If you want that green look in your garden and all around your house, external LED lighting has come a long way in the past few years. In fact, now you can be green, as in environmentally correct, and green as in, well, green.
Not so long ago, light-emitting diodes, or LEDs, were rather expensive and restricted to specific colors. Technology has blown the top off those limitations. Prices are coming down, and colors are going up.
Now you can bathe your garden, your house and yourself in almost any shade imaginable, and dim it up or down as you see fit. Plus, LED lighting can save a bundle of money because LEDs use up to 60 percent less electricity for the same wattage as traditional incandescent or halogen lighting.
LED lighting is ideal for covering your house in multicolored glory or spiffing up a planting for a garden party. For that matter, you can light your yard and garden and then call a party just so friends can see the gorgeous lights. LEDs are the talk of the town nowadays.
They’re also cool on cars, motorcycles, boats and planes, virtually anywhere there is a steady power source. And the LED party is just getting started as technology continues to forge ahead.
LEDs produce more light per watt than incandescent bulbs, emit colored light without the filters traditional lighting requires and don’t change color tint when dimmed. They are also low-maintenance because they have an extremely long life span, sometimes in excess of 100,000 hours.
In addition, LED fluorescent lighting is environmentally friendly, with no mercury, lead or phosphorous in the tubes; no noise or flicker; solid-state and vibration-resistant; and LED fluorescents are made of acrylic so they don’t shatter when dropped.
Not that anyone really cares about such technical stuff. What counts is that LEDs are a fantastic light source, both energy-efficient and decorative, allowing you to create an ambient setting or highlight a special feature.
They are ideal for discrete lighting, under fences or along stairs and borders. They come in a range of shapes and sizes and can be a direct replacement for incandescent lamps.
Because of the way LED lamps are made, there is no accurate way of calculating the equivalent wattage of an incandescent or halogen lamp.
LED output varies according to the size of light used and the prism over it that focuses the beam. The manufacturers usually do not offer equivalents for this reason.
Generally, however, LED output is about 10 percent of an average incandescent or halogen lamp, the experts say. For example, if you replaced a 100-watt incandescent lamp with a 1-watt LED, the light output would be approximately 10 watts.
Spotlight replacements are slightly brighter and produce approximately 15 watts of light from LEDs compared to 50 watts from halogen, according to the manufacturers.
Because LEDs are solid-state devices, they are not subject to sudden failure and can operate for more than 10 years at moderate temperatures.
On the negative side, static electricity and surges can damage LEDs.
And they do get hot. Some kind of forced cooling system may be needed if you cram a lot of little LEDS into a tight space. And cram you can.
Standard LED sizes range from 2 mm to 8 mm. The 5 mm cylindrical LED is the most common, estimated at 80 percent of world production, manufacturers say. That’s about the size of a wooden match head.
Outside LED lighting is now readily available at home centers, where installers can advise you on power sources and what temperatures the lights most delight in.
Note, however, that a dying LED is merely a diminished LED. They don’t flash out suddenly like traditional lights but give you plenty of time to plan the funeral and swap them out for fresh LEDs.
Perhaps the best place to go for instant LED education is the Internet. Just Google “external LED lighting” and you will get more information than you ever wanted to know about everything to do with LEDs.
They’re the wave of the future and are hitting us at the speed of light. Plus they’re extremely trendy. Your LED garden party will be the talk of the neighborhood.
Advantages
Efficiency: LEDs produce more light per watt than incandescent bulbs.
Color: LEDs emit colored light without the color filters that traditional lighting requires. This is more efficient and can lower initial costs.
Size: LEDs can be tiny, smaller than 2 mm and are easily attached to printed circuit boards.
On/off time: LEDs light up very quickly. A typical red indicator LED will achieve full brightness in microseconds. LEDs used in communications devices have even faster response times.
Cycling: LEDs are ideal for use in applications that are subject to frequent on-off cycling, unlike fluorescent lamps, which burn out quickly when cycled frequently, or lamps that require a long time before restarting.
Dimming: LEDs can very easily be dimmed, either by pulse-width modulation or lowering the forward current.
Cool light: In contrast to most light sources, LEDs radiate very little heat that can damage sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED.
Slow failure: LEDs mostly fail by dimming over time, rather than the catastrophic burn-out of incandescent and halogen bulbs.
Lifetime: LEDs can have a relatively long life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be longer. Fluorescent tubes typically are rated at about 10,000 to 15,000 hours, and incandescent light bulbs at 1,000 to 2,000 hours.
Shock resistance: LEDs, being solid state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile.
Focus: The solid package of the LED can be designed to focus light.
Incandescent and fluorescent sources often require an external reflector to collect light and direct it.
Toxicity: LEDs do not contain mercury, unlike fluorescent lamps.
Disadvantages
High initial price: LEDs are currently more expensive per lumen than most conventional lighting technologies. But that is changing rapidly.
Temperature dependence: LED performance largely depends on the temperature of the environment. Overdriving LEDs may overheat the LED package, eventually leading to failure.
Blue pollution: Because cool-white LEDs (LEDs with high color temperature) emit much more blue light than conventional outdoor light sources such as high-pressure sodium lamps, cool-white LEDs can cause more light pollution than other light sources. It is therefore important that cool-white LEDs be shielded when used outdoors.
How does an LED work?
The chemical makeup of the LED semiconductor determines the color of the light. An epoxy resin enclosure is designed to allow the most light to escape from the semiconductor, focuses the light and protects the semiconductor from the elements.
The entire unit is embedded in epoxy, which makes LEDs sort of indestructible. There are no loose or moving parts. An LED is a solid-state device that controls current without heated filaments and is therefore extremely reliable.
The development of LED technology has caused their efficiency and light output to increase exponentially, with a doubling occurring about every 36 months since the 1960s, experts say.
The advances are generally attributed to the development of other semiconductor technologies and advances in optics and the materials used to fire up LEDs.
The color of the LED light depends on the material used. All early devices emitted low-intensity red light, but modern LEDs are available across the visible, ultraviolet and infrared wavelengths, with very high brightness.
History
The first LED was conjured up in the 1920s by Oleg Vladimirovich Losev, a radio technician who noticed that diodes used in radio receivers emitted light when current passed through them.
There was a 40-year pause until 1962, when Nick Holonyak Jr. at General Electric developed the first practical visible-spectrum (red) LED.
Holonyak is today seen as the “father of the light-emitting diode.”
In January, researchers at Cambridge University reported a process that reduced production costs 90 percent by using 6-inch silicon wafers instead of 2-inch sapphire wafers, whatever that means.
You can see where this is headed.
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