US1983621A - Indirectly heated cathode - Google Patents

Indirectly heated cathode Download PDF

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Publication number
US1983621A
US1983621A US532480A US53248031A US1983621A US 1983621 A US1983621 A US 1983621A US 532480 A US532480 A US 532480A US 53248031 A US53248031 A US 53248031A US 1983621 A US1983621 A US 1983621A
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United States
Prior art keywords
cathode
indirectly heated
metallic
heated cathode
insulation tube
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Expired - Lifetime
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US532480A
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English (en)
Inventor
Loewe Siegmund
Wienecke Bruno
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Individual
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Individual
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Publication date
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/08—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances quartz; glass; glass wool; slag wool; vitreous enamels
    • H01B3/085—Particles bound with glass
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment

Definitions

  • the object of this invention is to produce electron valves with indirectly heated cathodes, the emissive layer of which is produced according to the known metal-vapour-process.
  • FIG. 1 shows an electron valve with an indirectly heated cathode according to the invention
  • Fig. 2 shows the cathode according to the invention on a larger scale.
  • the incandescent member 1 which serves for heating purposes and which is tensioned between the supports 2 and 3, is required to be made longer than any other part of the amplifier system, and more particularly longer than the insulation tube 4, which acts as the carrier for the equipotential cathode and which is shown in cross-section in the drawing.
  • This tube in turn must be longer than the actual equipotential cathode 6, which is wound upon the same preferably with the interposition of a metallic tube 5, composed for example of tungsten wire.
  • the highly incandescent parts of the heating element 1, consisting of metal, and also the two ends of the incandescent member 4 and more particularly the metallic base of the actual cathode 6 are coated with an emissive layer 7 by means of the vapour process.
  • this layer causes a passage of current from the filament 1, which is usually traversed by alternating current, to the parts and 6, resulting in a whistling or humming noise in association with valves fitted with cathodes of this description.
  • the emissive layer on the parts 1, 4 and 5, or on any one of these parts moreover adversely afiects the properties of the valve by reason of the fact that undesirable electrons pass from the edge portions of these parts to the anode, and are modulated by the grid only in inefficient manner.
  • the metallic base 5 is made merely of the same length as the cathode surface 6 intended for the emission.
  • the surface of the tube 4, and if necessary the remaining end portions of the metallic base 5 are coated with a rough, non-conductive material 8, such for example as zirconium oxide, 5 which gives no essential emission even when covered with a thin layer of barium, containing if desired a trace of binding agent, such as waterglass
  • the emissive layer '7 of the highly emissive, vaporizable metal is only on the surface of 10 said equipotential cathode, a cathode is thus produced in which the emission is confined to the desired range represented by the surface 6.
  • the valves produced according to the invention do not disclose any tendency to whistle or hum.
  • an indirectly heated cathode consisting of a heating body, an insulation tube surrounding said heating body, a metallic member on the surface of said insulation tube, said metallic member being shorter than said insulation tube, an equipotential cathode being of the same length as said metallic base and surrounding the metallic member, and an emissive layer of a highly emissive vaporizable metal merely on the surface of said equipotential metallic cathode, the ends of said insulation tube projecting from said metallic base being coated with zircon oxide.
  • an indirectly heated cathode consisting of a heating body, an insulation tube surrounding said heating body, a metallic member on the surface of said insulation tube, said metallic member being shorter than said insulation tube, an equipotential cathode, consisting of a spiral wire, being of the same length as said metallic base and surrounding the metallic member, and an emissive layer of a highly emissive vaporizable metal merely on the surface of said equipotential metallic cathode.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Solid Thermionic Cathode (AREA)
US532480A 1930-04-29 1931-04-24 Indirectly heated cathode Expired - Lifetime US1983621A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE375481X 1930-04-29

Publications (1)

Publication Number Publication Date
US1983621A true US1983621A (en) 1934-12-11

Family

ID=6344087

Family Applications (1)

Application Number Title Priority Date Filing Date
US532480A Expired - Lifetime US1983621A (en) 1930-04-29 1931-04-24 Indirectly heated cathode

Country Status (5)

Country Link
US (1) US1983621A (xx)
BE (1) BE379240A (xx)
FR (1) FR715895A (xx)
GB (1) GB375481A (xx)
NL (1) NL36929C (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2749470A (en) * 1952-06-11 1956-06-05 Int Standard Electric Corp Indirectly heated cathodes
EP1351275A1 (en) * 2000-12-13 2003-10-08 Hamamatsu Photonics K. K. Indirectly heated electrode for gas discharge tube
US20060071606A1 (en) * 2000-12-13 2006-04-06 Hamamatsu Photonics K.K. Indirectly heated electrode for gas discharge tube, gas discharge tube using said indirectly heated electrode, and lighting device for said gas discharge tube

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2749470A (en) * 1952-06-11 1956-06-05 Int Standard Electric Corp Indirectly heated cathodes
EP1351275A1 (en) * 2000-12-13 2003-10-08 Hamamatsu Photonics K. K. Indirectly heated electrode for gas discharge tube
US20040051435A1 (en) * 2000-12-13 2004-03-18 Koji Kawai Indirectly heated electrode for gas discharge tube
US20060071606A1 (en) * 2000-12-13 2006-04-06 Hamamatsu Photonics K.K. Indirectly heated electrode for gas discharge tube, gas discharge tube using said indirectly heated electrode, and lighting device for said gas discharge tube
US7218047B2 (en) * 2000-12-13 2007-05-15 Hamamatsu Photonics K. K. Indirectly heated electrode for gas discharge tube
EP1351275A4 (en) * 2000-12-13 2008-01-09 Hamamatsu Photonics Kk INDIRECTLY HEATED ELECTRODE FOR A GAS DISCHARGE TUBE
US7429826B2 (en) 2000-12-13 2008-09-30 Hamamatsu Photonics K.K. Indirectly heated electrode for gas discharge tube, gas discharge tube using said indirectly heated electrode, and lighting device for said gas discharge tube

Also Published As

Publication number Publication date
FR715895A (fr) 1931-12-10
NL36929C (xx)
BE379240A (xx)
GB375481A (en) 1932-06-30

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