DESIGN AND IMPLEMENTATION OF A PID-BASED LUMINANCE CONTROL AND LIGHT SENSING USING SMOOTHING AVERAGING TECHNIQUE

2016 ◽  
Vol 78 (6-3) ◽  
Author(s):  
Editha Macorol ◽  
Favis Joseph Balinado ◽  
Leo M. Flores ◽  
Ezekiel V. Pascual ◽  
Christian M. Silva ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Luminance Level ◽  
Light Sources ◽  
Averaging Technique ◽  
Light Emitting ◽  
Incandescent Light ◽  
Light Sensing ◽  
Light Stimuli ◽  
Compact Fluorescent Lamp ◽  
Global Energy Consumption

Nowadays, lighting shares a large part in the global energy consumption, lighting consumption can be easily reduced with the use of efficient light sources. The most commonly used light source is the incandescent light bulb. As time passed by, Compact Fluorescent Lamp and Light Emitting Diode use became prevalent because of their advantages over the incandescent light. The researchers were able to develop and implement a PID controlled lighting system using Light Emitting Diode utilizing the smoothing-averaging technique in its sensors. Tests were done with the system with and without smoothing technique to identify the effect of the technique used. The system automatically varies its light intensity output depending on the light stimuli maintaining the luminance level of the laboratory based on standards.

Human Factors Impacts of Light-Emitting Diode Airfield Lighting

2017 ◽  
Vol 2626 (1) ◽  
pp. 51-57 ◽  
Author(s):  
John D. Bullough
Keyword(s):  
Human Factors ◽  
Experimental Evidence ◽  
Energy Use ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Light Emitting ◽  
Incandescent Light ◽  
Color Identification ◽  
Lighting Systems ◽  
Maintenance Requirements

Light-emitting diodes (LEDs) differ from incandescent light sources in several ways that are relevant to energy and maintenance requirements of airfield lighting systems. They have higher luminous efficacy and, when designed properly, have longer useful operating lives; both factors make LEDs attractive candidates for airfield lighting. The photometric, colorimetric, and temporal characteristics of LEDs also differ from those of incandescent light sources, and these can have important implications for the appearance of runway and taxiway lighting systems. The present paper reviews publications summarizing experimental and analytical investigations designed to assess these implications with respect to the following human factors impacts: color identification, brightness and glare, visibility in fog and haze, response to onset of flashing lights, and stroboscopic effects such as the phantom array. Overall, this review of experimental evidence suggests that, in addition to their reduced energy use and maintenance requirements, LED airfield lighting can be advantageous in comparison with incandescent lighting systems used to delineate airport runways and taxiways.

scholarly journals Effectiveness of light emitting diode versus conventional phototherapy in neonatal hyperbilirubinemia: a hospital based observational study

2020 ◽  
Vol 8 (3) ◽  
pp. 1051
Author(s):  
Radheshyam Purkait ◽  
Manik Mondal
Keyword(s):  
Side Effects ◽  
Light Emitting Diode ◽  
Total Duration ◽  
Conventional Group ◽  
Light Sources ◽  
Fluorescent Lamp ◽  
Light Emitting ◽  
Led Phototherapy ◽  
Significant Difference ◽  
Compact Fluorescent Lamp

Background: The most commonly used light sources in the conventional phototherapy units are compact fluorescent lamp (CFL), halogen spotlights and fiberoptic blankets. Recently light emitting diodes (LED) has emerged as better light source for phototherapy and almost replacing all the available conventional light sources. Comparative studies on the efficacy of LED versus conventional phototherapy are limited from India. That is why; this study was undertaken.Methods: 48 neonates of ≥35 weeks gestational age with hyperbilirubinemia were participated in this study. Among them, 24 neonates received conventional phototherapy and rest of them received LED phototherapy. The rate of fall of bilirubin levels at 6 hours and at completion along with total duration of phototherapy in both groups was measured. Results analysed by standard statistical methods.Results: LED phototherapy units showed higher rate of fall in bilirubin at six hrs (LED group: 0.38±0.05 mg/dl/hr versus conventional group: 0.30±0.04 mg/dl/hr, p<0.05) and after completion of therapy (LED group:                      0.32±0.03 mg/dl/hr versus conventional group: 0.26±0.03 mg/dl/hr, p<0.05) compared to conventional group. Significant difference was documented in total duration of phototherapy in LED group (30.8±1.8 hours) when compared to conventional group (34.6±0.7 hours). None of the neonate showed phototherapy failure. Side effects were minimal and comparable in both the groups.Conclusions: The LED phototherapy units are more efficacious in terms of higher rate of fall of bilirubin levels and lesser duration of phototherapy compared to conventional phototherapy units.

