• Title/Summary/Keyword: High-Power LED

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The Optical Characteristics of 240 W High Power LED Fish Luring Lamp (240W급 고출력 LED 집어등의 광학적 특성)

  • Bae, Jae-Hyun;An, Heui-Chun;Kim, Sang-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.681-687
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    • 2013
  • This study analyzed characteristics of 240 W high power LED lamps by comparing with those of traditional metal halide lamps. In addition, it analyzed the propriety of LED lamps as a source of light, considering seawater transmission characteristics. When Applying white LED package with the color temperature color temperature of 6500K, a 240W-LED fishing lamp has a characteristics of the luminous angle to be expanded to ${\pm}45^{\circ}$, the illumination change was improved to 0.8, as well as the luminance efficiency was improved to 98.8lm/W. As results of comparison between one 1,500W-metal halide lamp and four 240W-LED lamp with considering a seawater transmission and a luminous efficiency of scotopic vision, the radiant flux of two lamps were almost equal level at 50m depth and the luminous flux was 5% higher LED lamp than metal-halide lamp even if only applying the luminous efficiency of scotopic vision. As the luminous flux of LED lmap was 14% higher than that of metal-halide lamp with applying the luminous efficiency of scotopic vision to radiant flux at 50m depth, so LED fishing lamp was verified to alternative possibility of metal-halide lamp.

Effects of ZnO Composition on the Thermal Emission Properties for LTCC Type of High Power LED Package (고전력 LED용 적층형 LTCC 패키징의 ZnO 조성 변화가 방열 특성에 미치는 영향)

  • Kim, Woojeong;Kim, Hyung Soo;Shin, Daegyu;Lee, Hee Chul
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.79-83
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    • 2012
  • LTCC (Low temperature co-fired ceramic) package have been paid much attention due its good reliability, miniaturization, and application of silver paste with complex wiring and printing. Therefore, LTCC package has been expected to replace vulnerable plastic package in the field of high power LED device. Currently, LTCC ceramic package is mainly made up of aluminum oxide powder. In this study, zinc oxide powder is added or replaced for the fabrication of LTCC ceramic body. By adding small amount of ZnO, thermal conductivity of the LTCC ceramic body could be remarkably increased by 25% leading to the extension of LED life time. The LTCC package structure with composition including ZnO has an increased thermal flux by 56% as a result of ANSYS simulation. Actually, the fabricated LED package with the addition of ZnO exhibits a decreased thermal resistivity by 14.9%.

Fabrication and analysis of luminous properties of ceramic phosphor plate for high-power LED (High-power LED용 ceramic 형광체 plate 제조 및 발광 특성 분석)

  • Ji, Eun-Kyung;Song, Ye-Lim;Lee, Min-Ji;Song, Young-Hyun;Yoon, Dae-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.1
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    • pp.35-38
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    • 2015
  • LEDs are considered to be an alternative for enhancement of energy efficiency, applied for numerous areas such as display, automotive headlight not only lights. Yellow phosphor is generally utilized with blue LEDs to generate WLED, $Y_3Al_{5}O_{12}:Ce^{3+}$ is typically used as the yellow phosphor. The phosphor, mixed with epoxy resin, has been used by being spread and hardened on the blue LED chip. This paste-based packaging gives rise to problems of degradation of phosphor by heat and decrease of luminous efficiency. Although phosphor plate is used instead of the epoxy-phosphor mixture to solve these problems, loss of luminous efficacy by total internal reflection inside the plate also should be solved. In this study, we coated the side of the plate with silver as one of the solution.

Analysis and Design of High-efficiency Boundary Conduction Mode Tapped-Inductor Boost Converter for LED Driver Applications (LED 구동 응용을 위한 고효율 경계모드 탭인덕터 부스트 컨버터의 분석과 설계)

  • Kang, Jeong-il;Han, Sang-Kyoo;Han, Jonghee
    • Proceedings of the KIPE Conference
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    • 2013.11a
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    • pp.5-6
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    • 2013
  • 본 논문에서는 모바일 기기 등에 사용되는 소형 디스플레이를 위한 고효율 경계모드 탭인덕터 부스트 LED 구동회로를 분석하여 장점을 밝히고 최적의 설계기준을 제시한다.

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4181Overcoming the High-current Efficiency Loss Mechanism in GaN-based Light-emitting Diodes

  • Kim, Jong-Gyu
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.23.2-23.2
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    • 2011
  • This presentation will include an overview of III-Nitride LED technology, applications, key areas for future improvements, challenges such as efficiency droop. GaN-based high-power light-emitting diodes (LEDs) suffer from high-current loss mechanisms that lead to a significant decrease in internal quantum efficiency at high drive currents, a well-known phenomenon commonly referred to as efficiency droop. Although many attempts have been made to uncover this LED's darkest secret, there is still a lack of consensus on the dominant mechanism responsible for this detrimental phenomenon. In this presentation, proposed origins and corresponding solutions to the droop-causing mechanisms will be reviewed and discussed.

