Using active cooling technology, Cool-View has developed a surgical headlight system that uses a single LED to match the light output of a 350W xenon fiber-optic system.

Headlight systems designed to illuminate delicate and complicated surgical procedures typically use a xenon lamp as the light source. However, LEDs are proving to be ideal for this application, and enable portable headsets with much improved performance.

Xenon-based systems typically comprise a 400W light source, mounted on a stand, which is connected to the surgeon’s headset via a fiber-optic cable. This causes movement restrictions, and carries the risk of overheating and electrical problems.

The use of an LED source eliminates the fiber-optic cable, and enables a battery-powered headset to be truly portable. However, one major issue is to ensure that sufficient light can be generated without the LED source becoming too hot.

Cool-View of Lakeland, Florida has developed a surgical headlight system (the Novalite Micro XL 1400) that uses a single LED source to produce 100,000 lux at a distance of 14 inches with a 50 mm-diameter light field. The beam diameter can be focused between 50 and 120 mm.

The light-source module contains a single LED from Cree. “We overdrive it at 125-150% of the recommended current,” says Cool-View’s Dave Medinis. “The light output is equivalent to a 350 W xenon system.”

The key to generating plenty of light is active cooling to prevent the LED getting too hot, explains Medinis. “Our first-generation system used liquid cooling, but we now have an air-cooled system covered by granted and pending patents,” he says. “Although we dissipate around 25W of heat, the LED is effectively at ambient temperature.”

Of course, this cool operation is necessary to prevent discomfort for the surgeon, who may have to wear the headset for several hours.

The LED-based light source is mounted onto a lightweight headset, and powered by a battery pack providing a 4-hour life from a 30-minute charge. The headset weighs 3.5 oz and the battery pack weighs 7 oz.

The 24 V battery produces up to 2.5 A, and the LED is driven in constant-current mode using an in-house driver built around a driver IC from Linear Technology.

The LED has a color temperature of 6500K, which is higher in value than halogen or xenon sources, and means the light is closer in appearance to daylight, further assisting the surgeon.

Over the last few years, AT&T re-branding efforts across the US included a redesign of its logo that necessitated the replacement of 7,000 channel letter signs on more than 6,500 AT&T office buildings and retail locations.

The company switched to the Tetra LED lighting system from Lumination, GE Consumer & Industrial’s LED business. In total, approximately 2.6 million GE LEDs replaced both the high-voltage, high-maintenance neon that is often used in small-building signs and less-efficient linear fluorescent lighting, which performs less favorably than LEDs in cold climates.

AT&T expects to save more than 5.8 million kilowatt hours (kWh) of electricity a year and eliminate 3,500 metric tons of carbon dioxide annually. This, says AT&T, is the equivalent of planting more than 950 acres of trees.

The new lighting system will also provide AT&T with financial savings, compared with neon. “We knew a switch to more efficient signage would be a sustainable business decision, both environmentally and financially,” said Shawn McKenzie, SVP of Corporate Real Estate, AT&T Services Inc. “We researched our options, analyzed the data and ultimately chose the GE system for its reliability, energy efficiency, environmental benefits and long-term value proposition. It also helped that GE is built to handle such large-scale efforts.”

According to Eric Stevenson, GE’s Global Product Manager – Signage, “companies like AT&T that pay to operate thousands of signs every day are quick to recognize the value of a high-quality LED signage system.”

The energy-savings differential is significant, but it’s often the maintenance savings that seals the deal, continued Stevenson. “Our GE Tetra(R) LED system with a 50,000-hour rated life eclipses the life of incumbent fluorescent systems by more than three years. Our LED system virtually eliminates the problem of burned out signs, which is common for both neon and fluorescent systems.”

According to Stevenson, high-rise backlit signage is challenging to maintain because the signs are frequently mounted many stories above ground level, requiring large cranes or helicopters to conduct maintenance or repairs. “It’s work that can cost thousands of dollars a day for rental equipment and services,” he noted.

DURHAM, N.C. – A new, more energy-efficient McDonald’s is now open in the Saltbox Village shopping center in Cary, N.C. Featuring LED lighting from Durham-based Cree, Inc. (Nasdaq: CREE), the new building is on-track to be the first LEED (Leadership in Energy and Environmental Design) certified McDonald’s in the state.

The site’s original McDonald’s restaurant was demolished in early 2009 and rebuilt specifically to achieve LEED certification from the U.S. Green Building Council. Ric Richards, franchise owner/operator, hopes to be LEED-gold-certified by October. The store is lit 97 percent with LED lights, and when compared to the standard lighting packages, this store consumes 78-percent less electricity for lighting.

“My efforts in building this store are two-fold – to be economically sound with energy-efficient methods and, at the same time, to provide a modern space for the enjoyment of customers,” Richards explained. “Cree’s LED lighting products are an important element in our ability to reach our energy-efficiency targets.”

The Cary McDonald’s uses a fully automated, intelligent lighting-control system that combines light from high-efficiency Cree LED lighting and daylighting from Solatube skylights with a photo sensor to maintain the proper light levels on work surfaces. For example, if it rains and the daylighting is reduced, the LED light levels are increased to compensate. The dimming capability of LED lighting provides the flexibility needed for this system to work effectively. Cree’s LED products are featured throughout the restaurant, including dining areas, kitchen, hallways and restrooms, as well as the drive-thru and entryways.

“By seeking LEED-gold certification, this McDonald’s demonstrates the importance of LED lighting as a crucial component for green building,” said Neal Hunter, president, Cree LED Lighting. “The full line of Cree LED lights is in use in this building, from our recessed downlights to our new LED bulb. The benefits of energy-efficiency and high-quality lighting make Cree LEDs a cost-effective option for retailers and businesses.”

Other features of the green design include LED lights in the parking lot, front counters made of recycled glass and concrete, a parking lot that utilizes recycled concrete as well as re-use of the restaurant’s original ENERGY STAR-rated equipment. The building uses water conservation measures such as low-flow toilets and landscaping consisting of native and adaptive plants and trees requiring little or no irrigation, which Richards expects will allow the restaurant to save 550,000 gallons of water annually.

About Cree
Cree is leading the LED lighting revolution and setting the stage to obsolete the incandescent light bulb through the use of energy-efficient, environmentally friendly LED lighting. Cree is a market-leading innovator of lighting-class LEDs, LED lighting solutions, and semiconductor solutions for backlighting, wireless and power applications.

Cree’s product families include recessed LED down lights, blue and green LED chips, high-brightness LEDs, lighting-class power LEDs, power-switching devices and radio-frequency/wireless devices. Cree solutions are driving improvements in applications such as general illumination, electronic signs and signals, variable-speed motors, and wireless communications.