US1961820A - Signaling system - Google Patents

Description

June 5, 1934. DOUGLAS 1,961,820

SIGNALING SYSTEM Filed Oct. 7. 1929 Fig.2

Inventor:

Nom/el Douglas,

BMW

His Attorneg.

' UNITED STATES PATENT OFFICE SIGNALING SYSTEM Norvel Douglas, Lawrence, Kans., assignor to General Electric Company, a corporation of New York Application October 7; 1929, Serial No. 397,893

'7 Claims. (01. 179-171) My present invention relates t signaling sys- November 20, 1928, entitled Signal transmitting terms including oscillation generators of the type I11eahSaIld Which is assigned to the Sa assignee disclosed in copending application, Serial No. 389,- aS the present application, d t at W th a con- 067, filed August 23, 1929 by El th stant value of field current the oscillations vary '5 entitl d High frequency magnetron apparatus, inversely as the anode potential through a cer- 60 and which is assigned to the same assignee as the tain range thereof- I the manner presently present application. It has for its purpose to probe described the anode potential y be Va vide means whereby oscillations produced by genin response to Signal Currents, Such as these p eraters of th t e i i t may be modulated duced by a microphone, or a like signal device,

1 10 in accordance with desired signals. and in this manner, modulation of the intensity 65 h novelfeatureswhichIb 1ie t b h of the oscillations produced in accordance with teristic of my invention are set forth with particuthe Signal Currents may he eiheiently accomlarity in the appended claims. My invention it- P self, however, both as to its organization and AS Shown in 1 this result is at a ned by "'15 method of operation, together with further obmeal-1S of an electron discharge device the 70 j t d advantages th f, may t be underspace between the anode and cathode of which, t d by reference t t following description is connected in shunt with the series connected t k i connection ith t accompanyingflrawreactor 9 and source 8. Signal currents produced ing in which Fig. 1 represents one emiiodiment in the microphone, in any Other ab e Big- 20 of my invention, and Fig. 2 represents a'modifihal device 11, may be pp to e g id of the 75 cation thereof. device 10 through an amplifier l2. Normally Referring to Fig. 1 of the drawing I have shown the grid of the device 19 is biased negatively by at 1 an electron discharge device comprising a means of a source of potential 13 to a degree such pair of oppositely disposed anodes 2 and 3 which that the magnitude of Current fl w g in the '25 are arranged insubstantially cylindrical formaanode circuit P e the rmal anode dissition about a filamentary cathode 4. Connected patioll f the discharge device. W S gnal between the anodes is an inductance 5 and, if de- Currents are pp t the id of device sired, a capacity 6 forming an oscillatory circuit. thiS grid becomes less negative, positive, th This oscillatory circuit also includes of course the respect to the Cathode and the p d ce bean inherent capacity between anodes 2 and 3. Where tween the Cathode and anode is thereby reduced.

the system is to be used for the producti of Hence an increase in current from the source 8 ultra high frequency oscillations the external cathrough reactor 9 d the p ce betweenthe paeity 6 d o tr t d indu ta 5 may h anode and cathode of device 10 will occur. This removed, the inherent capacity betw th change in current in the anode of the device 10 anodes and the inductance of the anode leads induces a Voltage in leaetel Which iS pp comprising the entire oscillatory circuit. The to that of the source 8 and which causes a cathode 4 is heated by means of an energy source diminution of potential on the anodes and a cor- 7, and the anodes are supplied with energy fro responding increase in the intensity of oscillaa direct current source 8 through a reactor 9 tions produced. When the potential on the grid 40 which is connected to the mid-point on the inof device 10 changes in the opp ect o ductance 5. the voltage induced in reactor 9 aids that of Encircling the discharge device 1 is a coil 16 source 7 and causes a corresponding decrease in which is energized from a source of unidirectional the intensity of oscillations produced. In this electromotive force 17 having a value such that Way the oscillations produced may be ehiciently the oscillations produced in the ir it 5, 6 are of modulated in intensity in accordance with the 100 desired intensity. By this means a magnetic field signals produced by the device 11. is produced between the anodes 2 and 3 the lines In the modification of my invention shown in of force of which extend parallel with the axis Fig. 2 the oscillatory circuit 5, 6, is in the form of the cylinder formed by the anodes and hence of a series resonant circuit connected between parallel with the cathode. one of the anodes and the cathode. Also in this 105 It has been found that the amplitude of oscilfigurethe two anodes are maintained at different lations produced by a generator of the type indipotentials, the potential on the anode 3 being cated vary directly with the intensity of the maghigher than the normal potential on the anode netic field as indicated in copending application 2, this potential being supplied by means of a I of Elmer D. McArthur, Serial No. 320,709, filed source 15 connected between the anode 3 and the n cathode. The potential on the anode 2 is supplied by a source 15 connected between the cathode and the anode 2 through the reactor 9. It has been found that, with a fixed value of potential of the source 14, and with the field current suitably adjusted, that for a certain range of voltages on anode 2 less than that on anode 3 the discharge device has negative resistance between the cathode and the anode 2, that is, as the potential of the anode increases the current flowing between the cathode and the anode decreases. If the oscillatory circuit 5, 6 be connected between the anode 2 and the cathode and the potential on anode 2 is adjusted within the negative resistance range it will be found that oscillations are produced in this circuit. These oscillations may be modulated in the manner described in connection with Fig. 1, the anode cathode circuit of discharge device 10 being connected in shunt with the reactor 9 and source 15.

