US2080628A - Gas-filled discharge tube - Google Patents

Gas-filled discharge tube Download PDF

Info

Publication number
US2080628A
US2080628A US582825A US58282531A US2080628A US 2080628 A US2080628 A US 2080628A US 582825 A US582825 A US 582825A US 58282531 A US58282531 A US 58282531A US 2080628 A US2080628 A US 2080628A
Authority
US
United States
Prior art keywords
cathode
enclosure
anode
chamber
tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US582825A
Other languages
English (en)
Inventor
Mulder Johannes Gijsbe Wilhelm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of US2080628A publication Critical patent/US2080628A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
    • H01J5/06—Vessels or containers specially adapted for operation at high tension, e.g. by improved potential distribution over surface of vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/50—Thermionic-cathode tubes
    • H01J17/52—Thermionic-cathode tubes with one cathode and one anode
    • H01J17/54—Thermionic-cathode tubes with one cathode and one anode having one or more control electrodes
    • H01J17/56—Thermionic-cathode tubes with one cathode and one anode having one or more control electrodes for preventing and then permitting ignition, but thereafter having no control
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0048—Tubes with a main cathode
    • H01J2893/0051—Anode assemblies; screens for influencing the discharge
    • H01J2893/0054—Cooling means

Definitions

  • This invention relates to a discharge tube comprising one or more anodes and an incandescible cathode, preferably an oxide cathode, as the source of electrons.
  • the filling of the discharge tube consists partly or wholly of a vapour, for example mercury vapour, or of a mixture of vapours with or without the addition of one or more gases.
  • Discharge tubes of this kind are very frequently used for rectifying alternating current, although they are also used for other purposes.
  • the invention has for its object to increase the life of the incandescible cathode of discharge tubes designed for more than 10,000 volts and more than 10 amperes.
  • the life of the incandescible cathode is materially shorter than in the case of low-voltage tubes of the same type. This is due to the fact that in high-voltage tubes a very low vapor pressure is required to prevent undesired discharges, and this low pressure is largely responsible for the disintegration of the cathode.
  • the discharge tube according to the invention is characterized by the feature that the discharge between the anode and the cathode passes through one or more chambers for the condensation of the vapour. This permits maintaining in the cathode chamber a comparatively high pressure, which avoids excessive disintegration of the cathode, whereas the pressure in the anode chamber is kept very low as the vapour condenses before reaching this chamber.
  • the discharge path to each anode may comprise an individual chamber or a plurality of individual condensing chambers, or again one or more condensing chambers common to all the discharge paths may be used.
  • the discharge tube consists consequently of alternate restricted and enlarged parts. It is well known that the ignition is rendered very difiicult by the contractions of the tube wall. It is possible to overcome this difficulty by a suitable form of construction in which the wall of the discharge tube comprises one or more metal portions and in which a chamber, situated preferably between two successive metal wall portions of the discharge tube, is of sufficiently large cross-section to cause the vapour to condense in it.
  • a suitable form of construction in which the wall of the discharge tube comprises one or more metal portions and in which a chamber, situated preferably between two successive metal wall portions of the discharge tube, is of sufficiently large cross-section to cause the vapour to condense in it.
  • artificial coolers for the condensing chamber may be important, they are superfluous in the form of construction described.
  • the discharge tube may be so shaped that the discharge path between the cathode and the anode forms one or more preferably acute angles.
  • the discharge tube may consist of a cathode chamber and of one or more condensation chambers arranged alongside the cathode chamber; in addition an anode chamber is provided above the last condensing chamber and the chambers are connected successively by insert tubes for the passage of the discharge.
  • the bend in the discharge path makes it very difficult for the high-speed positive ion emanating from the anode chamber to reach the cathode so that the risk of disintegration of the incandescible cathode by impact of ions is decreased.
  • these ions are slowed down in their travel by the increase in gas pressure which exists in the direction to the cathode.
  • the bending of the discharge path is important because the difference in gas pressure between the various chambers is increased, because of the change in the direction of the flow of vapor,
  • the condensation chambers and the cathode chamber are preferably not only connected by the tubes for the discharge but also successively connected at their lower ends by return conduits for the condensate.
  • These conduits are preferably provided with one or more bends to dampen the flow of the condensate therethrough. If the conduits were not provided with such bends, an increase in the vapor pressure Within the cathode chamber would occur each time a drop of condensate falls to the bottom of the condensation chamber.
  • the cathode chamber, condensation chambers, and the anode chamber are arranged one above the other.
  • one or more hoods are provided to prevent the condensate flowing back to the cathode chamber, from coming into contact with the cathode.
  • Those portions of the discharge tube in which the condensate collects are preferably provided with contractions or re-entrant parts to secure a high level of the collecting condensate even with a small amount thereof.
  • Figure 1 is a sectionized side view of a discharge tube in which the cathode chamber is arranged at the side of the condensation chamber
  • Figure 2 is a sectionized side view of a discharge tube in which the various chambers are arranged one above the other, and
  • Figure 3 is a sectionized side view of a discharge tube in accordance with another embodiment of the invention.
  • a press 2 in the cathode chamber I supports an incandescible cathode 3.
  • the cathode consists of a piece of rolled wire gauze 4 the successive convolutions of which are spaced apart at some intermediate distance, the coils of a heating helix being laid around the aggregate which is coated both internally and externally with a substance of high emissive power for instance with a suitable oxide coating.
  • a cathode of this kind has a very high electron emission.
  • the cathode chamber communicates through a tube 6 with the condensa tion chamber I.
  • the tube 6 consists of ferrochrome and is sealed on each side to the glass of the discharge tube.
  • the chambers I and 1 are connected by means of a tube 8 to form a communicating vessel for the mercury.
  • the condensation chamber 1 communicates by means of a ferrochrome tube 9 with the anode chamber ID.
  • the anode II is suitably supported, for example, by a ferrochrome plate I2 having its circumference sealed to the glass of the tube and the leading-in conductor connected to the plate.
