scholarly journals Development of portable device for measurement of dynamic and static light-emission WOLED characteristics

2021 ◽  
Vol 1 (1(57)) ◽  
pp. 30-33
Author(s):  
Ihor Helzhynsky ◽  
Stepan Kutsiy ◽  
Andriy Veryha ◽  
Khrystyna Ivaniuk ◽  
Taras Dudok
Keyword(s):  
Light Source ◽  
Data Exchange ◽  
Light Emission ◽  
Spectral Characteristics ◽  
Light Flux ◽  
Luminous Flux ◽  
Visible Range ◽  
Light Sources ◽  
Measuring Device ◽  
Routine Work

The research object of this work is the parameters of organic light-emitting diodes, namely power and luminous flux. Determination of these parameters can be carried out using a photodiode and requires measuring the dark current of the sensor (photodiode), measuring the current of the photodiode when illuminated by the LED under investigation. And also take into account the relationship between the light flux received by the sensor and its output current, and take into account the spectral characteristics of the sensor. Calculate the investigated parameters of the LED based on the measurements. Carrying out these measurements requires laboratory instruments and workplace organization, and further calculations are routine work. It is possible to increase the measurement accuracy by improving the existing methods for measuring the required parameters, and it is possible to automate the process of measurements and calculations using a modern microprocessor radioelement base. Microcontrollers are widespread such radioelements. They have the necessary peripherals for independent operation and have sufficient computing power to implement the required measuring device. Its application makes it possible to automate the measurement process, carry out the necessary calculations, save correction constants, accumulate and process the obtained data, analyze these received data, exchange data with a computer, etc. So, the work is aimed at developing a methodology that will allow the simultaneous measurement of power and luminous flux of planar light sources. And also on the feasibility of this technique in the device and software with the ability to measure the power of the light source in an arbitrary band of the spectral visible range. Thus, it is possible to determine what power in watts a light source emits with the dynamics of supply currents in the optical bands, knowing the spectrum of this source without using glass filters. So, the result of applying the technique is to determine the power of light radiation (in watts) or the luminous flux (in lumens) of the emitter (light sources).

scholarly journals Influence of a Light Source Installed in a Luminaire of Opal Sphere Type on the Effect of Light Pollution

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 306 ◽  
Author(s):  
Przemyslaw Tabaka ◽  
Pawel Rozga
Keyword(s):  
Light Source ◽  
Spectral Distribution ◽  
Spectral Characteristics ◽  
Measurement Data ◽  
Luminous Flux ◽  
Light Pollution ◽  
Light Sources ◽  
Pollution Effect ◽  
The Impact ◽  
Effect Of Light

The article presents the results of the studies concerning the influence of a light source installed in luminaire of opal sphere type on the light pollution effect of the night sky. It is known from literature reports that the effect of light pollution is influenced by the spectral distribution of light. Although the influence of the spectral distribution has been widely studied from different perspectives, there is still a need to study this phenomenon—for example, from the point of view of the spectral reflection properties of the ground, on which the lanterns are installed. Hence, the above-mentioned aspect was considered in the authors’ investigations. The luminaire considered has been equipped with 20 different light sources, including the latest generation of lamps (light-emitting diodes, LEDs) as well as the conventional ones. With respect to these light sources, the measurements of light distribution and spectral distribution of emitted radiation of the luminaire were performed. Having these measurement data, the simulations were carried out using the DIALux software, and the calculations were made using the specially prepared calculation tool. On the basis of the results obtained in this way this was stated that the type of light source installed in the luminaire has a significant effect on the sky glow. An important factor affecting light pollution is not only the value of the luminous flux emitted upward but also the spectral characteristics of the emitted radiation, the impact of which is most noticeable. The conclusions from the studies indicate the next steps in the analysis of the light pollution effect. These steps will be focused on extended analysis of LEDs as modern and developed light sources.

