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Encyclopedia > Neon lamp
Lighting neon lamp, two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp inside
Lighting neon lamp, two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp inside

A neon lamp is a gas discharge lamp containing primarily neon gas at low pressure. The term is also used for similar devices filled with other noble gases, usually to produce different colors. Image File history File links Please see the file description page for further information. ... Image File history File links Please see the file description page for further information. ... -1... Not to be confused with lightning. ... For other uses, see Neon (disambiguation). ... This article is about pressure in the physical sciences. ... Neon, like all noble gases, has a full valence (outermost) electron shell. ...

Contents

Description

A small electric current, which may be AC or DC, is passed through the tube, causing it to glow orange-red. The exact formulation of the gas is typically the classic Penning mixture, 99.5% neon and 0.5% argon, which has lower striking voltage than pure neon. The applied voltage must initially reach the striking voltage before the lamp can light. Once lit, the voltage required to sustain operation is significantly (~30%) lower. When driven from a DC source, only the negatively charged electrode (cathode) will glow. When driven from an AC source, both electrodes will glow (each during alternate half cycles). Neon lamps operate using a low current glow discharge. Higher power devices, such as mercury-vapor lamps or metal halide lamps use a higher current arc discharge. Electric current is the flow (movement) of electric charge. ... City lights viewed in a motion blurred exposure. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... A Penning mixture is a mixture of inert gas with another gas, with lower ionization voltage than either of them. ... For other uses, see Neon (disambiguation). ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Standard atomic weight 39. ... Breakdown Voltage (Insulator) = The minimum voltage that makes an insulator react as a conductor. ... Diagram of a copper cathode in a Daniells cell. ... Electric glow discharge is a type of plasma formed by passing a current at 100V to several kV through a gas - usually argon or another noble gas. ... A Mercury-vapor lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ... Example of a light source using a broad spectrum metal halide lamp pointing upward towards the sky. ... An electric arc can melt calcium oxide. ...

Lit neon lamp (NE-2 type)
Lit neon lamp (NE-2 type)

Once lit, a neon lamp has a negative resistance characteristic: increasing the current flow through the device increases the number of ions, thereby decreasing the resistance of the lamp and allowing even more current to flow. Because of this characteristic, electrical circuitry external to the neon lamp must provide a means to limit current flow through the circuit or else the current will rapidly increase until the lamp is destroyed. For indicator-sized lamps, a resistor is conventionally used to limit the current flow. Larger neon sign sized lamps often use a specially constructed high voltage transformer to limit the available current, usually by introducing a large amount of leakage inductance in the secondary winding. Download high resolution version (1280x960, 228 KB)Small Neon Lamp Photograph made by myself in 2004 --Rnbc 02:57, 2005 Feb 10 (UTC) File links The following pages link to this file: Neon lamp Categories: GFDL images | NowCommons ... Download high resolution version (1280x960, 228 KB)Small Neon Lamp Photograph made by myself in 2004 --Rnbc 02:57, 2005 Feb 10 (UTC) File links The following pages link to this file: Neon lamp Categories: GFDL images | NowCommons ... A VI curve with a negative differential resistance region Negative resistance or negative differential resistance (NDR) is a property of electrical circuit elements composed of certain materials in which, over certain voltage ranges, current is a decreasing function of voltage. ... This article is about the electrically charged particle. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Resistor symbols (non-European) Resistor symbols (Europe, IEC) Axial-lead resistors on tape. ... Neon signs are often used to advertise for hotels, bars and entertainment venues. ... Figure 1:Three-phase pole-mounted step-down transformer. ... Leakage inductance is that property of an electrical transformer that causes a winding to appear to have some pure inductance in series with the mutually-coupled transformer windings. ...


