US1874753A - Controlled arc discharge apparatus - Google Patents

Controlled arc discharge apparatus Download PDF

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Publication number
US1874753A
US1874753A US349436A US34943629A US1874753A US 1874753 A US1874753 A US 1874753A US 349436 A US349436 A US 349436A US 34943629 A US34943629 A US 34943629A US 1874753 A US1874753 A US 1874753A
Authority
US
United States
Prior art keywords
grid
cathode
current
anode
envelope
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
US349436A
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English (en)
Inventor
Albert W Hull
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 BE368819D priority Critical patent/BE368819A/xx
Application filed by General Electric Co filed Critical General Electric Co
Priority to US349436A priority patent/US1874753A/en
Priority to ES0116611A priority patent/ES116611A1/es
Priority to GB9097/30A priority patent/GB346957A/en
Priority to FR38862D priority patent/FR38862E/fr
Priority to FR40076D priority patent/FR40076E/fr
Priority to FR40301D priority patent/FR40301E/fr
Priority to FR40462D priority patent/FR40462E/fr
Application granted granted Critical
Publication of US1874753A publication Critical patent/US1874753A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
    • H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
    • H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/145—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
    • H02M7/15—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using discharge tubes only
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/04—Electrodes; Screens
    • H01J17/06—Cathodes
    • 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
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers

