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| Let's Know more about LED |
What is an LED? Light-emitting diodes, or LEDs, have been around for more than 30 years, but were used only in small electronic devices as indicator lamps until recently. LED, as the name states are diodes. A diode is a semiconductor device. Semiconductor diodes have a junction separated by two materials one material has a surplus of positive charge electrons, and the other a surplus of negative charge electrons. When you apply a forward voltage, electrons are brought together. They combine near the junction, and this releases light energy.
LED Advantages:
*Energy Saving
Generally, one LED is to operate at 2-3.6V and 0.02-0.03A, that mean, it need no more than 0.1W.
*Safety Operation
LEDs operate on extra low voltage which results in less cost and more safety than current incandescent lights. LEDs emit very little heat which makes them extremely safe to use.
*Long Life Span
Quality LEDs have a measured lifetime of up to 100.000 hours operating at right voltage and current.
*Different Colours
LEDs have optional colours for decorative lighting , and they can create vioriety different kinds of atmosphere, which makes the world very beautiful.
*Environmental Protection
LEDs produce cold lighting source which makes less lighting pollution. LEDs are made from no-toxic materials, unlike the fluorescent lights that have mercury that will cause a pollution danger.
The Electrical Characteristics of LED
A typical LED has a forward voltage rating between 2 and 4 Volts. The red, yellow, and orange types have a forward voltage around 2 Volts, while the blue, white, and true green types have a forward voltage around 3.3 Volts. The typical drive current for LEDs is 20 milliamperes (mA). From this you can see an LED uses a modest amount of power, a few tens of milliwatts compared to the few tens of Watts an incandescent bulb uses. In other words, the power used by an LED is one thousandth of that used by a familiar light bulb. Since an LED is a diode, even after it ceases to produce light, it will still use power, and if connected with other LED' s in series should allow the others to continue working.
White LED
The manufacturing process to create white is to combine red, green, and blue coloured Phosphor. When you get the right mix, the effect is white light. This is the same way your television works, the white object on the screen is really depicted using dots of red, green and blue lit up in proportions that form an impression of white, hence the cost of the white LED is governed by this expensive manufacturing process. Our white LEDs are photo-metrically tested to comply within the correct chromaticity boundaries for the Australian Design Rules. Some whites depicting a blueish (Cool White) or yellowish (Warm White) tinge are the product of the outer edges of the pure white material and are sold off for torch lights and decorative lights, however inferior quality manufacturers will try to use these for automotive lighting because they are less expensive.
The Future of LED lighting
LEDs - light emitting diodes ¨C have been popular for some years as indicator lights. More than you probably realise, these little lights are everywhere in your every day life: there is the red light of your digital clock at night, the green light from your cell phone display, ¡ LEDs are all around us. In the near future, they will be commonly used as an actual light source.
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