US1683194A - Regulating system for thermionic devices - Google Patents

Regulating system for thermionic devices Download PDF

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Publication number
US1683194A
US1683194A US178106A US17810627A US1683194A US 1683194 A US1683194 A US 1683194A US 178106 A US178106 A US 178106A US 17810627 A US17810627 A US 17810627A US 1683194 A US1683194 A US 1683194A
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US
United States
Prior art keywords
current
tube
thermionic
cathode
grid
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
US178106A
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English (en)
Inventor
William K Kearsley
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US178106A priority Critical patent/US1683194A/en
Priority to FR651405D priority patent/FR651405A/fr
Priority to GB7848/28A priority patent/GB287557A/en
Priority to BE349943A priority patent/BE349943A/fr
Application granted granted Critical
Publication of US1683194A publication Critical patent/US1683194A/en
Priority to BE377223A priority patent/BE377223R/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/34—Anode current, heater current or heater voltage of X-ray tube
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/10—Power supply arrangements for feeding the X-ray tube
    • H05G1/14—Power supply arrangements for feeding the X-ray tube with single-phase low-frequency AC also when a rectifier element is in series with the X-ray tube
    • H05G1/16—Reducing the peak-inverse voltage

Definitions

  • the present invention relates to thermionic apparatus, and in particular to the regulation of thermionic X-ray tubes and its object is to provide a stabilizer or regulater for maintaining a desired electron emissivity and thereby a desired space current in a thermionic device.
  • the X-ray output of an X-ray tube varies directly with the electron emission of the cathode.w
  • the electron emission varies both with variations of cathode temperature and variations of gas conditions in the X-ray tube.
  • Tubes containing targets backed with copper or other metal, which can be freed from gas only with great difiiculty, are particularly subject to such changes.
  • the control of the cathode heating current in the X-ray tube, or other thermionic device to be regulated is carried on by an auxiliary thermionic device which is provided with means, such as a grid, for controlling the duration of flow of space current therein.
  • This auxiliary tube operates in conjunction with regulating means to so vary the voltage of the heating current for the cathode of the main device that a desired space current is maintained in the main device.
  • FIG. 1 a diagrammatic illustration of my invention as applied to an X-ray tube
  • Fig. 2 illustrates a modification.
  • the thermionic device in which a predetermined space current is desired is indicated at 1.
  • This device for illustration, maybe ahi hly exhausted X-ray tube, such as the Coolldge tube, which is described in U. S. Patent 1,203,495 issued October 31, 1916.
  • This tube is provided with a thermionic cathode 2 and an anode 3, theseelectrodes being connected in the usual manner to current supply conductorsd, 5.
  • the cathode 2 is supplied with heating current by the conductors 4, 6 which are connected to the secondar of a transformer 7.
  • the prima winding of this transformer is connecte by the conductors 8, 9 to the supply mains 10, the cur rent in the main circuit 4, 5 and in the heating circuit 4, 6, therefore, being in synchronism.
  • the mainsupply conductors 4, 5 for the X-ray tube are connected to the high potential secondary of a transformer 12.
  • the primary winding of the transformer 12 is connected by the conductors 13, 14 in circuit with a switch 15 to the supply mains 10.
  • the secondary windings 16, 17 of the transformer 12 are connected in series through a non-inductive resistance'18, which is shunted by a condenser 19.
  • the condenser 19 prevents transient current impulses from starting the operation of the device 21 prematurely.
  • the space current through the tube would vary with the variation of voltage in the supply mains 10 or with a variation of gas content of the tube.
  • I have provided a thermionic regulator tube 21.
  • the tube 21 has a thermionic cathode 22, an anode 23 and a' grid 24,-, which has been re resented by a dotted line and which preferably surrounds-the anode.
  • This auxiliary tube should be first highlly evacuated and freed of water vapor an y then provided with a as or a source of vapor, such as mercury. t may be provided with some inert gas, such as argon, at a pressure, for example, of about five and one-half centimeters of mercury.
  • a th ratron An electrical valve tube of this general character is known as a th ratron.
  • n a thyratron the current flow is initiated suddenly from zero to fullnormal value when the char e of the grid changes from negative to positive. Should the grid charge become ne ative while space current is flowing throng a thyratron, no change of space current results.
  • the cathode 22 of this valve tube is supplied with heatin currentby a transformer 26, the primary 0 which is connected by the conductors 27, 28 to the sup 1 mains 10.
  • the cathode and the anode of the regulator tube 21 are. connected by the conductors 29, 30 to the primary circuit of the sup 1y transformer 7 and receive current from t e supply mains 10 through a non-inductive resistance 31.
  • the grid 24 and the cathode 22 are connected respectively by the conductors 32, 33 to the resistance 18, one of the terminals 34 referably being adjustable, as indicated.
  • a iasing battery 35 is provided in the grid circuit 3 33 and is connected as indicated to impress a negative potential on' the grid 24.
