The neon (also fluorescent lamp light ) is a miniature gas release lamp. The lamp usually consists of a small glass capsule containing a mixture of neon and other gases at low pressure and two electrodes (anode and cathode). When sufficient voltage is applied and sufficient current is applied between the electrodes, the lamp produces an orange light discharge. The shining part of the lamp is a thin region near the cathode; bigger and longer neon signs are also light releases, but they use positive columns that are not present in ordinary fluorescent lamps. Fluorescent lights are widely used as indicator lights in displaying electronic appliances and equipment.
Video Neon lamp
History
Neon was discovered in 1898 by William Ramsay and Morris W. Travers. Characteristics, the brilliant red color emitted by neon gas when electrically sparkled is recorded immediately; Travers later wrote, "the red light from the tube tells its own story and is a sight to be thought of and never forgotten."
Neon scarcity precludes its rapid application for electric lighting along the Moore pipeline, which uses the release of electricity in nitrogen. The Moore tube was commercialized by its inventor, Daniel McFarlan Moore, in the early 1900s. After 1902, Georges Claude's company, Air Liquide, produced a number of neon industries as a by-product of the air-liquefaction business, and in December 1910 Claude showed modern fluorescent lighting based on sealed fluorescent tubes. In 1915, US patents were issued to Claude which included the design of electrodes for fluorescent tube lamps; this patent became the basis for a monopoly held in the US by his company, Claude Neon Lights, until the early 1930s.
Around 1917, Daniel Moore developed a fluorescent lamp while working at the General Electric Company. The lamps have a very different design from the much larger fluorescent tubes used for fluorescent lighting. The difference in the design is sufficient that US patents were issued for lights in 1919. A Smithsonian Institution website noted, "This small, low power device uses a physical principle called coronal discharge." Moore mounted two adjacent electrodes in a sphere and added neon or gas argon The electrode will shine brightly in red or blue, depending on the gas, and the lamp lasts for years Because the electrode can pick up almost any imaginable shape, a popular application is a remarkable ornamental lamp.
Light lights were found to be practically used as indicators in instrument panels and many home appliances until the broad commercialization of light-emitting diodes (LEDs) in the 1970s.
Maps Neon lamp
Description
A small electric current (for a 5 mm diameter NE-2 lamp, a quiescent current of about 400 ÂμA), which may be AC ​​or DC, is permitted through the tube, causing it to glow orange-red. The gas is usually a Penning mixture, 99.5% neon and 0.5% argon, which has a lower striking voltage than pure fluorescent, at a pressure of 1-20 torr. The lamp illuminates the discharge lamp at a striking voltage. The striking voltage is reduced by ambient light or radioactivity. The required voltage to maintain the discharge significantly (~ 30%) is lower than the striking voltage. This is because the positive ion organization is near the cathode. Fluorescent lamps operate using low current light discharge. Higher power devices, such as mercury-steam lamps or metal halide lamps use higher current arc discharges. Low pressure steam sodium lamps use a fluorescent Penning mixture for heating and can be operated as giant fluorescent lamps when operated in low power mode.
Once the fluorescent light reaches damage, it can support large current flow. Due to these characteristics, the external electrical circuit to the fluorescent lamp must limit the current through the circuit or the current will rapidly increase until the lamp is destroyed. For indicator-sized lamps, resistors usually limit the current. In contrast, larger sized lamps often use specially constructed high-voltage transformers with high leakage inductance or other electric ballasts to limit the available current (see neon sign).
When the current through the lamp is lower than the current for the highest discharge current, the glow emission may become unstable and not cover the entire surface of the electrode. This may be a sign of an indicator aging bulb, and is exploited in a flame decorative "flicker flame" lamp. However, while too low currents cause flickering, too high currents increase the wear of electrodes by stimulating sputtering, which coats the internal surface of the lamp with metal and causes it to darken.
The potential required for a debit strike is higher than what is required to maintain the discharge. When there is not enough current, light only forms part of the electrode surface. Convection currents make the glowing areas flow upward, unlike the discharge on Jacob's stairs. The photoionization effect can also be observed here, since the area of ​​the electrode enclosed by the beam of light can be enhanced by the glowing light in the lamp.
Compared with incandescent light bulbs, fluorescent lamps have a much higher radiant efficacy. The incandescent lamp is a heat emission driven by heat, so most of the electrical energy put into the incandescent bulb is converted to heat. Non-incandescent light sources such as fluorescent lights, fluorescent bulbs, and light-emitting diodes are therefore far more energy-efficient than normal incandescent bulbs. Green fluorescent lamps can produce up to 65 lumens per watt of input power, while white fluorescent lights have a efficacy of around 50 lumens per watt. In contrast, standard incandescent light bulbs produce only about 13.5 lumens per watt.
Apps
Visual indicators
Small fluorescent lamps are mostly used as visual indicators of electronic equipment and equipment, due to low power consumption, long life, and the ability to operate on electrical power.
Voltage spikes
Fluorescent lamps are generally used as low-voltage surge protectors, but are generally lower than surge protector surge protector (GDT) (which can be designed for high voltage applications). Fluorescent lamps have been used as a cheap method to protect RF receivers from voltage spikes (lights connected to RF inputs and ground chassis), but they are not suitable for high power RF transmitters.
Voltage testers
Most small fluorescent lamps (size indicators), such as the common NE-2 , have a break-down voltage of about 90 volts. When it is driven from a DC source, only a negatively charged electrode (cathode) will start. When driven from the AC source, the two electrodes will light up (each for half an alternate cycle). These attributes make fluorescent lamps (with series resistors) as convenient cheap voltage testers. By checking which electrodes are shining they can reveal whether the given voltage source is AC or DC, and if the DC, polarity points are tested.