When the current through the lamp is lower than the current for the highest-current discharge path, the glow discharge may become unstable and not cover the entire surface of the electrodes. This may be a sign of aging of the indicator bulb, and is exploited in the decorative "flicker flame" neon lamps. However, while too low a current causes flickering, too high a current increases the wear of the electrodes by stimulating sputtering, which coats the internal surface of the lamp with metal and causes it to darken. Electric glow discharge is a type of plasma formed by passing a current at 100V to several kV through a gas - usually argon or another noble gas. ... Sputtering is a physical vapor deposition, PVD process whereby atoms in a solid target material are ejected into the gas phase due to bombardment of the material by energetic ions. ...

A small neon lamp (NE-2 type), with centimeter scale
A small neon lamp (NE-2 type), with centimeter scale

The flickering effect is caused by the differences of the ionization potential of the gas, which depends on spacing of the electrodes, temperature, ambient radiation, and the pressure of the gas. The potential needed to strike the discharge is higher than what is needed to sustain the discharge. When there is not enough current to ionize the entire volume of the gas around the electrodes, only partial ionization occurs and the glow forms around only part of the electrode surface. Convective currents make the glowing areas flow upwards, not unlike the discharge in a Jacob's ladder. A photoionization effect can also be observed here, as the electrode area covered with the discharge can be increased by shining light at the lamp. Image File history File linksMetadata Neon_lamp. ... Image File history File linksMetadata Neon_lamp. ... A spark plug. ... Photoionisation is a physical process in which a photon strikes an atom, ion or molecule, resulting in the ejection of an electron. ...


Applications

The digits of a Nixie tube.
The digits of a Nixie tube.

Most small neon (indicator-sized) lamps, such as the common NE-2, break down at between 90 and 110 volts. This feature enables their use as very simple voltage regulators or overvoltage protection devices. In the 1960s General Electric (GE), Signalite, and other firms made special extra-stable neon lamps for electronic uses. They even devised digital logic circuits, binary memories, and frequency dividers using neons. Such circuits appeared in electronic organs of the 1950s, as well as some instrumentation. At least some of these lamps had a glow concentrated into a small spot on the cathode, which made them unsuited to use as indicators. These were sometimes called "circuit-component" lamps, the other variety being indicators. A variant of the NE-2 type lamp, the NE-77, had three parallel wires (in a plane) instead of the usual two. It was also intended primarily to be a circuit component. Image File history File links Nixie. ... Josephson junction array chip developed by NIST as a standard volt. ... Electronic symbol for Voltage regulator A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. ... attention Electronic and other electric devices are rated at a certain voltage, and considerable damage can be caused by voltage that is higher than that for which the devices are rated. ... “GE” redirects here. ... Ge may refer to: Gê, a group of indigenous Brazilian tribes and their Ge languages Ge (Cyrillic) (Г, г), a letter of the Cyrillic alphabet Ge with upturn (Ґ, ґ), a letter of the Ukrainian alphabet Nikolai Ge, a Russian painter Gē, an ancient Chinese dagger-axe Ge (genus), a genus of butterflies Also... A logic gate is an arrangement of electronically-controlled switches used to calculate operations in Boolean algebra. ... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... For other uses, see Memory (disambiguation). ... FreQuency is a music video game developed by Harmonix and published by SCEI. It was released in November 2001. ... Classic Hammond B-3 organ. ...


Small neon lamps are used as indicators in electronic equipment. Called "tuneon's" in 1930's radio sets, they were fitted as tuning indicators, and would give a brighter glow as the station was tuned in correctly. Larger lamps are used in neon signage. Neon lamps, due to their low current consumption, are used as nightlights. Because of their comparatively fast response time, in the early development of television neon lamps were used as the light source in many mechanical-scan TV displays. They were also used for a variety of other purposes; since a neon lamp can act as a relaxation oscillator with an added resistor and capacitor, it can be used as a simple flashing lamp or audio oscillator. Also lately, the use of neon lights in automobiles has become a wide spread popularity and is becoming more common in today's growing custom car parts market. Neon lamps with several shaped electrodes were used as alphanumerical displays known as Nixie tubes. These have since been replaced by solid state devices. Novelty glow lamps with shaped electrodes (such as flowers and leaves), often coated with phosphors, have been made for artistic purposes. In some of these, the glow that surrounds an electrode is part of the design. Plasma globes use a central electrode excited by high voltage and high frequency. Their discharge is typically a thin stream that extends out to the bulb's inner surface, and wanders around randomly. Touching the glass makes the discharge move to where you touch it. a neon sign at night Neon signage is produced by the craft of bending glass tubing into shapes. ... Coleman lantern style nightlight A nightlight is a small, usually electrical, light source placed for comfort or convenience in indoor dark areas or areas that become dark at certain times. ... This schematic shows the circular paths traced by the holes in a Nipkow disk. ... A relaxation oscillator is an oscillator in which a capacitor is charged gradually and then discharged rapidly. ... See Capacitor (component) for a discussion of specific types. ... Sound is a disturbance of mechanical energy that propagates through matter as a wave. ... Oscillation is the periodic variation, typically in time, of some measure as seen, for example, in a swinging pendulum. ... The ten digits of a Z560M Nixie tube. ...