  • a space current through the thermionic tube 1 produces a drop of voltage in the resistance 18 which is connected to op ose in potential the biasing battery 35.
  • the grid potential is negative no current flow will take place throughthe valvetube 21.
  • the space current through the tube 1 increases in any half wave impulse to a value at which the potential drop across the resistance 18 exceeds the potential drop across the battery 35, then t e grid becomes positive and an electronic current flow begins through the valve tube 21.
  • thecurrent which flows through the valve tube 21 is derived through the resistance 31, an increase of current through this valve tube increases the potential drop in the resistance 31 and lowers.
  • the 0 eration of the regulator tube 21 occurs witiiout time la and the system is free from all mechanica ly moving parts and therefore remains at all times in proper working condition without mechanical adjustments.
  • the regulation is so quickly responsive to conditions and is so positive in its action that no perceptible variation. of average space current occurs in the circuit of the main tube 1 as shown by a meter. During each half wave of alternating current passing through the main thermionic tube the voltage of the heating current is so regulated that the electron emission of the cathode in the main device is maintained at the desired value.
  • Fig. 2 The system shown in Fig. 2 is similar in most respects to the s stem shown in Fig. 1
  • the primary winding of this transformer 37 is connected by the conductors 38, 39 to the conductors 13, 14 which sup 1y current to the main high potential transformer 12. It also differs from the system shown in Fig. liby the use of an inductance coil 40 as an impedance device in lace of the non-inductive resistance 18. he potential of the inductance coil 40 is op osed to the potential of the secondary of t a transformer 37.- Upon a rise of current in the main circuit 4, 5, the potential of the grid 24 of theregulator tube21 becomes ositive so that current flow begins through t e regulatortube. Current through the regulatortube will occur during periods of such duration that the space current through the tube 1 is maintained at the desired predetermined value. Should the s ace current in themain tube tend to rise,
  • thermoelectric X-ray tube means for deliveringv impulses of current to the cathode of said tube, thermionic regulating means for controlling said current impulses, means for rendering said device non-operative during a part of each such impulse of current, and means put into operation when the space current in said X-ray tube reaches a predetermined value for rendering operative said thermionic means.
  • An -ray apparatus comprising an X- ray tube having a cathode adapted to be heated by passage of current, a source of alternating currentv connected to the main electrodes of said X-ray tube, a heating circuit for the cathode arranged to receive alternating current in synchronism with said source, and thermionic regulating means responsive to load current in said X-ray tube, means for rendering said means non-operative at the beginning of successive current impulses through said X-ra tube, and means for withdrawing current y said thermionic means from said heating circuit for periods of such duration that the electron emission of said cathode is maintained at a substantially constant average value.
  • An electric apparatus comprising a thermionic device, a cathode heating circuit therefor, a thyratron, circuit connections for delivering impulses of variable current to said device, means for initially charging the grid of said thyratron to a negative potential, means for superimposing a positive potential upon said grid varying directly with the current through said thermionic device and circuit connections for regulating the electrical heating current of the cathode of said thermionic device inversely with current flow through said thyratron.
  • An X-ray apparatus comprising a thermionic pure electron discharge X-ray tube, a source of alternating current connected to the main electrodes of said tube, an impedance device in said circuit, a cathode heating circuit also connected to said source, a thyratron having a cathode, an anode and a grid, connections from the grid and cathode of said thyratron to said impedance device whereby an increase of current in said X-ray device produces an increase of length of the conductive periods of said thyratron and circuit connections from the cathode and anode of said thyratron whereby current is withdrawn therethrough from the heating circuit of said X-ray tube.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • X-Ray Techniques (AREA)
  • Medicines Containing Plant Substances (AREA)
US178106A 1927-03-24 1927-03-24 Regulating system for thermionic devices Expired - Lifetime US1683194A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US178106A US1683194A (en) 1927-03-24 1927-03-24 Regulating system for thermionic devices
FR651405D FR651405A (fr) 1927-03-24 1928-03-14 Perfectionnements aux moyens de régler le courant d'espace de tubes à bécharge thermionique
GB7848/28A GB287557A (en) 1927-03-24 1928-03-14 Improvements in and relating to regulating systems for thermionic devices
BE349943A BE349943A (fr) 1927-03-24 1928-03-24 perfectionnement aus moyens de régler le courant d'espace de tubes à décherge thermionique
BE377223A BE377223R (fr) 1927-03-24 1931-02-10 perfectionnement aus moyens de régler le courant d'espace de tubes à décherge thermionique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US178106A US1683194A (en) 1927-03-24 1927-03-24 Regulating system for thermionic devices

