US1587520A - Nonresonant system - Google Patents

Description

June 8 1926.

R. V. L. HARTLEY NoNREsoNANT SYSTEM Filed Feb. 5, 1919 /6 dlg/0136.]

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UNITED STATES PATENT ori-ica- RALPH Vf. L. HARTLEY, OF EAST ORANGE, NEW JERSEY, ASSIGNOIB TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

N ON RESONANT SYSTEM.

This invention relates to methods and means for generating alternating currents.

A well-known type of oscillation generator is that. in which one or more tuned circuits t containing inductance and capacity, in which oscillations are to be produced, are associated with a highly evacuated electron discharge device havingan anode, a. heated electron emitting cathode, and an impedance varying 10 element. Such a device is commonly known jas an audion and functions to set up and maintain the desired oscillations. The fre uency or frequencies of the oscillations pro uced by such an arrangement will depend principally upon the tuning of the tuned circuit or circuits.

It lias'been found, however, that it is possible to construct such a generator withr out a tuned circuit, thev fr uency 'of the generated oscillations beingedetermined by the magnitude of the electrical constants of certain other elements included in the arrangement. The period of any inherently unstable system whose condition changes cyclically is general a function of the stiffness factor and the' inertia. factor of the system. Any such system wherein one orthe other of these factors is negligible may be styled a non-resonant system. a0 The expression non-resonant generating system, as hereimapplied to electrical systems, is intended to define a generating system in which oscillations are set up by virtue of electrical energy from a source of euri ent alternately stored up by a reactance and discharged, the

means/,'-capacity and inductance. Incase 40 both capacity and inductanoe are included in sucha system they are .so related as not to constitute a resonant circuit and thereby determine the oscillation frequency. v

An -ob'ect of the invention is to provide improve arrangements wherein ,one or a plurality of'- impedance Vvarying devices,V

n uency of vthe generated oscillations being in ependent' of one ofthe usual frequency determining.

and lany incidental inductance of the connecting conductors being negligible and Wholly unessential to the operation of the provide such a to an impedance elegeneration of symmetrical osa pair of amplifiers' A further object is to rovide means suchA Y as herein describedwhere y alternating current of non-sinusoidal wave form as,for example, flat-topped or other symmetrical waves, may be reduced.

.A further o je'ct is the provision of eicient means for the production of low frequency oscillations.

A Other objects are the provision of various i improved details tending toward the production of simple, efficient, stable and easil adjustable non-resonant generators, as wi appear after consideration of the following detailed description. Certain novelifeatures ofthe described systems, moreover, are of lutility in other than generating systems and I are therefore claimed broadly. l The invention is illustrated in the accompanying drawing, wherein Fig. 1 represents a form of non-resonant generator inwhich two discharge devices and a capacity are included; Fig. 2, a similar form in which ind'uctance elements but no capacities are used; and Fig. 3, a modification of Fi 2 in which only. one of the twmsymmetrica y arranged halves ofthe system of Fig. 2 is employed.

In Fig. 1 the anodecathodecircu1t 2 of the vacuum tube or audion 1 includes the variable resistance 3, a source of current 4, variableresistance 5, and condenser 6. The anode-cathode circuit of tube 7 includes variable resistanoe 8, source 9, resistance 10 and condenser 6. Under certain conditions the resistances 3 and 8 may be of small or zero value. The condenser 6 is connected to the anode-cathode circuit of one of the tubes in a manner opposite to' that in which it is connected to the anode-cathode` circuit of the other. The input circuit 11 of .tube 1 so includes .the resistance 10 that increase of current through tube 7 and resistance 10 makes the grid of tube 1 more negative. The input circuit 12 of tube 7 is connected to the resistance 5 in a corresponding man-ner.

Batteries 13 are provided for AMA il@ alternating electromotive torce produced lll thereby any suitable "means, -tor example, an output line 16,. may he connected to the system in any suitable manner, as, for eX- auiple, across the condenser 6.V 'lhe output line leads to any load translating device 17. A therrnionic repeater 18 may be connected in the line 16 because ci its unidirectionally conducting properties andarnplifying povver. rlhe device 18 serves to rovide increased current of the generate Wave form andY to prevent reaction of the translating device upon the generating system.

