Friday, March 18, 2011
Understanding Led Lighting
Understanding Led Lighting: LED (Light Emitting Diode) is an electronic semiconductor device which converts electric current into light. These are tiny light bulbs that do not have a filament neither turn hot like your bed room blue bulb or club lights. The LEDs are illuminated solely by the movement of electrons in a semiconductor layer material. A diode in this mechanism is a simple sort of a device that is semi conductive. It emits approximately 20 lumens per watt. They are designed to give light in different colors and in a single direction than other kinds of bulbs because of their directional output.
Thursday, March 3, 2011
LED Lighting: A Primer on What LED Is
LED, more properly called a light-emitting diode, is a light source using semiconductor material. More popularly used is indicator lighting in a great deal of devices, they are gaining ground in being accepted as full-on light sources. They started out in 1962 as a low-intensity red light, but are now being seen across the board on most electronic devices, and in many sizes, shapes and colors.
When turning on an LED, the electrons within get back together with the electron holes in whatever device they are part of, and this action kicks out energy in what is known as photons. This entire process is named electroluminescence. The color of the LED is based upon how much energy gap present in its semiconductor material, reliant upon the energy amount kicked out by the photon.
The average size of most LEDs is less than a millimeter squared, and introducing other optical components allow for multiple shapes and sizes, by playing around with its radiation pattern. This gives the LED lighting an advantage over its cousin, the incandescent light. Some advantages are that they use up less energy, they last longer, they are more sturdy, they can be made in a smaller size, and they are more reliable. Quite a list of achievements. The downside is that if you want to light up an entire room using LEDs, you are going to see a sizeable chunk of change pass hands. Not only this, but their currents and heat management must be more precise in their layout than fluorescent or incandescent lighting of similar lighting output.
You see LEDs in many applications these days, from aviation and car lighting, but also in traffic lights. With its small sized capabilities and other positive traits (narrow bandwith, switching speeds and reliability), LEDs are responsible for new video displays and advances in communications technology. Infrared LEDs are seen in remote controls for TVs, DVD players and other appliances. LED is everywhere.
When turning on an LED, the electrons within get back together with the electron holes in whatever device they are part of, and this action kicks out energy in what is known as photons. This entire process is named electroluminescence. The color of the LED is based upon how much energy gap present in its semiconductor material, reliant upon the energy amount kicked out by the photon.
The average size of most LEDs is less than a millimeter squared, and introducing other optical components allow for multiple shapes and sizes, by playing around with its radiation pattern. This gives the LED lighting an advantage over its cousin, the incandescent light. Some advantages are that they use up less energy, they last longer, they are more sturdy, they can be made in a smaller size, and they are more reliable. Quite a list of achievements. The downside is that if you want to light up an entire room using LEDs, you are going to see a sizeable chunk of change pass hands. Not only this, but their currents and heat management must be more precise in their layout than fluorescent or incandescent lighting of similar lighting output.
You see LEDs in many applications these days, from aviation and car lighting, but also in traffic lights. With its small sized capabilities and other positive traits (narrow bandwith, switching speeds and reliability), LEDs are responsible for new video displays and advances in communications technology. Infrared LEDs are seen in remote controls for TVs, DVD players and other appliances. LED is everywhere.
LED: A Long Road to Modern LED Development
Electroluminescence, the process that makes LED lighting possible, has its origins going way back to 1907, when British scientist H. J. Round, working out of the famous Marconi Labs, was using a sliver of silicon carbide with a cat's whisker. This started scientists on the road to LED development that has lasted most of the last century.
In 1927, Oleg Vladimirovich Losev out of Russia created the first official LED. His country, plus the scientists in Germany and England, shared the information, but nothing was really done with the new technology until Rubin Brownstein of RCA discovered infrared emissions from a conductor alloy called gallium arsenide in 1955.
Moving ahead to 1961, and America joins the development history when Texas Instruments scientists Robert Biard and Gary Pittman discovered gallium arsenide let off radiation in infrared when electricity was introduced to it. This LED to the infrared LED patent.
Red LED had its first practical use a year later when GE employee Nick Holonyak Jr put it to use. Ten years later, Holonyak's grad student, M. George Craford, invented the first yellow LED and enhanced the red's and orange-red's brightness aspect to ten times more powerful than a decade earlier. Four years after that, T.P. Pearsall developed the high-efficiency, high-bright LEDs used in fiber optics. This changed the face of telecommunications permanently.
