Study of High-Power White LED's Lifetime Based on Accelerated Life Test

2013 ◽  
Vol 800 ◽  
pp. 205-209 ◽  
Author(s):  
De Sheng Li ◽  
Nian Yu Zou ◽  
Yun Cui Zhang ◽  
Xiao Yang He ◽  
Yi Yang
Keyword(s):  
High Power ◽  
Accelerated Life Test ◽  
Reliability Test ◽  
White Led ◽  
Life Test ◽  
Arrhenius Model ◽  
White Leds ◽  
Accelerated Life ◽  
Temperature Levels

The study of LED reliability becomes more and more important with LED widely used in various areas, and accelerated life test (ALT) as an element of reliability test is widely used to predict the lifetime of LED. In this paper, ALTs have been carried out at various current levels and various temperature levels. In the current ALT experiment, three kinds of stressing currents were demonstrated for 1W white LEDs and lumen flux of the tested LEDs were studied, and based on Eyting model, lifetime of the tested LEDs is calculated about 6.86×105h. In the temperature ALT experiment, two kinds of stressing temperature were demonstrated for the same type of white LEDs and lumen flux were also studied, and based on Arrhenius model, lifetime of the tested LEDs is calculated about 7.41×105h. In addition, the color shifting velocity is faster than lumens depreciation velocity was observed in our experiment, which means the lifetime evaluating of white LED should be paid more attention.

Accelerated Life Test for the Embrittlement of Natural Rubber Grommets

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1408-1414 ◽  
Author(s):  
Min Gyu Kong ◽  
Jin Woo Kim ◽  
Myung Soo Kim ◽  
Joong Soon Jang ◽  
Dong Su Ryu
Keyword(s):  
Natural Rubber ◽  
Zinc Stearate ◽  
Accelerated Life Test ◽  
Life Test ◽  
Arrhenius Model ◽  
Degradation Model ◽  
Compression Load ◽  
Failure Times ◽  
Accelerated Life ◽  
Field Samples

This paper presents an accelerated life test for embrittlement of natural rubber grommets. From the analyses of field samples, it is found that embrittlement is due to the decrease of plasticizer (zinc stearate for natural rubber) in the rubber. To estimate the embrittlement life, an accelerated life test is designed based on a factorial design. Temperature and compression load are selected as accelerating variables, and the hardness is measured for each specimen during the test. An analysis of variance indicates that the significant factor affecting the hardness is not load, but temperature. The embrittlement life and temperature relationship and the acceleration factor are estimated from the failure times using linear degradation model under the assumptions of Weibull lifetime distribution and Arrhenius model.

Comparative Study of High-Power White LED’s Lifetime Based on Temperature Accelerated Test

2014 ◽  
Vol 936 ◽  
pp. 1985-1988
Author(s):  
Shi Wei ◽  
Nian Yu Zou ◽  
Yun Cui Zhang ◽  
De Sheng Li
Keyword(s):  
Activation Energy ◽  
Comparative Study ◽  
High Power ◽  
Experimental Results ◽  
Life Test ◽  
Accelerated Test ◽  
Arrhenius Model ◽  
White Leds

The lifetimes of two white high-power LEDs were studied based temperature-acceleration life test. the acceleration temperatures were selected as 100°C and 90°C separately in the experiment, and the accelerated time was 800 hours. Based on Arrhenius model, activation energy of the two tested samples are 0.6978 and 0.7014 separately, and lifetime are7.41×105h and 1.46×105h separately. Our experimental results showed that the quality of the two type LEDs is very different, and lifetime of 50000 hours is recommended as the threshold of entering the market for high power white LEDs.

scholarly journals Current Status and Prospects of Reliability Test Research on Special Computers

2021 ◽  
Vol 261 ◽  
pp. 01054
Author(s):  
Chao Li
Keyword(s):  
Industrial Development ◽  
Developed Countries ◽  
Accelerated Life Test ◽  
Quality Analysis ◽  
Current Status ◽  
Reliability Test ◽  
Life Test ◽  
Key Technology ◽  
Accelerated Life ◽  
Computer Reliability

Special computers are widely used in aerospace, ships, weapons and other fields. More and more attention is paid to the reliability of special computers. Although my country started late in this regard, it has achieved some results after continuous exploration by a large number of scientific research institutions, and has gradually kept up with the pace of research in developed countries. This article first summarizes the research status and importance of accelerated life test in reliability test research, and analyzes the key technology and development of reliability test of special computer. Reliability analysis can solve the failure problems that cannot be explained by traditional quality analysis methods, and will surely make remarkable achievements in the future industrial development. The summary of this article will provide theoretical reference for subsequent related research.

Research on Accelerated Life Test System for Water Quality Analyzer

2014 ◽  
Vol 635-637 ◽  
pp. 738-741
Author(s):  
Guang Yue Shen ◽  
Jian Miao ◽  
Jian Wen Shao
Keyword(s):  
Water Quality ◽  
Computer Software ◽  
Test System ◽  
Accelerated Life Test ◽  
Reliability Test ◽  
System Control ◽  
Life Test ◽  
Accelerated Life ◽  
Quality Analyzer ◽  
Upper Computer

This research proposes an Accelerated Life Test System and has realized the reliability test of water quality analyzer. ALT (Accelerated Life Test) system is based on the principle of step stress accelerated life test and takes temperature as the accelerated stress. The system includes lower computer PLC and upper computer software of MCGS. In this research, Upper computer using configuration software to connect with the SIEMENS S7-300 PLC, in order to realize data acquisition and system control. This system improves the reliability test efficiency of the water quality analyzer, reduces the cost of test and has good economic efficiency.

AN ECONOMIC ACCELERATED LIFE TEST ACCEPTANCE SAMPLING PLAN

1995 ◽  
Vol 02 (01) ◽  
pp. 49-59 ◽  
Author(s):  
DAMING LIN ◽  
W.K. CHIU
Keyword(s):  
Life Stress ◽  
Cost Model ◽  
Sampling Plan ◽  
Accelerated Life Test ◽  
Acceptance Sampling ◽  
Life Test ◽  
Arrhenius Model ◽  
Acceptance Sampling Plan ◽  
Accelerated Life ◽  
The Cost

A cost model for an accelerated life test sampling plan is constructed. This model incorporates the cost of a life test and the cost of decision on a batch of components. The Arrhenius model is adopted for the life-stress relationship. Then the method of deriving an economic sampling plan is presented. A numerical example is given for illustration purpose.

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