US1610783A

US1610783A - Electron-discharge apparatus

Info

Publication number: US1610783A
Application number: US431746A
Authority: US
Inventors: Albert W Hull
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1920-12-18
Filing date: 1920-12-18
Publication date: 1926-12-14
Anticipated expiration: 1943-12-14

Description

Dec. 14 1926. 1,610,783

A. W. HULL ELECTRON DISCHARGE APPARATUS Filed Dec. 18, 1920 J I nvehtor-z "gand metho s of'operatin Patented Dec. 14, 1926. 7

UNITED STATES PATENT OFFICE.

.ALIBEB'I' W. HULL, OF SCHENEGI'ADY, YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 01' NEW YORK. A

ELECTRON-DISCHARGE APPWTUB.

a n anonaied December 15, 1920. sex-mm; 4am.

M present invention relates to the use of eliactron discharge apparatus of the well known'vacuum tube type, and the applica-' tion of such apparatus to various uses such as am lification of electric currents or the detection of radio signals. I I

An object of my invention is to provide new and im rovedcircuit organizations for such v ap aratus which are more efficient t an those ieretofore employed. I 7

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however; both as to its operation together with further ob ects and advantages thereof will best be un erstood by reference to the following description taken in connection' with the accompanying drawing in which Fig. 1 shows diagrammatically a cirorganization and method 0 cuit arrangement 'which may be used for the amplification ofvariable currents, .particularly of audio frequency. Fig. 2 shows a similar'circuit arrangement for the relaying or amdplification of radio frequency currents, an Fig; 3 shows acirciut arrange-' ment which maybe employed as a detector of radio signals. i

As indicated in the drawings, I employ an electron discharge device 1 having the usual l0 the otential of the cathode 2 and anode 3,

electron emitting cathode 2, anode 3, a third or grid electrode 4, and a grid or discharge controlling electrode 5.

The direct current source 6 which is connected in the plate or anode circuit between cathode 2 and anode 3 furnishes the current for the operation of the device. By means of this source a potential may also be ap lied to the grid electrode 4 which is interme late the esired reduction in potential being obtained by the use of a. potentiometer 7. The current to be plified is im ressed upon the grid circuit between catho e 2 and grid 5 by means ofa transformer 8. The amplified current in the plate circuit, if of'audio frequency, may be impressed by means of the transformer 9 u on the circuit of a telehone receiver. 10 or the purpose of producing an audible indication of the amplified current flowing in the plate circuit. In case the current to be amplified is not of audible frequency any other suitable form of indicating device may be associated with preferab be emittedfrom the grid electrode 4 to pro duce a negative resistancecharacteristic in the circuit between cathode 2. and grid electrode 4; When operated in this way the variation-in, the potential ofthe 'rid 5 will produce a high am lification of t e current flowing in the circu thetween cathode 2 and grid 4 by reason of the negative resistance characteristic of this circuit. There will at 3 the same time be produced a corresponding complementary chan e in the current in the circuit between catho e 2 and anode 3. This circuit will not possess a negative resistance characteristic over the usual operatingrange and therefore will be stable in itso eration.

In order to produce a high degree 0 amplification alpositive resistance 18 which should negative resistance inthe circuit etween the cathode 2 and id electrode 4. is inserted in that-circuit. have indicated the use of a single source 6 for obtaining the potential necessary for the'operation of the device, but separate sources may be employed for theapplication of the potentials to the two electrodes 3 and 4 in case it is not convenient to obtain the'desired potentials from a sin is source. v

In he arrangement of Fig. 2, I have indicated a murce 12 of radio frequency current which is amplified by the system and be approximately e ual to the i a plied to the transmitting antenna 13 for t e transmission of radio signals.

In the arrangement of 1g. 3 I have indicated the use of an electron dischar e device-as a detector of radio signals. 11 this case the signals to be detected which are received by the antenna 14 are. im ressed uponthe usual resonant idcircuit I5, this grid circuit being provi ed with theusual stopping condenser 16 and grid leak 17.