@parution of the system of Fig' I.

'Suppose the' circuit is so designed and the elements so proportioned that an increase in current e", through tube l causes a suciently large diderenceoi potential be-v tvveen the terminals ot resistance 5', that 'dou' ci current ,i2 through tube 'i' vvi'llbe reduced to zero or a small value. Similarly,

an increase oi current c, vvill vcut ed' or substantially reduce the current 'il through tube 1i Assume, moreover, a disturbance of equilibrium-V whereby the condenser V6 is charged as indicated in the drawing, then the volta-ge across condenser 6 is added to i' that normally em'sting in the anode-cathode circuit ot tube 1 and is subtracted troni that in the anode-cathode circuit oi tube i?. As a result, il is increased and @"2 decreased. rlhe w' increase in i cuts ed i2 or reduces it to a V'sinaller value. lhis in turn, by removing the voltage across resistance 10, tends to increase n1 still more. As e", is increased, all

the current c", must be supplied hom the condensen "so that the voltage across the VV/ 'Y tential above its average value and the ggg'rid condenser decreases. Upon reaching the normal or uncharged condition, the Ycon'- denser 'becomes` charged in theopposite direction because when the charge upon Vcondenser 6 has reached aero.l c", is still greater ont tube i a lower value. Consequently, it

Ais-not until the charfin ci the condenser in till' the'reverse direction has`Y reduced the anodecathode voltage across the tube 1 to a value where the current through tube l begins to decrease, that the grid voltage ot the tube 7 becomes high enough or suciently reduced ihrem a negative value, that current i2 begins to flow 'or increase. Ais soon as this happens, the vincreasedpotential'difterence across resistance 10 cuts oil' i1. Simultaneously 2 is further increased by the increase'`ol .grid voltageimdue to .the decrease ot potential dierence between the terminals or resistance 5. rlhis process continues indenitely and hence an alternating potential dilierence is produced across the terminals of the condenser 6.' While this potential diderence may in sonic instances be directly appliedv to a translating device, it vvill be advantageous to provide a potential-operated repeating device 18 Whose output circuit supplies the current to be utilized. 'lhe unidireotionally conducting properties oli` the device 18 serve to prevent variationsof electrical condition of the load device 17 from 'aecting the oscillatory condition ot the generating system. `Whilc the device 18 vvill produce a small capacity ef- -fect in parallel With capacity 6, this will usually be negligible.

rlhe generated Wave form will tend to be syetrical and `square-topped rather than sinusoidal and will approach a more nearly sinusoidal torni as the amplitude is de- `creased, vvhich inay be accomplished by increasing the resistances 3 and 8 or decreasing the mutual impcdances between the tvvo tubes, i. e. resistances 5 and 10. The :trequency is dependent to some extent upon every constant ot the system but it may be varied over a considerable range by variations in capacity 6.

The system ot h ig. 2 utilizes inductances but no capacities. 1lhe elements in general correspond to those described in connection with lig. 1, as vvill be seen by comparison ci the corresponding reference numbers. However, inductance 20 is substituted Y :for the capacity 6. 'lhe inductances 21, 22

are coupled to inductance 20 in such a inanner that increase et current in the direction et the arrovv through inductance 2O makes the grid ci tube 1 less negative and the .grin ot' tube 7 ymore negative. system there 'tore depends for its operation upon the electromagnetic induction between the input and output circuits. 'lhe action will be proved by desig the system so that elec'- lil trostatic edects will be reduced to a minimura.

@poration of the' aystem of Fig. f2.

Assume an increasing current iiowing in the direction ot the arrow. rlhis makes the grid ot tube 1 more positive and the grid of tube 7 more negative. lhe impedance ot tube 1 is therefore decreased and of tube 'i' increased. Current through tube l is turther increased up to some maximum value as determined by resistance 8, constants of tube y1, and the potentials oi batteries 4 and 13.

its soon as the current through the tube 1- positive or more negative, .as the case may be,

' Grease.

amount of the .energy since it is the increased otential-in a positive sense-on the grid) of tube 1,; which lowers the impedance of the tube sufficiently to`allow the increased current to pass therethrough. As soon as the positive otential on the,grid ceases to be maintains the in.

creased flow of current cannot be maintained.

