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PlanetChristmas Light Emitting Diodes (LEDs)
LEDs (Light Emitting Diodes) represent the newest breakthrough in lighting technology. LEDs are
a low-maintenance, energy efficient
solution for anyone looking for
dynamic lighting displays. They're versatile and have vivid colors
that don't fade with time.
Here is a semi-technical description of LED technology. It's not really necessary to understand the details but it is important to note LEDs have different electrical characteristics than the incandescent bulb we've grown used to for the last 100 years. In the Christmas lighting world, all the manufacturers are struggling to make LED strings that appear similar to the incandescent strings of the past. The good news is LED strings are nearly indestructible, theoretically last 30 times longer and use 80-90% less electricity than incandescents, The bad news is LED technology Christmas light strings can cost 2-10 times as much as the mass produced light strings we're so used to. 2008 appears to be the year LED based Christmas light strings are looking as bright and consistent as incandescent strings. Prices are dropping, but there is still a real premium paid for this technology. If you can afford to buy LED Christmas strings, now is a good time to start. Reasons why LED is right for you:
LEDs are now considered "the greatest invention in lighting since
Edison's light bulb in 1879." LEDs are rapidly replacing light bulbs in
a variety of high reliability applications including traffic lights,
brake lights, and emergency exit signs.
 LEDs
are constructed from tiny solid-state chips similar to those used in
computers. These chips directly convert electricity to light without the
use of a filament or glass bulb. Instead, the chips are encapsulated in
solid plastic that can be made into a variety of shapes and sizes.
Basic differences between conventional light bulbs and LEDs are shown in
the picture to the right.Caution! Science jargon coming in following paragraphsSince LEDs have no filament, there is nothing to burn out and no need for a breakable bulb. Without the burning filament, very little heat is produced.
The principle behind LEDs can be made easy to understand. An LED is a
special type of diode and is similar to a transistor. Diodes and
transistors are "solid state" devices that are made from semiconductors
such as silicon. The semiconductor is made to contain two types of
special impurities. The first type of impurity, called "N" for
negative, is a material with an excess of electrons. The other type of
impurity, called "P" for positive, has a deficiency of electrons in
"holes." These two kinds of impurities are dispersed into the
semiconductor at different regions, so that a "P-N junction," or active
layer, is created at the border.
Semiconductors do not freely conduct electricity like materials such as copper. Instead, they can be made to conduct electricity under certain conditions. For diodes and transistors, these amount to connecting electric power across the junction to make the "P" side more positive and the "N" side more negative. When this happens, electricity flows freely across the "P-N junction" and the electrons fill up the holes. The laws of physics describe the energy between electrons and holes and show that this energy is a fixed amount depending on the materials. LEDs differ from ordinary diodes in that the "P" and "N" materials take this energy and convert it to photons, or light. Since the energy involved is a fixed amount, the light that results has only a single wavelength, or color. Using different materials for the "P" and "N" impurities enables the light to be manufactured in different colors.  General
Electric introduced the first LEDs in 1962. These LEDs came only in
red, the lowest energy of all visible light colors. In the 1970s, yellow
and green were introduced, along with intermediate colors such as
orange. However, then the materials used were inefficient - very little
light was produced for each watt of electric power used. Conventional
light bulbs are also very inefficient yielding at best only about 6% of
their electric power used in the form of light. The rest of this power
turns into heat, as one finds out quickly when touching a lighted bulb.
Over the years, LED efficiency, brightness, and lowered cost have
exploded in parallel with computer components. Today, LED power
efficiency surpasses that of a fluorescent and is increasing with 75%
efficiency on the horizon. This growth in LED efficiency is shown in
the picture to the right.Costs have plummeted such that bright red, yellow, green and intermediate colors are now pennies apiece. With the introduction of blue in the 1990s, LEDs now come in a full palette of colors, including pure white. Blue and white are presently too expensive for most applications, costing dimes instead of pennies each, but this should change within a few years. LEDs have also evolved to last much longer. Today, LED lifetimes are not specified by a time to burnout because it simply takes too long to measure. Instead, LED lifetime is specified at time when a barely noticeable loss of light occurs. This lifetime is about 100,000 hours, or more than eleven years of time. If the LED is off for any portion of time, then this lifetime increases. Conventional light bulbs are typically rated at about 1000-2000 hours or so before they burn out. But even this rating assumes that the light bulbs are not turned off and on and that they are not jarred in any fashion. Anyone familiar with Christmas light strings is experienced with burnout. Our lights are built with patented circuitry to maximize efficiency of their LEDs. This revolutionary design concept eliminates the use of traditional components that add to cost and generate heat. While details are proprietary, in essence the circuitry allows the LEDs to flash on and off with AC power. Like a television set, the flashing occurs sixty times per second and is invisible to the eye. By flashing the LEDs on and off this way, the circuit can be made at least twice as efficient as is possible with traditional LED circuitry. In addition, the overall LED lifetime is more than twice as long, since the LEDs are off more than half of the time. Unlike conventional light bulbs, particularly fluorescent bulbs, switching LEDs off and on does not affect their longevity. The result is a cheaper, safer, and longer lasting product with less power consumption than could otherwise be designed. Lifetime is predicted to be over twenty years of continuous use, and much longer if just used seasonally. Beautiful DesignAt first glance, the flameproof bulbs in our lights look like bright conventional miniature light bulbs . A closer examination, however, reveals that our lights have a slightly different shape. This shape has facets that create a unique shimmering effect with different light levels when viewed at certain angles. The result is striking, particularly as the lights shimmer in the breeze outdoors or one walks around the tree or other object being lighted indoors. This latest development in decorative lighting technology promises to change the way people decorate their homes, businesses, and even towns for many years to come. Less power consumption, longer product life, and durability without the hazards of excess heat build-up should make the holiday season brighter, safer, and ecologically sounder. Why Non-replaceable Bulbs?
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