The use of fluorescent lamps has proven to be advantageous compared incandescent lights. Thus they are considered as a powerful alternative to the traditional lighting. The main features that attract consumers to fluorescent lights are longer life, less heat emission, less expensive, less energy consumption and more light output. Fluorescent lights are electronic devices that work through the process of conduction in a gas tube. A fluorescent light is actually a gas discharge tube which excite out mercury vapors with the aid of electricity. These excited mercury atoms develop some ultraviolet light of short wavelengths which makes phosphor to glow or in other words fluoresce and produce visible light. That is why they are called as fluorescent lights. This is the working principle.
The different points discussed below will clearly depict how fluorescent lights are made:
Glass: Like any other ordinary incandescent lights, the body of fluorescent lights is also made using glass material. The tubes or spirals are made by blowing molten glass through molds of desired shapes by using compressed air. Thus clear spirals or tubes shall be made with its ends open. The glass is made very thin, so that all the tubes and bulbs thus made are highly fragile and light.
Phosphors: After the glass tubes of desired shape and length are made. The next step is to coat a layer of phosphorus on the inner walls of this tube. The property of phosphor to convert ultra violet light into visible light is used here. The electrically excited mercury vapors allows the ultra violet light waves to power up and hence the tube or light bulb gets lighted up.
Filling gases: After the glass tube gets coated with a thin layer of desired phosphor salt, one end of the tube shall be fixed up with a cathode together with a cap. The other end gets fastened by a small glass tube. Then all air from the glass tube is removed using a vacuum tube. After that a small drop of mercury is allowed to pass to the tube along with some of the inert gases like argon, neon and xenon. The last step is sealing the free end of the tube with yet another cathode and a cap.
Electronics: The basic electronic component in the fluorescent light tubes is the cathode parts that are fixed with their capping on each end of the tube. The cathode component is actually a coil made of tungsten wire. The coil has a strong coating of strontium, calcium oxides and barium which conducts electricity into the tube. Hence the gasses filled inside gets excited. Thus free electrons are created by the cathodes at each end creating a plasma state inside the light tubes. A power supply is also required for power regulation. Hence while fixing such light bulbs; there is the need for separate ballast for power control.