LIGHT EMITTING DIODE

What is Light Emitting Diode(LED)?
A Light Emitting Diode(LED) is a semi conductor device that emits visible light when current flows through it. LED is the source of light which converts electrical energy to Light Energy. PN junction diode emits Monochromatic Light , occurring at single wave length.

Light Emitting Diodes are especially PN junction Diodes operated in Forward Bias.

Early LED's can produce Red Light only. But modern LED's can produce different colors including Red,Green,Blue(RGB).We can produce white light also with the help of advancement in the technology. LED requires 1.5-4 V and 10mA to power on. One needs to use a series resistor to prevent overloading.

LED CIRCUIT

In electronics , the basic LED circuit is an electric circuit used to power a Light Emitting Diode(LED).
This simplest circuit consists of a voltage source and a series resistance and an LED. Optionally a switch can be used to open or close the circuit. This switch may be replaced with another component or circuit to from a continuity tester.

HOW DOES LED WORK?

Each time an electron recombines with a positive charge, Electric potential energy is converted into electromagnetic energy. For each recombination of negative and positive charge a quantum of electromagnetic energy is emitted in the form of light with a frequency characteristics of the semi conductor material.
 
 Here are the some of the Advantages of LED over incandescent and fluorescent illuminating devices.
 1.Low Power requirement: Most of the LED's can be operated with Battery supplies.
 2.High Efficiency: Most of the power supplied to the LED has been converted into radiation with    minimum heat production.
3.Long Life: LED's have long life span (often more than 100,000 hours) .If the LED is properly designed then it can be function for decades.

APPLICATIONS :

1.LED's are used in Digital Clocks and display purpose in many applications.
2.They are used in Traffic Controlled systems, Indicator lights and remote controlled devices.
3.As the LED's have long life span they can replace traditional light bulbs in several areas. 

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