Changes brought by electric light: converting electric energy into light energy has greatly promoted the progress of human civilization, and you can still see light at night? .
Lighting electric light sources are generally divided into incandescent lamps, gas discharge lamps and other electric light sources. In the green lighting project, various light sources can be selected according to specific conditions.
Electric light is a device that converts electric energy into light energy to provide lighting, which appeared in the second industrial revolution. Its working principle is as follows:
When current passes through the filament (tungsten filament, melting point above 3000℃), heat is generated, and the spiral filament continuously accumulates heat, so that the filament temperature reaches above 2000℃. When the filament is incandescent, it shines like hot iron. The higher the temperature of the filament, the brighter the light it emits.
Extended data:
The earliest practical electric lamp was incandescent lamp, but before the birth of incandescent lamp, an Englishman Humphrey David made an arc lamp with 2000 batteries and two carbon rods, but this kind of arc lamp was too bright, generated too much heat and was not durable, so it could not be used in ordinary places.
1854, Henry Goldbert, a German watchmaker who immigrated to the United States, made the first practical electric lamp in a vacuum glass bottle with a carbonized bamboo wire, which lasted for 400 hours, but he did not apply for a patent in time.
1860, joseph swan, an Englishman, also made a carbon filament lamp, but he failed to obtain a good vacuum environment to make the carbon filament work for a long time. It was not until 1878 that the vacuum technology in Britain developed to the required level that he invented a light bulb powered by carbon wire under vacuum and obtained a British patent. Swan's own house is the first private house with electricity lighting in Britain.
1874, two electrical technicians in Canada applied for a patent for electric light: nitrogen was filled under a glass bulb and charged carbon rods were used to emit light, but they did not have enough financial resources to continue to improve this invention, so they sold the patent to Edison in 1875. Edison tried to improve the filament after purchasing the patent, and finally made a carbonized bamboo filament lamp that could last for 1200 hours in 1880.
However, after the US Patent Office ruled that Edison invented the carbon filament incandescent lamp, the patent was invalid. After years of litigation, Henry Goebbels won the patent, and finally Edison bought the patent from Goebbels poor widow. In Britain, Swan accused Edison of patent infringement. Later, they settled out of court and set up a joint venture company in Britain on 1883. Swan later sold his shares and patents to Edison.