An electric light source is a device that converts electrical energy into light energy. The electric light source is usually called an electric light.
Light is an electromagnetic wave. The light emitted by an electric light source and the light of nature are both electromagnetic waves. The electric light source that emits visible light with a wavelength of 380-780nm is called an illuminating light source. Ultraviolet rays and infrared rays are invisible light, and the electric light source that emits these two kinds of light is called a radiation source.
The electric light source is the main body of the lighting system, and it has made great progress in the past 200 years. At present, there are more than 3000 kinds of electric light sources and more than 50,000 specifications, which has created good conditions for mankind to enter the era of light culture of modern civilization.
There are many types of electric light sources. According to the working principle, they can be divided into two categories: solid light source and gas discharge light source. The specific types are as follows:
1. Solid light source
1. Thermal radiation light source is divided into: incandescent lamp (vacuum incandescent lamp, gas-filled incandescent lamp) halogen tungsten lamp (iodine tungsten lamp, bromine tungsten lamp)
2. Electroluminescent light source is divided into: electroluminescent lamp (EL light-emitting board) semiconductor light-emitting lamp (LED)
2. Gas discharge light source
1. Glow discharge lamp: neon lamp, neon lamp
2. Arc discharge lamps: low-pressure lamps (fluorescent lamps, low-pressure mercury lamps) high-pressure lamps (carbon arc lamps, high-pressure mercury lamps, metal halide lamps, high-pressure xenon lamps, high-pressure sodium lamps)
