scholarly journals The Development of LED-Based Dental Light Using a Multiplanar Reflector Design

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Chi-Chang Hsieh ◽  
Yan-Huei Li
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
High Power ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
International Standards ◽  
Light Sources ◽  
Light Emitting ◽  
Standards And Regulations ◽  
Reduce Energy Consumption

A multiplanar reflector was designed to enhance the application efficiency of light-emitting diode (LED) light sources that can be employed as LED-based dental lights. This study used a high-power LED developed by Nichia, that is, a single LED capable of providing a total luminous flux of 120 lm, as the primarily light source to design and develop an LED-based dental light. This LED complies with the international standards and regulations stipulated in ISO 9680:2007. The light spots produced by the prototype were rectangular, with a length of 200 mm and a width of 100 mm. These light spots achieved maximum illumination of 12,000 lux. The use of LEDs can reduce energy consumption from 50 W to 3 W, providing an energy saving of more than 90%.

Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Temperature Cycling ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Interconnection Material

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.

scholarly journals IN VITRO DEVELOPMENT OF YELLOW LAPACHO (BIGNONIACEAE) USING HIGH-POWER LIGHT EMITTING DIODE

2018 ◽  
Vol 42 (5) ◽  
Author(s):  
Ezequiel Enrique Larraburu ◽  
Gonzalo Sanchez Correa ◽  
Berta Elizabet Llorente
Keyword(s):  
In Vitro Culture ◽  
High Power ◽  
Stomatal Density ◽  
Light Emitting Diode ◽  
Dry Weight ◽  
Light Sources ◽  
Multiplication Rate ◽  
Light Emitting ◽  
Shoot Dry Weight

ABSTRACT Handroanthus ochraceus (yellow lapacho) is a medicinal, ornamental and timber tree which can be propagated by in vitro culture. Conventional methods use fluorescent lighting (FL), whereas light emitting diode (LED) has been used for this purpose only recently. The aim of this work was to evaluate the effects of FL and high-power LED (HP-LED) on the in vitro multiplication and rooting of yellow lapacho at different irradiances (15 to 60 µmol m-2s-1). Epicotyls obtained from half-siblings was multiplicated in WPM (Woody Plant Medium) supplemented with 20 µM benzilaminopurine and 1 mM IBA (indolebutiric acid). For rooting, shoots were cultured for 3 days in ½WPM supplemented with 50 µM IBA and for 42 days in auxin-free ½WPM under HP-LED or FL lighting. Under HP-LED, the multiplication rate of shoots increased significantly (61%) from 20 to 40 µmol m-2s-1 respect to FL. Differences in abaxial stomatal density and size were observed between light sources at 20 µmol m-2s-1. High HP-LED irradiance produced the highest rooting percentage. In the rooting stage, the marginal means of treatments without factors interaction showed that HP-LED irradiances significantly increased shoot length by 20%, shoot fresh weight by 77% and shoot dry weight by 30% in comparison to the values under FL. The maximum values calculated from the regression curves were around 50 µmol m-2 s-1 for HP-LED for all parameters except root lenght whereas were around 20 µmol m-2 s-1 for FL for all parameters except fresh and dry weigth of shoot. Here we show that HP-LED lighting improve in vitro culture of H. ochraceus, reduced 81% energy consumption respect to FL and uses only a multispectral LED instead of different single color LEDs. Therefore, HP-LED could be useful for the micropropagation of tree species contributing to sustainable agriculture and ecological restoration of degraded areas.

scholarly journals Comparison of Intracanopy Light-emitting Diode Towers and Overhead High-pressure Sodium Lamps for Supplemental Lighting of Greenhouse-grown Tomatoes

2013 ◽  
Vol 23 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Celina Gómez ◽  
Robert C. Morrow ◽  
C. Michael Bourget ◽  
Gioia D. Massa ◽  
Cary A. Mitchell
Keyword(s):  
High Pressure ◽  
Energy Consumption ◽  
Energy Savings ◽  
Light Emitting Diode ◽  
Significant Proportion ◽  
Fruit Production ◽  
Light Sources ◽  
Node Number ◽  
Light Emitting ◽  
Supplemental Lighting

