g？ Bel) invented the reliable light bulb with the same principle and material decades before Edison, and many people made many contributions to the invention of the light bulb before Edison. +080 1 year, British chemistry.
Scientist David electrified the platinum wire to make it glow. He also invented the electric candle in 18 10, which was illuminated by an arc between two carbon rods. 1854, Henry Goebbels used carbonized bamboo filaments to glow under a vacuum glass bottle.
Light. Today, his invention seems to be the first incandescent lamp with practical value. The light bulb he tested at that time could last for 400 hours, but he didn't apply for a design patent immediately.
1850, the Englishman Joseph Wilson Swan began to study electric lights. 1878, he obtained a British patent for a light bulb powered by carbon wire under vacuum and started to set up a company in Britain to install electric lights in every household.
1874, two electrical technicians in Canada applied for a patent for electric light. They filled the glass bulb with nitrogen to make the charged carbon rod glow. But they didn't have enough financial resources to continue developing this invention, so they sold the patent to Edison at 1875.
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After purchasing the patent, Dixon tried to improve the filament used. 1879, he changed to carbon filament to make a light bulb, which was successfully maintained for 13 hours. By 1880, his carbonized bamboo filament bulb was successfully maintained in the laboratory.
1200 hours. But in Britain, Swan sued Edison for patent infringement and won. Edison's electric light company in England was forced to let Swan join as a partner. But later, Swan sold his rights and patents.
Edison. In America, Edison's patent has also been challenged. The United States Patent Office ruled that his invention had a criminal record and was invalid. Finally, after years of litigation, Edison obtained the patent right of carbon filament incandescent lamp.
Edison's greatest discovery was that tungsten was used as the filament instead of carbon. Later, in 1906, General Electric invented the manufacturing method of tungsten wire for electric lamps. Finally, the method of manufacturing tungsten filament at a low price was solved, and the tungsten filament bulb has been used ever since.
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The biggest problem of light bulb is the sublimation of filament. The temperature will change due to the small resistance difference on the tungsten wire. Where the resistance is high, the temperature rises higher and the tungsten wire sublimates faster, which leads to the thinning of the tungsten wire and the further increase of the resistance.
A growing cycle; Finally, the tungsten wire was burnt out. Later, it was found that replacing vacuum with inert gas could slow down the sublimation of tungsten wire. Today, most light bulbs are filled with nitrogen, argon or krypton. So technology is constantly improving.