US2297454A - Cathode - Google Patents

Cathode Download PDF

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Publication number
US2297454A
US2297454A US374655A US37465541A US2297454A US 2297454 A US2297454 A US 2297454A US 374655 A US374655 A US 374655A US 37465541 A US37465541 A US 37465541A US 2297454 A US2297454 A US 2297454A
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Prior art keywords
core
cathode
tungsten
resistance
wire
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Expired - Lifetime
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US374655A
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English (en)
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Berger Hermann
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Individual
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Individual
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    • 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
    • H01J1/14—Solid thermionic cathodes characterised by the material
    • 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
    • H01J1/15—Cathodes heated directly by an electric current

Definitions

  • the invention relates to thoriated tungsten cathodes, and in particular to such cathodes having relatively high resistance and increased emissive power.
  • a highly emissive cathode comprises a thoriated tungsten wire wound in the shape of a helix upon a suitable core and arranged so that its windings -do not contact with each other.
  • the core is preferably of a material having relatively high resistance, and in a preferred form comprises tantalum carbide.
  • FIGs. 1 and 2 show the constituent parts of a cathode as represented in Fig. 3.
  • Figs. 4 to '7 illustrate other examples of cathodes as provided by the invention.
  • a straight thoriated tungsten wire I, Fig. 1 has a certain ohmic resistance.
  • a helix 2 of tungsten wire, Fig. 2 is adapted closely to contact with wire I when inserted over it, whereby the cathode structure shown in Fig. 3 is formed.
  • This structure constitutes a parallel connection of a wire coil and a core wire.
  • the total resistance of a cathode according to Fig. 3 is about 25% less than the resistance of the core wire alone.
  • the effective surface of such a cathode is approximately four times as large as that of the core I alone, whereby also the filament power and emission thereof are four times that of the core.
  • the ohmic resistance of the composite cathode is mainly determined by the core wire.
  • this core should be made of a material of relatively high ohmic resistance.
  • a helix wound upon a core of tantalum has been found to have a total resistance higher by about 25% than in the case of a core made of tungsten, and the resistance of such a combination may be greatly increased by carburizing the tantalum core.
  • the core decreases in rigidity. Such decrease, however, may be compensated by employing cores of correspondingly larger cross-sectional area.
  • Tantalum carbide has the advantage that the ductile metal tantalum may be rst formed into the shape of the core and then carburized to form the carbide. Since the thoriated tungsten wire must also be carburized to increase the specific emission of the structure, there is no danger of the tantalum carbide being decarburized due to the presence of tungsten carbide. Thus the structure, in accordance with the invention, lends itself to particularly simple manufacture.
  • Fig. 4 shows a strong core I', made of tantalum, and a coil of comparatively thin thoriated tungsten wire, the turns of which are each supported by the core.
  • a cathode is obtained that comprises a core of tantalum carbide and a carburized helix of thoriated tungsten.
  • Cathode structures as provided by the invention allow of carburizing them to a much higher degree than devices in which the helix is not supported as described.
  • a high carburization enables the use of a high operating temperature, whereby a higher specic emission of electrons may be obtained.
  • the overall resistance of such a carburized tantalum and thoriated tungsten cathode does not vary appreciably from its relatively high value throughout By carburizing this comthe complete range of operating temperatures and will not decompose at the highest operating temperatures.
  • a tubular core I of tantalum or of a similar material may be employed instead of a solid one.
  • Core I and the tungsten helix 2 are connected in parallel and are heated by an electric current passing through them.
  • the cathode shown in Fig. 6 has a wire helix 2 of different pitches, the pitch increasing from the middle of the cathode toward the ends thereof, that is to say, toward the points Where the current leads, not shown, are joined to the cathode.
  • This arrangement which may be adopted in the case of all the cathodes before described, acts to reduce the size of the emitting surface of the cathode toward the ends thereof.
  • the core supporting a Wire helix 3 may itself be a coil 2 or may comprise a combination of coil and solid wire, the coils 2, 3 constituting a sort of double helix.
  • the thoriated tungsten may be wound thereon in the same manner as in the case of Figs. 4, 5 and 6.
  • Such a structure pro- Vides a more compact cathode having greater emissive power, as Will be clear.
  • a large surfaced thoriated tungsten cathode comprising a core of tantalum carbide and a thoriated tungsten wire wound upon and in direct contact with said core.