Electric supplemental lighting can account for a significant proportion of total greenhouse energy costs. Thus, the objectives of this study were to compare high-wire tomato (Solanum lycopersicum) production with and without supplemental lighting and to evaluate two different lighting positions + light sources [traditional high-pressure sodium (HPS) overhead lighting (OHL) lamps vs. light-emitting diode (LED) intracanopy lighting (ICL) towers] on several production and energy-consumption parameters for two commercial tomato cultivars. Results indicated that regardless of the lighting position + source, supplemental lighting induced early fruit production and increased node number, fruit number (FN), and total fruit fresh weight (FW) for both cultivars compared with unsupplemented controls for a winter-to-summer production period. Furthermore, no productivity differences were measured between the two supplemental lighting treatments. The energy-consumption metrics indicated that the electrical conversion efficiency for light-emitting intracanopy lighting (LED-ICL) into fruit biomass was 75% higher than that for HPS-OHL. Thus, the lighting cost per average fruit grown under the HPS-OHL lamps was 403% more than that of using LED-ICL towers. Although no increase in yield was measured using LED-ICL, significant energy savings for lighting occurred without compromising fruit yield.

Heat Transfer Enhancement of the Liquid-Cooled LED Illumination Module

2013 ◽  
Vol 284-287 ◽  
pp. 768-772 ◽  
Author(s):  
Rong Yuan Jou
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Sources ◽  
The Finite Element Method ◽  
Liquid Cooling ◽  
Light Emitting ◽  
A Tec ◽  
Heat Sink Design ◽  
Temperature And Flow Fields

High-power light emitting diode (LED) modules offer several advantages over conventional light sources, but require effective thermal management for optimal performance, such as liquid cooling or thermoelectric cooling (TEC). This study compared the thermal performance of high-power LEDs with liquid cooling and TEC using both the finite element method and experiments. We considered a mutichip module in which the LEDs are immersed in one of three different cooling fluids in a metal enclosure with passive cooling or a TEC module. In the experiments, temperatures were measured by thermocouples. The temperature and flow fields of the liquid-cooled package inside the enclosure were analyzed in detail using a numerical model, and the results were validated against the experimental measurements. In this paper, we discuss the major design considerations when using liquid cooling and TEC. Our results show that for the illumination module considered in this study, appropriate heat sink design is crucial to optimizing performance with TEC, which can enhance the heat dissipation for small and compact LED modules.

Case Study for Replacement of Conventional Lights by Led Lights

2019 ◽  
Vol 7 ◽  
pp. 44-51
Author(s):  
Indu Duwal
Keyword(s):  
Energy Saving ◽  
Energy Demand ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Demand And Supply ◽  
Light Emitting ◽  
Return Of Investment ◽  
Science Group ◽  
Led Lights

With the increment in the gap between the demand and supply of energy, various alternatives for decreasing the demand of energy are major concern for the various stakeholders. In order to decrease the energy demand by lighting various energy efficient lights are available in market. However it is difficult to convince the residents to change conventional artificial light sources, since lighting system is an essential part in the building which ensures the comfort, productivity and safety of the occupants in the buildings. Among the various Light Emitting Diode (LED) lights are termed as one of the most efficient energy saving lights which aims to save almost more than 50 % of energy demand than that of CFL lights with same power of illumination. Hence, this study is carried out to calculate energy saving percentage after replacing the conventional lights like florescent, mercury lights and other forms of conventional lights by LED lights. Additionally the study also was focused to evaluate feasibility of the replacement of lights by LED lights in terms of energy saving and return of investment. The research was carried out in building used by Agrotechnology and Food Science (AFSG) science group of Wageningen University in the Netherlands. The results from the study showed that almost 50% of the energy can be saved after replacement by LED lights with around 5 years for return of investment. However, factors like 1) Number of operating hours, 2) Price of lights, 3) Energy cost, 4) Labour cost for replacement and adjustment and 5) Number of replacement and adjustment per hour are the influential features that effects in the performance of various types of lights

scholarly journals Model Parameter Identification and Validation for Energy Saving Light Bulbs

2020 ◽  
Vol 19 ◽  
Keyword(s):  
Energy Saving ◽  
Light Emitting Diode ◽  
Electrical Energy ◽  
Frequency Domain Analysis ◽  
Model Parameters ◽  
Light Sources ◽  
Fast Analysis ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
Harmonic Components