In AC-excited lamps, both electrodes produce light, but in a DC-excited lamp, only the negative electrode glows. Thus a neon lamp can be used to distinguish between AC and DC sources and to ascertain the polarity of DC sources.


Indicator-sized lamps can also be filled with argon, krypton, or xenon rather than neon, or mixed with it. While most operating characteristics remain similar, the lamps light with a bluish glow (including some ultraviolet) rather than neon's characteristic reddish-orange glow; the UV radiation then can be used to excite a phosphor coating of the inside of the bulb and provide a wide range of various colors, including white. A mixture of neon and krypton can be used for green glow. General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Standard atomic weight 39. ... For other uses, see Krypton (disambiguation). ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Standard atomic weight 131. ... For other uses, see Ultraviolet (disambiguation). ... Green screen A phosphor is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to light or energised particles such as electrons). ... For other uses, see Krypton (disambiguation). ...


History

Nikola Tesla displayed his neon lights at the World's Columbian Exposition in 1893. His innovations in this type of light emission were not regularly patented. Georges Claude invented a neon lamp in 1902, and displayed it in public in 1910. Nikola Tesla (1856-1943)[1] was a world-renowned Serbian inventor, physicist, mechanical engineer and electrical engineer. ... One-third scale replica of Daniel Chester Frenchs Republic, which stood in the great basin at the exposition, Chicago, 2004 The Worlds Columbian Exposition (also called The Chicago Worlds Fair), a Worlds Fair, was held in Chicago in 1893, to celebrate the 400th anniversary of Christopher... Inspired in part by Daniel McFarlan Moores invention, Moore’s Lamp, Paris born chemist and inventor, Georges Claude invented the neon light by passing an electric current through inert gases made them light very brightly. ...


See also

Timeline of lighting technology Since the world began, people used the sun as their main source of light. ... See also: Other events of 1911 List of years in science . ... A Standard Household Light bulb This page is a list of sources of light. ... Neon signs are often used to advertise for hotels, bars and entertainment venues. ... The ten digits of a Z560M Nixie tube. ...

External links

  • Neon lamps in LED Museum

  Results from FactBites:
 
Neon Lamp - MSN Encarta (214 words)
Neon Lamp, glass bulb or tube containing the gaseous element neon at low pressure, and two metallic electrodes.
The lamp produces a reddish-orange glow when an electric current, applied across the electrodes, is raised in voltage to the point at which it ionizes the gas in the tube (see Electric Lighting; Ionization).
Neon lamps of this type, and lamps using other gaseous elements such as, argon or krypton, are used extensively for advertising signs.
Neon - definition of Neon in Encyclopedia (577 words)
Neon is the second-lightest noble gas, glows reddish-orange in a vacuum discharge tube and has over 40 times the refrigerating capacity of liquid helium and three times that of liquid hydrogen (on a per unit volume basis).
Neon is usually found in the form of a gas with molecules consisting of a single neon atom.
Neon is a rare gas that is found in the Earth's atmosphere at 1 part in 65,000 and is produced by supercooling air and fractionally distilling it from the resulting cryogenic liquid.
  More results at FactBites »

 
 

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