US1877128A - Electron discharge device circuit arrangement - Google Patents

Description

Sept. 13, 1932. R HENTSCHEL 1,877,128

ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT Filed July 5, 1929 4 Sheets-Sheet 1 -OOOOJO0O O 55 INVENTOR. fa m wol Jtc-n l'od-efi,

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ELECTRON DISCHARGE. DEVICE CIRCUIT ARRANGEMENT Filed July 5, 1929 4 Sheets-Sheet 4 v 5a -46 c 50W 56 Wading "9.5.

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.-1TTORNEY Patented Sept. 13, 1932 own-:0 STATES PATENT OFFICE ERNEST R. HENTSCHEL, OF WASHINGTON, DISTRICT OF COLUMBIA; JOHN OLSON, AD MINISTRATOR OF SAID ERNEST R. HENTSCHEL, DECEASED, ASSIGNOR TO-WIRED RADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT Application filed July 5, 1929. Serial No. 376,181.

The subject matter of certain arrangements described but not claimed in the present application is claimed in my copending application Serial No. 554,345, filed July 31, 1931 which is a division of the present application.

This invention relates broadly to electron discharge device circuit arrangements. More specifically this invention relates to electron discharge device circuit arrangements in which compensation is provided for undesirable modulation of oscillations impressed upon the circuits of an electron discharge device by the unsteady character of the anode circuit energizing potential.

An object of this invention is to provide an arrangement in which the effect of the pul sating character of the cathode current supply of an electron discharge device is caused to neutralize the effect produced upon the out put oscillations of the electron discharge device by the pulsating character of the anode current supply.

Another object of this invention is to pro vide an arrangement in which the cathode energizing current of an electron discharge device is modulated in such a manner that the undesirable modulation by anode current supply of a pulsating character of oscillations impressed upon the circuits of the electron discharge device or oscillations developedin the circuits thereof is substantially neutralized.

Still another object of this invention is to provide an arrangement connected with an electron discharge device in which undesirable modulation of the output oscillations developed or amplified by the electron discharge device is neutralized through the countermodulation of the electrical energy supplied to a low potential electrode other than the cathode of the electron discharge device.

A further object of this invention is to provi dc an arrangement connected with an electron discharge device in which undesirable modulation by anode current of a pulsating character, of the oscillations developed or amplified by the electron discharge device is neutralized by counter-modulating the electrical energy employed for energizing an electrode other than the anode of the electron discharge device, by modulation in 180 degrees phase opposition. with the undesirable modulation through the action of a coupling circuit arranged between the anode circuit and the electrode upon the circuit of which the counter-modulated energy is impressed.

A still further object of this invention is to provide an arrangement in which the effect of undesirable modulation of the output oscillations of an electron discharge device caused by the pulsating character of electrical energy employed for energizing the circuits of an electrode of the electron discharge device is neutralized by causing the undesirable modulations to modulate the electrical energy employed for energizing the circuits of another electrode of the electron discharge device'in 180 degree phase opposition with the undesirable modulations.

Other objects and features of this invention will be apparent to those skilled in the art to Which this invention relates from the following specification and the appended claims.

According to this invention the modulating effect of the pulsations of a source of anode current supply upon the output oscillations of an electron discharge device'is substantially neutralized by introducing a modulated current upon one of the other electrodes of the electron discharge device. In this invention an arrangement is provided whereby the time phase relation between the pulsations of the anode source of current supply and the modulations of the modulated current impressed upon the other electrode may be varied so that the neutraliza-- tion of the undesirable modulations may be properly adjusted. v

In the drawings, Figure 1 illustrates an embodiment of this invention; Figs; 2, 3. 4, 5. 6 and 7 are graphs illustrating principles of operation of this invention: Figs. 8. 9 and 10 show modifications of this invention in which auxiliary grid electrode electron dis- 3 charge devices are employed and Fig. 11 illustrates a further modification of this in- Vention.

