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High Dynamic Range Imaging (HDRI) techniques for luminance measurement is gaining importance in recent years. This paper presents the application of the HDRI system for obtaining the photometric characteristics of lighting fixtures as well to assess the quality of lighting in colour viewing booth of a printing press. The process of quality control of prints in a printing press is known as graphic...
This paper focuses on battery charging/discharging through a converter tied to the DC link. PV and wind energy power system are used as sources. This work aims to develop a model that depends on the state of charge of the battery to decide its state of operation. The filter and converter design has been carried out and simulation results have been reported. The paper looks into the aspects of system...
Building envelope plays a substantial role in the energy flows of the building. Pertinent selection of the façade can help in reducing the total energy demand of the building. This is ensured by analyzing the load on the HVAC and lighting systems. A three storied office building is modeled using the simulation program. Design builder to study the effect of various envelope parameters and dynamic shading...
Spectrometers measure optical power as a function of wavelength. Optical spectrum analysis is very important part of optical spectroscopy applications. The work documented in this paper gives a working knowledge of converting spectrographs to spectrograms using color space transformation techniques. In this work it is demonstrated that how a webcam spectrometer can be used to measure spectral composition...
LED lighting technology is advancing at fast pace, LED lighting products in the market show a wide range of performance characteristics. This work explains the need for trustworthy, fair product performance information to promote the market for LED lighting products. In this work more than 120 LED down lights were tested using industry-approved test procedures and summary of the results is presented...
Spectrometers measure optical power as a function of wavelength. Optical spectrum analysis is very important part of optical spectroscopy applications. A low cost DIY spectrometer can be created using DVD-R as diffraction grating and camera as the sensor. Pre-calibration of the DIY spectrometer using a mercury vapor based reference light source is essential. The work discussed in this paper is a proposed...
The work documented in this paper gives a working knowledge of mapping the spectral lines in the emission spectra of physical objects to their corresponding wavelengths. In simpler terms RGB triplets in the spectrogram image are mapped to their corresponding wavelengths on the visible spectrum. Peaks of CIE RGB color matching functions are directly mapped one on one to peaks of the R, G and B intensity...
The application of communication protocols and wireless networking techniques are recent advancements for energy efficient implementation of automatic adaptive lighting control system. A review of communication protocols and wireless networking systems for lighting control is presented in this paper. The frame structure, communication methods, topologies, protocol stack architecture of standard protocols...
This paper presents design and simulation of PV (Photovoltaic)and wind hybrid Energy system (WECS) in isolated mode of operation. The output voltage from two sources are given to DC link by using to DC-DC converters in order to maintain constant DC link voltage. Single phase Inverter with unipolar voltage switching is used. The Total Harmonic Distortion (THD) of load voltage is analyzed. This work...
As the operating temperature of a LED lighting product increases, quite a few performance parameters experience a short-term and recoverable shift. With increasing operating temperature of a LED lighting product, forward voltage reduces, luminous flux reduces, and the color characteristics change from the desired characteristics. Furthermore, maximum junction temperature of the LEDs in the lighting...
Recent advancement in solid state technology has made LED lighting energy-efficient and today it is one of the rapidly-developing lighting technologies. Design of LED lighting luminaires is still repeatedly governed by misinterpretations and inappropriate use of the related solid state lighting technology. Heat is generated as byproduct of the light generation process at the LED junction; this heat...
Operating junction temperature of LEDs is linked directly to lifetime, long term reliability and failure modes of LED luminaires. It is important to measure the operating junction temperature to assess the health of a LED luminaire / solid state lighting product. Measuring the junction temperature of LEDs is a difficult task as in modern LED luminaires the tiny LEDs are surrounded by optical system...
Use of HDR (High Dynamic Range) images for critical luminance studies is an established fact now. Luminance measurement has to be done using a camera which is calibrated. The calibration factor, relating the luminance measured from the HDR images and luminance measured using a device, say a luminance meter, can be calculated using several methods. At the outset of launching new direction for general...
A model based control is used to control a complex system which has a large settling time. The system that is shown in this paper is a drum boiler system integrated with a solar water heating system to provide pre-heated feed water as input to it. Thus, making a hybrid energy system where energy conservation is obtained by the use of solar energy in conventional thermal power plants. Matlab/Simulink...
CIE standard illuminants are important for testing, calibration, printing quality testing, spices color testing and other photometric and calorimetric applications. Currently, fluorescent light sources represent these illuminants giving fixed and broad illumination spectra. Installation of all fluorescent illuminants in a light booth for testing and calibration of light sources becomes difficult and...
As a result of rising concern of global warming and the depletion of fossil fuel reserves, many are looking at sustainable energy solutions to preserve the earth for the future generations. Environmentally friendly solutions are becoming more prominent than ever as a result of concern regarding the state of our deteriorating planet. This paper presents one of the alternate ways for the power generation,...
The lifetime of LED luminaires, made of high power LED arrays, operating under hostile conditions is determined by their thermal design, operating junction temperature and thermal transients managed by the thermal system. Thermal transient characterization is a noninvasive study of the thermal resistance characteristics or thermal design of the LED luminaire. This procedure can identify anomalies...
LED luminaires are extensively used in a variety of applications. The LEDs are driven by from fraction of an ampere to nearly one ampere. LED luminaires are required to operate at high temperatures, depending on the application. High-power LED luminaires generate too much heat. If the heat generated is not dissipated away from the LED device it will affect the useful operating life and color characteristics...
DALI, as an acronym, stands for Digital Addressable Lighting Interface. DALI is a concept that stands for an intelligent lighting management system that provides increased energy savings, easier installation and maintenance, and maximum control and retrofit flexibility -- in an entirely open standard. DALI is not a single product. It is an industry standard protocol that allows DALI-compliant components...
This work presents our effort to predict the long term reliability of LED arrays using the application of accelerated life testing principles. Assessment of long term reliability and performance of LED arrays is a testing exercise but it is also vital for successful acceptance of Solid State Lighting (SSL) systems. The objective of this work is to analyze IESNA LM-80 test data obtained from the LED...
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