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US1653102A - Electron-discharge apparatus - Google Patents

Electron-discharge apparatus Download PDF

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Publication number
US1653102A
US1653102A US735266A US73526624A US1653102A US 1653102 A US1653102 A US 1653102A US 735266 A US735266 A US 735266A US 73526624 A US73526624 A US 73526624A US 1653102 A US1653102 A US 1653102A
Authority
US
United States
Prior art keywords
current
cathode
tube
ray
heating
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
US735266A
Other languages
English (en)
Inventor
Jr 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
Priority to GB9919/21A priority Critical patent/GB170546A/en
Priority to NL19656A priority patent/NL9214C/nl
Priority to DEI21656D priority patent/DE407939C/de
Priority to FR542381D priority patent/FR542381A/fr
Priority to US533070A priority patent/US1698334A/en
Priority to GB19381/22A priority patent/GB201741A/en
Priority to FR27289D priority patent/FR27289E/fr
Application filed by General Electric Co filed Critical General Electric Co
Priority to US735266A priority patent/US1653102A/en
Priority to FR31070D priority patent/FR31070E/fr
Priority to GB21852/25A priority patent/GB239511A/en
Application granted granted Critical
Publication of US1653102A publication Critical patent/US1653102A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B15/00—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area
    • B08B15/02—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area using chambers or hoods covering the area
    • 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

