Lifetime Prediction method of LED Light-emitting Device Based on Approximate Analysis

Compared with other light sources, LED light source has a longer service life and will not suddenly fail. Due to its high efficiency, energy saving and long life, LED has become the most popular light source at present. However, it is no longer considered to meet the application requirements, and the time that the light flux decays to this level is considered to be the life of the LED. This paper introduces the approximate method used to predict the lumen maintenance life of LED lamps. The experimental results obtained by the approximate method are compared with the TM-21 standard. Eventually, it is concluded that the approximate method provides more reliability information than the original TM-21 standard, and the obtained results are more reference, more accurate and more reliable.

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Elimination of the blinding effect in landscape luminaires

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.13.12673 ◽

2018 ◽

Vol 7 (2.13) ◽

pp. 252

Author(s):

Albert Ashryatov ◽

Dinara Churakova

Keyword(s):

Light Curve ◽

Light Source ◽

Light Flux ◽

Light Distribution ◽

Light Sources ◽

Mirror Surface ◽

Light Emitting ◽

Lighting Technology ◽

Initial Task ◽

Flat Beam

The article presents one of the possible options for implementing the lighting technology "Flat beam" for landscape lighting purposes. One of the possible ways to control the light distribution of a number of light sources based on LEDs with different radiation patterns is considered. As a secondary optics, it is proposed to use a mirror surface that redistributes the light flux of an LED light source. It is indicated that, depending on the initial type of the light-emitting diodes light curve and the features of mounting the mirror surface, the resulting light distribution can vary widely, depending on the initial task that the designer sets for himself.

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An Emerging White LED Technology and associated Thermal Issues – A Review

Journal of Applied and Emerging Sciences ◽

10.36785/buitems.jaes.301 ◽

2019 ◽

pp. 106-120

Keyword(s):

High Efficiency ◽

Heat Sinks ◽

Light Sources ◽

White Led ◽

Color Gamut ◽

Light Emitting ◽

White Leds ◽

Long Life ◽

White Light Emitting Diodes ◽

Color Rendering

White light emitting diodes (white-LEDs) are the promising light sources of new lighting technology due to their high efficiency, energy saving, long life and environmentally friendly. In this review, different techniques proposed for the development of white-LEDs have been discussed in terms of their performance efficiency and potential usage. The Phosphor based white-LEDs are widely used LEDs, as compared to RGB based white-LEDs, due to their luminous efficacy, service life, display color gamut and the color rendering. Furthermore, thermal issues related to high power white-LEDs have been discussed as it greatly impacts the performance efficiency. To resolve thermal issues, heat sinks having high thermal conductivity are most widely used among others.

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Organic Light Emitting Diodes - Innovative Light Sources

Light & Engineering ◽

10.33383/2018-157 ◽

2019 ◽

pp. 101-107

Author(s):

Sergei A. Stakharny

Keyword(s):

Light Source ◽

Organic Light Emitting Diodes ◽

Organic Leds ◽

Light Sources ◽

High Quality ◽

Light Emitting ◽

Organic Light ◽

Lighting Systems ◽

Physical Principles ◽

Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

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

Applied Sciences ◽

10.3390/app11094035 ◽

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.

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Towards the Optimum Light Source Spectrum

Advances in OptoElectronics ◽

10.1155/2010/596825 ◽

2010 ◽

Vol 2010 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

Andrew Chalmers ◽

Snjezana Soltic

Keyword(s):

Light Source ◽

Large Scale ◽

Source Spectrum ◽

Light Sources ◽

Luminous Efficacy ◽

Light Emitting ◽

Spectral Bands ◽

Good Energy ◽

Lighting Systems ◽

Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

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Photobiocatalytic alcohol oxidation using LED light sources

Green Chemistry ◽

10.1039/c6gc02008a ◽

2017 ◽

Vol 19 (2) ◽

pp. 376-379 ◽

Cited By ~ 25

Author(s):

M. Rauch ◽

S. Schmidt ◽

I. W. C. E. Arends ◽

K. Oppelt ◽

S. Kara ◽

...

Keyword(s):

Light Source ◽

Photocatalytic Oxidation ◽

Alcohol Oxidation ◽

Light Sources ◽

Blue Led ◽

Led Light

The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported.