scholarly journals Controlling Flowering of Photoperiodic Ornamental Crops with Light-emitting Diode Lamps: A Coordinated Grower Trial

2014 ◽  
Vol 24 (6) ◽  
pp. 702-711 ◽  
Author(s):  
Qingwu Meng ◽  
Erik S. Runkle
Keyword(s):  
Light Emitting Diode ◽  
Michigan State University ◽  
Light Sources ◽  
State University ◽  
Flower Bud ◽  
Light Emitting ◽  
Bedding Plant ◽  
Ornamental Crops ◽  
Greenhouse Growers ◽  
Compact Fluorescent Lamp

Photoperiodic lighting from lamps with a moderate ratio of red [R (600–700 nm)] to far-red [FR (700–800 nm)] light effectively promotes flowering of long-day plants (LDPs). Because of spectral controllability, long life span, and energy efficiency, light-emitting diodes (LEDs) have emerged as an alternative to conventional light sources, such as incandescent (INC) and high-pressure sodium (HPS) lamps. We conducted a coordinated trial with five commercial greenhouse growers to investigate the efficacy of R + white (W) + FR LEDs, with an R:FR of 0.82, to regulate flowering of daylength-sensitive ornamental crops. The trial was also performed in two replicate greenhouses at Michigan State University (MSU). Ageratum (Ageratum houstonianum), calibrachoa (Calibrachoa ×hybrida), dahlia (Dahlia ×hybrida), dianthus (Dianthus chinensis), petunia (Petunia ×hybrida), snapdragon (Antirrhinum majus), and verbena (Verbena ×hybrida) were grown under natural short days (SDs) with 4-hour night-interruption (NI) lighting provided by the R + W + FR LEDs or conventional lamps typically used by each grower. Two companies used HPS lamps, whereas the other sites used INC lamps. In addition, a natural SD treatment, a truncated 9-hour SD treatment, or a compact fluorescent lamp (CFL) NI treatment was provided at three different sites. With few exceptions, time to flower and flowering percentage of the bedding plant crops tested were similar under the R + W + FR LEDs to that under the conventional lamps at all sites. At MSU, ageratum, dianthus, petunia, snapdragon, and verbena flowered earlier under NI lighting treatments than under 9-hour SDs. In addition, plant height and visible flower bud or inflorescence number at flowering were similar under the R + W + FR LEDs and INC lamps for most crops. Therefore, we conclude that the R + W + FR LEDs are as effective as lamps traditionally used in greenhouses at controlling flowering of photoperiodic plants.

scholarly journals Proposed Safe Distance between Object & Artificial Light Sources in Historical Building or Museum in Terms of Conservation

2019 ◽  
Vol 9 (1) ◽  
pp. 4047-4052
Keyword(s):  
Light Emitting Diode ◽  
Light Sources ◽  
Main Body ◽  
Fluorescent Lamp ◽  
Historical Building ◽  
Light Emitting ◽  
Heritage Building ◽  
Compact Fluorescent Lamp ◽  
Ultraviolet Ray ◽  
Living Objects

It is well known fact that light is associated with its neighbouring spectrum of Ultraviolet ray (UV ray). UV has deleterious effects upon living and non-living objects. In order to avoid this bad effect of UV some simplified methods to need to try out. Experimentation has been carried out with Incandescent lamp, Conventional Fluorescent lamp, Compact Fluorescent Lamp (CFL) and Light Emitting Diode (LED) lamps and separately UV content as well as illuminance at various distances have been measured. UV-measurement has been made by UV meter made through world reputed make- Konica Minolta, Japan and illuminance is measured by Lux-Meter. The observations have been shown in the main body of the paper which shows successful results as per expectations. The system can be adopted for Museum lighting where important archives can be saved from bad effects of emitted UV from the ambient light sources. This simple methodology can thus be adapted for indoor application in Museum lighting/ Heritage building lighting where archives can be easily conserved.

Electrically driven single microribbon based near-infrared exciton-polariton light-emitting diode

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mingming Jiang ◽  
Fupeng Zhang ◽  
Kai Tang ◽  
Peng Wan ◽  
Caixia Kan
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Coherent Light ◽  
Light Emitting ◽  
Exciton Polaritons ◽  
Laser Devices

Achieving electrically-driven exciton-polaritons has drawn substantial attention toward developing ultralow-threshold coherent light sources, containing polariton laser devices and high-performance light-emitting diodes (LEDs). In this work, we demonstrate an electrically driven...

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.