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  • Solid Thermionic Cathode (AREA)
US374655A 1940-01-20 1941-01-16 Cathode Expired - Lifetime US2297454A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE222367X 1940-01-20

Publications (1)

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US2297454A true US2297454A (en) 1942-09-29

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US374655A Expired - Lifetime US2297454A (en) 1940-01-20 1941-01-16 Cathode

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US (1) US2297454A (fr)
BE (1) BE440246A (fr)
CH (1) CH222367A (fr)
IT (1) IT392129A (fr)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2525565A (en) * 1948-07-12 1950-10-10 Eitel Mccullough Inc Filamentary cathode for electron tubes
US2625666A (en) * 1950-02-27 1953-01-13 Eitel Mccullough Inc Filament for electron tubes
US2629065A (en) * 1948-05-14 1953-02-17 Westinghouse Electric Corp Overwound filament
US2693546A (en) * 1948-07-10 1954-11-02 Eitel Mccullough Inc Electron emitter for electron tubes
US2731581A (en) * 1950-12-18 1956-01-17 Krefft Hermann Eduard Electrode for gaseous discharge lamps
US2733371A (en) * 1950-05-12 1956-01-31 Internally conducttvely coated
US2829297A (en) * 1954-04-15 1958-04-01 Machlett Lab Inc Filament structure
US2922916A (en) * 1953-11-10 1960-01-26 Duro Test Corp Electrode for fluorescent lamps
US3237284A (en) * 1962-02-05 1966-03-01 Polaroid Corp Method of forming carbide coated coiled filaments for lamps
US4611146A (en) * 1981-12-31 1986-09-09 Raytheon Company Indirectly heated cathode
JP2009535770A (ja) * 2006-05-03 2009-10-01 オスラム ゲゼルシャフト ミット ベシュレンクテル ハフツング カーバイド含有発光体を備えたハロゲン白熱ランプ
US20130315575A1 (en) * 2012-05-23 2013-11-28 Osram Sylvania Inc. Concentric coil infrared emitter lamp
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US20150157871A1 (en) * 2012-02-13 2015-06-11 Medical Energetics Ltd. Health applications of a double helix conductor
US9406421B2 (en) 2012-04-26 2016-08-02 Medical Energetics Ltd System configuration using a double helix conductor
US9463331B2 (en) 2014-04-07 2016-10-11 Medical Energetics Ltd Using a double helix conductor to treat neuropathic disorders
US9636518B2 (en) 2013-10-28 2017-05-02 Medical Energetics Ltd. Nested double helix conductors
US9717926B2 (en) 2014-03-05 2017-08-01 Medical Energetics Ltd. Double helix conductor with eight connectors and counter-rotating fields
US9724531B2 (en) 2013-10-28 2017-08-08 Medical Energetics Ltd. Double helix conductor with light emitting fluids for producing photobiomodulation effects in living organisms
US9861830B1 (en) 2013-12-13 2018-01-09 Medical Energetics Ltd. Double helix conductor with winding around core
US10008319B2 (en) 2014-04-10 2018-06-26 Medical Energetics Ltd. Double helix conductor with counter-rotating fields
US10083786B2 (en) 2015-02-20 2018-09-25 Medical Energetics Ltd. Dual double helix conductors with light sources
US10130044B1 (en) 2012-01-27 2018-11-20 Medical Energetics Ltd. Agricultural applications of a double helix conductor
US10155925B2 (en) 2015-09-01 2018-12-18 Medical Energetics Ltd. Rotating dual double helix conductors
US10224136B2 (en) 2015-06-09 2019-03-05 Medical Energetics Ltd. Dual double helix conductors used in agriculture

