Lightbulb

Lightbulb

- Historians found that there is more then 20 inventors, who were trying to invent perfect lightbulb. But Thomas Alva Edison, an American inventor and businessman, is considered for inventor of lightbulb, which is today an integral part of our everyday life. Edison’s version of lightbulb was the best because of a combination of three factors: an effective incandescent material, a higher vacuum than other were able to achieve and a high resistance that made power distribution from a centralized source economically viable. The first public successful test of lightbulb was on October 22, 1879.

- What is the incandescent lightbulb?

It makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process returns metal to the filament, extending its life. The light bulb is supplied with electrical current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections. Incandescent bulbs are produced in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent lamp is widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting.

- Before lightbulb people used candles, torches, candle lamps, or people used only light of the sun or the moon.

- I found these information on the internet. I used only wikipedia.