White Papers

White Papers

White Paper | Standardization + Regulation | Nov 14, 2013
Zhaga Publishes Book 7 and Book 8 Interface Specifications for LED Light Engines
Zhaga Publishes Book 7 and Book 8 Interface Specifications for LED Light Engines Two more interface specifications for LED light engines have been published by the Zhaga Consortium. Zhaga is an international organization that is enabling the interchangeability of LED light sources made by different manufacturers. The interface specifications, designated Book 7 and Book 8, can now be downloaded from the Zhaga website . Read more »
White Paper | IP, Reports & Roadmaps | Oct 28, 2013
DOE Publishes Report on Color Stability of LED Lighting Products
DOE Publishes Report on Color Stability of LED Lighting Products The U.S. Department of Energy (DOE) has published a new report, Color Maintenance of LEDs in Laboratory and Field Applications. Although concern for parametric failure of LED lighting products has largely been focused on lumen maintenance, color shift is a cause of early failure for some products, especially in applications where visual appearance is critical. Read more »
White Paper | Technology | Oct 23, 2013
Latest LRC Program Aims to Fine Tune Light for Greenhouse Crops & Medicinal Plants
Light and plants expert Tessa Pocock, Ph.D., recently joined the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute as a senior research scientist, leading the development of a new plant physiology lighting program. Her research focuses on plant photosynthesis, and plant development and regulation by light for traditional greenhouse crops and the emerging field of medicinal plants. Read more »
White Paper | Technology | Oct 08, 2013
Two-Switch Flyback Solution for LED Street Lighting
Two-Switch Flyback Solution for LED Street Lighting LEDs provide high efficiency and long life compared to conventional lighting sources. Therefore, they are becoming first priority of lamp types to reduce energy consumption for internal or external lighting. This is also the case in street lightings where better efficiency and longer life are essential for less cost. A switching power supply designed to power up LED lamp should also have high efficiency and robustness to assure maintenance free lifetime as long as LED lamp. Resonant converters are one of the most popular power supply topologies here since their performance delivers increased power efficiency. LLC resonant converter has drawn attention thanks to its features such as high power conversion efficiency and low voltage stress on secondary rectifier. However, complicated design and high manufacturing cost of LLC resonant converters have been obstacles to fast time-to-market and cost reduction. Another problem of LLC resonant converter is large circulating current that is required to maintain zero voltage switching (ZVS). It causes relatively high power consumption at light load. LLC resonant converter also has potential failure issue when MOSFET with poor body diode performance is used. Two-switch flyback converter is proposed as an alternative solution to overcome the limitations of the LLC resonant converter. With additional switch on the high side, leakage inductance energy is clamped and recycled back to input to improve efficiency. The dissipative snubber circuit is no longer needed. A 120W rated switching power supply is designed utilizing two-switch flyback topology. The details of design specification and test results are presented. Read more »
White Paper | Technology | Oct 08, 2013
Why Pin Fin LED Coolers Perform Better Under Tilted Position?
