The structure and function of fluorescent lamps: there is a filament at each end of the fluorescent tube, and the main material of the filament is tungsten filament. At the temperature of more than 2000, tungsten is a rich electron emitter. It is difficult to have the material to receive the high temperature. The general electrode uses the emitting material to strengthen the electron emission, which is usually applied to the electrode. The tube is filled with a small amount of argon and thin mercury vapor. The inner wall of the lamp is coated with phosphor, and when the gas between the two filament conducts electricity, it sends out ultraviolet light, so that the phosphor can emit visible light.
The characteristics of the fluorescent lamp: the light tube starts to ignite a high pressure, when the normal light is allowed to pass only a small current, then the voltage at both ends of the lamp is lower than that of the power supply.