Definitions

  • the present invention relates to thermionic discharge devices containin an ionizable medium and which are rovi ed both with cooperating electrodes or maintaining an arclike discharge and also an electrostatic control electrode (or grid) the invention is d1- rected more particularly to a novel construction and arrangement of the grid electrode for use in this type of apparatus.
  • Electric discharge apparatus which is provided with control electrodes may be divided into two general classes (l) Devices in which the space current is mainly electronic and is continuously variable by variations in potential of the grid electrode.
  • such devices contain suflicient gas to modify by its ionization the electron current for special purposes, such as the detection of radio signals, but ionization of gas, generally spea ing, is a secondary phenomenon in this class of devices.
  • the voltage drop increases with an'increase of current, that is, the volt-ampere characteristic is positive.
  • Such devices contain gas or vapor, at a pressure high enough to ionization to neutralize space charge comp etely and to operate with a voltage between anode and cathode not appreciably higher than the ionization potential of the residual gas.
  • the current voltage characteristic of such devices is generally flat or slightly negative, that is, the voltage drop decreases with an increase of current.
  • the dischage is considered as being arc-like in its characteristics.
  • Controlled-arc discharge apparatus to which invention relates belongs to the second class of devices and has heretofore been constructed in several representative types which differ mainly in respect to the. position of the control member or grid.
  • the control electrode constitutes a metal mesh arranged across a glass envelope transversely of the discharge space
  • the grid surrounds the anode
  • the grid member surrounds the cathode. All of these cons ructions are operative and useful but there are certain difiiculties attending the same.
  • the maximum current that can be controlled is limited to the value that will heat the grid to the point of electron emission; in other words, when the control member is positioned close to the cathode its increased effectiveness gained by reason of its position is partially lost on account of the increased absorption of heat in this position which may cause the grid to emit electrons.
  • this limiting current is of the order of one-half an ampere per square inch of grid surface where reliable control with small energy consumption is desired.
  • the grid constitutesa mesh or perforated structure, through the openings of which the arc current must pass.
  • One of the objects of the present invention is to provide an improved control arrangement which avoids the difliculties of all the above mentioned types while retaining their advantages.
  • the improvement consists, in brief, of a novel form of grid member which may take the configuration of a, hollow cylinder or other shape suitable for cooling, the member being of sufiicient length and positioned withln the tube in such a manner that it completely surrounds the arc path between the anode and cathode.
  • the cylinder may be separate from the envelope or combined therewith; in the latter case, the container within which the anode and cathode are disposed may be fabricated of metal, suitable provision bein made to insulate the cathode, anode and gri members from one another.
  • the improved grid member which constitutes the feature of the present invention and will be described hereinafter has been found to control the starting of an arc discharge, i. e. to perform the function of an electrical trigger as accurately as does a mesh grid interposed transversely between the cathode and anode and is not open to the objections which ordinarily accompany a grid of this sort. It also has the advantage of being easily cooled thus precluding deleterious grid electron emission and allowing large currents to be controlled by elements of moderate size.
  • the device shown in Fig. 1 comprises an elongated glass receptacle 1 in which are mounted a cathode unit 2 which will be described in detail presently, an anode 3 which is shown as a cup but may be a disc, rod, or other form and may be made for example of nickel and an electrostatic control electrode 4 also constituted of nickel, or other suitable metal, which will be briefly referred to as a grid.
  • the discharge s ace contains an at-, tenuated gas or vapor, or example, argon at a pressure between 5 'to 250 microns of mercury, or vapor derived from a globule of mercury introduced into the envelope; when mercury is employed, a portion of the envelope should be maintained at a temperature suflicient to produce a vapor pressure less than one millimeter.
  • the cathode which may consist of nickel or iron comprises a central enclosure 5 upon which are mounted by welding or otherwise outwardly extending vanes 6 and inside 0 which is positioned a heater 7, in the form of a helically coiled wire of tungsten or other suitable refractory material.
  • the heater 7 should be insulated from the enclosure 5 in any suitable manner to prevent short-circuiting of the coil during operation of the device. Electrical connections to the heater 7 may be made in any convenient manner through the press 8 by means of leading-in conductors 9, 10.
  • One end of'the helical filament may be connected as by welding to the end of the enclosure 5-
  • an outer cylinder 11 arranged concentrically with the enclosure and closed at the end remote from the anode and whose main function is to reduce the radiation heat losses from the vanes 6, thus to conserve the heating current required to" maintain the cathode at a desired elevated temperature.
  • the vanes 6 and adjoining surfaces within the enclosure 11 are coated with a suitable material of high electron emissivity of a rare earth metal, an alkaline earth metal or a compound of an alkaline earth metal, e.
  • a cathode coated with barium carbonate should be'formed by heating in a vacuum to a temperature adjacent the melting point of nickel, gas given off being pumped out of the envelope.
  • the improved form of grid consists of a metallic c linder 4: which is arranged concentrically a out the cathode and anode and is interposed between these electrodes and the interior surface of the envelope.
  • the cylinder is of such a length as to extend substantially to the rear surfaces of the electrodes completely encompassing the same in the manner shown and is positioned within the 5 and one should be carried to the exterior to serve as a lead-in conductor 15,
  • the grid is removed from the concentrated arc path between the cathode and anode its temperature remains relatively low and hence no electrons are emitted by the grid even under high current density but at the same time it has been found that its control function is quite effective.
  • the heat-radiating capacity of the control member maybe enhanced, hence further removing the possibility of undesired electron emission, by affixing to the external surface of the cylinder, heat radiating fins or, as will be descrlbed in connection with other figure, by exposing the control member directly to the alr in WhlCh case it may comprise a portion of the envelope.
  • the grid element 4 const1- tutes a portion of the envelope in the reg on of the electrodes 2 and 3, said electrodes being insulated from one another and from the control member by means of glass portions 16 interposed between metallic portions whlch constitute the remainder of the envelope.
  • the manner of sealing glass to metal is well known and will not be described in detail.
  • the anode 3 is shown as a graphite rod provided with a screw thread to receive the conductor 17 which is secured to a meta cap 18 terminating the envelope. It is evident that the types of control member described, i.
  • WlllCh restrlcts the current at practical voltages to values very small compared with those that can be ob tained with grid-controlled arc discharge devices.
  • the maximum pure electron current depends, according to the Child-Langmuir space charge equation, on the ratio of control 0 linder diameter to distance between catho e and anode.
  • the maximum current at 100 volts is 1 milliampere. This is very small compared with the currents obtained in practical pure electron tubes.
  • the tube shown in Fig. 2 when'used as an arc discharge device, has a normal rating of 300 amperes at 12 volts. This current can be controlled by the same energy and with the same reliability as the 1 milliampere of pure electron emission. For example, with 20,000 volts impressed between'anode and cathode, a negative potential of 20 volts prevents the flow of any current, while 19 volts negative potential allows the full 300 amperes to flow. Thus 6000kilowatts of power can be reliably controlled by a variation of potential of 1 volt applied to the grid with an expenditure of energy of the order of 1 microwatt.
  • the cathode unit 2 may be similar to that described in connection with'Fig. 1 and is mounted at the roper distance from the anode by means 0 a hollow metal tubin 19, which is connected to one terminal o the cathode to constitute a lead-in conductor.
  • the other cathode lead-in wire is formed by an insulated conductor 20 which passes through the center of the tubing 19 and is attached to a metal contact cap 21.
  • Devices of the character described when energized by alternating current of a voltage sufiicient to produce an arc-like discharge, may be used for relay and other purposes whlch require large amounts of current e. g. of the order of many am eres, this current being reliably controlled y the application of direct or alternating current energy of thedorder of a fraction of a microwatt to the What I claim as new and desire to secure by Letters Patent of the United States, is
  • Electrical apparatus comprising an evacuated cylindrlcal envelope containing a plurality of cooperating electrodes, an electrostatic control electrode adapted to cooperate therewith, a charge of inert gas in said envelope at a pressure sufiioient to sustain an arelike discharge, said control electrode being constituted of a metallic cylinder which extends substantially to the rear surface of each of said electrodes.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
US349436A 1927-10-15 1929-03-23 Controlled arc discharge apparatus Expired - Lifetime US1874753A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE368819D BE368819A (enrdf_load_stackoverflow) 1929-03-23
US349436A US1874753A (en) 1929-03-23 1929-03-23 Controlled arc discharge apparatus
ES0116611A ES116611A1 (es) 1929-03-23 1930-01-27 MEJORAS EN DISPOSITIVOS DE DESCARGAS TERMOIoNICAS
GB9097/30A GB346957A (en) 1929-03-23 1930-03-21 Improvements in and relating to electron discharge devices
FR38862D FR38862E (fr) 1927-10-15 1930-03-22 Perfectionnements aux dispositifs à décharge thermionique
FR40076D FR40076E (fr) 1927-10-15 1930-04-24 Perfectionnements aux dispositifs à décharge thermionique
FR40301D FR40301E (fr) 1927-10-15 1931-04-03 Perfectionnements aux dispositifs à décharge thermoionique
FR40462D FR40462E (fr) 1927-10-15 1931-06-26 Perfectionnements aux dispositifs à décharge thermionique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US349436A US1874753A (en) 1929-03-23 1929-03-23 Controlled arc discharge apparatus