scholarly journals Elimination of the blinding effect in landscape luminaires

2018 ◽  
Vol 7 (2.13) ◽  
pp. 252
Author(s):  
Albert Ashryatov ◽  
Dinara Churakova
Keyword(s):  
Light Curve ◽  
Light Source ◽  
Light Flux ◽  
Light Distribution ◽  
Light Sources ◽  
Mirror Surface ◽  
Light Emitting ◽  
Lighting Technology ◽  
Initial Task ◽  
Flat Beam

The article presents one of the possible options for implementing the lighting technology "Flat beam" for landscape lighting purposes. One of the possible ways to control the light distribution of a number of light sources based on LEDs with different radiation patterns is considered. As a secondary optics, it is proposed to use a mirror surface that redistributes the light flux of an LED light source. It is indicated that, depending on the initial type of the light-emitting diodes light curve and the features of mounting the mirror surface, the resulting light distribution can vary widely, depending on the initial task that the designer sets for himself.  

scholarly journals Mesopic Photometry and Street Lighting

2019 ◽  
pp. 67-72
Author(s):  
L. Nazarenko ◽  
H. Kononenko ◽  
Т. Mozharovska ◽  
V. Chernets
Keyword(s):  
Traffic Safety ◽  
Spectral Characteristics ◽  
Luminous Flux ◽  
Maximum Efficiency ◽  
Light Sources ◽  
Photometric System ◽  
Street Lighting ◽  
Factors Affecting ◽  
The Road ◽  
Lighting Systems

The article reveals the question of achieving security for people on the streets at night with the help of artificial lighting. The author analyzed the factors affecting traffic safety and the possibility of creating the necessary visual conditions for this by means of street lighting. In addition, the article raised an important question regarding the characteristics of the roadway. It is noted that the modern pavement is not standardized on the lighting characteristics. Knowing the spectral characteristics of the applied light sources, these data could be applied in the development of new types of canvases that would allow achieving a new level of illumination in terms of both improving the quality and its efficiency and economy. Without this, it is impossible to talk about the maximum efficiency of the use of the luminous flux as a whole. For existing lighting systems, the brightness calculation is performed by measuring the illumination and reflectivity of the road surface. The obtained brightness values are entered into the mesopic photometric system in order to determine the parameters of the complete system, which provides equivalent visual perception of the illuminated objects and is intended to replace the existing installation. To determine the required lamp power when replacing existing luminaires, it is recommended to use a mesopic photometric system, which allows you to perform calculations taking into account the S/P ratios. In this regard, it is necessary to thoroughly review the computer programs used in the creation of the lighting project, as well as to ensure active participation in international cooperation in the formation of modern lighting standards.

scholarly journals Quantitative express estimation of humine and fulvo acids content in aqueous solutions by photo-stimulated luminescence

2018 ◽  
Keyword(s):  
Quantum Yield ◽  
Dynamic Range ◽  
Light Flux ◽  
Low Noise ◽  
Light Sources ◽  
Colloidal Systems ◽  
Colloidal Solutions ◽  
Measuring Device ◽  
Light Emitting ◽  
Quantum Yield Of Luminescence

The work substantiates the expediency of using the methods of recording the quantum yield of luminescence of humic and folic compounds in the process of determining the relative concentrations of these substances in aqueous and colloidal solutions. The efficiency of using modern high-power ultraviolet semiconductor light sources with high monochromaticity of light flux has been proved, followed by the registration of reviews of the samples under investigation with the help of a low-noise semiconductor photodetector with a connected operational amplifier, which allows to provide a wide dynamic range of current and voltage measurements. The subject of the study is the process of recording the quantitative and qualitative parameters of the se- lected chemical compounds in colloidal systems in the liquid phase developed in the course of research by the model of the measuring instrument. The novelty of the work is to improve the classical methods for recording the quantum yield of lumines- cence, using a modern element base and testing the model of a measuring device with powerful ultraviolet light-emitting diodes as a light source and low-noise photodetector with a clear dynamic range designed for recording the quantum yield of luminescence of the samples under investigation.