Definitions

  • My invention is particularly applicable to the operation of an X ray tube of the in cande'scent cathode type, and is embodied in an apparatus whereby a constant" X-ray output may be secured even though the source of cathode heating current varies in voltage.
  • Fig. 1 is a diagram of an X-ray system embodying my lnvention
  • Fig. 2 is a graph-of electrical characteristics of a? de-.
  • a vibrator 'used'm my tube 1 of the type now known as the self rectifying Coolidge tube is shown connected to the high tension secondary winding of I 4o'tlie transformer 2, having the low tension primary circuit connected to a suitable source of current represented by mains 8, 4, carrying alternating current.
  • the X-ray tube 1 contains a cathode shown'in detailin Fig;
  • the anode is preferably i i in good thermal relation to a radiator 8, but auxiliary devices such as this radiator, are
  • r '4 consisting of a heated filament 5 surrounds ed by a focusing device 6 and an anode 7 consisting preferably of a. rodof coppcr.con-' forms of electron-discharge devices, diife'riiig in function and structural details from an X ray tube. 7 I 1 I The cathode 5 of the X-ray tube is connectod by the conductors '9, 10 to the secondary winding of a transformer 11, .the
  • a. r-Xresis-tancelel' is included, 111' the auxiliary heating circuit 9, .10 111 series with the secondary winding of the transformer 11.
  • a shunt circuit to the re sistance 14 are vibrating or make-and-break contacts 15, 16, one at .leastof which is adlliese contacts 15, 16 are caused to open and close at a rapid rate during the, operatioirof the tube, the relative durations of periods of make as compared withthe periods of break being determined by the strength of the current flowing through an electromagne-t 17, the winding of which is included in the circuit 18 carrying the cur rent flowing from cathode to anode through the.
  • X-ray tube In a shunt circuit to the re sistance 14 are vibrating or make-and-break contacts 15, 16, one at .leastof which is adlliese contacts 15, 16 are caused to open and close at a rapid rate during the, operatioirof the tube, the relative durations of periods of make as compared withthe periods of break being determined by the strength of the current flowing through an electromagne-t 17, the winding of which is included in the circuit 18 carrying the cur rent flowing from cathode to
  • a vibrator magnet is shown in Fig; -Inv the apparatus illustrated in this figure the vibrating armature- 19 of the magiietiopposes in its downward motion a springQO, the tensionof whichmay be adjusted by ascrew "21.
  • the vibrator is adjustedtoi operatesubstantially in synchronism with the I alternating current supply.
  • a condenser 22 may 'beprovided connected across the con- Before.describing-the operation or fund tion of the apparatus illust-ratediby.
  • a device having a cathode which emits elec trons independently of ionization efiects and from which hence a saturation current may be obtained such for example as a hot cathode X-ray tube
  • the transmitted current becomes substantially con stant with wide variations of voltage.
  • an increase of voltage from 82 to 87 volts produces no, appreciable change of current
  • the current through the tube is maintained substantially constant. This action occurs by reason of the variations in magnetic attraction of the core of the stabilizer magnet 17 upon the armature 19 of the vibrator, as already indicated.
  • the magnet 17 for any particular current setting varies the effective length of the cyclic impulses ofv the current fed to the cathode, the impulse of current depending in duration on the conditions governing electron emission, thus heating the cathode to'the temperature required to maintain the desired current value.
  • I mean the length of the current wave before it is reduced to a low value, as'when a resistance is inserted in the circuit. For example, if the current has atendency to in-' crease the time required for the magnet 17 to build up to a strength required to open the contacts 15, 16' each wave of current is reduced. Hence, the contacts 15, 16 are open longer and the resistance 14 is included in series with the circuit 9, 10 for relatively longer periods, thereby weakening the cathode heating current sufficiently to oppose any further increase of thecathode temperature.
  • my invention may be "used advantageously in an 7 X-ray apparatus which has a resistance in series with the primary of the high voltage transformer in order to limit the current which may be drawn from this transforn'ler.
  • a resistance in X-ray devices operating at exceedingly high voltages, say, for therapeutic purposes, such a resistance can be used to limit the current to a value not fatal to life.
  • My invention in such a system can be used to give a substantially constant current through the X-ray tube instead of a. variable current as would otherwise be the case.
  • Fig. 5 l have illustrated an X-ray system suitable for operation with a regulable resistance 26 in series with the primary winding of. a high potential transformer 27.
  • the X-iay tube 28 in this case is con ected to the secondary windings of the transformer 27in series with a mechanical rectifier 29 driven by a synchronous electric motor 30.
  • this motor is supplied with current by the conductors 31 connected to the supply mains 32 in common with the X-ray transformer 27.
  • the cathode 5 of theX-iay tube is supplied with a heating current by a transformer 11 in the primary winding of which are vibrating contacts 15, '16, con-. trolled by a magnet 17 connected by the con-- ductors 33, 34, in series with the secondary coils 35, 36, of the X-ray transformer.
  • a resistance 14 preferably is connected across the contacts 15, 16'.
  • Fig. 5 The system shown in Fig. 5 is closely similar to'the system shown in Fig. 1 except that the use of a resistance in the primary or" the main transformer 27 renders the use of a special rectifier in series with the X ray tube desirable inorder to protect the tube from high potential during the periods of polarity reversal when a rectifying direct connected X-ray tube, as shown in Fig. l, is not taking current.
  • V V
  • the regulator maintains in response to space current flowing through the X-ray tube, an Xray output which s constant in quantity.
  • the energy input 'to the cathode is regulated to maintain a constant em ssion of electrons regardless not only of voltage varlations of the cathode heatlng source but also of variations of conditions inthe X-ray tube-which affect the emissivity of the cathode, such for example, as the evointerior parts of the X-ray tube.
  • Fig. 6 In which the actuating coil 17 is connected by the conductors 38, 39 to the respective supply lines 3, 4E.
  • the parts and electric connections otherwise correspond to the apparatus described inconriection with Fig. 1.
  • An X ray tube such as shown in Fig. 5 may be used. Fluctuations oi supply voltage will advance or retard'the instant the circuit is broken each half wave, thus increasing or decreasing as required the. doles of current received by the cathode.
  • the 'coil 37 will cause the contact 16 to open sooner, thus decreasing the periods. during. y reason of the increased voltage the current rises at atast-e'r' rate and hence" energy delivered during these shorter periods remains unchanged.
  • this internnttent heat input will produce continuously a substantially constant cathode temperature.
  • An Xray apparatus comprising the combination of an Xray tube having main" electrodes including a cathode which is heat-' ed; by passage or current therethrough, .a main operating circuit connected to the main electrodes of said tube, an independent heating circuit connected to said cathode, a
  • source of alternating current subject to volt- I age variation for supplying both circuits, and means responsive to load current in said main circuit'for reducing the current in said heating circuit :durln'g each half wave for periods of suchlength that the load. current is maintained substantially constant.
  • An X-ray apparatus comprising the combination ofan X-ray tube hav ngv a cathode operable at incandescence, a main supply circuitftor said tube, a heating circuit for Sfi-lClCEltllOdQ,-l resistance in said heatingcircuit, a circuit containingmake and break contacts connected in shunt toisaid resistance,
