Effect of Temperature and Current on Luminous Efficiency of High Power LED

2011 ◽  
Vol 347-353 ◽  
pp. 310-313 ◽  
Author(s):  
Feng Rao ◽  
Zhi Chen Ge ◽  
Jin Lian Zhu
Keyword(s):  
Energy Saving ◽  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Luminous Efficiency ◽  
Effect Of Temperature ◽  
Light Emitting ◽  
Led Light ◽  
High Power Led ◽  
Changing Rate

Luminous efficiency of high power white light LED (light emitting diode) at different temperature and driver current is measured with the photometric, chromatic and electric characteristics analyzer. It is shown that the luminous efficiency decreases as the temperature and (or) the driver current increases. The highter the driver current is, the more strongly temperature worsens the efficiency. However, the changing rate of efficiency with current is similar at different temperature. At last, a luminous efficiency model with temperature and current is constructed. This research is very important for the design of energy-saving LED lamps.

Color Offset in the Process of High-Power LED Life Aging

2016 ◽  
Vol 693 ◽  
pp. 498-503 ◽  
Author(s):  
L.Y. Zhang ◽  
Y.P. Cui ◽  
Z.N. Luo ◽  
L. Zhou
Keyword(s):  
Blue Light ◽  
White Light ◽  
High Power ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Color Temperature ◽  
Constant Current ◽  
Light Emitting ◽  
Color Coordinate ◽  
High Power Led

In order to study color offset of the high-power white light and blue light LED in the whole life, a series of high-power white light and blue light emitting diodes are lighted continuously under a constant current. In the light of different period of time, measured the light emitting diode emission spectrum, color coordinate, color temperature of the light emitting diodes are measured at different periods; light luminous flux, color coordinate and color temperature changes are also measured under different currents. The experimental results show that the color of LED is different at different period under the same current, and is also different under a variable current. The article studied the influence of different factors on the color offset, and pointed out that the high-power LED color offset is caused by not only phosphors aging but also more major changes of the material itself. Furthermore, the results will provide a reference to the application of white LED and for the further study.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

Phosphor concentration and geometry for high power white light emitting diode

2010 ◽  
Author(s):  
Kyung-Mi Moon ◽  
Se-Hwan An ◽  
Hyung-Kun Kim ◽  
Jung-Hye Chae ◽  
Yong-Jo Park
Keyword(s):  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Light Emitting

Phosphor–silicone interaction effects in high power white light emitting diode packages

2017 ◽  
Vol 28 (23) ◽  
pp. 17557-17569 ◽  
Author(s):  
Jiajie Fan ◽  
Mengni Zhang ◽  
Xiao Luo ◽  
Cheng Qian ◽  
Xuejun Fan ◽  
...  
Keyword(s):  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Interaction Effects ◽  
Light Emitting

Analysis of high-power packages for white-light-emitting diode lamps with remote phosphor

2005 ◽  
Vol 892 ◽  
Author(s):  
Hong Luo ◽  
Jong Kyu Kim ◽  
Yangang Xi ◽  
E. Fred Schubert ◽  
Jaehee Cho ◽  
...  
Keyword(s):  
Ray Tracing ◽  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Yellow Phosphor ◽  
Blue Phosphor ◽  
Remote Phosphor ◽  
Optical Modes ◽  
Diffuse Reflector

AbstractAn optimized packaging configuration for high-power white-light-emitting diode (LED) lamps that employs a diffuse reflector cup, a remote phosphor and a hemi-spherically-shaped encapsulation is presented. Ray tracing simulations for this configuration show that the phosphor efficiency can be enhanced by up to 50% over conventional packages. It is experimentally shown that dichromatic LED lamps with remote phosphor and diffuse reflector cup configuration have higher phosphor efficiency by 15.4% for blue-pumped yellow phosphor and by 27% for ultraviolet-pumped blue phosphor over conventional packages. Those improvements are attributed to reduced absorption of the phosphorescence by the LED chip and the reduction of deterministic optical modes trapped inside the encapsulant.

Al2O3-Ce:GdYAG composite ceramic phosphors for high-power white light-emitting-diode applications

2019 ◽  
Vol 39 (6) ◽  
pp. 2149-2154 ◽  
Author(s):  
Xin Liu ◽  
Xinglu Qian ◽  
Zewang Hu ◽  
Xiaopu Chen ◽  
Yun Shi ◽  
...  
Keyword(s):  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Composite Ceramic ◽  
Light Emitting
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