• 전력전자학회논문지
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• 제20권3호
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• pp.262-272
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• 2015

An integrated two-in-one transformer applicable to PSUs for a 120 W LED TV is proposed. This transformer comprises a PFC inductor and an LLC transformer placed and integrated on an E-I-E type magnetic core. Performance is evaluated by observing the coupling coefficients of the proposed two-in-one transformer under various air gap topologies. Among the topologies studied, an integrated transformer with centered air gap shows stable operational characteristics with a minimized mutual coupling (interference). Furthermore, applicability of the proposed integrated transformer to PSUs for a 120 W LED TV is studied from the viewpoint of integrating different magnetic components into one core, resulting to low weight, low cost, and high power density.

• Journal of Information Display
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• 제5권2호
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• pp.6-9
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• 2004

We have developed the Scan-backlight Stereoscopic LCD that is a kind of field-sequential -Stereoscopic LCD combining the Dual- Directional- Backlight and the fast-response OCB panel. The Dual-Directional-Backlight using a double-sided prism sheet can change the direction of light by switching the LED light sources. The OCB panel using Feed-Forward Drive can realize frame rate of 120 Hz. As a result, the Scan-backlight Stereoscopic display works at its original resolving power, and produces flicker-free stereoscopic images. This auto- stereoscopic display can resolved the problems of the double images and the pseudoscopic images in case of watching at oblique angles.

• 한국전자통신학회논문지
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• 제6권5호
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• pp.643-648
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• 2011

본 연구에서는 공항, 철도, 항만 등 대형 교통수단의 표시등으로 사용하기 위하여 SMPS에 의하여 구동되는 LED 신호등을 설계하고 제작된 LED 신호등의 전기적 특성과 EMI 특성을 조사하였다. 10V 이상의 교류 및 직류입력전압에 대한 출력전류는 1.67A이었다. 0.15~30MHz에서 측정한 잡음단자전압은 허용기준 준첨두치와 허용기준 평균치 보다 낮았으며, 30~1000MHz에서 측정한 잡음전계강도는 59.96MHz에서 $23.96dB{\mu}V/m$이었다.

• 조명전기설비학회논문지
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• 제27권9호
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• pp.36-43
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• 2013

The prevalence of electronic devices in our modern life is accompanied with the generation of harmonics caused by the nonlinear characteristic load. Especially, the employment of LED have brought the rapid use of SMPS. SMPS is used for supplying the constant DC electric power to the LED display board, but it has a big problem which gives birth of harmonics causing by its high-speed switching. measurement HIOKI 3196 equipment to solve these harmonics were measured. In this study, we are LED Display Board Load Measuring the impedance response with $X_L$ changes for removing harmonics in the measured. And we adopted the suitable passive filter by the impedance response characteristic obtained in the $X_L$ variation experiments. We are trying to deeply the application of passive harmonic filter characteristics that generation in the LED Display Board through EDSA LED simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.2158_2159
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• 2009

본 논문에서는 DC전원설비 접속부에서의 접촉불량에 의한 발열 특성에 대하여 실험, 분석하였으며 사용된 DC 전원설비는 상용 교류전원을 직류전원으로 변환하는 AC/DC 컨버터의 출력전원을 이용하는 LED 가로등 조명설비의 전원 접속부을 대상으로 하였다. 외부의 기계적 진동에 의해 동전선 접속부에 아크와 열이 발생하며 이때 발생한 발열 온도와 열 분포를 측정하였으며 적열부가 형성된 후 25분이 경과하였을 때 최고 $842.68^{\circ}C$까지 온도가 상승하였으며 접속부의 접촉전압은 1.5~1.6V, 통전전류는 6.6~6.9A로 약간의 변화만 나타남을 볼 수 있었다. 또한 DC전원에서 동전선 접속부에서의 산화물 생성과 증식 거동에 대하여 분석하였으며 AC전원에서와 유사하게 산화물이 형성되어 성장함을 볼 수 있었다. 이러한 실험과 분석 결과는 향후, DC 전원설비에서의 전기화재 예방을 위한 자료로 활용 가능할 것으로 기대된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.184-185
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• 2011

