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LED's for Home Lighting
Introduction to LED's
In simple terms, LED's are simple devices made up of semiconductors which emit light when electricity is applied to them. LED's or Light Emitting Diodes are becoming extremely popular owing to their extremely low power consumption, bright light, and longer life. Till a few years back, LED's were being used in Avionics, such as beacons, landing guidance lights, etc, but, the advances in the LED technology and drastically reduced prices have made them extremely popular for other applications. Most of us would have seen the LED's are fast replacing the buggy old signals on roads and railway lines. This is because of extremely compact design, high durability and higher light intensity adding to higher visibility and power efficiency the LED technology has provided us.Excerpts taken from wikipedia
A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Appearing as practical electronic components in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness. Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.
Wikipedia Link: Light-emitting diode - Wikipedia, the free encyclopedia
Basic Design of an LED
*www.off-road.com/aimages/articlestandard/trucks4x4/242009/603132/LED-labelled.jpg
Shapes and sizes in which LED's are available
*upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Verschiedene_LEDs.jpg/640px-Verschiedene_LEDs.jpg*linova.cn/upfile/hpledcomp/DGL-100-W.jpg*linova.cn/upfile/ledcomp/5050w.jpg*linova.cn/upfile/hpledcomp/1-3W.jpg*linova.cn/upfile/hpledcomp/1-3WnoBase.jpg
Various Colours Available in LED's and the Semiconductor Materials Used in Producing Them
Conventional LEDs are made from a variety of inorganic semiconductor materials. The following table shows the available colors with wavelength range, voltage drop and material:
From Wikipedia
Color Wavelength [nm] Voltage drop [ΔV] Semiconductor material Infrared λ > 760 ΔV < 1.63 Gallium arsenide (GaAs)
Aluminium gallium arsenide (AlGaAs)Red 610 < λ < 760 1.63 < ΔV < 2.03 Aluminium gallium arsenide (AlGaAs)
Gallium arsenide phosphide (GaAsP)
Aluminium gallium indium phosphide (AlGaInP)
Gallium(III) phosphide (GaP)Orange 590 < λ < 610 2.03 < ΔV < 2.10 Gallium arsenide phosphide (GaAsP)
Aluminium gallium indium phosphide (AlGaInP)
Gallium(III) phosphide (GaP)Yellow 570 < λ < 590 2.10 < ΔV < 2.18 Gallium arsenide phosphide (GaAsP)
Aluminium gallium indium phosphide (AlGaInP)
Gallium(III) phosphide (GaP)Green 500 < λ < 570 1.9[SUP][55][/SUP] < ΔV < 4.0 Indium gallium nitride (InGaN) / Gallium(III) nitride (GaN)
Gallium(III) phosphide (GaP)
Aluminium gallium indium phosphide (AlGaInP)
Aluminium gallium phosphide (AlGaP)Blue 450 < λ < 500 2.48 < ΔV < 3.7 Zinc selenide (ZnSe)
Indium gallium nitride (InGaN)
Silicon carbide (SiC) as substrate
Silicon (Si) as substrate — under developmentViolet 400 < λ < 450 2.76 < ΔV < 4.0 Indium gallium nitride (InGaN) Purple multiple types 2.48 < ΔV < 3.7 Dual blue/red LEDs,
blue with red phosphor,
or white with purple plasticUltraviolet λ < 400 3.1 < ΔV < 4.4 Diamond (235 nm)[SUP][56][/SUP]
Boron nitride (215 nm)[SUP][57][/SUP][SUP][58][/SUP]
Aluminium nitride (AlN) (210 nm)[SUP][59][/SUP]
Aluminium gallium nitride (AlGaN)
Aluminium gallium indium nitride (AlGaInN) — down to 210 nm[SUP][60][/SUP]Pink multiple types ΔV ~ 3.3[SUP][61][/SUP] Blue with one or two phosphor layers:
yellow with red, orange or pink phosphor added afterwards,
or white with pink pigment or dye.[SUP][62][/SUP]White Broad spectrum ΔV = 3.5 Blue/UV diode with yellow phosphor
The beauty of LED's is that they are extremely compact, very power efficient and in the recent times, have become almost dirt cheap. Those who have some experience of working with electronics components and soldering can easily make an LED light with some cheap components and some LED's from any local electronics components store. However, for those who don't have any experience in working with electronics components and soldering, well, they can try working on with some simple circuit designs with less number of components. And at last, those who don't want to get their hands dirty buying components and putting up a circuit to power up the LED's can simply buy LED's and LED drivers and just connect the LED's to these drivers or simply go and buy LED lamps. Though, they are costly, but will simply save you the cost difference between the CFL's and the LED lamps within one year.
