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2006-08-05 21:41:15 · 7 answers · asked by Anonymous in Science & Mathematics Engineering

what caused it to be coloured

2006-08-08 22:21:04 · update #1

7 answers

wrong answers above...
Neon tubes are made of transparent or coloured glass.
They use two kinds of gas: neon or argon.
If the glass is clear, neon will give you a red colour, and argon will give you blue.
For the other colours, we use tinted glass or/and powder inside the tube.
the combination of the gas, the powder and the tinted glass gives you nearly any colour you want.

2006-08-05 23:37:56 · answer #1 · answered by just "JR" 7 · 0 0

Neon gas is transparent. When it is stimulated with electric current it causes the electrons in the outer level to jump to a higher energy level. When they fall back, a ditinct distance they give off that energy that they absorbed as a wavelength of light. Neon gives off that red orange. Other gases give off other colors.

2006-08-06 10:52:10 · answer #2 · answered by science teacher 7 · 0 0

Different input current results in different output by the neon atoms. Hence, the colours are different.

2006-08-06 05:12:02 · answer #3 · answered by Anonymous · 0 0

They have gasses inside that when excited, the electrons change energy levels. Depending of this change of level (according to quantum mechanics) Photons are emitted, depending on the energy is the frequency and wave lenght which is perceived by the eye as different colors

2006-08-13 22:09:13 · answer #4 · answered by jjrb230 2 · 0 0

Lighting neon lamp,
two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp insideA neon lamp is a gas discharge lamp containing neon gas (or in types with different colors also other noble gas) at low pressure. A small electric current, which may be AC or DC, is passed through the tube, causing it to glow orange-red. In AC-excited lamps, both electrodes produce light, but in a DC-excited lamp, only the negative electrode glows. This simple fact can be used to distinguish between AC and DC sources using a neon lamp and to distinguish the polarity of DC sources.

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.

Small neon lamps are used as indicators in electronic equipment. Larger lamps are used in neon signage. 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.

Neon lamps with several shaped electrodes are used as alphanumerical displays known as Nixie tubes.


Small Neon Lamp (NE-2 type)Most small neon (indicator-sized) lamps, such as the ubiquitous NE-2, start conducting at a fairly consistent 60 to 80 volts, so they were used as very simple voltage regulators or overvoltage protection devices. 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. 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.

Neon lamps are negative resistance gradient devices where increasing the current flow through the device increases the number of ions, thereby decreasing the resistance of the lamp, thereby allowing increased current flow. Because of this, the electrical circuitry external to the neon lamp must provide a means to limit the current flow in the circuit or else the current will increase until the neon lamp destroys itself. For indicator-sized lamps, a resistor is conventionally used to limit the current flow. For sign-sized lamps, the high voltage transformer usually limits the available current, often by its having a large amount of leakage inductance in the secondary winding.

Indicator-sized lamps can also be filled with argon 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.

Neon lamps, due to their low current consumption, are good as nightlights.

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 covering 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 current causes flickering, too high current in turn increases the wear of the electrodes by stimulating sputtering, which coats the internal surface of the lamp with metal and causes its darkening.

The flickering effect is caused by the differences of the ionization potential of the gas, which depends on spacing of the electrodes, the temperature 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. The convective currents make the areas with glow flowing upwards, not unlike the discharge in a Jacob's ladder. A photoionization effect can be observed here, as the electrode area covered with the discharge can be increased by shining light at the lamp. [1]

A helium-neon laser is a distant cousin of a neon lamp.

2006-08-06 07:49:58 · answer #5 · answered by Anonymous · 0 0

Neon is an element, a gas.

2006-08-06 04:45:44 · answer #6 · answered by Anonymous · 0 0

see jrc_skyexpress, the 15 yr sign manufacturer. That's it in a nut shell.

2006-08-13 19:27:12 · answer #7 · answered by flyfisher_20750 3 · 0 0

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