We always enjoy history videos from [The History Guy] but they don’t always cover technology history. When they do, though, we enjoy them twice as much as with the recent video he posted on the history of neon signs. Of course, as he points out, many neon lights don’t have actual neon in them — they use various noble gasses depending on the color you want. Sure, some have neon, but the name has stuck.
The back part of the video is more about the signs themselves, but the early portion talks about [William Ramsay], a Scot chemist who started extracting component gasses out of the atmosphere. The first one found was argon and then helium. Krypton and neon were not far behind. The other noble gas, Xenon, also fell to his experiments. He and another scientist won the Nobel for this work.
Continue reading “The History Of Neon Lights”
Neon lights are that kind of nostalgic item that everybody seems to love. The neon lamp is a type of gas discharge lamp, they generate light when an electrical discharge travels through an ionized gas, or plasma. When the voltage between the electrodes exceeds certain threshold, the gas ionizes and begins conducting electricity. The basic process that generates light is the return of the ions to the ground energy state, with the emission of a photon of light. The light color depends on the emission spectra of the atoms in the gas, and also on the gas pressure, among other variables. Gas discharge lamps can be classified by the pressure of the gas:
- Low pressure: includes the neon lamp, fluorescent lamps and low pressure sodium lamps.
- High pressure: such as the metal halide, high pressure sodium and mercury vapor lamps.
Another classification comes from the heating method of the cathode:
- Hot cathode lamps: the electric arc between the electrodes is created via thermionic emission, where electrons are expelled from the electrodes because of the high temperature.
- Cold cathode lamps: In these, the electric arc results from the high voltage applied between the electrons, that ionizes the gas and conduction can take place.
High intensity lamps are another type of gas discharge lamp where a high power arc is formed between tungsten electrodes. Power levels of several kilowatts can be easily produced this type of lamp. Of course we can’t forget to mention nixie tubes, which are a type of cold cathode neon lamp, popular for building retro clocks. Fortunately, they are now in production again.
Continue reading “The Many Uses Of The Neon Lamp”