scholarly journals Calibration of an Autonomous Instrument for Monitoring Light Pollution from Drones

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5091 ◽  
Author(s):  
Pietro Fiorentin ◽  
Carlo Bettanini ◽  
Damiano Bogoni
Keyword(s):  
Light Emission ◽  
Imaging System ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Light Flux ◽  
Ground Level ◽  
Horizontal Resolution ◽  
Light Pollution ◽  
Light Sources ◽  
Emission Measurement

The paper presents the calibration activity on the imaging system of the MINLU instrument, an autonomous sensor suite designed for monitoring light pollution using commercial off-the-shelf components. The system is extremely compact and with an overall mass below 3 kg can be easily installed as a payload for drones or sounding balloons. Drones and air balloons can in fact play an important role in completing upward light emission measurement from satellites allowing an increased spatial and time resolution from convenient altitudes and positions. The proposed system can efficiently measure the luminous intensity and the spectral power density of on-ground emissions providing a useful tool to identify polluting sources and to quantify upward light flux. The metrological performance of the imaging system has been verified through an extensive laboratory test activity using referenced light sources: the overall uncertainty of the multi-luminance meter has been calculated to be 7% of the reading, while the multi-spectrometer has shown a full width at half maximum (FWHM) equal to 10 nm within the measuring range between 400 nm and 700 nm. When operating at an altitude of 200 m, the system can achieve a horizontal resolution at a ground level of 0.12 m with a wavelength resolution able to identify the different lamp technology of outdoor light sources, including light-emitting diode (LED) lights that are undetected by satellites.

scholarly journals Lifetime Prediction method of LED Light-emitting Device Based on Approximate Analysis

2021 ◽  
Vol 271 ◽  
pp. 01031
Author(s):  
Cai Wenting ◽  
Li Sheng ◽  
Meng Qinghui ◽  
Huang Haisong
Keyword(s):  
Approximate Method ◽  
Light Source ◽  
High Efficiency ◽  
Light Flux ◽  
Prediction Method ◽  
Light Sources ◽  
Light Emitting ◽  
Led Light ◽  
Long Life ◽  
Application Requirements

Compared with other light sources, LED light source has a longer service life and will not suddenly fail. Due to its high efficiency, energy saving and long life, LED has become the most popular light source at present. However, it is no longer considered to meet the application requirements, and the time that the light flux decays to this level is considered to be the life of the LED. This paper introduces the approximate method used to predict the lumen maintenance life of LED lamps. The experimental results obtained by the approximate method are compared with the TM-21 standard. Eventually, it is concluded that the approximate method provides more reliability information than the original TM-21 standard, and the obtained results are more reference, more accurate and more reliable.

scholarly journals Molecular Emitters as a Tunable Light Source for Optical Multisensor Systems

2021 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Anastasiia Surkova ◽  
Aleksandra Paderina ◽  
Andrey Legin ◽  
Elena Grachova ◽  
Dmitry Kirsanov
Keyword(s):  
Surface Water ◽  
Emission Spectrum ◽  
Light Source ◽  
Visible Range ◽  
Light Sources ◽  
Multisensor Systems ◽  
Phosphate Quantification ◽  
Analytical Device

In this study, optical multisensor systems based on molecular emitters as a light source are introduced. To obtain such light sources, cyclometalated Ir(III) complexes and Cu(I)-based complexes were synthetized and investigated. Since each complex has its own emission spectrum in the visible range, it is possible to choose an appropriate set of emitters for specific analytical tacks. The developed analytical device was successfully applied for fluoride and phosphate quantification in surface water.

scholarly journals Light Ripples and their Effects per Person and per Bird

2021 ◽  
Vol 247 ◽  
pp. 01040
Author(s):  
Dmitry Gladin ◽  
Alexey Kavtarashvili
Keyword(s):  
Rapid Development ◽  
Physiological State ◽  
Light Flux ◽  
Luminous Flux ◽  
Light Sources ◽  
Led Lighting ◽  
Lighting Systems ◽  
Technical Features ◽  
The Impact ◽  
Poultry Farming