Why Pin Fin LED Coolers Perform Better Under Tilted Position? For the experiment we compare the ModuLED 9980 with the LPF11180-ZHE. The ModuLED 9980 is a passive LED cooler from extruded aluminium with a diameter. of 99mm and a height of 80 millimeter, thermal resistance under vertical position 1.02°C/W. The LPF11180-ZHE is a passive LED cooler with pin fin structure with a diameter of 111mm and a height of 80mm, thermal resistance under vertical position 1.07°C/W. Read more »
White Paper | IP, Reports & Roadmaps | Sep 12, 2013
New Comprehensive Investigation on LED Phosphors and Down-Converters Patents
New Comprehensive Investigation on LED Phosphors and Down-Converters Patents Yole Développement announces its new market & technology patent investigation, LED Phosphors and Down-Converters. Hundreds of companies are involved in LED phosphor IP. Most of the major LED players are present in the list of the top patent assignees. But independent phosphor manufacturers are also emerging as major forces in the IP landscape. Read more »
White Paper | Technology | Aug 28, 2013
PI's New Reference Design, DER-350 for PAR38 LED Spotlight, Promises Excellent Dimming Performance with TRIAC Dimmers
PI's New Reference Design, DER-350 for PAR38 LED Spotlight, Promises Excellent Dimming Performance with TRIAC Dimmers Power Integrations, the leader in high-efficiency, high-reliability LED driver ICs, today announced a reference design for a dimmable PAR38 spotlight, developed in collaboration with Cree, Inc., a leading LED lighting company. The new reference design, described in DER-350, uses Power Integrations’ new LYT4317E, a member of the company’s LYTSwitchTM-4 family of single-stage drivers, along with Cree’s MT-G2 EasyWhite® LEDs. Read more »
White Paper | IP, Reports & Roadmaps | Jul 31, 2013
DoE Publishes CALiPER Snapshot Report on Outdoor Area Lighting
DoE Publishes CALiPER Snapshot Report on Outdoor Area Lighting The U.S. Department of Energy's CALiPER program has released a Snapshot Report on outdoor area lighting, which utilizes the LED Lighting Facts® program's extensive product database to help industry stakeholders understand the current state and trajectory of the market for LED outdoor area and roadway, parking garage, and canopy luminaires. Read more »
White Paper | Technology | Jul 31, 2013
Rensselaer Researchers Identify Cause of LED “Efficiency Droop”
Rensselaer Researchers Identify Cause of LED “Efficiency Droop” Rensselaer Polytechnic Institute researchers have identified the mechanism behind a plague of LED light bulbs: a flaw called “efficiency droop” that causes LEDs to lose up to 20 percent of their efficiency as they are subjected to greater electrical currents. Efficiency droop, first reported in 1999, has been a key obstacle in the development of LED lighting for situations, like household lighting, that call for economical sources of versatile and bright light. Read more »
Fundings + Projects | White Paper | Jul 18, 2013
Supported Project “cyCESH” for Cost‐Efficient Printed OLEDs
Supported Project “cyCESH” for Cost‐Efficient Printed OLEDs On June 1, 2013, BMBF launched the project cyCESH involving cynora GmbH, Novaled AG and the University of Regensburg with the workgroup of Prof. Dr. Hartmut Yersin. The project is set to run for a duration of three years with a total funding of 6.1 million euros. The research of new soluble materials for the inexpensive production of organic light emitting diodes (Organic Light‐Emitting Diodes ‐ OLEDs) and the production of OLED devices with high efficiency are the main focus of the project. Read more »
White Paper | Jul 02, 2013
Alternative Calculation Method Will Improve Thermal Analysis of LEDs - by Michiel Krüger, Ph.D. - Philips Lumileds
Alternative Calculation Method Will Improve Thermal Analysis of LEDs - by Michiel Krüger, Ph.D. - Philips Lumileds An alternative method to estimate the amount of heat generated by LEDs will help increase the accuracy and streamline the thermal analysis of white LEDs. Up until now, thermal analysis of white LEDs has been an imperfect science. Too often LED lamp and luminaire manufacturers rely on insufficient, inaccurate or intangible data to determine the thermal performance of the LEDs in their applications, and, as a result, may over-engineer their heat sink design. Read more »
White Paper | Standardization + Regulation | Jun 27, 2013
Zhaga Announces Several Updates and Reports About Activities in their Latest June Newsletter
June has been a very busy month for Zhaga, with the consortium’s first meeting in China combined with an open session for government officials and representatives from China’s lighting industry. Meanwhile, the first products have now been certified for Zhaga interface specification Books 4, 7 and 8, while Zhaga has signed a liaison with the Global Lighting Association. Read more »
White Paper | Standardization + Regulation | Apr 22, 2013
Model Specification for Adaptive Control and Remote Monitoring of LED Roadway Luminaires, V1.0