The cost of both infrared and visible LEDs were through the roof until around 1968, so these expensive units weren't developed for practical use. Monsanto stepped in to develop mass-produced visible LEDS, with gallium arsenide phosphide in indicator lights. Hewlett Packard came next, bringing LEDs to the general market in '68. They started by using the gallium arsenide phosphide coming directly from Monsanto, and began commercial life in HP's calculators.
The 70s brought on inexpensive LEDs, thanks to Fairchild Optoelectronics, which produced them at a cost of less than five cents a unit. This opened the door to further develop and use LEDs in practical daily usage.
In 1927, Oleg Vladimirovich Losev out of Russia created the first official LED. His country, plus the scientists in Germany and England, shared the information, but nothing was really done with the new technology until Rubin Brownstein of RCA discovered infrared emissions from a conductor alloy called gallium arsenide in 1955.
Moving ahead to 1961, and America joins the development history when Texas Instruments scientists Robert Biard and Gary Pittman discovered gallium arsenide let off radiation in infrared when electricity was introduced to it. This LED to the infrared LED patent.
Red LED had its first practical use a year later when GE employee Nick Holonyak Jr put it to use. Ten years later, Holonyak's grad student, M. George Craford, invented the first yellow LED and enhanced the red's and orange-red's brightness aspect to ten times more powerful than a decade earlier. Four years after that, T.P. Pearsall developed the high-efficiency, high-bright LEDs used in fiber optics. This changed the face of telecommunications permanently.
The cost of both infrared and visible LEDs were through the roof until around 1968, so these expensive units weren't developed for practical use. Monsanto stepped in to develop mass-produced visible LEDS, with gallium arsenide phosphide in indicator lights. Hewlett Packard came next, bringing LEDs to the general market in '68. They started by using the gallium arsenide phosphide coming directly from Monsanto, and began commercial life in HP's calculators.
The 70s brought on inexpensive LEDs, thanks to Fairchild Optoelectronics, which produced them at a cost of less than five cents a unit. This opened the door to further develop and use LEDs in practical daily usage.
LEDs: The Practical Uses of Light-Emitted Diodes
LEDs: The Practical Uses of Light-Emitted Diodes: As to practical uses, the light-emitted diode didn't see widespread, common uses that we know today. Instead, they were first used to replace incandescent lighting and neon indicators. This took place first in fancy and expensive devices like lab and electronic test equipment, but eventually found their way into the things we are familiar with today as consumers: TVs, radios, handheld calculators, watches and our appliances.
These early, commercial use, LEDs were read, and had barely enough luminosity to be used as indicator lights, like in the above mentioned devices. There was no thought to lighting up a room or large area back then. The handheld calculator's readout screen were so tiny that little plastic "magnifier lenses" had to be placed over these early LEDs so they could be seen more clearly. Along the way, more colors were introduced, and a great many more appliances and devices benefited.
Along with the advancement in LED technology came an increase in the lighting capabilities. These little lights were no longer being considered for just indicators on readout screens in electronic devices. More and more, as light output increased, and efficiency and reliability grew more stable, the practical use of LEDs entered the lighting arena, where their high power white lights led the way to more practical and cost-effective illumination uses.
Coming commonly in sizes around 3mm and 5mm packages, heat became an issue as power output rose. So, in order to handle reliability, heat had to be trimmed down. This led to intricate packages that allowed for better heat dissipation. Looking back and comparing those first generation LEDs with today's high powered LEDs, you'd not recognize them as being related to each other. Their practical use has come a long way.
These early, commercial use, LEDs were read, and had barely enough luminosity to be used as indicator lights, like in the above mentioned devices. There was no thought to lighting up a room or large area back then. The handheld calculator's readout screen were so tiny that little plastic "magnifier lenses" had to be placed over these early LEDs so they could be seen more clearly. Along the way, more colors were introduced, and a great many more appliances and devices benefited.
Along with the advancement in LED technology came an increase in the lighting capabilities. These little lights were no longer being considered for just indicators on readout screens in electronic devices. More and more, as light output increased, and efficiency and reliability grew more stable, the practical use of LEDs entered the lighting arena, where their high power white lights led the way to more practical and cost-effective illumination uses.
Coming commonly in sizes around 3mm and 5mm packages, heat became an issue as power output rose. So, in order to handle reliability, heat had to be trimmed down. This led to intricate packages that allowed for better heat dissipation. Looking back and comparing those first generation LEDs with today's high powered LEDs, you'd not recognize them as being related to each other. Their practical use has come a long way.