The article discusses the influence of light pulsation on the physiological state of humans and birds, some aspects of its occurrence, the main characteristics and the alleged role in the deterioration of chickens’ zootechnical indicators under the conditions of using light sources with light flux pulsations of different frequencies. The current state of lighting equipment in poultry farming is characterized by the rapid development of technologies and the active introduction of LED lighting. Having undeniable advantages, LED lighting systems have some technical features that are currently insufficiently studied and can affect the zootechnical indicators of poultry. A clear definition of the threshold values of the characteristics of the pulsation of illumination in the poultry house will make it possible to produce lighting equipment for poultry farming with a safe value of the pulsations of the luminous flux of light sources in their composition. The analysis of numerous literature sources has shown that the influence of light pulsation on the physiological state of humans and zootechnical indicators in birds is associated with a complex effect, depending on such characteristics as the depth and frequency of the pulsation of the light flux of light sources. Despite some differences in the values of the threshold impact of light pulsation, the nature of its impact is similar in humans and birds, which allows us to develop and apply targeted measures to reduce the impact of light pulsation on poultry and the deterioration of its zootechnical indicators.

MODELLING OF VERTICAL SURFACES RADIATION IN CONNECTION WITH THE EVALUATION OF THE OBTRUSIVE LIGHT

2021 ◽  
Author(s):  
P. Becak ◽  
T. Novak
Keyword(s):  
Light Source ◽  
Distribution Curve ◽  
Field Measurements ◽  
Active Surface ◽  
Vertical Surface ◽  
Luminous Flux ◽  
Real Field ◽  
Light Sources ◽  
The Real ◽  
The Creation

The issue of the luminous flux radiation to the upper hemisphere is very broad and complex. The paper deals with the modelling of the vertical surface radiators. It presents an approach to unify the behaviour of these types of light sources. These will be understood as cosine radiators. If this cosine distribution curve is taken into account, then only the luminance and the light-active surface can be known to supplement the information about the radiation of such the light source. The luminance and radiated surface can be obtained relatively easily from real field measurements. The article presents the implementation of this data into lighting calculations and the creation of the distribution curves which are necessary for the radiation calculations of these surfaces. It also analyses the influence of the luminance and active areas on the radiated luminous flux and assign these values to the real radiators.

Effect of different soldering temperatures on the properties of COB light source

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhao Wang ◽  
Yuefeng Li ◽  
Jun Zou ◽  
Bobo Yang ◽  
Mingming Shi
Keyword(s):  
Light Source ◽  
Void Ratio ◽  
Light Attenuation ◽  
Luminous Flux ◽  
Luminous Efficiency ◽  
Junction Temperature ◽  
Light Sources ◽  
Content Type ◽  
Soldering Temperature ◽  
Practical Engineering

Purpose The purpose of this paper is to investigate the effect of different soldering temperatures on the performance of chip-on-board (COB) light sources during vacuum reflow soldering. Design/methodology/approach First, the influence of the void ratio of the COB light source on the steady-state voltage, luminous flux, luminous efficiency and junction temperature has been explored at soldering temperatures of 250°C, 260°C, 270°C, 280°C and 290°C. The COB chip has also been tested for practical application and aging. Findings The results show that when the soldering temperature is 270°C, the void ratio of the soldering layer is only 5.1%, the junction temperature of the chip is only 76.52°C, and the luminous flux and luminous efficiency are the highest, and it has been observed that the luminous efficiency and average junction temperature of the chip are 107 lm/W and 72.3°C, respectively, which meets the requirements of street lights. After aging for 1,080 h, the light attenuation is 84.64% of the initial value, which indicates that it has higher reliability and longer life. Originality/value It can provide reference data for readers and people in this field and can be directly applied to practical engineering.

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