scholarly journals An Efficient Method for LED Light Sources Characterization

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1089 ◽  
Author(s):  
Sara Raggiunto ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Piergiovanni Ceregioli ◽  
Massimo Gattari ◽  
...  

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs’ power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED’s response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions.

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.


2009 ◽  
Vol 29 (10) ◽  
pp. 2791-2794 ◽  
Author(s):  
林岳 Lin Yue ◽  
叶烈武 Ye Liewu ◽  
刘文杰 Liu Wenjie ◽  
吕毅军 Lü Yijun

2021 ◽  
pp. 50-55
Author(s):  
Albert A. Ashryatov ◽  
Dinara K. Churakova

The article discusses one of the ways to obtain a contrasting boundary between the illuminated and unlit areas of the object (illumination technology Flat Beam) in LED lighting systems using secondary optics in the form of a flat mirror surface. The results of studies of high-power LED light sources with different emitting surface areas and with three proposed options for fixing a flat mirror surface are presented. It is shown experimentally that the optical system for LED light sources in the form of a flat mirror surface allows changing the luminous intensity curve of LED light sources, converting it in a given plane from a cosine to a concentrated one. This is how the Flat Beam lighting technology is realized. Variants of the practical application of this lighting technology obtained by using a flat mirror surface with LEDs are also proposed.


2010 ◽  
Author(s):  
Xuan Li ◽  
Shangzhong Jin ◽  
Yanhua Wang ◽  
Songyuan Cen ◽  
Pei Liang ◽  
...  

2021 ◽  
Vol 15 (3) ◽  
pp. 28-34
Author(s):  
L. Yu. Yuferev

he properly selected lighting for livestock farms is noted to ensure the optimal productivity of bred animals and poultry and to generate profit for the enterprise. (Research purpose) The research purpose is to substantiate the parameters of energy-saving lighting for agricultural premises and to develop methods for its calculation. (Materials and methods)  It has been shown that greenhouse farms most often use high and low pressure sodium lamps for lighting, but their spectrum only partially substitutes the natural one. It has been assumed that expanding the spectrum and approximating it to the solar one could improve product quality and yield. It has been stated that incandescent and fluorescent lamps are traditionally used to illuminate livestock and poultry premises, but they cannot create a lighting system with a «dawn - sunset» function, and their spectrum does not correspond to the full range perceived by animals and birds. It has been noted that the LED light sources’ functioning has such features that make the application of standard calculation methods impossible. We obtained formulas for calculating the light level and flux of photons. (Results and discussion) We provided examples of applying the energy-saving lighting systems developed by us in poultry houses with floor housing system, in cowsheds with tethered housing system and in an experimental phyto-laboratory for growing seedlings. It has been found that after replacing the lighting system based on DRL-125 lamps with a new one, with 36 nine-watt LED lamps, the power consumption decreased from 2,250 to 336 watts, the average light level increased and amounted to 90 lux, while the  illumination uniformity and color rendition improved. We have developed a resonant power supply system for LEDs to create lighting systems with a «sunrise - sunset» function. (Conclusions)  We have shown the possibility and provided examples of using the developed by us energy-saving controlled lighting systems based on LED light sources. 


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