2009-04-01 P & R Packet - Laserfiche WebLink

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LEOS are solid-state devices which contain no mercury and last five times longer than metal halides - helping to reduce environmental waste. Lumens per watt has long been the standard for measuring the efficiency of lighting fixtures. Sol's latest Quad Series delivers the most lumens per watt of any LED configuration. Since 1990, Sol has had a solid reputation of providing reliable solar lighting products. Our engineers are experts at maximizing light output. What makes LEOs so great? LED lighting is increasingly used in a variety of lighting applications because it offers many benefits, including: . Long Life . Highly Efficient . Energy Savings . No warm up time . Better quality of light output . No hazardous disposal - unlike CF, CCFL, LPS and HPS which contain mercury . Intrinsically safe . Durable LED lighting systems have already proved to be very effective in indicator applications where brightness, visibility, and long-life are important. Outdoor lighting applications such as street lighting, parking lot lighting, and security lighting can benefit as well. What is the life of an LED? LEOS generally do not fail by burning out but slowly reduce light output over time. As solid-state devices, they will continue to operate even after 100,000 hours (solar applications). Comparisons of lumen maintenance near the end of the rated life for traditional light sources (I.e., incandescent. fluorescent, HID) have shown that with the exception of metal halide lamps, these traditional light sources usually have at least 80% of their initial light output by the time they have operated 10,000 hours. Furthermore, when light level reductions occur over time, people tend not to notice them until the light level reaches 80% of the initial output. This is the basis for "useful life" for lighting sources. What is an LED lighting system? As with other light source technologies, such as fluorescent, CCFL and HID, lighting systems using LEOS can be thought of as having a light source (typically the combination of LEOS that form the light source itself), a ballast (for LEOS it is often called a driver), and a luminaire (the fixture). LEOS require a specific electrical polarity. Applying voltage in reverse polarity can destroy them. A slight change in voltage can result in very large changes in current. Since the light output of an LED is proportional to its current, LEOS can be driven at various light outputs. If the resulting current exceeds limits recommended by the specific LED manufacturer, the long term performance of the LED can be affected resulting in shorter useful life. This means that many LEOS can produce a high light output, but have a very short life. An LED driver performs a function similar to a ballast for discharge lamps. It controls the current flowing through the LED. Most LED drivers are designed to provide current to a specific device or array. It is very important that a driver be matched to the specific device. LED systems are rated in terms of luminous intensity in candelas (foot-candles) rather than light output in terms of lumens. Luminous intensity is a function of the angle from which an LED is seen, so this value should be considered carefully when used to characterize light output of a particular LED source. Two LEOS with the same luminous flux output can have very different peak luminous intensities, if they are designed to produce different beam angles. II