Publications (1)

Publication Number Publication Date
US1874753A true US1874753A (en) 1932-08-30

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US349436A Expired - Lifetime US1874753A (en) 1927-10-15 1929-03-23 Controlled arc discharge apparatus

Country Status (4)

Country Link
US (1) US1874753A (enrdf_load_stackoverflow)
BE (1) BE368819A (enrdf_load_stackoverflow)
ES (1) ES116611A1 (enrdf_load_stackoverflow)
GB (1) GB346957A (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422819A (en) * 1944-08-15 1947-06-24 Eitel Mccullough Inc External anode electron tube
US2459997A (en) * 1947-05-24 1949-01-25 Electrons Inc Partially indirectly heated cathode structure for gas tubes
US2492665A (en) * 1945-03-29 1949-12-27 Sylvania Electric Prod Thyratron tube
US2594897A (en) * 1945-09-19 1952-04-29 Bell Telephone Labor Inc Cathode structure for electron discharge tubes
US2763806A (en) * 1950-11-24 1956-09-18 Hanovia Chemical & Mfg Co Vapor electric discharge device
US2841735A (en) * 1955-03-15 1958-07-01 Philips Corp Electron discharge tube
US2937303A (en) * 1957-09-11 1960-05-17 Edgerton Germeshausen & Grier Electric discharge device
US2942136A (en) * 1955-08-11 1960-06-21 M O Valve Co Ltd Low pressure gas filled thermionic valve
US3075114A (en) * 1956-07-17 1963-01-22 Edgerton Germeshausen & Grier Gaseous-discharge device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5994850A (en) * 1995-09-08 1999-11-30 Eev Limited Switching arrangements wherein a cylindrical trigger electrode is arranged around a gap between an anode and cathode for establishing a discharge therebetween

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422819A (en) * 1944-08-15 1947-06-24 Eitel Mccullough Inc External anode electron tube
US2492665A (en) * 1945-03-29 1949-12-27 Sylvania Electric Prod Thyratron tube
US2594897A (en) * 1945-09-19 1952-04-29 Bell Telephone Labor Inc Cathode structure for electron discharge tubes
US2459997A (en) * 1947-05-24 1949-01-25 Electrons Inc Partially indirectly heated cathode structure for gas tubes
US2763806A (en) * 1950-11-24 1956-09-18 Hanovia Chemical & Mfg Co Vapor electric discharge device
US2841735A (en) * 1955-03-15 1958-07-01 Philips Corp Electron discharge tube
US2942136A (en) * 1955-08-11 1960-06-21 M O Valve Co Ltd Low pressure gas filled thermionic valve
US3075114A (en) * 1956-07-17 1963-01-22 Edgerton Germeshausen & Grier Gaseous-discharge device
US2937303A (en) * 1957-09-11 1960-05-17 Edgerton Germeshausen & Grier Electric discharge device

Also Published As

Publication number Publication date
BE368819A (enrdf_load_stackoverflow)
ES116611A1 (es) 1930-02-16
GB346957A (en) 1931-04-23

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