In any of the cases illustrated the device may be operated as a negative resistance device 1n accordance with the methods of operation described in the paper entitled The Dynatron published by me in the Proceedings of the Institute of Radio Engineers for 1918 at page 5.

In case itis not desired to employ the negative resistance characteristic of the device it may however, be employed in the same manner as the usual three-electrode device. In this case the grid electrode 4 should be maintained at a ositive potential intermediate the potentia s of cathode 2 and anodefi, The desired potential for the operation of the grid 4 may in this case be obtained either by means of the potentiometer 7 of F; 1 and 2 or by. va ng the resistance 18 one as indicated in ig. 3. In the operation of the usual three-electrode devices it has been foundthat there is a marked tendency for the roduction of undesired high frequency oscillations by reason of the capacity between the dischar e controlling grid and the anode. The use 0 the extra grld electrode 4 be tween 'the discharge controlling grid and the anode,'however, screens the two electrodes in such a way that this tendency s reduced. In this case the resistance18 is preferably shunted by a condenser 11, which a will permit the alternating component of the current flowing to grid electrode 4 around the resistance 18.

The capacity eifect between IE1 and .anode for athree electrode device a so great- 2/ reduces the ossible amplification of the vice when ra l0 frequencies are employed.

' The use of the extra grid electrode 4 reduces the capaci eflr'ect in such cases and'permits a big 1 degree of amplification with radio frequencies.

4 In the usual threeelectrode device, a high plate impedance, which is desirable for operation, can be obtained only at the sacrifice of grid control so that in Ipractice it. has been found best to make the p ate impedance between 10,000 and 100,000 ohms. The use of the extra grid electrode in the manner described, however, screens the cathode from the effect of late voltage, thereby maki'n it possible to ave a very high plate 'impe ance without sacrificing grid control and thereby greatly increasing the amplification. While I have shown and described only three circuit arrangements in which my invention is employs it will be apparent that my invention is by no means limited to the exact form of apparatus or the precise circuit connections indicated, as man modifications, both in the apparatus use as well as in the circuit connections, may be made without departing from the scope of my invention as set forth in the ap ended claims.

What I claim as new and esire to secure byLetters Patent of the United States, is,-

1. An electron discharge device com rising an electron emittin cathode and at east two other electrodes enc osed in an evacuated receptacle, and sources of potential applied 2. An'electron discharge comprising an electronemitting cathode, an anode and a grid electrode which is interposed between cathode-and anode, a source of potential for maintaining the anode at a positive potential with respect to the cathode, and means for maintaining the id electrode at a potential which 1s interme 'ate the potentials of cathode and anode, the potentials of the anode and grid electrode being so chosen that the n current. between cathode and grid electrode Wlll, over a defimte working range of potential vary inversely as the (potential difierence between cathode and gri 3. An electron dischar device comprisin an electron emitting cat 1ode,an anodean a grid electrode interposed between cathode and anode, means for impressing a constant positive potential upon said anode, means for impressing a positive potential upon the grid electrode of such a value as to produce an emission of secondary electrons from said grid electrode, the potentials applied to said electrodes being of such values that the device will have a ne ative resistance characteristic between cathode and grid electrode.

4. The method of operating an electron discharge device comprising an t electron emitting cathode, an anode, and a third electrode interposed between cathode and anodewhich' consists in'applying a constant positive potential to the :inode and applying a positive potential to the third electrode of such a, value as to produce an emission of secondary electrons therefrom sufficient to give the device a negative resistance characteristic.

5. The method of operating an electron discharge device comprising an electron emitting cathode, an anode and a third electrode between cathode and anode which consists in applying a constant positive potential to the anode and applying a positive potential to the third electrode of such a value as to give the device a negative resistance characteristic.

