Who invented the first electric light in the world when?

An Englishman, Humphrey David, made an arc lamp with 2000 batteries and two carbon rods, but this kind of arc lamp is too bright and generates too much heat, which is not durable and can't be used in ordinary places at all.

1854, Henry Gaubert, a German watchmaker who immigrated to the United States, made the first practical electric lamp with carbonized bamboo wire in a vacuum glass bottle, which lasted for 400 hours, but he did not apply for a patent in time.

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.

Extended information Ordinary incandescent lamps are commonly used incandescent bulbs.

Features:

A widely used light source can emit warm and faint yellow light, which is what most of us think of as a light bulb. It has the advantages of low price, good color rendering (Ra= 100), continuous dimming and simple structure. Therefore, tungsten filament bulbs also have different styles to match different lamps.

However, tungsten filament bulbs have short life, low light efficiency, no power saving and low temperature, so don't be too close to paper, textiles or plastic products.

The causes of incandescent lamp blackening

The tungsten wire that glows in the electric lamp can remain stable at extremely high temperature, and it will not melt, but sublimate directly into gas. When the lights are turned off, the temperature drops, and the tungsten gas condenses into a solid again, covering the inner wall of the bulb. Because tungsten is a black solid, after the incandescent lamp is used for a long time, tungsten accumulates repeatedly on the inner wall of the lamp, and the bulb will turn black.

References:

Baidu encyclopedia-electric light