본 논문에서 coupled inductor를 이용한 새로운 고승압비 컨버터를 제안한다. 제안하는 컨버터는 스위치 전압 스트레스를 낮게 가져갈 수 있고 출력 다이오드 전압 스트레스도 출력 전압으로 제한된다. 추가적으로 공진 탱크의 최적 설계를 통해 스위치 턴 오프 손실을 저감시킬 수 있다. 기본적인 동작원리 및 특성을 좀더 자세하게 다루고, 실험 결과를 통해 제안하는 컨버터의 효용성을 보인다.

• 전자공학회지
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• 제22권3호
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• pp.92-105
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• 1995

각 분야에서 고화질 고해상도의 Flat Panel Display(FPD)에 대한 요구가 급증하고 있으며, FPD 소자들도 다양하다. FPD를 위한 구동방식은 근본적으로 matrix addroessing 방식을 사용하지만 FPD 소자의 동작 원리, 특성, 구동상의 문제점 등에 따라서 구동방식도 매우 다양하다. 다양한 FPD 소자들이 구동 방식과 구동회로를 다 살펴볼 수 없으므로 본고에서는 FPD소자인 PDP, EL, LED, EC, LCD, DMD, AMA, GLV, FED 등의 동작 원리를 설명하고, 이 소자들 중에서 AMLCD와 dc-PDP 소자의 구동방식과 구동회로에 대하여 논의한다. AMLCD의 구동방식으로는 펄스 구동 방식과 용량 구동 방식을 살펴보고, AMLCD의 문제점들을 극복할 수 있는 방법들을 설명한다. dc-PDP의 구동 방법인 pulse-memory 구동방식과 새로운 pulse-memory 구동 방식을 살펴보았다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.504-505
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• 2011

Decreasing actual greenhouse gas will be difficult if it is not solved addressed in architectural fields. Zero emission building or zero energy building, maximize the efficiency of energy, which means the building can operate by their own renewable energy facility without any other supplying. To be a zero emission building, a building needs realization of high efficiency low energy consumption, construction of building its own energy production facilities and lastly a power grid connection. According to increasing of DC load about TV, LED lighting, computer, IT in building for living and business, it is expected the save of energy when the system of AC power distribution change into the system of DC power distribution. Renewable energy exists a big different rate produced by outside environment. When electrical power overproduce, it can supply for system. Otherwise, if electrical power produce less, it can receive supply from system. Send and receive power can lead to zero to annual standard. This paper shows the simulation about efficient control of power conversion which is related to DC power distribution of architecture and DC output of renewable energy by using L-type converter.

• 산업기술연구
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• 제34권
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• pp.71-78
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• 2014

Recently, using the electronic devices was increased with semiconductor developments. So, the EMI(Electromagnetic interference) problem become to important issue for coexistence with each electronic devices. The EMI is caused by switching operation from the power switches as the FET and the transistor in power conversion devices. In this paper, the hybrid EMI filter that composed with active components and passive components was described. The EMI filter is applied to the 160 watts LED driver experimentally verify the performance. The hybrid EMI filter is compared with non-filter, only passive filter and only active filter. The proposed EMI filter attenuated CM noise more than traditional passive filter.

• 전력전자학회논문지
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• 제21권1호
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• pp.42-48
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• 2016

Light-emitting diode (LED) drivers are recently replacing fluorescent lamps; these drivers can operate adaptively with various ballasts without modifying and removing such ballasts. To satisfy these trends, a LED driver that is compatible with both electronic and magnetic ballasts is proposed in this study. Unlike conventional LED drivers, the proposed driver has a ballast recognition circuit and a mode selection circuit to operate ballasts at optimal conditions. Therefore, it features low voltage stress, high efficiency, and good compatibility with both electronic and magnetic ballasts. Moreover, it can be compatible with a wide selection of ballasts from various manufacturers. To confirm the validity of the proposed LED driver, results of the theoretical analysis and experimental verification performed on a 15 W-rated prototype are presented.