6. An electron discharge device comprising an electron emittmg cathode, an anode and two grid electrodes enclosed in an evacuated receptacle, a source of potential for maintaining the \anode at a positive otential with respect to the cathode, means or maintaining one of the grid electrodes which is interposed between cathode and anode at a potential which is intermediate nemfras the potentials of the cathode and anode,-the

potentials of the anode and grid electrode being so chosen that the current between cathode and grid electrode will, over a def: inite working range of potential vary nversely as the Jotential difference between and two grid electrodes interposed between cathode and anode, a source 0 potential for maintaining the anode at a positive potential witlr respect to the cathode, means for maintaining the rid electrode nearest the.

anode at a potential intermediate the potentials of the cathode and anode, the potentials of the anode and said grid electrode being so chosen that secondary electrons will be emitted from the grid in sufl'icient amount to give the device a negative resistance characteristic between cathode and said grid electrode, and means for varying the potential of the second gridto var the current. flow between cathode and ano e.

8. The method of operating an electron discharge device having an electron emitting cathode, an anode and two rids enclosed in an evacuated receptacle, at least one of said grids being interposed between cathode and anode, which consists in maintaining the anode and grid electrode nearest the anode at such potentials with respect to the cathode that a sufficient flow of secondaryelectrons.

from grid electrode to anode will be pro duced to give the device a negative resistance characteristic between cathode and grid electrode, and varying the potential of the second grid electrode and thereby varying the current flow between cathode and anode.

'9. The method of operating an electron discharge device having an electron emitting cathode, an anode and two grid electrodes interposed between cathode and anode which consists in maintaining the anode an grid electrode nearest the'anode at such potentials with respect to the cathode that the device will have a negative resistance characteristic between cathode and said grid electrode, and varying the potential of the grid electrode nearest the cathode and thereby varying the current flow between cathode and anode.

10. An electron discharge device comprising an electron emitting cathode, an anode, a third electrode and a discharge controlling member, of means, for supplying adefinite positive potential to said anode, means for supplying a lower positive potential to the third electrode of such a value as to give the device a negative resistance characteristic between cathode and third electrode, means for applying a variable potential to the dischar 0 controlliifig member to vary the cur rent etween cathode and anode, and means associated with the circuit between cathode and anode for producing an indication of the current- 'variationsin that circuit.

11. An electron discharge device comprising an electron emitting cathode, an anode and two grid electrodes interposed between cathode and anode, oi means for supplying a definite positive potential to said anode, means for supplying a vlower positive potential to the grid electrode nearest the anode of such a value as to give the device a negative-resistance characteristic between cathode and "rid electrode, means for applying a variable potential to the id electrode nearest the cathode'to vary t 1e current between cathode and anode, and means associated with the circuit between cathode and anode for producing an indication of the current variations in that circuit.

12. The method of operating an electron discharge device comprising an electron emitting cathode, ananode, a third electrode and a discharge controlling member which consists in producing an emission of secondary electrons from the third electrode sufiicientto give the device a negative resistance characteristic between cathode and third electrode, applying a variable potential to the discharge controlling member to vary the current between cathode and anode and producing a desired indication of the current changes between cathode and anode.

13. The method of operating an electron discharge device comprising an electron emittin cathode, an anode and two grid electrotias interposed between cathode and anode, which consists in producing an emission of secondary electrons from the grid electrode nearest the anode suificient to give the device a negative resistance characteristic between cathode and said id electrode applying a variable potentia to the grid electrode nearest the cathode to vary the current between cathode and anode and producing a desired indication of the current changes between cathode and anode.

14. In a system for detectin radio signals, the combination of an e ectron discharge device having an electron emitting cathode, an anode, and two grid electrodes enclosed in an evacuated receptacle, a source ofpotential for maintaining this anode at a ositive potential with respect to the cath o e, means for maintaining one of the grid electrodes which is interposed between cathode and anode at a potential intermediate the potentials of the cathode and anode, the potentials of anode and grid electrode being so chosen that the current between cathode and grid electrode will, over a definite working range of otential vary inversely as the potential di erence between cathode and grid electrode, means for supplying the redio signals to be detected to the second grid to vary the current flow between cathode and anode in accordance with the signals cathode and anode, to detect radio signals which consists in maintaining the anode and grid electrode nearest the anode at such po tenlials with respect to the cathode-that a sufiicient flow of secondar electrons from grid electrode to anode wi l be produced to give the device a negative resistance characteristic between cathode and grid electrode, supplying the signals to be detected to the second grid electrode and thereby varying the current flow between cathode and anode in accordance with the signals and producing a desired indication of the signal ing current flowing between cathode and anode.

