scholarly journals Calculation of the thermal mode of the LED device

Author(s):  
Natalia Kulik ◽  
Jakov Danchenkov

The problem of heat removal from the substrate of LED light sources is considered. Modern methods of cooling of LEDs are reviewed. The calculation method is given and the radiator area for passive heat removal is calculated. The radiator was selected according to the given criteria.

Author(s):  
Sergey Sedykh ◽  
Dmitriy Gadashev ◽  
Alexandr Drakin

The analysis of some circuitry options that contribute to reducing the ripple of the light flux is carried out, as well as the modeling of the simplest and most intuitive LED lamp circuits for a more qualitative assessment of the result in the form of the given dependence of the ripple coefficient on the total capacitance of the capacitors included in the filter circuit.


2018 ◽  
pp. 3-8
Author(s):  
A. Kolesnyk ◽  
D. Usichenko ◽  
L. Nazarenko

LED lighting sources, appeared on the market in the 60s of the last century, are the most effective option and it is the fastest developing lighting technology for now. The problem of efficient heat removal from the LED becomes to be one of the basic ones. Due to high heat flux on the individual diodes surface, problems related to the light source cooling become to be one of the most. Modeling and thermal calculations are the solution to the problem of heat sink and maintenance of optimal thermal mode of operation of LEDs. One of the biggest drawbacks of LED lighting is the excessive price, so it is important to take into account the cost-effectiveness in selecting the components of the luminaire, and use the resour­ces correctly. In the conducted research the model of the LED light in the software complex has been designed and analyzed. And a real sample was made. As a rule, the corresponding photometric characteristics are determined depending on the field of application of the light device. In addition, the conditions of this coil are taken into account in the overload mode. Photometric characteristics and thermographic calculations for 75 W and 90 W have been measured. This proves the cost-effectiveness of a projected luminaire, using a power supply of Mean Well. The paper presents the results of light enginee­ring calculations and thermographic analysis of a sample LED device. Experimental and computational data have been compared and discussed.


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.


2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang

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.


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.


2016 ◽  
Vol 63 (21) ◽  
pp. 2151-2158 ◽  
Author(s):  
Zhenfeng Zhuang ◽  
Phil Surman ◽  
Feihong Yu

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