Reference numeral 1 of Fig. 1 of the drawings, designates an electron discharge device having an anode 1a, a grid electrode 1?) and a cathode 10. A condenser 2 is connected to the grid electrode 1?; for coupling the grid electrode 1?) to the output circuit of another electron discharge device in cases where the electron discharge device 1 is employed as an amplifying device.

If it is desired a tuned circuit may be connected between the grid electrode lb and a convenient point of the cathode circuit and the device 1 may be employed as a generator of high frequency oscillations. The device 1 is not, however, limited in its use to that of an amplifier or oscillation generator but may be used also as a repeater valve or detector.

A choke coil or impedance element 3 is connected to the contactor 1 on potentiome ter 5 for impressing a biasing potential upon the grid electrode 16. The potentiometer 5 has a portion thereof shunted across the cathode 10. High frequency oscillation bypass condenser 6 is connected across the cathode. Another by-pass condenser 7 is pro vided across the adjustable tap 4. The anode 1a is connected to the output circuit 9 which may be of any of the conventional types and may consist of the primary of an audio frequency transformer in cases where the system herein described is employed in conjunction with the audio frequency amplifier of a signal receiving system or a wire relay system, or it may consist of the primary of a tuned or untuned radio frequency transformer. High frequency oscillation by-pass condenser 8 is provided between the low potential end of the output circuit and the cathode 10. Where the system of this invention is employed in conjunction with electron discharge devices operating at low frequencies the bypass condensers 6. 7 and 8 will be of course larger in value than where the system is employed at high frequencies It will be observed that a source of potential is provided in the grid bias circuit in series with tap connection 4 and impedance element 3. whereby a. predetermined potential in com bination with the variable potential secured by movement of contactor 4 may be obtained on the grid 16.

A filter system 10 which may consist of any suit-able combination of inductance and capacity units is connected into the circuit of the cathode source of current supply. The filter system 10 is connected to the output circuit of the rectifier system which comprises the rectifier tubes 11 and 12 and transformer 13. The rectifier tubes 11 and 12 may be of the hot cathode gaseous arc type or any approved type suitable for rectifying a low voltage alternating current. The transformer 13 is preferably of the type having two secondary windings 13a and 13b and a primary wind ing 130. The anodes of the tubes 11 and 12 are connected to the terminals of the secondary 13a and the cathodes are connected together across the secondary winding 13b. The electrical centers of the secondary windings 13a and 135 are connected to the input terminals of the electrical filter 10.

The anode source of current supply for the electron discharge device 1 comprises a filter 14:, which is made up of a choke coil 15 and condensers 16 and 17. A high frequency choke coil 18 is connected into the circuit of the anode current source of supply between the filter let and the output circuit 9 to prevent high frequency currents of large magnitude from flowing through the circuits of the filter 14. The anodes of a pair of rectifier tubes 19 and 20 are connected to the terminals of the secondary winding 24 of the transformer 21. \Vhere it is more convenient, asingle rectifier tube which is either of the vacuum or gas content type and which employs a pair of anode electrodes may be used instead of two rectifier tubes.

A secondary winding 23 is provided to the transformer 21 for sumalying the cathode heating current for the rectifier tubes. The primary windings 130 and 25 of the transformers 13 and 21. respectively, are connected to the source of alternating current supply 27. A phase shifting device 26 is connected into the primary circuit of the transformer 13 whereby the phase of the secondary current of transformer 13 may be shifted with respect to the phase of the secondary current of the transformer 21. at will. The secondary windings 13a and 13?) of transformer 13 and the secondary windings 23 and 24 of transformer 21 may be mounted upon one core where it is desirable to combine the two transformers 13 and 21. In case all of the secondary windings 130, 137). 23 and 24 are wound upon a single core the phase shifting deivoe 26 must be connected into the circuit of the secondary 13a.