  • X-ray tube having a cathode adapted tobe independently heated and an anode, 1621118 for heating said cathode,- a main operating circuit connected to the electrodes of said X-ray tube, and a vibrating regulator .arranged to maintain the electron emission 0]": said cathode at a predetermined relation to an electrical characteristic of said main circuit.
  • An X-ray apparatus comprising a source ct alternating currentsubject to variations of voltage, an X-ray tube operatively connected thereto, said tube having a cathode i supplied 7 with heating current from said sourceand means responsive to load current in said tube and operating in synchronism with said source for controlling the cathode heating current.
  • An X-ray apparatus comprising an i tube having an incandescible cathoce and an anode, a main supply circuit connected to said electrodes, a circuit for supplyingheat ingf energy to said cathode, vibrating contacts in said heating circuit, and electromagnetic means responsive to current in said main circuit for regulating the relative duration of the periods of make and break off? said contacts thereby preventing departures oi current in said main circuit from a predeter mined value.
  • an auxiliary transformer having a whirling connected to supply heating current to the cathode oi? sa d tube, a resistance in circuit with said winding, electric make and break contacts connected in shunt to said refstance, and electromagnetic means in circuit *ith said X- ray tube tor operating said contacts in syntion from a source of variable voltage com- 7 prising an X-ray device having an electrode capable ofeinitting electrons When heated, a main load circuit, a'heating circuit for said electrode, a resistance in said heating circuit andelectromagnetic means responsive to the current in said main circuit having contacts arranged to insert and Withdraw said resistance intermittently, and means for controlling the relative durat on of the periods 0.
  • An X-ray apparatus comprising an of insertion and withdrawal to maintain the load current at a predetermined value.
  • An X-ray apparatus comprising an.
  • X-ray tube having a cathode adapted to be heated by passage ot current and operating without substantial gas ionization, a source of alternating current subject to variations variable voltage con'iprising the combination or" an X-ray tube'having a cathode adapted to emit electrons when heatedby passage of current, means for deriving energy from the supply sourceto operate said tube, separate means for deriving energy fromthe supply source toheat said cathode, and means oper- I ated by current from said source for intermittently reducing said cathode current synchronously with the alternations of said source for periods varying in duration in such measure that the quantity of X-ray out put remains substantially constant When the voltage of said source varies.
  • an electron discharge device which" is constructed and evacuated to be capable of operation substantially independently of positive ionization, and having a cathode adapted to generate electrons independently of a load current in said device, means for energizing said cathode with alternating current, and means responsive to a load currentin said device for varying the el'l'ective duration of the i cyclic impulses of said alternating circuit in such measure that the load current is maintained substantially constant.
  • An Ix-ray apparatus adapted for operation from an alternating current supply source of variable voltage comprising the combination of an X-ray tube provided with a cathode adapted to emit electrons When heated by passage of current, a main circuit coni cctedto the electrodes of said tube, a heating circuit for said cathode connected to derive current from said source, and arranged for operation at voltages at which current in the main circuit is limited by electron emission of the cathode, and regulating means responsive to current in said load circuit for decreasing the cathode heating current during each Wave of current flowing therein for periods of such duration that the cathode temperature and current in the main circuit will remain substantially constant.
  • An X-ray apparatus adapted for operation from a source of alternating current subject to variations of voltage comprising an X-ray tube of the Coolidge type having a cathode operable at incandescence, a high potential transformer connected v.to said source for supplying said tube with current,
  • electron'iagnetic means responsive to a load current in said tube and operating in synchronismwith said heating current for varying the effective resistance of said heating circuit during each wave of heating current for periods of such duration that the electron emission in said X-ray tube and consequently the output of X-rays aremaintained substantially constant.
  • the method of operating a thermionic discharge device which is subject to changes of operating conditions which consists in supplying to the cathode of said device a heating current of materially higher value than is required to give a desired electron emission, intermittently reducing said current at intervals recurring per second with a frequency of the order of cyclic changes of commercial alternating current and varying the relative duration of the intervals of reduced current in such measure that-the load current in said device is maintained at a substantially predetermined value.
  • a thermionic X- ray device a supply circuit therefor, means for supplying a heating current to said cathode, means for materially reducing said current at intervals recurring with a frequency of the order of commercial alternat ing current and means responsive to a space current in said device for varying the duration of said intervals of reduced heating current relative to the unreduced' heating current to produce a desired electron emission by said cathode, whereby the X-ray output is maintained substantially constant.
  • An X-ray apparatus comprising the combination of an X-ray. tube which is operable independently of positive ionization and is provided with a cathode rendered active by passage of current, means for supplying a cyclic heating current to said cathode, and
  • apparatus is conducting current that a constant current carrying capacity 1s maintained in the X- ray tube when changes occur in the electron emissivity of said cathode or in the voltage of the cathode heating current.
  • X-ray tube of the hot cathode type with a secondary of a step up' transfori'ner divided into two coils, a relay in'sai'd system with its magnet connected to said coils, a transformer for generating a hot cathode current and suitable connections including a resistance so that when the system is in use the resistancewill be thrown in and out of circuit accordingtov the action of the relay -magnet.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US735266A 1922-01-31 1924-09-02 Electron-discharge apparatus Expired - Lifetime US1653102A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
GB9919/21A GB170546A (en) 1924-09-02 1921-04-04 Improvements in and relating to electron discharge apparatus
NL19656A NL9214C (nl) 1924-09-02 1921-06-16 stabilisator voor electronen-ontladingsbuizen en dergelijke toestellen
DEI21656D DE407939C (de) 1924-09-02 1921-06-17 Regelvorrichtung fuer die Temperatur der Gluehkathode in Entladungsroehren
FR542381D FR542381A (fr) 1924-09-02 1921-10-15 Perfectionnements aux dispositifs à décharge électronique
US533070A US1698334A (en) 1922-01-31 1922-01-31 X-ray apparatus
GB19381/22A GB201741A (en) 1924-09-02 1922-07-14 Improvements in and relating to x-ray apparatus
FR27289D FR27289E (fr) 1924-09-02 1923-01-29 Perfectionnements aux dispositifs à décharge électronique
US735266A US1653102A (en) 1924-09-02 1924-09-02 Electron-discharge apparatus
FR31070D FR31070E (fr) 1924-09-02 1925-09-01 Perfectionnements aux dispositifs à décharge électronique
GB21852/25A GB239511A (en) 1924-09-02 1925-09-01 Improvements in and relating to electron discharge apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US735266A US1653102A (en) 1924-09-02 1924-09-02 Electron-discharge apparatus

