scholarly journals The Circadian Effect Versus Mesopic Vision Effect in Road Lighting Applications

2020 ◽  
Vol 10 (19) ◽  
pp. 6975
Author(s):  
Min Li ◽  
Peiyu Wu ◽  
Jianhua Ding ◽  
Qi Yao ◽  
Jiaqi Ju
Keyword(s):  
Threshold Value ◽  
Lighting Design ◽  
Color Temperature ◽  
Light Sources ◽  
Good Strategy ◽  
Significant Issue ◽  
Mesopic Vision ◽  
Road Lighting ◽  
Circadian Effect

Several models on the circadian effect have been applied to indoor circadian lighting design, but applications in road lighting have not yet been clarified. Based on existing models and circadian research, we examined equivalent melanopic lux (EML), circadian light (CLA), and circadian stimulus (CS) representing the circadian effect and the S/P ratio representing the mesopic vision effect, among a dataset of light sources at photopic adaptation illuminance values of 1, 3, 10, 30, and 100 lx. The results show that the S/P ratio correlates with EML and CS (or CLA) much stronger than it correlates with color temperature. The EMLs of light sources are below 50 EML in mesopic vision, and the CSs of most light sources are below or around the threshold value of 0.05. We conclude that the circadian effect is not a significant issue in mesopic vision under most conditions and that optimization for mesopic efficiency is still a good strategy. There are quite a few light sources that may achieve both ideal mesopic efficiency and low CS. This work clarifies the circadian effect and mesopic vision effect performance of light sources in mesopic vision and will help guide choosing suitable light sources and optimization strategies for road lighting.

scholarly journals The Influence of Luminaire Photometric Intensity Curve Measurements Quality on Road Lighting Design Parameters

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3301
Author(s):  
Dariusz Czyżewski ◽  
Irena Fryc
Keyword(s):  
Spectral Sensitivity ◽  
Measurement Errors ◽  
Spectral Composition ◽  
Lighting Design ◽  
Color Temperature ◽  
Design Stage ◽  
Design Parameters ◽  
Intensity Curve ◽  
Road Lighting ◽  
Typical Measurement

This article presents the research on a road lighting design. In this kind of design for a specific type of a roadway, the number and spacing of luminaires are calculated on the basis of luminaire photometric parameters such as intensity curve (LPIC) and luminous flux. The values of these parameters are measured using the luxmeter, i.e., a measuring instrument in which the spectral sensitivity should imitate spectral sensitivity of the human eye V(λ). However, the luxmeter’s spectral sensitivity S(λ) is not perfectly matched with the required one and varies for different instruments, resulting in measurement errors. To avoid this measurement error, the spectral mismatch correction factor (SMCF) should be applied to luxmeter’s readings. For a given luxmeter, the SMCF values depend on the measured light’s spectral composition SPD (described also by the lamp’s correlated color temperature CCT). Unfortunately, many laboratories do not apply SMCF to their luxmeter readings. Typical measurement laboratories are not in possession of SMCF data as this kind of data is hard to obtain and can be provided only by the state-of-the-art photometric laboratories for a high cost. Consequently, these typical measurement laboratories provide inaccurate LPIC data to costumers. In this article, it has been shown that a design process of road lighting installations needs to be based on lighting fixture LPIC’s measurements with SMCF values being taken into account. Omitting this fact may result in road lighting installation made on the basis of a design utilizing incorrect LPIC data, which would have higher energy consumption then expected at a design stage.

The mesopic effect of different correlated color temperature LED light sources on road lighting

2010 ◽  
Author(s):  
Xuan Li ◽  
Shangzhong Jin ◽  
Yanhua Wang ◽  
Songyuan Cen ◽  
Pei Liang ◽  
...  
Keyword(s):  
Color Temperature ◽  
Light Sources ◽  
Led Light ◽  
Road Lighting

Equivalent Brightness Fitting Calculation Method about White LEDs

2011 ◽  
Vol 121-126 ◽  
pp. 2721-2725
Author(s):  
Yong Yang ◽  
Lei Wang ◽  
Chuan Zheng Zhu
Keyword(s):  
Relative Strength ◽  
Luminous Efficiency ◽  
Color Temperature ◽  
Light Sources ◽  
White Led ◽  
Excellent Correlation ◽  
Efficiency Function ◽  
White Leds ◽  
Mesopic Vision ◽  
Brightness Curve

White LEDs can show different correlated color temperature (abbreviated as CCT) by adjusting the luminous spectrum peak distribution and relative strength. Recent research results indicate that spectral luminous efficiency function of mesopic vision Vmes(λ) and equivalent brightness are associated with luminous spectra of light sources. A series of white LEDs with different CCT are tested and calculated, it shows white LED with higher CCT has higher mesopic vision equivalent brightness, although the brightness are identical when the tester corrected by traditional photopic vision spectral luminous efficiency V(λ). From the equivalent brightness curve fitting, the curve can be described as a polynomial function, for it excellent correlation, the more value of equivalent brightness could be calculated without complex derivation.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

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.

The Research on the Application of Two Kinds of Light Sources in the Training Venue for Physical Education of Universities

2012 ◽  
Vol 430-432 ◽  
pp. 1786-1790 ◽  
Author(s):  
Shu Fang Li
Keyword(s):  
Energy Efficiency ◽  
High Pressure ◽  
Physical Education ◽  
Lighting Design ◽  
Light Sources ◽  
Metal Halide Lamp ◽  
Sodium Lamp ◽  
Electric Light ◽  
High Pressure Sodium Lamp ◽  
Power And Energy

The energy efficiency experiment of electric light is implemented according to the lighting design of the physical training venues. In the experiment, the corresponding illumination, power and energy efficiency ratio of the commonly used high pressure sodium lamp and metal halide lamp which work under the voltage ranging from 187V to 234V are experimentally measured and the lighting effect characteristics of the two kinds of electric light sources compared, proving that the high pressure sodium light source should be employed in the training venue for physical education of universities.

scholarly journals An Efficient Method for LED Light Sources Characterization

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1089 ◽  
Author(s):  
Sara Raggiunto ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Piergiovanni Ceregioli ◽  
Massimo Gattari ◽  
...  
Keyword(s):  
Efficient Method ◽  
Least Squares Method ◽  
Color Temperature ◽  
Experimental Setup ◽  
Light Sources ◽  
Careful Study ◽  
Source Characterization ◽  
Led Light ◽  
Lighting Systems ◽  
Led Drivers

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.

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