The operation of the arrangement illustrated in Fig. 1 is as follows:

The alternating current from the source 27 is transmitted through the phase shifting device 26 to the transformer 13 in which the voltage is stepped up or down to a certain value. The output of the secondary winding 13a is rectified through the action of the ull wave rectifier system employing rectifier tubes 11 and 12. The rectified potential impressed upon the input circuit of the filter 10 from the output of the rectifier system is of a pu sating nature of a wave form simiar to that illustrated by Fig. 2 of the drawings. The output of the rectifier system is partially filtered through the operation of the filter system 10. The wave form of the potential supplied to the cathode 1c from the out u of the filter 10 is illustrated in Fig. 3 of the drawings. A negative biasing poential of a pulsating character. such as illustrated in Fig. 4 of the drawings, is impressed upon the grid electrode 1?) due to voltage drop in potentiometer 5. It will be noted that this grid biasing potential is 180 degrees out of phase with the potential wave delivered by filter 10, that is, the maximum negative value of the grid bias occurs at the same instant as the maximum positive value of the filament current. The connection l between the potentiometer 5 and the source of grid biasing potential is adjusted as explained below so that when the current through the cathode 10 is maximum the numerical magnitude of the negative biasing potential on the grid electrode 1?) increases because of the pulsating character of the cathode current. Th s increase in the negative biasing potential applied to the grid electrode 1?) tends to reduce the anode current flowing through the electron discharge device 1 and compensate for the increase in cathode energization caused by the pulsating character of the cathode energizing current.

With the connections as shown in Fig. 1, the right terminal of potentiometer 5 is positive and the left terminal is negative. Since the midpoint of the cathode is at zero potential, the point of the potentiometer is also at zero potential midway between the two cathode connections. If the grid return 4 is connected to the point of the potentiometer 5 midway between the cathode connections, the potential applied to the grid will be due only to source 65. If the grid return 4 is connected to the left of this midpoint of the potentiometer, as shown, the voltage drop from this midpoint to the grid return connection will apply to the grid a voltage negative with ref erence to the midpoint of the cathode, and will include pulsations or ripples present in the current supplied to potentiometer 5 from the filter 10. The farther the return connection 4 is connected to the left of the midpoint, the more ripple it will pick up. The negative voltage drop from the midpoint of the potentiometer 5 to the return connection' l is added to the negative voltage supplied by source 65. At the instant when the pulsations of the voltage impressed on potent ometer 5 have their peak, the current flowing through potentiometer 5 has its peak and the negative grid bias voltage has its peak. Therefore at the instant when the pulsating voltage impressed on the cathode has its peak and tends to cause a maximum instantaneous Value of anode current, the pulsating negative grid bias voltage has its negative peak and tends to cause a minimum instantaneous value of anode current, so that the two effects oppose each other. The grid return connection 4 on potentiometer 5 can be adjusted so that the effects on the ode current will be equal and, opposite. and the anode current will then be without pulsations due to the source of cathode potential. The source 65 can then be adjusted to the proper value of continuous current operating potential.

The position of the variable filament tap on potentiometer 5 depends on the value of potential required to be impressed across the filament terminals in operation.

The anode current of the electron discharge device 1 is supplied from the source of alternating current 27 through the operation of the transformer 21, the rectifier system which includes the rectifier tubes 19 and 20 and the filter 14. The anode current is also pulsating in character. When the cathode 1c of the electron discharge device 1 is energized by a steady current and the anode circuit of the device 1 is supplied with partially filtered rectified alternating current it has been found that the wave form of the anode current is of the type illustrated. in Fig. 5.

Under the conditions of operation in which a steady source of anode current supply and the grid electrode biasing potential arrangement such as illustrated in Fig. 1 are employed, the wave form of the anode current of device 1 will he of a form such is illus trated in Fig. 6. When the anode is supplied with pulsating voltage from rectifier 19-20, it is necessary to make further adjustments to secure anode current free from pulsations.

By properly adjusting the phase shifting device 26 so that the phase relations between the maxima of the cathode energizing current and the maxima of the anode current are in phase and by properly adjusting the variable connections of the potentiometer 5 so that the maxima of the cathode current are in 180 degree phase opposition with respect to the maxima of the grid electrode biasing potential and the maxima of the grid bias potential and so that the magnitude of the pulsations impressed on. the grid are of proper magnitude, are in 180 degree phase opposition with respect to the anode potential, the pulsating character of the anode current is eliminated and the anode current is caused to assume a steady character as illustrated in Fig. 7, which is a curve of substantially the same character as is obtained by adding the curves of Figs. 5 and 6.