Due to electrical energy reduction need, in the recent years, alternative light sources like Compact Fluorescent Lamps (CFL) and Light Emitting Diode lamps (LED) are replacing the classical incandescent light bulbs. Although they consume less power, these lamps have the disadvantages of being a significant source of harmonics. This means that the lightning network should be redesigned taking into account the magnitude of the current harmonic components and of the null current. To this aim, an accurate model easy to build and a fast analysis are very useful. This paper presents three models for different types of energy saving light bulbs, two existing ones and a new implementation, a procedure for model parameters identification and a comparison of the models. Some errors criteria are considered, both qualitative and quantitative. The periodic steady state response is computed using a frequency domain analysis.

scholarly journals Study of Temperature Effect on Luminous Flux of High Power Chip on Board Light Emitting Diode

2014 ◽  
Vol 24 (3) ◽  
pp. 267
Author(s):  
Cao Xuan Quan ◽  
Vu Khanh Xuan ◽  
Luu Thi Lan Anh ◽  
Vo Thach Son
Keyword(s):  
Solid State ◽  
Temperature Effect ◽  
Measurement System ◽  
High Power ◽  
Light Emitting Diode ◽  
Flux Measurement ◽  
Luminous Flux ◽  
Light Emitting

High power chip on board light emitting diode (HPCOBLED) are a promising solid state light technology for a variety of lighting applications. In this study, we studied temperature effect on luminous flux of HPCOBLED using VMI-PR-001 system of Vietnam Metrology Institute. The results according to the temperature Tc is increasing, luminous flux reduced. Especially HPCOBLED is larger power, decreasing luminous flux is larger. Reason of this is chance power.   HPCOBLED model describes the temperature affection on luminous flux of HPCOBLED. The results of HPCOBLED model matched with that measured by the luminous flux measurement system (VMI-PR-001, Vietnam).

Performance Analysis of Various Types of High Power Light Emitting Diodes

2018 ◽  
pp. 91-98 ◽  
Author(s):  
Kamalika Ghosh ◽  
Debashis Raul
Keyword(s):  
High Power ◽  
Light Emitting Diode ◽  
Life Time ◽  
Effect Of Temperature ◽  
Light Sources ◽  
Test Results ◽  
Light Emitting ◽  
Tropical Countries ◽  
Cause Of Failure ◽  
Very High

Solid state, energy efficient light emitting diode (LED) technology is coming up to replace the conventional gas discharge, etc. light sources. Although declared life of LED is very high but in tropical countries their life time appears very short. This phenomenon is becoming the most drawbacks for usage of LED. To search out the reason for the failure lead to undertake thorough study on the performance of LED specifically on the various environmental conditions. Experimentation was carried out with various types of commercially available high power LED. Failure in tropical countries may be due to effect of temperature. Test results have been noted at various major parts of LEDs, e.g. die, and sink area. Detail analysis of test results at various parts of LEDs in different conditions tends to have some idea about the cause of failure of the LEDs in tropical countries with high ambient temperature and less scope of heat generation by the light source.

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.

scholarly journals Application of Electric Energy Saving Light Source and Light Emitting Diode in the Landscape of Buildings under Optical Spectroscopy Theory

2021 ◽  
Vol 2083 (2) ◽  
pp. 022104
Author(s):  
Xiaojing Shi
Keyword(s):  
Energy Saving ◽  
Environmental Protection ◽  
Quantitative Research ◽  
Light Emitting Diode ◽  
Electric Energy ◽  
Light Sources ◽  
Light Emitting ◽  
High Rise ◽  
High Rise Building ◽  
Selection Of

Abstract How to reflect energy conservation and environmental protection in the landscape of high-rise buildings is a hot topic of current research. How to use environmentally friendly materials to show the charm of high-rise building landscape is the main content of this article. Based on the colour samples of the high-rise building landscape, the thesis uses environmental protection and energy-saving light sources to simulate the lighting of the building colour samples in the laboratory. This article realizes the quantitative research on the colour authenticity performance of colour paintings under commonly used LEDs in high-rise building landscapes, and provides a reliable basis for the selection of LEDs in colour painting lighting design.

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