As lsoon las the current begins to decrease,

-the transformer action between coils 20 and 21 decreases the otential of the grid of tube 1, thereby'stil further decreasing the current. Meanwhile, the grid of tube 7 has become more positive-or less negative-and the current through it begins to flow or in- The last-mentioned current is in a direction in the coil/20 opposite to that in which the cur-rent throu h tlie tube 1 flows. When the current'throug the tube 7 exceeds that through the tube 1, the current through the c oil 20 reverses and a cycle of operations occurs'in the tube 7 similar to that described for the tube 1.. This action willV be maintained indefinitely, rovided the total issipated in the System and lin the output circuit 16 is not too -prising one of' the symmetrically arranged halves of the system .of Fig. 2. The operation ofthis system is similar to that of the system of Fi 2. The inductances 20, 21 must, as in t e arrangement of Fi/g. 2, be coupled so that increasing current through coil 20 in the direction of the arrow, renders the grid of tube 1 more positive or less negative. The amplitude and frequency may be regulated by varying the electro,- motive force of source 4, resistance 3,A inductance 20, 421 and the mutual inductance therebetween. Inasmuch as the electrostatic inductive effect between the grid'and the anode of the tube 1 may tend to cause the device to produce oscillations in a manner analogous to previously known types of oscillation generators with a frequency de ending upon the capacity, between the gri and *the anode of tubel, and the inductances 20, 21 and the mutual inductance therebetween,

` the variable elements of the system areso adjusted as to preventthis action. Imgen-v eral, this may be accomplished by adjusting the system so that the mutual conductance between` the grid and plate circuits is too small tosup ort undesired oscillations of the fr uen'cyfvyv ich tend to occul.. The mutual .con uctai'i'ce may be reduced in various ways which are known to those skilled in the art,

such as changing-the coupling'between coils 20 and 21, making the inductancsof coil 21 .relatively sinallQ or b increasing the resistance 3. Undesirab e oscillations of any frequency which tend to occur will be of relatively high frequency because of the small magnitudes of the grid-plate capacity, the other internal capacities of the tube and the1 distributed capacities ofthe associated coi s.

The novel features inherent in tlie iiivcntion are defined 'in the appended claims.

lVhat is lclaimed is:

1. A non-resonant oscillation generator comprising a pure electron discharge device, an anode, a cathode, and an impedance s controlling element therefor, an output circuit connected-to the anode and tlie cathode, a. feed-back connection from tlie output circuit to the impedance controlling element,

said output circuit containing a iesistance externa-l to said device, said output circuit containing react-.ance of one kind only which is effective in controlling the frequency of the oscillations generatedL 2. A generating system` comprising a series circuit, said sciies circuit containing consecutively arranged current sources, anodes, and electron-emitting cathodes, said sources being so connected as to tend to drive current in tli'esanie direction through said circuit, in combination with a frequency de- V termining. reactance. Fig. 3 illustrates a system employing a d single discharge device or amplifier and com- 3. A system Acomprising a plurality of 'ielectron-discharge repeaters, means tending vto drive current through each repeater, and

tablishing the periodicity of said generator.

5. A non-resonant oscillation generator comprising an energy storing electric capacity and an energy dissipatin device vof negligible inductance connected t ereto, said dissipating device and the electric capacity constituting a non-resonant requenc determining circuit, and an electric disc arge device for periodically reversing the current flow in thel circuit comprising said energy dissipating device and said energy storing electric capaeity.

6. A nonigesonant oscillation generator comprising electron discharge means, impedance controlling means therefor, and a capacity-f connected to saidi discharge means,

saidcapacity being included in a non-resonant frequency determining circuit. i

7. A non-resonant os-icillation,v` generator comprising a lhighly 'evacuated el`ectroii discharge tube, a capacity, and conneptin impedance means, said capacity land sai impedance means constituting a non-resonant frequency determining circuit.

- and' charged 8. A non-resonant oscillation generating system comprising a pair ot thermionic discharge tubes having anodes, circuits thereit'or, and a capacity oppositely connected conductively to corresponding anodes ol said tubes by conductors of negligible inductance. 9. An electrical system comprising a network ot circuits having several conductive paths in an unvarying state of continuity, a capacity in said system, and means whereby said capacity is successively charged through one of said paths and discharged through another path, said last mentioned paths having their common portion of negligible impedance except for the impedance of said capacity.

