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• 2012

LEDs are becoming the most suitable candidate replacing traditional fluorescent lamps because of its eco-friendly characteristics. LEDs are also actively used to design green building system and to make outdoor billboard as a back-light system due to its high energy efficiency. In this paper, we have developed AC direct driver for $12{\times}12$ FLB(flexible LED board) and LED flat light without SMPS. It has LID-PC-R101B driver IC that can support the high power factor and be composed of LED switching circuit in group. Also, an elaborate system designs can guarantee a high luminous efficiency, a high reliability and a low power consumption. The proposed FLB has the ultra slim shape of $450{\times}450$ mm, width of 4 mm and weight of 280 g. In the end, we have developed a prototype of FLB for billboard and flat light for room lighting with AC direct driver iposrder to verify the performance of the proposed system.