LED lights are bright and colorful and can be found in signs and displays as well as airport landing strips. Ever wonder how they work or what the different colors are?
How a Neon Light works
A fake neon sign can be made by you, but real neon lights are made from a tube of glass filled with a small amount of neon gasoline. Because it is one of the noble gas, neon is used. These elements have one characteristic: each atom has an electron shell filled with electrons. This means that they don’t react with other molecules and it takes a lot more energy to remove an element.
An electrode is located at each end of the tube. The neon light can be used with either AC (alternating current or direct current), however, if DC current was used, the glow will only be visible around one electrode. Most neon lights that you see use AC current.
An electric voltage of approximately 15,000 volts is applied to the terminals. This provides enough energy to remove one outer electron from the neon atoms. The insufficient voltage will cause the electrons to lose their kinetic energy and nothing will be done. The negatively charged neon atoms ( Cations) attract to the negative terminal while the free electrons attracted to it. These charged particles are called plasma and complete the electrical circuit of the lamp.
Where does the light come from? The tube’s atoms are moving around hitting each other. They also transfer energy to one another, and a lot of heat is generated. Some electrons are released from their atoms while others get enough energy to be ” excited “. They are in a higher energy state. Exciting is similar to climbing a ladder. An electron can be at a specific rung on the ladder and not all along its length. By releasing the energy as a photon, an electron can return to its initial energy (ground state). The distance between the excited energy and the original energy determines the color of the produced light. This interval is similar to the distance between rungs on a ladder. Each excited electron in an atom emits a particular wavelength of light. This means that each excited noble gas emits a particular color of light. This is the reddish-orange color of neon.
What are other colors of light?
There are many different signs that you can see, so it is not surprising that there are so many. You can produce other colors of light than neon orange-red. There are two main methods. The other way to make colors is to use another gas or a combination of gases. Each noble gas emits a particular color of light, as mentioned previously. For example, helium is pink and krypton green while argon emits blue light. Intermediate colors can be created if the gases are mixed.
Another way to create colors is to coat glass with a chemical or phosphor that glows a particular color when it’s energized. Modern fluorescent lamps no longer use neon because of the wide variety of coatings that are available. Instead, they rely on mercury/argon and a phosphor coating. A noble gas light is a light that glows in a particular color if it’s clear.
You can also control the energy that is supplied to the light to alter the color. Although you may only see one element in a light source, there are many energy levels that can be used to excite electrons. This corresponds to the spectrum of light an element can produce.
A Brief History of the Neon Light
Heinrich Geissler (1857)
- Geissler is known as the father of fluorescent lamps. Geissler’s “Geissler Tube” is a glass tube that contained a partial vacuum of gas and had electrodes on either end. To produce light, he experimented with arcing current through different gases. This tube was used as the base for the fluorescent, neon, mercury vapor, fluorescent, and sodium lamps.
William Ramsay & Morris W. Travers (1898).
- Ramsay and Travers invented a neon lamp. However, neon was very rare so it was not economically feasible.
Daniel McFarlan Moore (1904).
- Moore installed the Moore Tube commercially. It ran an electric current through carbon dioxide and nitrogen to produce light.
Georges Claude (1902)
- Although Claude didn’t invent the neon lamp himself, he did develop a way to separate neon from the air. This made the light more affordable. Georges Claude demonstrated the neon light at the Paris Motor Show in December 1910. Claude started with Moore’s idea, but he developed a reliable lamp design and dominated the light market until the 1930s.