LED Lighting Systems in Smart Buildings with DC Microgrids
LpR 72 Article, page 60: While electric motors for ventilation and air-conditioning systems were already DC-based in the past, powerful IT systems, LED lighting systems, photovoltaic systems with batteries and charging systems for electro mobility are now increasingly being used in modern building environments. They all need direct current (DC). Therefore, an obvious step is to equip modern buildings with DC grids. Carsten Moellers from Abalight discusses a number of unresolved questions and presents possible solutions in this article.
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Semi-Empirical Characterization of Freeform Microlens Arrays
LpR 72 Article - page 42: Microlens arrays (MLA) have been used for imaging and non-imaging applications for a long time as cost-effective solutions. Non-symmetrical beam shapes require more advanced non-symmetrical freeform microlens arrays (FMLA). The required FMLA molding tools convey a high cost and an iteration process is required for the final design. Oscar Fernández, Tamara Aderneuer, Rolando Ferrini from the Centre Suisse d'Electronique et de Microtechnique, CSEM, and Julien Duchene from ANSYS proposed a method to overcome these limitations based on 3D surface sampling, computer generation of a ray-traceable model and ray-tracing performance simulation and demonstrate feasibility for several commercially available freeform asymmetric thin-film diffusers.
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Technologies for Shared Office Space
LpR 72 Article, page 66: Shared office spaces are gaining popularity as a flexible, resource-efficient and creativity-inspiring way to work. The dynamic nature of such office spaces requires building automation and lighting control solutions that can quickly be deployed and easily be adapted to new office layouts. Matthias Kassner, Vice President Product Marketing at EnOcean GmbH, takes a look at different connectivity architectures (wired, wireless, hybrid) and protocols (Bluetooth, ZigBee, EnOcean, PoE) to assess their usability and show how minimizing the need for maintenance is a key for increasing profitability of service-based offerings.
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What the Heck Is Future Proof?
Commentary from LpR 72: The first time the question about future proofing LED systems came up seriously, was at LightFair 2018 when Siegfried Luger interviewed Patrick Durand. Since then, it has been the buzzword throughout the industry. Discussions concerning future proofing are often limited to wireless communications, IoT and some type of AI. But isn't there more?
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Circadian-Friendly Light Emitters: From CCT-Tuning to Blue-Free Technology
Common levels of blue radiation are sufficient to disrupt the circadian cycle, calling for blue-depleted emitters in the evening. Most current solutions employ low-CCT and suffer from poor light quality. Aurelien David, chief scientist at Soraa explains the melanopic lumen and its possible sources of inaccuracy related to the uncertainty in assessing the circadian action spectrum. In addition, he also discusses the concept of a blue-free emitter with minimal melanopic lumen at very low CCT and how such a spectrum providing a good light quality can be optimized.
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Flex LED Based Smart Light System for Healing of Chronic Wounds
LpR 71 Article - page 48: Chronic wounds are notoriously challenging to treat, because they do not follow the typical healing process or time-frame. The resulting burden is significant, affecting over 40 million patients. Blue light is known for its anti-microbial and anti-inflammatory effects in the initial stages of the healing process. David Kallweit, researcher at CSEM, reports about the joint development of a chronic wound treatment device with their MEDILIGHT partners, URGO RID, University of Heidelberg, SignalGenerix, Microsemi, Technical University of Berlin, and Amires. He furthermore shows how it works and discusses future prospects.
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Tech-Talks BREGENZ - Dr. Octavio Perez, Adjunctant Researcher, Mt. Sinai Hospital
Dr. Perez received the LED professional Scientific Award 2018 for his paper on "Light and ED Clinical Wellness and Performance Improvement", which was published in LpR 70. The evaluation jury had the following to say about why they selected his paper: "The paper is based on the clear definition of the research question, hypothesis and objective of the research. The methodology of the screening study is described in detail and both subjective and objective parameters have been measured. Although Emergency Department lighting is a very special application, the paper provides interesting results." This interview provides background information on Octavio Perez, his work in general, his opinion on human centric lighting risks, opportunities and applications and how he became involved in this interesting research topic. Dr. Perez also provides additional details about the presented paper.
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Voice Controlled Lighting that Protects Privacy and Data
LpR 71 Article - page 54: Intelligent lighting systems undoubtedly offer high comfort and energy efficiency. But especially conventional voice control systems like Amazon Alexa, Apple Siri or OK Google, with connected lamps and lighting fixtures are also becoming targets for uninvited guests. The benefits and technology of a new approach offering local voice control and artificial intelligence will be explained by Genia Shipova, Director Global Communications at Snips.
