US2012435A

US2012435A - Thermionic discharge device

Info

Publication number: US2012435A
Application number: US660093A
Authority: US
Inventors: John F Peters
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1923-08-30
Filing date: 1923-08-30
Publication date: 1935-08-27
Anticipated expiration: 1952-08-27

Description

Aug. 27, 1935. J, ETE zmmw- THERMIONIC DISCHARGE DEVICE Filed Aug. 150, 1923 u WITNESSES: INVENTOR Mw 10/10 F e fen? ATTORNEY Patented Aug. 27, 1935 v 1 UNITED STATES PATENT OFFICE)? THERMIONIC' DISCHARGE DEVICE John F. Peters, Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application August 30, 1923, Serial No. 660,093

. 4Claims. (Cl. 250-275) My invention relates to thermionic discharge netic modulation efiect which occurswith the devices. single filament when heated by alternating cur- Broadly speaking, the object of my invention rent. is to provide a cathode for a thermionic discharge Other objects and structural details of my in- 5 device which avoids the difiiculties encountered vention will be apparent from the following de- 5 in heating thermionic cathodes by alternating scription and claims when read in connection current. with the accompanying drawings, wherein:

More specifically, the object of my invention is Figure 1 is a view in elevation of a cathode conto provide a heated cathode construction for a structed according to my invention. thermionic discharge device in which means are Fig. 2 is a view in elevation of a vacuum tube 10 provided whereby the cathode can be heated by having a cathode constructed according to my alternating current and means whereby the modinvention in operative relation to a fiat grid and ulating effect of the alternating magnetic field plate of the pattern employed in a typical triode, produced by alternating current as encountered and in the usual single filament cathode structure of Fig. 3 is a view similar to Fig. 2 illustrating the 15 the'prior art is nullified. cathode in conjunction with a cylindrical grid In thermionic discharge devices constructed and cylindrical plate. according to the prior art,asingle filament is cus- In the figures, similar structures have the tomarily used. This filament is usually heated same reference numbers. by a flow of low voltage direct current. Many In the structure of Fig. 1, a press I carries 20 such devices have been constructed with a filasealed-in conductor and supporting wires 2, 3, 4, ment cathode of such size as to be heated to the 5 and 6. Two adjacent filaments I and 8 are operating temperature by a current of approxi attached at their ends to conductor wires 3 and mately one ampere, supplied at a voltage of ap- 5 and are supported at their centers by supportproximately 6 volts. This current is customarily ing wire 2. Wires II and I2 serve as connectors 25 supplied from a storage battery. However, it for conducting the current from the lead wires would be much more convenient to supply the 3 and 5 to the ends of filaments l and 8.

heating energy as alternating current from com- In the arrangement shown in Fig. 2, a press I mercial frequency circuits by a transformer at a is provided, as before. Lead and supporting wires suitable voltage. 2, 3, 4, 5, 6, l3 and M are also provided as are 30 When this s been attempted in the pas filaments l and 8. In addition, a grid I5 suphowever, difliculties have been experienced due ported n wires 6 and I4 and a plate 5 supported to the fact that the magnetic field incident to any n wire 4 and I3 are provided, A container 11 heating Current produces l influence p n the of glass or other suitable material is provided.

electron stream. When direct current is used for Th structure of Fig. 3 is similar to that of 35 a hea r y pp y h ma n i efiect i Fig. 2 except that a cylindrical grid 2| and a S a and Steadyinvalue, and therefore, produces cylindrical plate 22 are provided instead of the no pulsating modulation effect on the electron fiat grid and plate. stream to be recognized as a sound in the receiv- I the operation of my device, an alternating i c app atus p y d i njun ti n with t current source is connected to leads 3 and 5. 40 tube. When, howeve alternating Currentisused Current fiows between the leads by way of filawith a single filament cathode, the pulsations of ments 1 and 3 in Such manner t t t reSPecthe curren p d a Varying magnetic effect tive portions of the filaments of opposite polarity p the electmn Stream which causes a agand in juxtaposition to each other carry currents netic modu a on and is perceived as a und in in opposite directions. Potential is also impressed 45 a telephone device employed in Conjunctifln Wi between the filament structure and an adjacent the system containing such filament cathode. anode structure, whereupon an electron stream My invention provides a cathode construction carries the current between the anode and the consisting of two filaments placed in juxtaposicathode. Modulation of this electron stream by tion, and connected to the same energy source in a magnetic field produced by the alternating cur- 50 such way that they carry substantially equal rent in the filament cathode structure is, howcurrents in opposite directions. These opposite ever, avoided by reason of the neutralization of currents produce opposing magnetic fields. the field of one filament by the field of the adja- These fields, by virtue of their opposition, neucent filament.

56 tralize each other and thereby avoid the mag While I have illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of my invention and it is desired, therefore that only such limitations shall be imposed thereon as are indicated in the prior art or as set forth in the appended claims.

I claim as my invention:

1. Air electron-discharge device comprising a cathodestructure having more than two currentcarrying members comprising two groups to carry current in opposite directions, individual members of one group being more closely adjacent to a member of the other group than to any member of their own group. H

2. An electron-discharge device comprising a cathode structure having a pair of current-carrying loops, the sides of each" loop being more dis tant from that side of the other loop which car ries current of the same direction than from that side of the other loop which carries current of the opposite direction.

3. An electron-discharge-tube device comprising a cathode having two substantially hair-pinshaped filaments, said filaments crossing each other at their bights, a common support for said bights, the sides of each filament being relatively far apart from each other, each filament-side being farther from that side of the other-filament which carries current inthe samedirection than from that side of the other filament that carries current in the opposite direction as itself.

4. A thermionic tube having plate and grid element's therein, an even number of filaments, and connections for conveying a heating current to said filaments, each of said filaments having a part lying substantially alongside a neighboring filament, and connected to cause the instantaneous direction of flow in such parts of the two filaments to be substantially opposite.

JOHN PETERS.