An invention that brought huge changes to human life: the electric light; the inventor was Edison;
The changes brought by the electric light: converting electrical energy into light energy greatly promoted human civilization With progress, can we see light at night?
Lighting electric light sources are generally divided into three categories: incandescent lamps, gas discharge lamps and other electric light sources. In green lighting projects, various light sources can be selected according to specific conditions.
Electric light is a device that converts electrical energy into light energy to provide lighting. It appeared in the second industrial revolution. Its working principle is:
Current passes through the filament (tungsten filament, melting point When the temperature reaches above 3000℃, heat is generated. The spiral filament continuously gathers heat, causing the temperature of the filament to reach above 2000℃. When the filament is in an incandescent state, it emits light just like red-hot iron. The hotter the filament, the brighter the light it emits.
Extended information:
The earliest practical electric light was an incandescent lamp, but long before the birth of incandescent lamps, the Englishman Humphry Davy used 2000 batteries and two carbon rods to An arc lamp was made, but this arc lamp was too bright, produced too much heat and was not durable, so it could not be used in general places.
In 1854, Henry Goebel, a German watchmaker who immigrated to the United States, used a carbonized bamboo wire placed in a vacuum glass bottle to make the first practical electric lamp, which lasted 400 times. hours, but he did not apply for a patent in time.
In 1860, the Englishman Joseph Swan also made a carbon filament electric lamp, but he failed to obtain a good vacuum environment that could keep the carbon filament working for a long time. It was not until 1878 that British vacuum technology developed to a desirable level that he invented a light bulb powered by carbon filaments under vacuum and obtained a British patent. Swann's own house was the first private house in Britain to be lit by electricity.
In 1874, two Canadian electrical technicians applied for a patent for an electric light: filling nitrogen gas under a glass bulb and using an electrified carbon rod to emit light. However, they did not have enough financial resources to continue to perfect this invention. So the patent was sold to Edison in 1875. After purchasing the patent, Edison tried to improve the filament, and finally created a carbonized bamboo filament lamp in 1880 that could last for 1,200 hours.
However, the U.S. Patent Office ruled that Edison's carbon filament incandescent lamp invention was behind others and the patent was invalid. After years of legal battles, Henry Goebbels won the patent, which Edison eventually purchased from Goebbels' impoverished widow. In England, Swann sued Edison for patent infringement, and they later settled out of court and established a joint company in England in 1883. Swann later sold his shares and patents to Edison.