Publications (1)

Publication Number Publication Date
US1683194A true US1683194A (en) 1928-09-04

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Family Applications (1)

Application Number Title Priority Date Filing Date
US178106A Expired - Lifetime US1683194A (en) 1927-03-24 1927-03-24 Regulating system for thermionic devices

Country Status (4)

Country Link
US (1) US1683194A (fr)
BE (2) BE349943A (fr)
FR (1) FR651405A (fr)
GB (1) GB287557A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2518539A (en) * 1944-09-27 1950-08-15 Picker X Ray Corp Waite Mfg Filament current stabilizer
US2544716A (en) * 1947-10-31 1951-03-13 Univ Minnesota Filament-plate voltage system
US2715186A (en) * 1946-10-21 1955-08-09 Harvard L Hull Isotope separating apparatus
US2733345A (en) * 1956-01-31 Regulator for calutron ion source
US2733344A (en) * 1956-01-31 Ion generator regulator
US2810838A (en) * 1953-04-20 1957-10-22 Gen Electric Beam current stabilization circuit for x-ray tubes
US2813978A (en) * 1948-01-07 1957-11-19 Irving R Brenholdt Electron emission regulating means

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733345A (en) * 1956-01-31 Regulator for calutron ion source
US2733344A (en) * 1956-01-31 Ion generator regulator
US2518539A (en) * 1944-09-27 1950-08-15 Picker X Ray Corp Waite Mfg Filament current stabilizer
US2715186A (en) * 1946-10-21 1955-08-09 Harvard L Hull Isotope separating apparatus
US2544716A (en) * 1947-10-31 1951-03-13 Univ Minnesota Filament-plate voltage system
US2813978A (en) * 1948-01-07 1957-11-19 Irving R Brenholdt Electron emission regulating means
US2810838A (en) * 1953-04-20 1957-10-22 Gen Electric Beam current stabilization circuit for x-ray tubes

Also Published As

Publication number Publication date
BE377223R (fr) 1931-03-31
FR651405A (fr) 1929-02-19
BE349943A (fr) 1928-04-30
GB287557A (en) 1929-07-15

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