The yellow light-emitting diode (LED) gap always trouble Philips till now. Recently, researchers with Philips Lumileds (San Jose, CA) have developed a monochromatic nitride diode to closes the gap. The phosphor-converted (PC) amber LED demonstrated by Regina Mueller-Mach and her colleagues uses the down-conversion of blue light from an indium-gallium-nitride (InGaN) LED to longer-wavelength light by a phosphor, in a variation of a well-established process for producing cold or warm white light from blue LED light (see also “Fluorescent microspheres create white-light LEDs”).
Monochromatic light-emitting diodes cover a large part of the visible spectrum with high efficiency. For blue light, nitride diodes achieve external quantum efficiencies in excess of 65%. For red light, phosphor diodes achieve efficiencies of approximately 50%. However, so far no highly efficient monochromatic LEDs have been available for the “yellow gap” at around 560 nm.
Leveraging previous research on warm white light, the researchers succeeded in down-converting blue LED light into monochromatic amber light with a 595 nm wavelength and a color purity of 98.7%. The external quantum efficiency of the PC amber LED is at 30-40%, depending on temperature. Compared to direct amber LEDs, the new PC amber LED is two to five times as bright. It achieves a light output of 70 lumens at a 350 mA current.
There are numerous applications for the LUXEON Rebel PC Amber LED. It can be used in yellow traffic lights or signals as well as in cars’ turn signals or warning lights for construction sites. They could also be used in consumer electronics and their high efficiency makes them inexpensive.
The LED Street Lights Testing was hold in California. As we all know that high-efficiency white LED street lights will cut energy use by 30 percent to 60 percent every year.
Garden Grove is testing four 250-watt LED street lights on Civic Center Drive at Acacia Parkway, said Senior Analyst Chau Vu. Whether the city will switch over to LED will depend on how this testing goes, she said.
“In the next six months to one year, we’ll look at how much wattage these lights use up,” she said. “If it does what they say it can do, then it’s definitely worth it for the city. These lights can save a lot in terms of energy and money.”
LED lights are also easy to maintain because they last longer, Vu said. The downside is that they cost significantly more. While a regular street light costs $300 a fixture, LED lights cost about $2,000 a fixture.
LED lights are constructed with 100 percent recycled aluminum, contain no mercury or lead and do not require hazardous waste disposal handling. The city of Los Angeles is testing 100-watt LED lights.
Garden Grove was one of the first cities in the state to install LED lights on traffic signals. These test lights are manufactured by a company called Leotek and were donated to the city by South Coast Lighting.
So, if the tests prove successful, the city should do their best to change all street lights to LED.
Nighttime commuters may notice a bluish glow coming from the ten pairs of street lights lighting their way. Mounted 40 feet above the traffic, similar to those found in stoplights and laser pointers, the lights are not bulbs but rows of LEDs.
“This is the first interstate highway to be lit with LED lighting,” said Kevin Orth, director of sales for Wisconsin-based Beta LED, which makes the lights. LEDs are coming to the streets of Eden Prairie, where officials are replacing the city’s old street lights, and already illuminate the parking lot of a Cub Foods store in St. Paul’s Phalen neighborhood, which last month became the second certified energy-efficient supermarket in the country.
For large projects like these, the long-run savings in energy and maintenance, as well as the environmental concerns, generally outweigh the short-run costs.
This growing use of LEDs by government and industry marks a move away from traditional incandescent bulbs and, more recently, the more-efficient fluorescent lights that have come on the market. Although LEDs cost more to manufacture than other lighting options, they consume a small fraction of the energy of even fluorescent bulbs and last 25 to 30 years.
Lighting still accounts for as much as 20 percent of electricity used around the world, so improving lighting technology by even a little bit can lead to great savings in energy and reductions in greenhouse gases.
This artical shows you how to push a 1920s house into a modern, low-carbon age. The last few touches – appliances and rare light bulbs.