For those living in Delhi, BSES is offering (selling on subsidy) upto 4 LED lamps per bill. You can go and get one of these. *articles.timesofindia.indiatimes.c...8089_1_leds-cfls-and-incandescent-bulbs-light
Comparision Between LED, Incandescent and Compact Fluorescent Lamps
Source: www.designrecycleinc.comLink: *www.designrecycleinc.com/led comp chart.html
Comparison Chart
LED Lights vs. Incandescent Light Bulbs vs. CFLs
Energy Efficiency
& Energy Costs
*www.designrecycleinc.com/A1304-Pearlled-1.jpg
Light Emitting Diodes (LEDs)
*www.designrecycleinc.com/INBulb.jpg
Incandescent
Light Bulbs
*www.designrecycleinc.com/CFL.jpg
Compact Fluorescents (CFLs) Life Span (average) 50,000 hours 1,200 hours 8,000 hours Watts of electricity used
(equivalent to 60 watt bulb).
LEDs use less power (watts) per unit of light generated (lumens). LEDs help reduce greenhouse gas emissions from power plants and lower electric bills 6 - 8 watts 60 watts 13-15 watts Kilo-watts of Electricity used
(30 Incandescent Bulbs per year equivalent) 329 KWh/yr. 3285 KWh/yr. 767 KWh/yr. Annual Operating Cost
(30 Incandescent Bulbs per year equivalent) $32.85/year $328.59/year $76.65/year
Environmental
Impact *www.designrecycleinc.com/pearlled_30-h60.JPG
Light Emitting Diodes (LEDs)
*www.designrecycleinc.com/INBulb.jpg
Incandescent
Light Bulbs
*www.designrecycleinc.com/CFL.jpg
Compact Fluorescents (CFLs) Contains the TOXIC Mercury No No Yes - Mercury is very toxic to your health and the environment RoHS Compliant Yes Yes No - contains 1mg-5mg of Mercury and is a major risk to the environment Carbon Dioxide Emissions
(30 bulbs per year)
Lower energy consumption decreases: CO2 emissions, sulfur oxide, and high-level nuclear waste. 451 pounds/year 4500 pounds/year 1051 pounds/year
Important Facts *www.designrecycleinc.com/pearlled_30-h60.JPG
Light Emitting Diodes (LEDs)
*www.designrecycleinc.com/INBulb.jpg
Incandescent
Light Bulbs
*www.designrecycleinc.com/CFL.jpg
Compact Fluorescents (CFLs) Sensitivity to low temperatures None Some Yes - may not work under negative 10 degrees Fahrenheit or over 120 degrees Fahrenheit Sensitive to humidity No Some Yes On/off Cycling
Switching a CFL on/off quickly, in a closet for instance, may decrease the lifespan of the bulb. No Effect Some Yes - can reduce lifespan drastically Turns on instantly Yes Yes No - takes time to warm up Durability Very Durable - LEDs can handle jarring and bumping Not Very Durable - glass or filament can break easily Not Very Durable - glass can break easily Heat Emitted 3.4 btu's/hour 85 btu's/hour 30 btu's/hour Failure Modes Not typical Some Yes - may catch on fire, smoke, or omit an odor
Light Output *www.designrecycleinc.com/A1304-Pearlled-1.jpg
Light Emitting Diodes (LEDs)
*www.designrecycleinc.com/INBulb.jpg
Incandescent
Light Bulbs
*www.designrecycleinc.com/CFL.jpg
Compact Fluorescents (CFLs) Lumens Watts Watts Watts 450 4-5 40 9-13 800 6-8 60 13-15 1,100 9-13 75 18-25 1,600 16-20 100 23-30 2,600 25-28 150 30-55
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