The load circuit upon the oscillation generator may be coupled to the oscillatory circuit by any form of coupling well known in the art although as shown in the drawing an inductive coupling represented by transformer 5, 18 is employed.

While I have shown but a particular means for modulating the oscillations it will of course be understood that I do not wish to be limited thereto since other means may be employed for accomplishing the purpose as, for example, that of varying the field current by means of a microphone connected in that circuit.

While I have shown particular embodiments of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications, both in the circuit arrangement and in the instrumentalities employed, may be made without departing from the spirit and scope of my invention, as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an electron discharge device comprising a pair of oppositely disposed anodes, a cathode extending between said anodes, means for producing a magnetic field between said anodes, a resonant circuit connected to said cathode and to at least one of said anodes, means for supplying potential to said anodes whereby oscillations are produced in said resonant circuit having a frequency determined by the characteristics of said resonant circuit, said magnetic field between said anodes being maintained constant during the production of said oscillations, a source of continuously variable signal current, and means for modulating the amplitudes of oscillations of said frequency in accordance with the continuous variations in said signal current.

2. In combination, an electron discharge device having a pair of oppositely disposed anodes, a cathode extending between said anodes, a resonant circuit connected between said anodes, means for producing a magnetic field between said anodes, means for impressing positive potential on said anodes, a source of continuously variable signal current, and means connected between the anodes and cathode for modulating the oscillations produced in accordance with the continuous variations in said signal current.

3. In combination, an electron discharge device comprising a pair of oppositely disposed plate members, a cathode extending between said members, means for producing a magnetic field between said plate members and parallel with said cathode, a resonant circuit including the capacity between said plate members, means for supplying unidirectional potential to said plate members having value such that oscillations are produced in said resonant circuit, a source of continuously variable signal current, and means for varying said potential in accordance with the continuous variations in said signal current thereby to modulate the oscillations produced.

4. In combination, an electron discharge device, comprising a pair of oppositely disposed anodes, a cathode extending between said anodes, means for producing a magnetic field between said anodes, an oscillatory circuit comprising the inherent capacity existing between said anodes and an inductance connected between said anodes, a reactor connected between a point on said inductance and said cathode, means for supplying potential through said reactor to said anodes such that oscillations are produced in said oscillatory circuit, and means for varying the potential on said reactor in accordance with desired signals thereby to modulate the oscillations produced.

5. In combination, an electron discharge device, comprising a pair of oppositely disposed anodes, a cathode extending between said anodes, means for producing a magnetic field between said anodes, an oscillatory circuit comprising the inherent capacity existing between said anodes and an inductance connected between said anodes, a source of unidirectional potential and a reactor connected in series between a point on said inductance and said cathode, said potential being of value such that oscillations are produced in said oscillatory circuit, an electron discharge path connected in shunt with said series connected source and reactor, and means for varying the impedance of said path in accordance with desired signals thereby to modulate the oscillations produced.

6. In combination, an electron discharge device comprising a pair of oppositely disposed anode members, an electron emitting cathode extending between said members, means for supplying positive potential to both of said anode members, means for producing a magnetic field between said anodes, an oscillatory circuit connected to the cathode and to one of said anodes, the potential on said anodes being such that sustained oscillations are produced in said oscillatory circuit, and additional means connected across a portion of said oscillatory circuit to modulate the oscillations produced.

7. An oscillation generator comprising an hermetically sealed container wherein are contained an electron emitting cathode and a plurality of anodes, means for subjecting electrons flowing from said cathode to said anodes to a magnetic field, a tunable circuit connected to said anodes, a source of potential for polarizing saidanodes with unidirectional potential, and means for varying the potential applied to the anodes in order to modulate the oscillations generated in IMO

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