Light Emitting Diode (LED)
I start with a disclaimer up front on this topic. The technology of LED used as general lighting for home use is changing on a daily basis (for the better). This does not mean that use of LED’s is not viable. As a matter of fact, I personally believe that it is a better light source than incandescent, florescent, mercury or others.
What is a Diode?
First let’s understand a diode. A diode (which is a solid state device) in electronics is an electronic component built to regulate and stabilize current (Amperage) and voltage in an electronic circuit. The most common function of a diode is that it lets electric current flow only one way through it. It works sort of a check valve. Solid state components like diodes and transistors replaced the use of vacuum tubes in electronic circuitry allowing the miniaturization of electronic circuitry. Think transistor radios, so they are very important in our lives today.
Can you imagine a world without them? Consider the power of a computer. The size of the computer that sent astronauts to the moon in 1969 took up several floors of computer power. Comparatively, you have the same amount of power and more data storage in your iPad. Yep, pretty amazing stuff.
What is an LED?
Diodes can do more than being a one way street. By varying materials and introducing impurities into Semiconductor diodes they can be used as temperature sensors, voltage sensors, protect circuits from high voltage, and to produce light. Ah Ha, a Light Emitting Diode.
You have all seen LED’s. All the little red and green lights on electronic devices of almost every type, the digital clocks on the front of them and on your alarm clocks are LED’s. Now you see them in computer screens, television screens, Christmas Lights, tail lights on your car and motorcycle, plus many show cars and motorcycles use them to highlight their vehicles. I have a blue and white Harley Davison with side car that I highlight all the chrome on the motor with blue LED’s. Don’t laugh, this MC has taken first place several years in a row at Bike Week in Daytona, Florida; Sturgis, South Dakota; Milwaukee, Wisconsin; and Virginia State HOG Rallies.
There are several types of LEDs that can be used such as the conventional semiconductor light emitting diodes, organic LEDs (OLED, or the newest version polymer light emitting diodes (PLED) which at this writing is not available for commercial use. The PLED will be used eventually for your LED computer and television screens. PLEDs are produced as a film which can be printed vice manufactured saving a bunch for future applications.
The light output of individual LEDs is small compared to incandescent and florescent lamps so multiple diodes are often used together, like on my accent lights on my Harley. But as I inferred in the disclaimer at the beginning, this technology is changing all the time and the new diode technology has improved. Now, high power light emitting diodes with a higher of lumen (brighter) makes it possible to utilize them in general lighting applications, as a matter fact, more applications every day.
The advantage of LED lighting is power usage and lighting power (lumens). For a comparison:
100W incandescent bulbs emits 1,710 lumens
100W LED for commercial use emits 7,500 lumens
The difference is about 4.39 times more light for the same cost. So application of use is growing big time.
DC Power Versus AC Power (Transitioning the Power)
Diodes use direct current (DC) electrical power, so how can you connect them to alternating current (AC) electrical power? Pretty basic electrical circuits like most of your TV’s, Radios, Audio Systems, Blue Ray machines and the like already use.
For example, to replace a standard incandescent bulb in a lamp, your hot and return wires connect just like the standard bulb through screw part of the bulb. The AC power connects to a circuit board which includes power modulation and a AC to DC converter, heat management through heat sink and cooling fin elements as well as the LEDs.
Other applications of LED lighting include almost all common light bulb applications. For florescent tube bulbs like used in many offices a overhead lighting, LED lights and circuitry is encapsulated and shaped like a florescent bulb so all you do is replace the florescent bulb with the LED replacement. Using the same methods you can replace floodlights in your back yard, reading lights, household lamps, and low-power accent lighting.
How LED Compares to other Lighting
60 Watt incandescent bulb; lasts 1000 hours; cost $2.00; heat 85%energy
–CFL replacement uses 14 Watts; lasts 8,000 hours; cost $2.00; heat 65%
–LED replacement uses 12 Watts; lasts 45,000 hours; cost $24.00; basically 0%
The above information was discerned from Home Depot website on 5 January 2012. It is important to note that incandescent bulbs are in the process of being prohibited by the US government; two years ago the CFLs cost was $6.25 from the same store; using the same reasoning the cost will come down on LEDs as they become the norm.
With solar lighting being used more and more throughout the world, LED technology is a perfect fit. LEDs use much less power, which means less battery usage and drain so the light stay lit longer, plus LEDs last much longer longer than incandescent and CFL bulbs.
I have ordered solar powered floodlights, entrance lights and 6 foot pole lights for my retirement home in Arkansas. I plan to install them in March 2012.
The floodlights and entrance lights come on only at night when motion is detected. Perfect for security and having light to get my keys in the door locks. The pole lights I will use in key areas around the property. They glow at a low level all night, but when movement is about, they brighten. I have a rock fountain in back of the house where I’m going to test those pole lights. The entrance sconce lights (ordered 2) were $39 each (60 watt bulb equivalent), floodlights (ordered 3) were $79 each (2ea 150 watt bulb equivalent) and the 6 foot pole lights (ordered 2) were $97 each (20/60 watt bulb equivalent).
The advantage is they are solar powered and include, solar panel, light fixture, bulbs, lighting circuits and 12 foot cord (sconce and floods). So there is no electrical power used from the house and will work well as security lights while I’m still in Virginia.
I encourage anyone to start replacing their standard lighting with LED lighting because they make good sense. Incandescent bulbs burn hot, use a bunch of expensive electricity and don’t last long at all. CFL bulbs cost about the same as incandescent bulbs, still burn pretty hot and use much less electricity than incandescent, last about 8 times longer that incandescent, but use mercury and hard to dispose of safely. The future is LED technology with no heat to the touch, uses the same or less electricity as CFLs and lasts about 5 years of continual burn or approximately 20 years in normal use which is close to 3 times longer than CFLs.
Utilizing solar LED exterior lighting for you’re out of doors needs will save you a great deal of money from your electric bill. You will also save on bulb replacement as prices go down with supply and demand, just like the CFLs.