The development of neon lights can be traced back to the study of gas discharge by British physicist and chemist Faraday. When the current passes through a gas containing a small amount of positive and negative ions, it is affected by ultraviolet rays, cosmic rays, and trace amounts of radioactive substances. Under the effect of a high enough applied voltage After moving and colliding with neutral gas molecules, the neutral molecules are ionized, so the number of ions is doubled.
When the current passes through the gas, it is also accompanied by a phenomenon of luminescence, the so-called glow discharge. The color of its light varies with the gas inflated. Faraday’s theory and its experimental effects laid a solid foundation for the development of neon technology.
Neon lights originated in France. The diameter of the lamp body glass tube used at that time was 45 mm. First, the glass neon tube was bent into the required text or image, and then a transformer with a voltage of more than 10,000 volts was used to supply power to make it glow. At that time, the electrodes at both ends of the lamp were made of graphite, and the interior was filled with nitrogen or carbon dioxide gas, the former would emit red light, and the latter would emit white light.
Because these two gases are more vivid, it is easy to react chemically with the graphite electrode. The graphite sputtered from the cathode quickly forms a black film layer on the inner wall of the glass tube, and absorbs a lot of the gas charged into the lamp tube, making the lamp tube inflatable. The pressure drops quickly, causing the neon to have a short lifespan.
In order to deal with this problem at that time, a special electromagnetic valve was added to the neon light tube, and a certain amount of gas was added to the lamp after the neon light was used for a period of time, but this did not fundamentally defeat the above shortcomings. . Therefore, this kind of lamp not only has a short lifespan, a messy manufacturing process, but also is expensive and difficult to widely use.
Between 1907 and 1910, scientists Claude and Linde discovered the fractionation of liquid air. Using this creation, a certain amount of inert gas is filled in the neon light, which significantly slows down the consumption rate of the gas inside the lamp tube, and the color is also rich, which can produce red, green, blue, yellow and other colors. On the eve of World War II, photoluminescence materials were developed.
This material can not only announce various colors of light, but also has high luminous power, which we call phosphors.
After the phosphor is used in the manufacture of neon lights, the brightness of the neon lights is not only significantly improved, but also the color of the lamps is more dazzling and changeable, which also simplifies the process of making lamps. Therefore, after the end of the Second World War, neon lights have been expanded rapidly.
Neon lights are divided into 3 types according to the powder coating on the inner wall of the glass tube: the first is that the inner wall of the glass is not coated with any fluorescent powder, and the colorless and transparent glass neon tube is directly selected , which is generally called bright tube; The inner wall of the transparent glass tube is coated with fluorescent powder, we call it a powder tube; the third is to use a colorful glass tube, and evenly coat the inner wall of the glass tube with fluorescent powder, we call it a color tube.
The life of neon lamps is normally higher than that of fluorescent lamps and incandescent lamps. To reach this level, it is necessary to do three things:
- The level of manufacturing personnel is excellent, and the exhaust personnel bombarded properly and thoroughly;
- The transformer that starts it shall not be overloaded;
- Detailed and reasonable equipment for equipment personnel; as long as the above requirements are met, practice has proved that the life of neon lamps is higher than that of fluorescent lamps and incandescent lamps.
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