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Effects of Artificial Light Treatments on Growth, Mineral Composition, Physiology, and Pigment Concentration in Dieffenbachia maculata “Compacta” Plants

Sustainability ◽

10.3390/su11102867 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2867 ◽

Cited By ~ 5

Author(s):

Pedro García-Caparrós ◽

Eva Almansa ◽

Rosa Chica ◽

María Lao

Keyword(s):

Mineral Composition ◽

High Efficiency ◽

Light Emitting Diodes ◽

Plant Biomass ◽

Soluble Sugars ◽

Dry Weight ◽

Spectral Energy ◽

Photosynthetic Parameters ◽

Light Sources ◽

Light Emitting

Specific wavebands may allow precise control of plant growth. However, light sources must be carefully evaluated before the large-scale use of supplemental light sources can be implemented. Dieffenbachia maculata “Compacta” plants were grown for 8 weeks in pots in a growth chamber under tightly controlled temperature and humidity in order to assess the effects of supplemental light. Three treatments were applied: (i) using 18-W fluorescent bulbs (T1), (ii) using the same bulbs with supplemental light emitting diodes (LEDs) (Pure Blue and Pure Red Mix-Light-Emitting Diodes (BR-LEDs)) (T2), and (iii) using high-efficiency TL5 fluorescents (T3). Plant biomass, mineral composition, and physiological and photosynthetic parameters were assessed under each light treatment. Total plant dry weight was highest in plants grown under treatments T1 and T3. Other differences were observed between different light treatments, including variation in biomass partitioning as well as N and K concentrations in roots, stems, and leaves. Further, proline and indole 3-acetic acid (IAA) levels were higher in plants grown under the T1 treatment, whereas total soluble sugars and starch were higher in plants grown under treatment T3. Plants grown under treatment T1 had the lowest chlorophyll concentrations. No differences were observed in organ water content and P concentration. T2 was not the best treatment, as expected. The model proposed a linear regression between integrated use of spectral energy (IUSE) and total dry weight (TDW), which showed a good relationship with an R2 value of 0.83. Therefore, we recommend this methodology to discern the effects of the different spectral qualities on plant biomass.

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A replacement for incandescent bulbs: high-efficiency blue-hazard free organic light-emitting diodes

Journal of Materials Chemistry C ◽

10.1039/c6tc04402f ◽

2017 ◽

Vol 5 (1) ◽

pp. 176-182 ◽

Cited By ~ 11

Author(s):

J. H. Jou ◽

H. H. Yu ◽

F. C. Tung ◽

C. H. Chiang ◽

Z. K. He ◽

...

Keyword(s):

Energy Saving ◽

Light Source ◽

High Efficiency ◽

Light Emitting Diodes ◽

Organic Light Emitting Diodes ◽

Light Emitting ◽

Organic Light

A blue-hazard free, healthy light source will become the mainstream of future lighting wherein higher energy saving is always a must.

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1.331μm Narrow-Bandwidth Light Source Based on Polymer Micro-Blazed Grating

2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems ◽

10.1115/micronano2008-70207 ◽

2008 ◽

Cited By ~ 1

Author(s):

Hairong Wang ◽

Xianni Gao ◽

Guoliang Sun ◽

Yulong Zhao ◽

Zhuangde Jiang

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Low Cost ◽

Diffraction Order ◽

Blazed Grating ◽

Light Emitting ◽

Led Light ◽

Narrow Bandwidth ◽

Narrow Width ◽

The Cost

In order to detect methane (CH4) accurately and reliably, this paper presents a sensor which consists of infrared diode, fixtures, blazed grating, to realize the extremely narrow-bandwidth light at wavelength of 1.331μm. Based on factors such as compatibility with the transmission characteristics of silica fiber and the cost, a LED (light-emitting diode) with center wavelength of 1.3μm is selected. The LED light is modulated as the parallel light beam. As the light is incident in a micro-blazed grating with certain angle, by diffraction and interference, the light will output the maximum light intensity of its diffraction order at 1.331 μm, which just is an absorption peak of CH4. Micro-blazed grating applied here is low cost and easy replication by various ways, which makes extreme narrow width wavelength possible. Simulation and analysis indicate the designed prototype can output 1.331μm with bandwidth from 1.32907μm to 1.332495μm. With the light source basing on light dividing system, more reliable and higher sensitive measurement of the dangerous gases such as methane and carbon monoxide (CO) can be realized.

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