The DOE Municipal Solid-State Street Lighting Consortium's Model Specification for Adaptive Control and Remote Monitoring of LED Roadway Luminaires is a tool designed to help cities, utilities, and other local agencies accelerate their adoption of systems that can further reduce the energy and maintenance costs of operating their streetlights. Read more »
White Paper | Technology | Feb 27, 2013
PI's New LED-Downlight Reference Design Achieves High-Performance Dimming While Further Reducing Component Count
PI's New LED-Downlight Reference Design Achieves High-Performance Dimming While Further Reducing Component Count Power Integrations, a world leader in high-efficiency, high-reliability LED driver ICs, today announced RDR-347, an LED-downlight reference design. The new circuit demonstrates the capabilities of the recently launched LYTSwitch™ IC family, which offers the industry’s best high-end dimming performance from a single-stage LED driver– together with all the associated efficiency, space and cost benefits that the single-stage approach brings. Read more »
White Paper | Technology | Feb 14, 2013
Cree Sets New R&D Performance Record with 276 Lumen-Per-Watt Power LED
Cree, Inc. delivers another industry first with a barrier-breaking 276 lumen-per-watt white R&D power LED. This significant milestone exceeds Cree’s previous R&D industry record of 254 lumens per watt and demonstrates Cree’s continued commitment to innovate and accelerate the adoption of LED lighting. Read more »
White Paper | IP, Reports & Roadmaps | Feb 01, 2013
New Patent Aims to Improve Light Distribution of Tubular Lamps and Luminaires
New Patent Aims to Improve Light Distribution of Tubular Lamps and Luminaires Appropriate even light distribution in LED replacement tubes respectively tubular LED lamps and luminaires is still one of the weak points of LED lighting. Recently the interesting patent application "Light distribution using tapered waveguides in LED-based tubular lamps as replacements of linear fluorescent lamps" covering that topic became a granted patent, with patent number US8,348,467 B2. Read more »
White Paper | Technology | Jan 30, 2013
New Options for Transparent Contact Electrodes
New Options for Transparent Contact Electrodes Found in flat screens, solar modules, or in new organic light-emitting diode (LED) displays, transparent electrodes have become ubiquitous. Typically, they consist of metal oxides like In2O3, SnO2, ZnO and TiO2 . Read more »
White Paper | Standardization + Regulation | Jan 10, 2013
SEMI's LED Standards Committee HB-LED Standard Published
After the formation of the high-brightness light-emitting diode (HB-LED) Standards Committee in November 2010 the committee was working hard on HB standards. The committee is happy to announce that it now has approved its first standard, SEMI HB1: Specifications for Sapphire Wafers Intended for Use for Manufacturing High Brightness-Light Emitting Diode Devices. Developed by the HB-LED Wafer Task Force, SEMI HB1 defines and specifies the physical geometry of 150 mm diameter sapphire wafers used in HB-LED manufacturing. HB1 covers dimensional, wafer preparation, and crystallographic orientation characteristics, as well as the appropriate measurement methods. The document was approved by the HB-LED Committee during the North America Fall 2012 meetings, recently completed procedural review and will be published soon. Read more »
White Paper | Technology | Jan 09, 2013
Scientists Mimic Fireflies to Make Brighter LEDs
Scientists Mimic Fireflies to Make Brighter LEDs The nighttime twinkling of fireflies has inspired scientists to modify a light-emitting diode (LED) so it is more than one and a half times as efficient as the original. Researchers from Belgium, France, and Canada studied the internal structure of firefly lanterns, the organs on the bioluminescent insects’ abdomens that flash to attract mates. The scientists identified an unexpected pattern of jagged scales that enhanced the lanterns’ glow, and applied that knowledge to LED design to create an LED overlayer that mimicked the natural structure. The overlayer, which increased LED light extraction by up to 55 percent, could be easily tailored to existing diode designs to help humans light up the night while using less energy. The work is published in a pair of papers today in the Optical Society’s (OSA) open-access journal Optics Express. Read more »
White Paper | IP, Reports & Roadmaps | Jan 03, 2013
DoE Releases CALiPER 2012 Year in Review Report
DoE Releases CALiPER 2012 Year in Review Report The CALiPER program has tested more than 500 products since its inception in 2006, revealing a variety of performance trends, holding manufacturers accountable for claims, and identifying concerns that limit adoption. Over the past six years, the LED marketplace has changed substantially; previously relegated to niche status, LED products are now a viable alternative in many product categories and market share is expected to grow rapidly. Starting in 2012, Summary Reports focus on a single product type or application. Read more »
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