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2629065A (en) * 1948-05-14 1953-02-17 Westinghouse Electric Corp Overwound filament
US2693546A (en) * 1948-07-10 1954-11-02 Eitel Mccullough Inc Electron emitter for electron tubes
US2525565A (en) * 1948-07-12 1950-10-10 Eitel Mccullough Inc Filamentary cathode for electron tubes
US2625666A (en) * 1950-02-27 1953-01-13 Eitel Mccullough Inc Filament for electron tubes
US2733371A (en) * 1950-05-12 1956-01-31 Internally conducttvely coated
US2731581A (en) * 1950-12-18 1956-01-17 Krefft Hermann Eduard Electrode for gaseous discharge lamps
US2922916A (en) * 1953-11-10 1960-01-26 Duro Test Corp Electrode for fluorescent lamps
US2829297A (en) * 1954-04-15 1958-04-01 Machlett Lab Inc Filament structure
US3237284A (en) * 1962-02-05 1966-03-01 Polaroid Corp Method of forming carbide coated coiled filaments for lamps
US4611146A (en) * 1981-12-31 1986-09-09 Raytheon Company Indirectly heated cathode
JP2009535770A (ja) * 2006-05-03 2009-10-01 オスラム ゲゼルシャフト ミット ベシュレンクテル ハフツング カーバイド含有発光体を備えたハロゲン白熱ランプ
US10130044B1 (en) 2012-01-27 2018-11-20 Medical Energetics Ltd. Agricultural applications of a double helix conductor
US9504845B2 (en) * 2012-02-13 2016-11-29 Medical Energetics Ltd. Health applications of a double helix conductor
US20170072211A1 (en) * 2012-02-13 2017-03-16 Medical Energetics Ltd. Health applications of a double helix conductor
US10532218B2 (en) * 2012-02-13 2020-01-14 Medical Energetics Ltd. Health applications of a double helix conductor
US20150157871A1 (en) * 2012-02-13 2015-06-11 Medical Energetics Ltd. Health applications of a double helix conductor
US9406421B2 (en) 2012-04-26 2016-08-02 Medical Energetics Ltd System configuration using a double helix conductor
US20130315575A1 (en) * 2012-05-23 2013-11-28 Osram Sylvania Inc. Concentric coil infrared emitter lamp
US10264629B2 (en) * 2013-05-30 2019-04-16 Osram Sylvania Inc. Infrared heat lamp assembly
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US9724531B2 (en) 2013-10-28 2017-08-08 Medical Energetics Ltd. Double helix conductor with light emitting fluids for producing photobiomodulation effects in living organisms
US9636518B2 (en) 2013-10-28 2017-05-02 Medical Energetics Ltd. Nested double helix conductors
US9861830B1 (en) 2013-12-13 2018-01-09 Medical Energetics Ltd. Double helix conductor with winding around core
US10688309B2 (en) 2013-12-13 2020-06-23 Medical Energetics Limited Double helix conductor with winding around core
US9717926B2 (en) 2014-03-05 2017-08-01 Medical Energetics Ltd. Double helix conductor with eight connectors and counter-rotating fields
US9463331B2 (en) 2014-04-07 2016-10-11 Medical Energetics Ltd Using a double helix conductor to treat neuropathic disorders
US10008319B2 (en) 2014-04-10 2018-06-26 Medical Energetics Ltd. Double helix conductor with counter-rotating fields
US10497508B2 (en) 2014-04-10 2019-12-03 Medical Energetics Limited Double helix conductor with counter rotating fields
US10102955B2 (en) 2015-02-20 2018-10-16 Medical Energetics Ltd. Dual double helix conductors
US10083786B2 (en) 2015-02-20 2018-09-25 Medical Energetics Ltd. Dual double helix conductors with light sources
US10224136B2 (en) 2015-06-09 2019-03-05 Medical Energetics Ltd. Dual double helix conductors used in agriculture
US10155925B2 (en) 2015-09-01 2018-12-18 Medical Energetics Ltd. Rotating dual double helix conductors

Also Published As

Publication number Publication date
IT392129A (fr)
BE440246A (fr)
CH222367A (de) 1942-07-15

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