2015年8月11日星期二

The Future of LEDs

As LEDs gain a greater portion of the lighting market, they are currently used in a variety of devices and applications ranging from traffic control devices (e.g. traffic lights, which include the single signal device that changes colors from green to yellow to red), Battery Powered Outdoor String Lights, hazard signs, message displays (e.g. Times Square, New York, commodities and news message boards, scoreboards), cell phones, televisions, large video screens used at sporting and other outdoor events (e.g. Miami Dolphins end-zone screen), calculators, digital clocks and watches, flashlights (including models for which 60 seconds of manual winding provides one-hour of light, eliminating the need to stockpile fresh batteries for emergencies), Christmas lights, airport runway lights, buoy lights, and automotive applications (e.g. indicator lights as well as head lights and signal lights in some vehicles; driver’s of the new 2006 Ford Mustang can even change the color (125 different varieties) of their “LED-laden dashboard by using the ‘My Color’ feature”.

Metal Halide Flood Light

In fact the automotive industry plans to replace all bulbs with Metal Halide Flood Light by 2010, while efforts are currently underway to replace all traffic signals with LED devices. At the same time, plans are in place to eventually use LEDs to light streets as well as much of the Third World and other areas “with no means of electricity” since “solar charged batteries” can power LEDs for the duration of each night. In addition, “Phillips Electronics is developing remote-controlled LED room lighting [while] Boeing Corp. plans to use LED’s throughout the interior of its new 787 Dream liner commercial jet.”

With the promise that Dimmable LED Track Lighting Fixtures hold, it is likely that someday they will provide illumination for houses and offices, X-Ray capabilities for the medical field, power computer monitors, as well as an assortment of other devices and applications. The possibilities are endless. However, before LEDs can supplant the traditional bulb, “designers and advocates of the technology must overcome… the usual obstacles to mainstream market adoption: Industry-accepted standards must be developed and costs must be reduced.”

Currently costs are coming down and some companies are moving towards these industry standards (e.g. Phillips Electronics is working on LED bulbs that can screw into existing light sockets, while besthomeledlighting.com already offers LED screwball bulbs -- one consisting of 70 LEDS that emits a "warm white color similar to the light from an incandescent bulb" using only 3 Watts of energy and another LED bulb that actually changes colors when lit). With these efforts along with the adoption, exploitation, and production of LED technology by growing numbers of companies, it is inevitable that LEDs will become the sole source of lighting rendering traditional incandescent and fluorescent bulbs extinct. In short, LEDs are the light of the future, a light that will benefit not only consumers but also industry and the Earth in general. You can visit deedoptoelectronics.com for more details.

2015年8月3日星期一

Brief Description of Light Emitting Diodes

Light Emitting Diodes (LEDs), “semiconductors that emit light when zapped with [positive polarity] electricity,” are on the verge of taking over the commercial and consumer sectors of the lighting industry. With greater efficiency, longer useful lives, and their “clean” nature, LEDs are the future of light, pushing traditional incandescent and fluorescent bulbs toward extinction. Only the higher production costs for LEDs have extended the existence of traditional bulbs.
Ultra Bright LED Street Light
When viewing the history of traditional bulbs, the higher costs associated with producing LEDs is not an insurmountable hurdle to overcome. The incandescent bulb lingered for about 70 years before supplanting “candles, oil lanterns, and gas lamps” as the main source of Petrol Station LED Light. When the first crude incandescent bulb was created in 1809 by Humphrey Davy, an English chemist, using two charcoal strips to produce light, it remained impractical. Later when the first true incandescent bulb was created by Warren De la Rue in 1820, utilizing a platinum filament to produce light, it was too expensive for commercial use. Only when Thomas Edison created an incandescent bulb utilizing a carbonized filament within a vacuum in 1879, did the incandescent bulb become practical and affordable for consumer use.

Although considered relatively novel, the concept for LEDs first arose in 1907 when Henry Joseph Round who is one of the Commercial Hotel Lighting Manufacturers used a piece of Silicone Carbide (SiC) to emit a dim, yellow light. This was followed by experiments conducted by Bernhard Gudden and Robert Wichard Pohl in Germany during the late 1920s, in which they used “phosphor materials made from Zinc Sulphide (ZnS) [treated] with Copper (Cu)” to produce dim light. However, during this time, a major obstacle existed, in that many of these early LEDs could not function efficiently at room temperature. Instead, they needed to be submerged in liquid nitrogen (N) for optimal performance.

Before long these red LEDs were producing Ultra Bright LED Street Light and even orange-colored electroluminescence when Gallium Phosphide (GaP) substrates were used. By the mid 1970s, Gallium Phoshide (GaP) itself along with dual Gallium Phosphide (GaP) substrates were being used to produce red, green, and yellow light. This ushered in the trend “towards [LED use in] more practical applications” such as calculators, digital watches and test equipment, since these expanded colors addressed the fact that “the human eye is most responsive to yellow-green light.”

However, rapid growth in the LED industry did not begin until the 1980s when Gallium Aluminium Arsenides (GaAIAs) were developed, providing “superbright” LEDs (10x brighter than LEDs in use at the time) – “first in red, then yellow and… green,” which also required less voltage providing energy savings.  Find LED lighting products? Please visit deedoptoelectronics.com