10. A system comprising a network of circuits having several unsymmetrically conducting branches in an unvarying state of continuity, a capacity in said network, and means whereb said capacity is discharged by each of said branches in succession and impedance controlling means for varying the discharge through each of said branches.

11. A system comprising a pair of vacuum tubes each having an anode, a cathode and an impedance-varying element, a capacity connecting said catliodes, anodecathode circuits for each of said tubes, each of said circuits containing said capacity and two resistances, an input circuit foreach ot said tubes, each input circuit comprising one of said resistances in the anode-cathode circuit of the other tube, a wave utilizin circuit connected across said capacity, t?

a voltage operated unidirectionally transferring device for current in said utilizing circuit.

12. A system comprising a capacity, a

plurality of unidirectionally conducting paths having negligible inductance connecting the terminals of said capacity, andy means whereby current-flow in one of said paths tends to increase the impedance of another of'said paths.

13. A system comprising a capacity, a plurality of unidirectionally conducting pathsfof negligible inductance connecting the terminals of saidv capacity, and means whereby variation in current-ilow-in-one of said paths causes simultaneous variation in impedance of anotherof said paths.

14. An oscillation generator comprising a branched circuit, a source of current in said circuit, a capacity in one branch of said circuit, an impedance-varying device rin each lof a plurality of said branches, means assoeiated with each of said impedance-varying devices responsive to current in saidv circuit forcontrolling the impedance-varying devices respectively, and means for determining the frequency of oscillations substantially independent of inductive reactance.

15.",A non-resonant oscillation 'generator comprising 'a space discharge devicejhaving an electron emitting cathode, an anode,

stant primarily determines the frequency of said generator.

16. An electrical system comprising a pair u of space discharge devices, a branch circuit having capacitative reactance at all frequcncics, and means whereby the direction A ot current flow through said branch determines the relative impedance of.' said devices.

17. An electrical generating system comprising means for establishing a plurality of electron streams in space, an electrostatic control means for each stream, a path having reactance of the same kind for a large range of frequencies both above and below the generated frequency in series with the space path of each stream, and means controlled by thc direction and intensity of current `in .said path for acting on said streams through said control means.

18. ln thermionic apparatus, the combination of a plurality of ionic tubes, each having a filament, a gridand an anode, connections including sources of current be,

tween the anode 'of one tube and the grid of a second'tube in said apparatus, and between the anode of said second tube and the grid of said first mentioned tube, and a.

common branch connection including high ohmic resistances in the anode and grid circuits of both of said tubes, whereby the anode of one tube and the grid of the second tube in said apparatus are connected, and the anode of said second tube and the Vgrid of the first mentioned tube are connected, to form a closed circuit cascade system.

19. In thermionic apparatus the combif nation comprising a lurality f thermionic l tubes each having a ament, a grid and an anode, anode and grid circuits for said tubes, the grid circuit of one tube being connected to the anode circuit of a secon tube, whilst the grid circuit of the second tube is connected to the anode circuit of the first tube, a plurality of hi vl1 ohmc resistances, one of the resistances sing ineluded in the common branch for the anode circuit of the first tube and the grid circuit of the second tube, and one of the high ohmic resistances being included in the common branch for the anode circuit of the second tube and the grid circuit of the first tube. l

21. In thermionic apparatus comprising a plurality vof thermionic tubes, each havin Aa filament, a grid and an anode, anode an id cirgrid circuits for said tubes, the

to the cuit of one tube being connecte anode circuit of a. second tube while the' tube and the grid circuit of the second tube andthe other of the high ohmic rsistances being included in the common branch for the anode circuit of the second tube and the grid circuit of the first tube, means connecting the grid of a third tube included in the apparatus to the anode circuit of the first tube and the filament of the third tube to the anode circuit of the second tube, said connections 'being such that the electromotive forces set up in the first two tubes are applied to the grid filament circuit of the third tube and effect changes in the anode circuit of said third tube.

In witness whereof, I hereunto subscribe my name this 30 day o f January A. D., 1919.

RALPH V. L. HARTLEY.

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