After spending the past year reducing the home’s heating bills by adding stacks of insulation, the owner has now turned her attention to slashing her electricity needs. She buy electricity from Good Energy which is a 100% renewable electricity supplier, but she would like to reduce our dependence on it, as all electricity is expensive – green or not. She monitor her energy usage with weekly measurements taken directly from both the gas and electricity utility and currently the house consumes 8kWh of electricity every day.
As part of her drive to save eneergy, She has reviewed the efficiency of all of her electrical appliances. Fridge freezers are significant consumers of electricity in the average house because they are switched on 365 days a year. As she was old, she recently replaced it with an A-rated one to minimise energy usage. Their television is an old-fashioned boxy cathrode ray tube, which is quite energy-hungry, consuming 300 watts per hour when on. The plan – when she has the money – is to change it over to a LCD type. They’ll plan their purchase with a great site called Sust-It which you can use to determine the energy cost per year of new tellies and other products.
What else? Well, she changed most of our conventional light bulbs to energy-savers several years ago. That was easy with standard bulbs, so now she is replacing the more obscure ones.
The garage security floodlight was rated at an energy-guzzling 500 watts – the equivalent of around 50 standard energy-saving bulbs. Although it produced an instant bright light , it was repeatedly set off by animals wandering into the garden at night. So she found a low-energy bulb from B&Q which, although less than half as bright, consumes just 18 watts and reaches full brightness within a few seconds. B&Q now sells a better version using an incandescent bulb for instant bright white light, but after a few seconds the more efficient but slower compact fluorescent bulb takes over.
Continuing outside, our garden lights used to consume only 6 watts each, but having eight of them she was determined to replace them with a more efficient option. Compact fluorescent bulbs don’t exist for such a small wattage so an LED light was the obvious choice. She has now replaced each of them with a very bright 1 watt LED version which nicely lights up the path to the house. A timer ensures the overall energy consumption is minimised.
She has used LED technology inside too. Earlier in the year she bought several Deltech LED bulbs from ebulbshop.com and was very impressed with its brightness and warm-white colour. It matches the incandescent GU10 bulbs (one of the most common spotlight-style fittings) very well and most importantly it has the same physical size, so it fits in her bathroom ceiling’s recessed bulb-holders. These GU10 LED bulbs consume just 5 watts each but come close to the light output from their 50 watt incandescent equivalents. They won’t pay for themselves for more than 10 years because they’re so expensive up-front, so I justify the LEDs on the grounds that their carbon payback is immediate.
It is reported that the latest LED breakthrough comes from the University of Connecticut, and it uses salmon DNA to create very long-lasting white LEDs (though they can be tuned to other colors). By now a lot of cool LED technology still needs to make its way from the lab to the store, it’s exciting to see that engineers are still finding new ways to squeeze more performance out of those semiconductor diodes.
Fluorescent dyes (two different ones, spaced between 2 and 10 nanometers from each other) are added to the DNA molecules, which are then spun into nanofibers. These are very durable because DNA is a particularly strong polymer (it has to be!) (they should last 50 times longer than acrylic, for example).
A LED emitting ultra-violet light is then coated with the DNA nanofibers: “When UV light is shined on the material, one dye absorbs the energy and produces blue light. If the other dye molecule is at the right distance, it will absorb part of that blue-light energy and emit orange light.” Using DNA has the benefit of orienting the dyes “in an optimum way for efficient [fluorescence energy transfer] to occur,” according to David Walt, a chemistry professor at Tufts University.
To tune the light quality, all you need to do is vary the ratios of dye. The light can be tuned from cool white to warm white, for example.
Unfortunately, numbers on how many lumens per watt these LEDs produce haven’t been released yet (though that might just be because they’re still improving them), so it’s not clear if the main benefit from these will be the longer life, or if the extra fine tuning will also mean better light quality than other white LED (like those that use quantum dots, for example), or if energy efficiency will also be superior. But it’s a new trick that will no doubt be useful. Maybe someday we’ll have a bit of DNA in our lights.