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Analysis of Thermal Properties in LED Package by Via hole of FR4 PCB (FR4 PCB의 Via-hole이 LED 패키지에 미치는 열적 특성 분석)

  • Lee, Se-Il;Lee, Seung-Min;Park, Dae-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.12
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    • pp.57-63
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    • 2010
  • The efficiency of LED package is increasing by applying the high power, and a existing lighting is changing as the LED lighting. However, many problems have appeared by heat. Therefore, in order to solve thermal problems, LED lighting is designing in several ways, but the advantages of LED lighting is fading due to increase the prices and volumes. In this study, we try to improve the thermal performance by formation of via holes. The junction temperature and thermal resistance in the FR4-PCB with via-holes of 0.6[mm] was excellent in experiment and FR4-PCB with Via-holes of 0.6[mm] was excellent in simulation without solder. Further, the thermal resistance and the optical properties can be improved through a formation of via-holes.

Design of Photovoltaic System for LED Lighting (LED 조명을 위한 태양광 시스템 설계)

  • Lee, Hoong-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.371-374
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    • 2011
  • In this paper, a software development for design of the small photovoltaic system which is used to LED lighting is presented. For optimal design of photovoltaic systems, the operating power consumption of the LED load is considered to estimate the capacity of the solar module and battery. In order to give system design engineers a high ease of use, the software tool provides a graphical user interface and monitoring function to check operation of the system prior to installation.

Improvement the Junction Temperature Measurement System Considering the Parasitic Capacitance in LED (LED 기생 커패시턴스를 고려한 접합온도 측정 시스템의 개선)

  • Park, Chong-Yun;Yoo, Jin-Wan
    • Journal of Industrial Technology
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    • v.29 no.B
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    • pp.187-191
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    • 2009
  • Recently, we have used LEDs to illumination because it has a high luminous efficiency and prolong lifespan. However the light power and lifetime is reduced by junction temperature increment of LED. So it is important to measure the junction temperature accurately. In case of using a electrical method measuring junction temperature of LED. Temperature measurement errors are spontaneously generated because of a parasitic capacitances in LED. In this paper, we proposed a method that reducing LED's parasitic capacitance effects for electrical measurement. It was demonstrated by the experimental result that is more correct than established method.

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The Destruction Effects of Semiconductors by High Power Electromagnetic Wave (고출력 과도전자파에 의한 반도체 소자의 파괴효과)

  • Hwang, Sun-Mook;Hong, Joo-Il;Huh, Chang-Su
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1638-1642
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    • 2007
  • This paper investigated the destruction effect of the semiconductors by impact of high power electromagnetic wave. The experiments is employed as an open-ended waveguide to study the destruction effects on semiconductor using a 2.45 GHz 600 W Magnetron as a high power electromagnetic wave. The semiconductors are located at a distance of $31cm\sim40cm$ from the open-ended waveguide and are composed of a LED drive circuit for visual discernment. Also the chip condition of semiconductor is observed by SEM(Scanning Electron Microscope) analysis. The semiconductor are damaged by high power electromagnetic wave at about 860 V/m. The SEM analysis of the destructed devices showed onchipwire and bondwire destructions. Based on the result, semiconductor devices should have plan to protect the semiconductor devices form high power electromagnetic wave. And the database from this experiment provides the basis for future investigation.

A study on the improvement of thermal characteristics of high power light source (고출력 광원의 방열특성 개선에 대한 연구)

  • Lee, Han-myung;Kim, Young-woo;Chun, Woo-young;Kim, Yong-hyung;Kim, Jin-hong
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1285-1285
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    • 2015
  • 현재 전력난에 의해 에너지 절감이라는 말은 가정 및 산업 현장 곳곳에서 들을 수 있다. 에너지 절감 대책 중 하나가 몇 년전 정부에서 발표한 백열등 수입 및 유통금지가 있다. 그 효과로 LED 산업이 각광 받게 되었다. 다양한 LED 산업 및 기술에서도 신뢰성 및 성능 분야는 항상 진화하고 많은 기업들이 집중하고 있다. LED에서 중요한 요소인 방열성능을 개선시키기 위해 많은 연구를 행하고 있다. 그리고 광원 개발분야에서도, 반도체 광원의 LED PKG의 다량 실장으로 고출력을 행하는 것 보다는 기판위에 Blue Chip을 실장하여 제작하는 고출력 광원의 기술로 집중되고 있다. 이 논문에서는 고출력 광원인 COB(Chip On Board) LED의 방열성능 개선을 다루었다. 기판의 구조 변형으로 방열특성 개선 대안을 제시하였다. Via hole과 Cavity를 이용한 구조를 제안하였다. 그에 대한 해석 방법으로는, 구조적인 해석과 수치적인 해석을 활용하였다. 그 결과로는 약 13~40%의 방열성능 개선을 나타내었다.

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