Publications (1)

Publication Number Publication Date
US1653102A true US1653102A (en) 1927-12-20

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ID=24955045

Family Applications (1)

Application Number Title Priority Date Filing Date
US735266A Expired - Lifetime US1653102A (en) 1922-01-31 1924-09-02 Electron-discharge apparatus

Country Status (5)

Country Link
US (1) US1653102A (fr)
DE (1) DE407939C (fr)
FR (3) FR542381A (fr)
GB (3) GB170546A (fr)
NL (1) NL9214C (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2824925A (en) * 1951-06-23 1958-02-25 Westinghouse Electric Corp Electromagnetic trip circuit interrupters

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE765930C (de) * 1938-03-27 1954-02-08 Siemens Reiniger Werke Ag Einrichtung zur selbsttaetigen Konstanthaltung der Emission von Gluehkathodenentladungsroehren, insbesondere Roentgenroehren

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2824925A (en) * 1951-06-23 1958-02-25 Westinghouse Electric Corp Electromagnetic trip circuit interrupters

Also Published As

Publication number Publication date
FR31070E (fr) 1926-11-22
GB201741A (en) 1923-08-09
FR27289E (fr) 1924-05-31
NL9214C (nl) 1923-06-15
DE407939C (de) 1925-01-06
GB170546A (en) 1922-06-15
GB239511A (en) 1926-08-05
FR542381A (fr) 1922-08-10

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