16. Means for amplifying variable electric currents comprising an electron dis charge device having an electron emitting cathode, an anode and two grid electrodes enclosed'in an evacuated receptacle, a source of potential for maintaining the anode at a positive potential with respect to the oathode, means for maintaining one of the grid electrodes which is interposed between cath' ode and anode at a otential which is intermediate the potentials of the cathode and anode, the potentials of cathode and grid electrode being so chosen that the current between cathode and grid electrode will over a definite working range of potentiai vary inversely as the otential difference between cathode and grid electrode, a circuit between cathode and second grid and means for supplying the current to be amplified to said circuit to vary the current flow between cathode and anode in accordance with the current to be amplified.

17. The method of operating an electron discharge device having an electron emitting cathode, an anode and two grid electrodes inierposed between cathode and anode to amplify a variable electric current which consists in maintaining the anode and grid electrode nearest the anode at such otentiais with respect to the cathode that t e device will have a ne alive resistance characteristic between cat ode and said grid electrode, and supplying the current to be amplified to a circuit between the cathode and the grid electrodenearest the cathode and thereby varying the current flow between cathode andanode in accordance with the current to be amplified.

In witness whereof, I have hereunto set my hand this 17th day of December, 1920.

ALBERT W. HULL.

dio signals to be detected to the second grid to vary the current flow between cathode and anode in accordance with the signals and means associated with the circuit between cathode and anode for reducing a desired indication of the signa ing current in that circuit.

15. The method of operating an electron discharge device having an electron emitting caihode, an anode and two grids enelosed in an evacuated receptacle at least one of said grids being interposed between cathode and anode, to detect radio signals which consists in maintaining the anode and grid electrode nearest the anode at such potentials with respect to the cathode-that a sufiicient flow of secondary electrons from grid electrode to anode will be produced to give the device a negative resistance characteristic between cathode and grid electrode, suppl ing the signals to be detected to the secon grid electrode and thereby varying the current flow between cathode and anode in accordance with the signals and producing a desired indication of the signalode, means for maintaining one of the grid electrodes which is interposed between cathode and anode at a potential which is intermediate the potentials of the cathode and anode, the potentials of cathode and grid electrode being so chosen that the current between cathode and grid electrode will, over a definite working range of potential vary inversely as the otential difference between cathode and gri electrode, a circuit between cathode and second grid and means for supplying the current to be amplified to said circuit to vary the current flow between cathode and anode in accordance with the current to be amplified.

17. The method of operating an electron discharge device having an electron emitting catl1ode, an anode and two grid electrodes inierposed between cathode and anode to amplify a variable electric current which consists in maintaining the anode and grid electrode nearest the anode at such otentials with respect to the cathode that t e device will have a negative resistance characteristic between cathode and'said grid elec trade, and supplying the current to be amplitied to a circuit between the cathode and the grid electrode nearest the cathode and thereby varying the current flow between cathode andanode in accordance with the current to be amplified. p

ALBERT W. HULL.

Certificate of Correction. It is hereby certified that in Letters Patent No. 1,610,783, ranted December 14,

1926, upon the ap improvement in lication of Albert W. Hull, of Schenect y, New York, for an lectron-Discharge Apparatus, an error appears 111 the printed specification requiring correction as follows: Page 2, line 76, claim 2, after the word dischar e insert the word device; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent ce.

Signed and sealed th s lstday of February, A. D. 1927.

M. J. MOORE, Afifing Oomvisaiomr of Patmta.

Certificate of Correction.

It is hereby certified that, in Letters Patent No. 1,610,783, qranted December 14, 1926, upon the ap vlicatrion of Albert W. Hull, of Schenectmf New York, f or an improvement in llectron-l)ischarge Apparatus, an error appears in the printed specification requiring correction as follows: Page 2, line 76, claim 2, after the word discharge insert; the word device; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent 0 fice.

Signed and sealed th s 1st. day of February, A. D. 1927.

[mm] M. J. MOORE,

Afdting Umnmdssiomr of Patents.