  • the temperature and thus the vapor pressure of the mercury in this chamber is comparatively high.
  • the mercury vapor which passes from the cathode chamber to the anode chamber I0 condenses, however, in the chamber I.
  • This'chamber always remains comparatively cool as it is remote from the incandescible cathode and has a large surface which readily dissipates the heat to the surrounding air.
  • the tube 8 enables the condensed mercury to fiow back to the cathode chamber.
  • a U-shaped portion I 4 of the tube 8 dampens the flow of mercury so that fluctuating movements of the liquid and the variations in pressure incidental thereto are avoided.
  • each of the chambers I and I comprises a re-entrant part I3 that constitutes a core.
  • the mercury has consequently a high level while the amount of mercury is kept small. At the same time in spite of the small quantity of mercury in chamber I a large area of mercury can be heated by the cathode 3.
  • the tubes 6 and 9 are provided with leads 2!] and 2
  • the voltage applied to these tubes generally falls between that of the anode and that of the cathode, and may be obtained, for example, from a separate secondary coil on the filament supply transformer.
  • FIG. 2 like parts are designated by the same reference numerals as those used in Figure l.
  • the construction shown in Fig. 2 mainly differs from that in Figure 1 in that the discharge path has no bend, but the various chambers are arranged in axial alignment with each other. However should the mercury which condenses in the condensation chamber I and drips down, find it way to the incandescible cathode, this would cause a rapid deterioration at those points of the cathode on which mercury settles.
  • the ferrochrome tube 6 is provided with two internal and upward tapering tubes I5 and I6 made of the same metal.
  • the mercury condensing in the chamber I is guided to flow between the tube I5 and the wall of the discharge tube and thence down along the wall of the tube 6 and along the exterior of the tube I6.
  • the tube I6 forms a hood over the incandescible cathode so that dripping down of the mercury on the cathode is prevented.
  • the tubes I5 and I6 having a high temperature, may cause the mercury drops coming into contact with them to volatilize. This has the drawback that it leads to sudden increases in pressure.
  • the tubes I5 and I6 may be instead of metal, for example of quartz.
  • the condensed mercury may be returned to the chamber I through a circulating conduit I1.
  • a hood I8 may be useful in protecting the seal II! from excessive heating.
  • such a hood is adapted to improve the ignition. Similar services are also rendered by the hood I6 in Figure 2.
  • one or more gases may be enclosed within the tube.
  • Discharge tubes according to the invention can be'constructed, for example, for voltages of kilovolts and for discharge currents of 1 amp., and their life may be over 2000 hours. These values may be materially increased.
  • a discharge tube comprising a vapor filling, a large diameter glass bulb for serving as a condensation vessel, a second glass bulb containing a highly electron-emissive cathode and a quantity of the material of the filling in its nonvaporized state, a third glass bulb containing an anode and having a substantially smaller diameter than said first bulb, and two metal tubes having a diameter less than the diameter of said first bulb, each of said tubes connecting in a hermetical manner said first bulb to one of said latter two bulbs, the axes of said tubes forming an acute angle.
  • a discharge tube comprising a vapor filling
  • a large diameter glass bulb serving as a condensation vessel
  • a second glass bulb containing a high- 1y electron-emissive cathode and a quantity of the material of the filling in its liquid form
  • a third glass bulb containing an anode and having a substantially smaller diameter than said first bulb
  • two metal tubes having a diameter less than the diameter of said first bulb, each of said tubes connecting in a hermetical manner said first bulb to one of said two latter bulbs, the axis of said tubes forming an acute angle
  • a return tube having a loop, said return tube being connected between the bottom portions of said first and second bulbs to allow the condensate to return to said second bulb.
  • a discharge tube comprising an anode, and incandescible oxide cathode, a gaseous filling consisting partly of mercury vapor, an enclosure for the cathode, an enclosure for the anode, a condensation enclosure between said cathode and anode enclosures, a tube connecting said anode enclosure to said condensation enclosure, and a second tube connecting said cathode enclosure to said condensation enclosure, said tubes having a smaller cross section than that of the condensation enclosure, the axes of said tubes forming an acute angle with each other.
  • a discharge tube comprising an anode, an incandescible oxide cathode, a filling consisting partly of vapor, an enclosure for said cathode, an enclosure for said anode, a condensation enclosure in axial alignment with said anode enclosure, and tubes individually connecting the condensation enclosure with the cathode and anode enclosures and having a smaller cross-section than the condensation enclosure, the axis of the tube connecting the condensation enclosure to the cathode enclosure forming an acute angle with the common axis of the anode enclosure and the condensation enclosure.
  • a rectifier tube having a cathode of high electron-emitting capacity, an anode, an enclosure for the anode, a condensation enclosure, an enclosure for the cathode, said anode and condensation enclosures being in axial alignment, said cathode enclosure being disposed laterally from said anode and condensation enclosures and spaced therefrom, a metal tube connecting the cathode enclosure to the condensation enclosure, and a second metal tube connecting the anode enclosure to the condensation enclosure, said tubes having a smaller cross section than that of the condensation enclosure.
  • a rectifier tube for high voltages comprising a high electron-emitting cathode, an anode, a filling consisting partly of vapor, an enclosure for the cathode, an enclosure for the anode, a condensation enclosure for the vapor and interposed between the cathode and anode enclosures, metal tubes connecting said condensation enclosure to said cathode and anode enclosures and having a smaller cross-section than the condensation enclosure, the main discharge path between said cathode and anode leading from said cathode enclosures through said condensation enclosure to said anode enclosure, and a tube having a U-shaped bend and connecting the bottom of said condensation enclosure to the bottom of said cathode enclosure for the return of condensate to said cathode enclosure.
  • a discharge tube having a cathode, an anode, a filling comprising a vapor, an enclosure for the cathode, an enclosure for the anode, an enclosure intermediate between the anode and cathode enclosures for the condensation of said vapor, metal tubes connecting said condensation enclosure with the other enclosures and having a smaller cross-section than the condensation enclosure, the main discharge path between said cathode and anode leading from saidcathode enclosure through said condensation enclosure to said anode enclosure, and a tube for the return of the condensate to said cathode enclosure, said return tube being provided with a loop and connecting the bottom part of said condensation enclosure to the bottom part of said cathode enclosure.