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Healthy Light - LED Technology for Health and Care Applications
The right light, at any time during the day or night, is absolutely essential for health and well-being especially in health and care applications. Peter Haumer, Head of Technical Sales at Lumitech/Kiteo reveals why, besides full spectrum and high color rendering, mimicking real daylight conditions with extended daylight curves, a direct and an indirect component (CCT 1.800–16.000 K), are essential. The article discusses the benefits that can be derived from special colors for medical staff, patients and residents.
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Well-Being, Light and Exhibition Lighting
Commentary from LpR 71: Well-being is the state of feeling healthy and happy, a good or satisfactory condition of existence, including the emotional and psychological sphere. In 1810, Goethe published a theory based on a human-based approach, combining visual appearance with harmony, culture, sensations and psychology. His color wheel was entitled "allegorical, symbolic, mystic use of color" and was composed of six hues, i.e. red (the beautiful), orange (the noble), yellow (the good), green (the useful), blue (the common) and violet (the unnecessary). The position on the wheel was harmonically relevant and in particular the colors in opposite position generated a strong psychological contrast and were called "opposite colors". Primary colors were yellow, blue and red, and the opposites were green, violet and orange, respectively. Goethe's wheel and the particular matching of opposites soon became popular and was used by the Impressionism movement, especially by Vincent van Gogh and Claude Monet. In this artistic movement, the special impact given by the combination of opposite colors were deliberately aimed to create special psychological effects and sensations.
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Implications for Human-Centric Lighting Design in Tropical Nursing Homes: A Pilot Study
Light synchronizes our physiological and psychological rhythms to the 24-hour rhythm of the ambient changes. For the elderly, adequate environments to compensate for increasing frailty and sensory loss are crucial. Dr. Szu-Cheng Chien, Assistant Professor at the Singapore Institute of Technology reports from a pilot study that aimed to explore HCL design strategies in nursing homes in Singapore. Pre-/post implementation user surveys and quantitative evaluations were conducted.
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Melanopic Green - The Other Side of Blue
LpR 71 Article - page 74: For years now, there has been a controversial discussion about the amount of blue light in LEDs. Medical studies have shown that, depending on the amount, blue light at night disrupts the circadian rhythm. As a result, warm white (<3000 K) light sources are often touted as a solution for street lighting as well. Ian Ashdown, P. Eng. (Ret.), FIES Senior Scientist at SunTracker Technologies discusses whether or not it is sufficient to only look at the CDT or if other wavelengths and aspects should be considered.
Numerous medical studies have shown that exposure to blue light at night suppresses the production of melatonin by the pineal gland in our brains and so disrupts our circadian rhythms. As a result, we may have difficulty sleeping. It is therefore only common sense that we should specify warm white (3000 K) light sources wherever possible, especially for street lighting. - True or false?
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Enriching Horticultural Lighting for Faster Growth and Better Crops
Horticulture lighting is no new lighting application, but it gained momentum with the introduction and evolution of LED lighting, and it is meanwhile one of the fastest growing markets in lighting. Dr. Richard Blakey, Application Engineer at Würth Elektronik eiSos, explains how LED-based horticultural lighting can deliver even bigger advantages for commercial growers by introducing additional wavelengths that increase photosynthetic response - like Würth Elektronik's new members of the WL-SMDC SMD Mono-Color Ceramic LED Waterclear family that is used as a reference in the article.
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48 VDC Integrated Drivers Offer New Options
LpR 70 Article, page 102: In the telecommunication and IT businesses, especially, 48 VDC grids have become quite popular. This growing global trend to facilitate direct current (DC) power supply in building "microgrids" presents new opportunities for solid state lighting designers. TE's Lighting Industry Manager, Ron Weber, and Global Product Manager, Scott Hamilton, describe how LED lighting fixture designers can now design luminaires around a 48 VDC constant voltage input, available to take advantage of the benefits of a low voltage DC distribution grid in a building.
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Standardized Programming of Lighting Components Using NFC Technology
LpR 70 Article, page 88: NFC programming of LED drivers is rapidly gaining popularity as a fast, feature-rich, flexible and easy method to set the operating characteristics of LED drivers inside luminaires. Arnulf Rupp, Chair of MD-SIG, describes how the MD-SIG specification for NFC programming of lighting components makes it easy for luminaire manufacturers to use NFC programming in a production line where multiple brand drivers are used one after the other.
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