In-Use Photostability Practice and Regulatory Evaluation for Pharmaceutical Products in an Age of Light-Emitting Diode Light Sources

2019 ◽  
Vol 108 (3) ◽  
pp. 1172-1176 ◽  
Author(s):  
Leonardo R. Allain ◽  
Brittany C. Pierce ◽  
W. Peter Wuelfing ◽  
Allen C. Templeton ◽  
Roy Helmy
Keyword(s):  
Light Emitting Diode ◽  
Pharmaceutical Products ◽  
Light Sources ◽  
Light Emitting ◽  
Regulatory Evaluation

Manufacture and Evaluation of Light Emitting Diode Package Substrate Using Flexible Printed Circuit Board

2015 ◽  
Vol 15 (10) ◽  
pp. 7578-7581
Author(s):  
Jung-Kab Park ◽  
Jin-Ha Shin ◽  
Mun-Gi Jung ◽  
Tomabechi Shigehisa ◽  
Hwa-Sun Park ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Light Emitting Diode ◽  
Thermal Conductance ◽  
Polyimide Film ◽  
Luminous Efficiency ◽  
Circuit Board ◽  
Light Sources ◽  
Thermal Shock Test ◽  
Light Emitting ◽  
Au Electrode

Unlike other light sources such as fluorescent lamps and incandescent bulbs, light-emitting diodes (LED) convert 70∼80% of energy into heat. If the heat produced an LED chip is not effectively released, its luminous efficiency and lifespan are reduced. Therefore, as a method effectively release heat, an LED PKG substrate containing a heat-releasing material with excellent thermal conductance was fabricated, and its thermal resistance and luminous efficiency were analyzed. In this experiment, a thin polyimide film with excellent ductility was used to fabricate the LED PKG substrate. A 35-μm-thick Cu foil with excellent thermal conductance was subjected to high temperature and pressure and attached to both sides of the polyimide film. By electroplating Ag or Au, which has excellent thermal conductance, for us as the electrode and heat-releasing material, LED PKG substrate was fabricated with a thickness of approximately 170 μm. (−40 °C → RT → 120 °C). The results revealed that the LED PKG substrate having a Ag electrode with excellent thermal conductance had an excellent thermal resistance of approximately 4.2 °C/W (Au electrode: 5.6 °C/W). The luminous flux after 100 cycles in the thermal shock test was reduced by approximately 0.09% (Au electrode: 2.77%), indicating that the LED PKG substrate had excellent thermal resistance without any mechanical and material defects in a rapid-temperature-changing environment. The advantages and excellent thermal resistance can be exploited in cellular phones and LCD panels, and heat-releasing problems in thin panels be solved.

scholarly journals Analysis of Energy and Cost Performance of Retrofitting Fluorescent Tubes with Compact Fluorescent and Light Emitting Diode Lamps

2020 ◽  
pp. 34-46 ◽  
Author(s):  
J. S. Adeleke ◽  
A. B. Wahab ◽  
E. A. Olanipekun
Keyword(s):  
Light Emitting Diode ◽  
Electricity Consumption ◽  
Poor Performance ◽  
Payback Period ◽  
Optimal Performance ◽  
Light Emitting ◽  
Tertiary Institutions ◽  
Fluorescent Lamps ◽  
Significant Difference ◽  
Compact Fluorescent Lamp

Over the years, visual comfort has been described as a major requirement needed to enhance optimal performance of occupants in any learning environment in tertiary institutions. This is reflected in the poor performance of the commonly used Fluorescent Lamps (FL) occasioned by its constant burn-off, high failure rate and reduced durability. Hence, there is a shift to the adoption of Compact Fluorescent Lamp (CFL) and Light Emitting Diode (LED). This study therefore examined the pattern of electricity consumption involving the adoption of FL, CFL and LED in the purposively selected lecture theatres of Obafemi Awolowo University, Ile-Ife, Nigeria. The study was carried out using energy monitor to obtain the consumption data of the lamps for periodic logging at intervals of 1 hr, 3 hrs, 6 hrs, 12 hrs, 1 day, 7 days, 1 month and 3 months respectively; and also to determine the payback period of each of the lamps. From the data collected, patterns of electricity used, electricity savings were calculated and compared to establish performance potentials of each of the lamps. The study found that there was a significant difference in the pattern of electricity consumption of FLs compared with that of CFLs and LEDs, but a reduced margin existed between CFLs and LED lamps. It showed that the FLs consumed 681.576 kWh, 1619.466 kWh and 5652.432 kWh, CFLs consumed 387.302 kWh, 692.479 kWh and 1936.600 kWh, while LED consumed 294.188 kWh, 426.608 kWh and 1499.015 kWh. There were significant differences in consumption with 43, 47 and 65% reduction in electricity consumption using CFLs while 57, 73 and 73% using LED fittings were obtained. The CFLs performed better in terms of return on investments by having a lower payback period when compared to LED. The study concluded that replacing FL with CFL and LED would be desirable option in order to enhance optimal performance of lecture theatres, but in terms of payback period, it would be beneficial to retrofit FLs with CFLs.

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