The beautiful, sleek, yet simple design of the Kast light is complemented by its quarter-shaped array of two five-watt LED clusters which are precisely angled to deliver glare-free light projection.
Kast has been manufactured with sustainability in mind, using over 80 percent recyclable aluminum and steel, composed of 40 percent recycled material with 27 percent post-consumer recycled content, and 100 percent solvent free powder coat finishes. The LED light helps make the task light affordable to the user, offering an average rated life of 100,000 hours which is ten times greater than most compact fluorescent lamps. In addition, the LED diodes are nearly 25 percent more energy-efficient than comparable compact fluorescent technology.
This is the first year for the Green GOOD DESIGN Award. It is a specialized edition of the GOOD DESIGN Award program which was founded in 1950 by architects Eero Saarinen, Charles and Ray Eames, and Edgar Kaufmann Jr. The GOOD DESIGN Awards bestow international recognition on designers and manufacturers for advancing innovation and originality. The awards are presented by The Chicago Athenaeum: Museum of Architecture and Design and the European Centre for Architecture Art Design and Urban Studies.
The purpose of the Green GOOD DESIGN Award is to emphasize the importance of sustainable design and to develop a public awareness program to the international general public educating about which companies are doing the greatest job creating sustainable design for our world environments. The Green GOOD DESIGN Award received hundreds of submissions from over 40 nations. Only 105 products, programs, people, government, environmental planning, and architecture were selected as outstanding examples of Green Design.
The Kast(TM) LED task light by Details, a Steelcase company, recently received a 2009 Green GOOD DESIGN(TM) Corporate Award. This award sets the bar for outstanding examples of Green Design. The beautiful, sleek, yet simple design of the Kast light is complemented by its quarter-shaped array of two five-watt LED clusters which are precisely angled to deliver glare-free light projection.
As the adoption of more energy-efficient light sources becomes more widespread in the coming years, the resulting energy savings naturally will increase. “LEDS are semiconductor light sources that produce directional light. Thus, the light is delivered precisely where it is needed so much less light is wasted as scattered light, and light pollution is reduced,” said Dr. Berit Wessler, Head of Innovation Management for OSRAM Opto Semiconductors (Regensburg,Germany). “LED light sources already consume much less electricity than most other conventional light sources.”
Light-emitting diodes have considerable potential for increases in brightness and efficiency, and can deliver even more potential energy savings than traditional light sources. Development work is ongoing and light-emitting diodes already are penetrating the general illumination sector.
The Imaging Source (Charlotte, N.C.) announces a new series of cost-effective LED lighting modules, which seamlessly integrate with The Imaging Source USB, FireWire and GigE cameras. Features include: very bright LEDs; direct connection to the camera; all parameters can be set via the shipped software, IC Capture and IC Imaging Control or by custom-built software; compatible with The Imaging Source USB, CCD, FireWire and GigE cameras. All cameras manufactured by The Imaging Source ship with IC Capture and IC Imaging Control.
As a result of CoolLED’s (Andover, Hampshire, U.K.) continuous development program, the company is pleased to announce the latest release of new LED wavelengths for its fluorescence excitation products. The new wavelengths are at 365, 380, 440, 470, 550, 615, 700 and 770 nm. These wavelengths are provided on LAMs (LED Array Modules) that can be interchanged within CoolLED’s modular fluorescence excitation sources and systems.The additions expand the wavelength range into the UV and IR regions. CoolLED offers its LED technology for wide-ranging applications. A total of 18 wavelengths now are available. CoolLED’s LAMs are arrays of LEDs that are actively cooled for the highest stability and intensity. Lifetime is measured in tens of thousands of “on” hours with no warm-up or cool-down periods required. There is very little reduction in intensity over lifetime. Switching is almost instantaneous.LED technology does not use hazardous materials.
It is said by LedEngin (a US LED company) that the high flux LED gives the brightest 40W light source with the highest light output and flux density for architectural and general lighting applications.
