Crackle tube


Crackle tube
A small battery powered Luminglas device, turned on.
A small battery powered Luminglas device, turned off.

A crackle tube is a type of plasma lamp that is used most commonly in museums, night clubs, movie sets, and other applications where its appearance may be appealing for entertainment. Such a device consists of a double walled glass tube with a hollow center. The cavity between the inner and outer glass tubes is filled with thousands of small phosphor coated glass beads. A 5–14 kV transformer sends a very low power, high frequency electrostatic discharge into the bead filled cavity, producing filaments of light that simulate lightning. Crackle tubes get their name not because of the sound they produce but rather because of the appearance of their internal behavior. The "lightning" (filaments or streamers) is forced around and in between the phosphor-coated glass beads, due to the beads' dielectric nature. In so doing, the phosphor is excited by the electrical energy and fluoresces producing visible light. Like plasma globes, crackle tubes respond to touch; the filaments appear to be "attracted" toward the point of contact and usually become more luminous (brighter) as the electricity is grounded. The tubes are also filled with a noble gas like neon, argon, or xenon which acts as the electron transfer medium of the cavity. The gas is typically kept at only slightly above atmospheric pressure.

Typically, crackle tubes are cylindrical in geometry, however, they can be made into virtually any solid shape, even flat plates (trademarked by the name "Luminglas" [1]). The filaments can also be made to any color by combining different chemicals with the base phosphor. The chemical that is used to produce blue filaments is also responsive to ultraviolet light. UV light may have something to do with how the phosphor is excited by the ESF (electrostatic field). The filaments themselves can change color as they progress along the length of the tube. This effect is created by using glass beads with different chemical coatings on them, and the color of the filament changes as the ESD transitions from one color layer to another. Chemical coatings can also be combined onto a single coating, allowing for a crackle tube to have multiple simultaneous filaments of several different colors.

Crackle tubes appear white when viewed in their off state under normal lighting conditions. Their luminosity, or light intensity, depends on several factors, but generally crackle tubes are not very bright when compared to a fluorescent light or incandescent lamp. Still, they are quite bright compared to similar devices. However, they are best viewed in darkness. Their transformers can also be linked to an acoustic modulator, allowing the tubes to 'respond' to music or ambient noise.

See also


References

  1. ^ http://www.strattman.com/products/luminglas/index.html

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Neon sign — …   Wikipedia

  • Neon lighting — Times Square, New York City, has been famous for elaborate neon lighting displays since th …   Wikipedia

  • Plasma lamp — Plasma lamps (also variously plasma globes, balls, domes, spheres, or orbs) are novelty items which were most popular in the 1980s. The plasma lamp was invented by Nikola Tesla after his experimentation with high frequency currents in an… …   Wikipedia

  • Plasma globe — Not to be confused with Sulfur lamp or Plasma lamp. A plasma globe Plasma globes, or plasma lamps (also called plasma balls, domes, spheres, tubes or orbs, depending on shape), are novelty items that were most popular in the 1980s.[1 …   Wikipedia

  • Raku ware — A 16th century black Raku style chawan, used for thick tea (Tokyo National Museum) File:Tea bowl with designs of pine boughs and interlocking circles, unknown raku ware workshop, Kyoto, 18th 19th Cent, Freer Gallery of Art.jpg Tea bowl with… …   Wikipedia

  • arts, East Asian — Introduction       music and visual and performing arts of China, Korea, and Japan. The literatures of these countries are covered in the articles Chinese literature, Korean literature, and Japanese literature.       Some studies of East Asia… …   Universalium

  • radio — /ray dee oh /, n., pl. radios, adj., v., radioed, radioing. n. 1. wireless telegraphy or telephony: speeches broadcast by radio. 2. an apparatus for receiving or transmitting radio broadcasts. 3. a message transmitted by radio. adj. 4. pertaining …   Universalium

  • pottery — /pot euh ree/, n., pl. potteries. 1. ceramic ware, esp. earthenware and stoneware. 2. the art or business of a potter; ceramics. 3. a place where earthen pots or vessels are made. [1475 85; POTTER1 + Y3] * * * I One of the oldest and most… …   Universalium

  • Trinitron — A 1985 27 Trinitron Trinitron is Sony s brand name for its line of aperture grille based CRTs used in television sets and computer display monitors. One of the first truly new television systems to enter the market since the 1950s, the Trinitron… …   Wikipedia

  • Fireworks — Firework redirects here. For other uses, see Fireworks (disambiguation). Pyrotechnics portal …   Wikipedia