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LEDs

, Posted by ADMIN at 3:48 AM

Light emitting diodes (LEDs) are semiconductor light sources. The light emitted from LEDs varies from visible to infrared and ultraviolet regions. They operate on low voltage and power. LEDs are one of the most common electronic components and are mostly used as indicators in circuits. They are also used for luminance and optoelectronic applications.

Based on semiconductor diode, LEDs emit photons when electrons recombine with holes on forward biasing. The two terminals of LEDs are anode (+) and cathode (-) and can be identified by their size. The longer leg is the positive terminal or anode and shorter one is negative terminal.

The forward voltage of LED (1.7V-2.2V) is lower than the voltage supplied (5V) to drive it in a circuit. Using an LED as such would burn it because a high current would destroy its p-n gate. Therefore a current limiting resistor is used in series with LED. Without this resistor, either low input voltage (equal to forward voltage) or PWM (pulse width modulation) is used to drive the LED.



Why LED's ?
This is a question that millions of people will be asking for the foreseeable future. The answer is Simple. LED bulbs can save you thousands of dollars on your Electric Bill.  LED bulbs will help make the Planet we live, a cleaner one. LED bulbs last so long, you won't need to change them for years. Finally, the incandescent Fluorescent bulb will be obsolete in 10 years.





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