The LED light source has a thermal resistance of 0.7 C/W, and the company claims, is brighter than the competition by between six to 10 times.
The company is also offering 24 and 35 lenses optimized for the LED and mazimizes the light with uniform color. LedEngin says that there are no shadows or fringe effects that other lenses offer.
The 40W LED and lenses are available now, and the company is sampling them on a custom MCPCB for easier installation and alignment with the lens and lens holder.
Recently, LED light sources have been widely applied in many domestic and foreign brands of projectors. Especially in the second half of 2008, LED projectors in the market has experienced unprecedented success, that among micro-projection, handheld projectors and home theatre projectors, LED light sources reviewed a clear lead in sales figures.
LED sources are being considered in the industry as the alternative for ultra-high pressure mercury halogen lamps and new projector bulbs, due to its excellent performance. As a cold-light source, LED light source advances over the traditional light bulb with its low heat, long service life of 20,000 hours. Therefore, LED projector sizes can be reduced mobile phone sizes, while also easy to maintain, without having the trouble to replace light bulbs every two years. In addition, LED light sources are also more environmentally friendly, as they do not cause mercury pollution.
In fact, as early as three or four years ago, LED light sources have been applied on projectors, but with a performance of dozens lumens brightness, those products cannot meet the general requirement of thousands of lumens, thus they were largely in the laboratory stage, without going into mass production. The development bottleneck was finally being overcome in 2008, with the projector light bulb manufacturer, Osram developed a new LED light source system that can achieve a brightness of more than 500 lumens. The breakthrough in technology allows LED projectors to finally emerge onto the markets, and with prices coming down quickly, the current home projector now costs about RMB8,000.
At present, the technology may not have reached a highly mature level, LED projector sales is no better than traditional projectors, but its energy-saving, environmental friendly, and other extraordinary features will make it a new favour in the projector market.
Just like the public telephone, the conventional incandescent bulb’s and the ubiquitous (and ugly) fluorescent tube’s days may be numbered in U.S. New federal standards announced June 29, 2009 sets new national minimum energy standards for the standard bulbs that light our offices, homes, stores, and factories. The standards also phase out conventional incandescent reflector lamps, effectively extending the phase out of inefficient incandescent products initiated by Congress in 2007 to the common cone-shaped bulbs used in recessed light fixtures and track lighting.
According to the Department of Energy (DOE), lighting uses nearly 40% of all electricity used in commercial buildings. The standards announced today affect the more than 500 million fluorescent tube lamps and 265 million reflector lamps sold each year in the United States. About 7% of all energy consumed in the United States is for lighting.
According to DOE, the new standards announced today will save up to 1.2 trillion kilowatt-hours over thirty years, an amount about equal to the total consumption of all homes in the U.S. in one year. Businesses and consumers will gain up to $35 billion in net savings and global warming carbon dioxide emissions will be cut by up to 594 million metric tons, an amount equal to the annual emissions of nearly 110 million cars.
For the past several years the City of Milwaukee has actively tried to reduce energy use in City Hall and other city facilities. Since 2005 or so the Department of Public Works has been installing LED traffic signals throughout the City of Milwaukee. An LED (light emitting diode) traffic light provides as much or more light as a conventional bulb using a quarter of the energy, while lasting much longer. Mayor Barrett was quoted in today’s Milwaukee Journal Sentinel that street lighting aacounts for well over 50% of the energy used by the city. According to Ann Beier, Director of Environmental Sustainability, the city has been replacing incandescent bulbs with fluorescent lamps and replacing older, less efficient fluorescent lamps with smaller, more efficient bulbs.
With the change of standards it should get easier for the average consumer to make the shift to more efficient light bulbs. No more standing in the store aisle and reading labels to make sure the bulb in your hand is “energy smart”.
LED Bulb, LED Lighting, LED Research, LED Technology | Administrator | 
July 29, 2009 2:02 am | 
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