LEDs Are Lighting Up A Whole New World
LEDs Are Lighting Up A Whole New World: With high power, high efficiency LEDs, lighting the world in a whole new way is growing in its possibilities. You'll find LED lamps everywhere now, inside and outside. They are found in street lights and parking lot lights. Some buildings even use different lighting possibilities to create masterful illusions to landscaping. Because LED lamps last a long time and are built tough, car lighting has been dramatically transformed, as well as the lighting on bicycles and motorcycles.
In 2007, the entire village of Torraca, Italy converted all of its street lights and outside lightings to an LED lamp style. This led to massive savings in cost and energy output. In aviation, LED lamps have found their way not only throughout the airports, and along runways, but on their airplanes as well. The Airbus A320 Enhanced has been using LED only lighting since 2007. Boeing is following suit, converting to all LED lighting on their 787s. You'll see LED lamps in airport interiors and exteriors, and on heliports. Out on the runway, the lights are LED, including the center line, edge and taxiway lights. Guidance signage and obstruction lights are converted to LED lamps.
In the consumer market, advances in television manufacturing has led to the integration of LED lighting in LCD TVs, and laptop displays have benefited from this backlighting technology. DLP projectors also contain LED lamps. Color television has increased value by almost have with the introduction of RGB LED lighting. LED lamps have led to the rush of flat screens for television and computer monitors.
In 2007, the entire village of Torraca, Italy converted all of its street lights and outside lightings to an LED lamp style. This led to massive savings in cost and energy output. In aviation, LED lamps have found their way not only throughout the airports, and along runways, but on their airplanes as well. The Airbus A320 Enhanced has been using LED only lighting since 2007. Boeing is following suit, converting to all LED lighting on their 787s. You'll see LED lamps in airport interiors and exteriors, and on heliports. Out on the runway, the lights are LED, including the center line, edge and taxiway lights. Guidance signage and obstruction lights are converted to LED lamps.
In the consumer market, advances in television manufacturing has led to the integration of LED lighting in LCD TVs, and laptop displays have benefited from this backlighting technology. DLP projectors also contain LED lamps. Color television has increased value by almost have with the introduction of RGB LED lighting. LED lamps have led to the rush of flat screens for television and computer monitors.
LEDs and Some Real World Applications
LEDs and Some Real World Applications: Since their inception, Light-Emitted Diodes have powered the indicator light features of electronic devices. As time wore on and the cost to develop multiple uses for LEDs came about, LED applications stretched as wide and as far as human imagination could take them. One of the most common applications using LEDs today are still for indicators and signs, although which indicators and which signs certainly don't resemble the LED usage of yesteryear.
These days you will find LED lighting up stadiums at sporting events, dynamic billboard signage, at train, bus and airport stations, including on the planes, trains and automobiles themselves. Single color lighting is used in traffic signals, emergency vehicle lighting, navigation lights on ships and planes, even Christmas lighting. Yellow and red LEDs are useful applications in areas where night vision is critical, such as in the cockpit of airplanes, on board ships, and within submarines. Observatories also benefit from these low heat, low energy light sources.
In the automotive industry, LED applications have found their way into the brake lights, turn signals and marker lights. Because LED has a faster switching time, they have actually increased automotive safety, by lighting up faster than the old incandescent styles, thereby increasing the reaction time by as much as one car length. There are even some manufacturers who are introducing LEDs into the headlamps, producing a thinner, more pleasing light beam
You'll find, because the low output LEDs are so inexpensive to produce, that growing popularity has increased in items that don't have a long shelf life, like glowsticks and things at concerts and event, and the photonic textile known as Lumalive. There is even a movement known as LED art, where artists use LEDs in their creative pieces.
These days you will find LED lighting up stadiums at sporting events, dynamic billboard signage, at train, bus and airport stations, including on the planes, trains and automobiles themselves. Single color lighting is used in traffic signals, emergency vehicle lighting, navigation lights on ships and planes, even Christmas lighting. Yellow and red LEDs are useful applications in areas where night vision is critical, such as in the cockpit of airplanes, on board ships, and within submarines. Observatories also benefit from these low heat, low energy light sources.
In the automotive industry, LED applications have found their way into the brake lights, turn signals and marker lights. Because LED has a faster switching time, they have actually increased automotive safety, by lighting up faster than the old incandescent styles, thereby increasing the reaction time by as much as one car length. There are even some manufacturers who are introducing LEDs into the headlamps, producing a thinner, more pleasing light beam
You'll find, because the low output LEDs are so inexpensive to produce, that growing popularity has increased in items that don't have a long shelf life, like glowsticks and things at concerts and event, and the photonic textile known as Lumalive. There is even a movement known as LED art, where artists use LEDs in their creative pieces.
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