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The heated filament, or cathode, was capable of thermionic emission of electrons that would flow to the plate ( or anode ) when it was at a higher voltage.
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heated and filament
Externally heated electrodes are often used to generate an electron cloud as in the filament or indirectly heated cathode of vacuum tubes.
Modern vacuum tubes use thermionic emission, in which the cathode is made of a thin wire filament which is heated by a separate electric current passing through it.
A cathode made of a wire filament heated red hot by a separate current passing through it would release electrons into the tube by a process called thermionic emission.
The two main families of electric light are incandescent lamps, which produce light by a filament heated white-hot by electric current, and gas-discharge lamps, which produce light by an electric arc through a gas.
In this type of gauge, a wire filament is heated by running current through it.
A common variant is the Pirani gauge, which uses a single platinum filament as both the heated element and RTD.
In the hot cathode version, an electrically heated filament produces an electron beam.
When the bulb's filament is heated white-hot, electrons are boiled off its surface and into the vacuum inside the bulb.
The filament ( cathode ) has a dual function: it emits electrons when heated ; and, together with the plate, it creates an electric field due to the potential difference between them.
While early tubes used the directly heated filament as the cathode, most ( but not all ) more modern tubes employed indirect heating.
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which produces light with a filament wire heated to a high temperature by an electric current through it, until it glows ( see Incandescence ).
Thermionic emission — electrons escaping from the heated negatively-charged filament ( hot cathode )— is important in the operation of vacuum tubes.
This device superimposed a thin, heated filament over the object to be measured and relied on the operator ’ s eye to detect when the filament vanished.
When heated in the correct conditions, these chains bond side-to-side ( ladder polymers ), forming narrow graphene sheets which eventually merge to form a single, columnar filament.
A cold cathode is a cathode, an electrode that emits electrons, which is not electrically heated by a filament.
The other type of cathode is a hot cathode, which is heated by a filament which has electric current passing through it.
Externally heated electrodes are often used to generate an electron cloud as in the filament or indirectly heated cathode of vacuum tubes.
Incandescence is exploited in incandescent light bulbs, in which a filament is heated to a temperature at which a fraction of the radiation falls in the visible spectrum.
In addition, charge did not flow from the foil to the filament because the foil was not heated enough to emit charge ( later called thermionic emission ).
The electrons that make up the beam are emitted from a heated cathode filament.
This usually happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and then breaking the filament of ionized gas.
heated and cathode
This allowed all the tubes to be heated through a common circuit ( which can as well be AC ) while allowing each cathode to arrive at a voltage independently of the others, removing an unwelcome constraint on circuit design.
In the 1930s indirectly heated cathode tubes became widespread in equipment using AC power.
Directly heated cathode tubes continued to be widely used in battery-powered equipment as their filaments required considerably less power than the heaters required with indirectly-heated cathodes.
Indirectly heated cathodes enable the cathode circuit to be separated from the heater circuit, thereby eliminating hum and mains noise from the signal circuit.
Although it resembles a vacuum tube in appearance, its operation does not depend on thermionic emission of electrons from a heated cathode.
A cold cathode does not necessarily operate at a low temperature ; it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas.
A cold cathode is distinguished from a hot cathode that is heated to induce thermionic emission of electrons.
A beam of electrons is produced by a thermionic cathode ( a heated pellet of low work function material ), and accelerated by high-voltage electrodes ( typically in the tens of kilovolts ).
heated and was
The office was of logs, four rooms, each heated by an iron stove.
To stir cattle up and get 'em heated and excited was to `` mustard the cattle '', and the act was called `` ginnin' 'em 'round '', or `` chousin' 'em ''.
Strolling down to the galley, he lit the butane under the coffee pot and when the brew was heated, poured himself a cup and went up to the chartroom.
When the light from a heated material was passed through a prism, it produced a multi-colored spectrum.
The amalgam was applied as a paste and then heated until the mercury vaporized, leaving the gold, silver, or tin behind.
If amber is heated under the right conditions, oil of amber is produced, and in past times this was combined carefully with nitric acid to create " artificial musk " – a resin with a peculiar musky odor.
But the design of the idealized free library was the subject of prolonged and heated debate.
Brass was produced by the cementation process where copper and zinc ore are heated together until zinc vapor is produced which reacts with the copper.
The heated debate that resulted was settled by the Bundestag ( Germany's parliament ) only on 20 June 1991.
To separate berkelium from the unreacted americium, this solution was added to a mixture of ammonium and ammonium sulfate and heated to convert all the dissolved americium into the oxidation state + 6.
Disraeli's first premiership was dominated by the heated debate over the established Church of Ireland.
Lenin was able to persuade the Central Committee, after a long and heated discussion, to initiate the October Revolution.
Their initial studio work was marred by a heated disagreement between Bowie and Cambridge over the latter's drumming style ; matters came to a head when Bowie, enraged, accused, " You're fucking up my album.
Durán Ballén's vice president, Alberto Dahik, was the architect of the administration's economic policies, but in 1995, Dahik fled the country to avoid prosecution on corruption charges following a heated political battle with the opposition.
After a very heated national debate, legislation was passed in 1985 that gave women an equal right to decide what surname or surnames they and their children would use.
After a heated discussion, Odin swore that he would grant victory to the first tribe he saw the next morning upon awakening — knowing full well that the bed was arranged so that the Vandals were on his side.
In 2007, Coleman was cited for misdemeanor disorderly conduct in Provo, Utah after a " heated discussion " in public with his wife.
He remained to the end a staunch Catholic, though all Chemnitz had gone over to the Lutheran creed, and it is said that his life was ended by a fit of apoplexy brought on by a heated discussion with a Protestant divine.
Another advance was the manufacture of kiln charcoal by distilling wood in heated iron retorts instead of burning it in earthern pits ; controlling the temperature influenced the power and consistency of the finished gunpowder.
These two texts are also the only two sources that explicitly mention that the substance was heated over a furnace before being discharged ; although the validity of this information is open to question, modern reconstructions have relied upon them.
The whole process was fraught with danger, as the mounting pressure could easily make the heated oil explode, although there are no recorded circumstances of such accidents.
For years the solution was to park the car in heated areas.
In some parts of the world the oil was actually drained and heated over night and returned to the engine for cold starts.
The sodium sulphate was heated with limestone ( calcium carbonate ) and coal to give a mixture of sodium carbonate and calcium sulphide.
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