Voltage settings
Characteristics of light discharge lamp damage allow them to be used as voltage regulators or over-voltage protection devices. Beginning around the 1930s, General Electric (GE), Signalite, and other companies created voltage regulating tubes. A voltage regulator tube is used in Mark 6 exploder.
Shifting element/oscillator
Like other gas discharge lamps, fluorescent light bulbs have negative resistance; the voltage drops with increasing current after the bulb reaches its breakdown voltage. Therefore, the bulb has hysteresis; the turn-off voltage is lower than the turn-on voltage. This allows it to be used as an active switching element. Fluorescent lamps are used to create relaxation oscillator circuits, using this mechanism, sometimes referred to as Pearson-Anson effects for low frequency applications such as flashing warning lights, tone stroboscope generators in electronic organs, and as time bases and oscillator deflections in the early cathode oscilloscope rays. Neon light bulbs can also be bent, and are even used to build digital logic circuits such as logic gates, flip-flops, binary memory, and digital counters. These applications are quite commonly used by special fluorescent lighting manufacturers for this use, sometimes called "circuit-component" lamps. At least some of these lights have concentrated light to a small spot on the cathode, which makes them unsuitable for use as an indicator. The variant of the NE-2 type lamp for the circuit application NE-77 has three wire electrodes in a non-standard two-plane (in plane) plane, a third for use as a control electrode.
Detector
Fluorescent lamps have historically been used as microwave and millimeter wave ('plasma diodes' or GDDs-Glow Discharge Detectors) to about 100 GHz or more and in such services are said to exhibit comparable sensitivity (from a sequence of some 10s to perhaps 100 microvolts) to 1N23 the familiar catwhisker-type silicon diode contacts are everywhere in microwave equipment. It has recently been found that these lamps work well as detectors even at sub-millimeter (terahertz) frequencies and they have been successfully used as pixels in some experimental imaging arrays at these wavelengths.
In this application the lamp is operated either in starvation mode (to reduce the current light noise) or in normal light discharge mode; some reference literature uses it as a radiation detector into the optical regime when operated in an abnormal light mode. The incorporation of microwaves into the plasma may be in free space, in waveguide, by means of a parabolic concentrator (eg, Winston cone), or via capacitive means through loops or dipole antennas mounted directly to the lamp.
Although most of these applications use ordinary double electrode lights, in one case it was found that a special 3 (or more) electrode lamp, with an extra electrode acting as a coupling antenna, gave a better result (lower noise). and higher sensitivity). The invention received a US patent
Alphanumeric display
Fluorescent lamps with multiple shaped electrodes are used as alphanumeric displays known as Nixie tubes. It has been replaced by other display devices such as light-emitting diodes, vacuum fluorescent displays, and liquid crystal displays.
At least since the 1940s, the argon, neon, and phosphorus glow thyratron stick to the indicator (which will ignite the impulses on their starter electrodes and extinguish only after their anode voltage is cut) available for example as self-displaying shift registers in large format, text-dot-matrix display, or combined in a 4x4, four-color phosphored-thyratron matrix, as a stackable RGBA 625-color pixel for large graphics video arrays. Multiple-cathode and/or anode glow thyratrons are called Nearer can count forward and backward while their count status is seen as the light on one of the numbered cathodes. This is used as a self-displaying counter-by-n counter/timer/prescalers in the calculation instrument, or as an adder/meter in the calculator.
More
In the 1930s radio set, fluorescent lamps were used as tuning indicators, called "tuneons" and would give a brighter light because the station was tuned properly.
Because of its relatively short response time, in the early development of television fluorescent lights were used as a light source on many TV scanning screens.
New lights with shaped electrodes (like flowers and leaves), often coated with phosphorus, have been made for artistic purposes. In some of these, the light surrounding the electrode is part of the design.
Color
The fluorescent indicator light is usually orange, and is often used with colored filters on it to increase contrast and change the color to red or red, or less often green.
They can also be filled with argon, krypton, or xenon rather than neon, or mixed with it. While the characteristics of electrical operations remain the same, these lights are illuminated with bluish light (including some ultraviolet light) rather than a hypnotic reddish-orange light. Ultraviolet radiation can then be used to stimulate the phosphor coating inside the bulb and provide a variety of colors, including white. The 95% fluorescent, 2.5% krypton, and 2.5% argon mixture can be used for green light, but the "neon green" light is more commonly based on phosphorus.
See also
- Aerolux Light Corporation
- Tube contains gas
- Light art
- List of light sources
- The magic eye tube
- Neon sign
- Pearson-Anson Effect
- Lighting technology timeline
References
Further reading
- Using and Understanding Mini Neon Lights ; Ed 1; William G. Miller; Howard W. Sams Company; 127 pages; 1969; LCCN 69-16778. (first Ed in 1969)
- Cold Cathode Tubes ; Ed 1; J.B. Dance; Iliffe Book; 125 pages; 1967.
- Glow Lamp Manual - Theory, Circuit, Rating ; 2nd Ed; General Electric (GE); 122 pages; 1966.
- Application of Neon Lamps and Discharge Tubes ; Ed 1; Edward Bauman; Carleton Press; 1966.
External links
- Neon Bulb Relaxation Oscillator - Clifton Laboratories
- Neon Indicator Lamp Datasheet - VCC (Visual Communications Company) Company from Chicago Miniature Lighting (CML)
Source of the article : Wikipedia
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