LED Bulb

LED BULB

An LED bulb is a semiconductor device that emits visible light when an electric current passes through it. The colour of the emitted light will depend on the type of materials used. With the help of the chemical compounds like Gallium Arsenide and Gallium Phosphide, the manufacturer can produce LED bulbs that radiates red, green, yellow and orange colours. Displays in digital watches and calculators, traffic signals, street lights, decorative lights, etc., are some examples for the use of LEDs.

1. Seven Segment Display

A ‘Seven Segment Display’ is the display device used to give an output in the form of numbers or text. It is used in digital meters, digital clocks, micro wave ovens, etc. It consists of 7 segments of LEDs in the form of the digit 8.

These seven LEDs are named as a, b, c, d, e, f and g (Figure 4.12). An extra 8^th LED is used to display a dot.

2. Merits of a LED bulb

·                 As there is no filament, there is no loss of energy in the form of heat. It is cooler than the incandescent bulb.

·                 In comparison with the fluorescent light, the LED bulbs have significantly low power requirement.

·                 It is not harmful to the environment.

·                 A wide range of colours is possible here.

·                 It is cost-efficient and energy efficient.

·                 Mercury and other toxic materials are not required.

One way of overcoming the energy crisis is to use more LED bulbs.