Landscapes

  • Lasers (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
US582825A 1931-01-26 1931-12-23 Gas-filled discharge tube Expired - Lifetime US2080628A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE386063X 1931-01-26
DEN31939D DE648516C (de) 1931-01-26 1931-04-21 Gleichrichterroehre mit Bogenentladung zwischen einer oder mehreren Anoden und einer Gluehkathode

Publications (1)

Publication Number Publication Date
US2080628A true US2080628A (en) 1937-05-18

Family

ID=25875991

Family Applications (2)

Application Number Title Priority Date Filing Date
US582825A Expired - Lifetime US2080628A (en) 1931-01-26 1931-12-23 Gas-filled discharge tube
US602598A Expired - Lifetime US2011904A (en) 1931-01-26 1932-04-01 Gas filled discharge tube

Family Applications After (1)

Application Number Title Priority Date Filing Date
US602598A Expired - Lifetime US2011904A (en) 1931-01-26 1932-04-01 Gas filled discharge tube

Country Status (5)

Country Link
US (2) US2080628A (en))
DE (1) DE648516C (en))
FR (2) FR729219A (en))
GB (2) GB386063A (en))
NL (2) NL42082C (en))

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3707639A (en) * 1969-09-16 1972-12-26 English Electric Valve Co Ltd Electron discharge tubes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3707639A (en) * 1969-09-16 1972-12-26 English Electric Valve Co Ltd Electron discharge tubes

Also Published As

Publication number Publication date
DE648516C (de) 1937-08-02
GB386111A (en) 1933-01-12
GB386063A (en) 1933-01-12
NL42082C (en))
US2011904A (en) 1935-08-20
NL36709C (en))
FR729219A (fr) 1932-07-20
FR41744E (fr) 1933-03-29

Similar Documents

Publication Publication Date Title
US1949347A (en) Electric discharge tube
US1963059A (en) Incandescible cathode discharge tube having a gaseous filling
US2080628A (en) Gas-filled discharge tube
US1701356A (en) Electrical discharge device
US2193600A (en) Carbon grid for transmitting vacuum tubes
US1905692A (en) Rectifier
US2027241A (en) Thermionic discharge device
US1989954A (en) Electric discharge tube
US2236289A (en) Thermionic device
US3069581A (en) Low pressure discharge lamp
US2151783A (en) Secondary electron discharge tube
US2070816A (en) Gas-filled discharge tube
US2329126A (en) Electric discharge device and electrode therefor
US2210674A (en) Cathode for electronic tubes
US2489938A (en) Hot cathode grid control gas tube
US1929124A (en) Space current device
US1987338A (en) Mercury vapor rectifier
US2146580A (en) Secondary electron discharge tube
US2747120A (en) Single-ended thyratron discharge device
US1945979A (en) Electron discharge tube
US2537150A (en) Electron multiplier tube
US1906119A (en) Gaseous discharge device
US2053501A (en) Thermionic gaseous discharge rectifier
US2115147A (en) Electrical discharge device
US2072993A (en) Electronic switch