Fig. 8 of the drawingsillustrates a modified form of this invention employing an electron discharge device having an auxiliary or shield grid electrode which is energized by a pulsating direct current for neutralizing the effect of a pulsating anode potential. A coupling condenser 31 is connected together with the choke coil 30 to the grid electrode 29?; of the electron discharge device. A source of grid electrode biasing potential 32 is connected to the choke coil 30 and an adjustable connection of the potentiometer 36.

A source of current supply 33 is connected to the cathode 290. The source 33 may be a steady or pulsating direct current source or it may be an alternating current source. The negative terminal of the source of direct current supply 34 is connected to theca-thode circuit and the positive terminal is connected to the auxiliary grid electrode 29d, through alternator 35.

An alternating potential of relatively small magnitude is impressed upon the circuit of the auxiliary grid electrode 29d by the source 35. Th effect of superimposing an alternating potential upon the potential of the source. 34 which is a direct current generator is such that a pulsating potential will be impressed upon the auxiliary grid electrode 294. The phase and amplitude of the alternating potential supplied by the source 35 may be varied by any convenient means so that the maxima of the potential applied to the auxiliary grid electrode occur at the proper time with respect to the maxima of the cathode current. the anode current and the grid electrode biasing potential. The sources 34 and 35 may be combined into one, where a direct current generator is employed as the source 34, since the proper pulsating character may be imparted to the supply derived from a direct. current generator by regulating the commutation. High frequency by-pass condenser 37 is connected across the source of grid electrode biasing potential for reducing any hi h frequency potential that may have a tendency to develop across the source 32 to a low value. Another by-pass condenser 38 is connected across the terminals of the cathode 29c. Condenser 39 is connected between the auxiliary grid electrode 29d and the cathode 290. The high frequency circuit between the output circuit 41 and the anode is completed through the condenser 40. A rectified alternating current source of anode current supply similar to the anode current supply illustrated in Fig. 1 is provided for the electron discharge device 29.

In Fig. 9 of the drawings an embodiment of this invention in which the alternating component of the pulsating anode current supply is impressed upon the circuits of the auxiliary grid electrode 42d of the electron discharge device 42 through the operation of the transformer 43 the primary winding of which is connected in series with the current supply of the anode 42a. The coupling between the secondary winding of the transformer 43 and the primary winding may be varied so that the amplitude of the secondary potential as well as its phase relation may be varied. A phase shifting device 44 is connected to the secondary of transformer 43 and the resistance unit 45 which serves as a coupling means for conveniently impressing the alternating current obtained from the trans former upon the circuit of the direct current source 46. The phase relation between the maxima of the pulsating potential applied to the auxiliary grid electrode is adjusted with respect to the phase of the maXima of the pulsating potential applied to the other electrodes by the phase shifting device 44 or by varying the coupling of the transformer 43. lVhere complete neutralization of the modulating effect of the pulsating anode current cannot be obtained by varying the coupling of the transformer 43 and the phase shifting device 44, the position of the adjustable contacts associated with the potentiometer 47 may be varied so that the phase relation between the maxima of the grid biasing potential and the maxima of the cathode current may be properly adjusted.

In Fig. 10 another modification of this invention similar to the modification illustrated in Fig. 9 is shown. The electron discharge device 48 is provided with an anode 48a, a grid electrode 485, a cathode 48c and an auxiliary grid electrode 48d. The circuits of the cathode 48c and the grid electrode 48?) are energized in a manner similar to that in which the circuits of the cathode and grid electrode of the electron discharge device 29 illustrated in Fig. 8 are energized. A voltage divider 52 which may be in the form of a resistance unit or a choke coil to which connection at a multiplicity of places may be made is provided across the source of anode current supply. A transformer 50 having primary and secondary windings between which the coupling may be varied is connected with its primary winding in series with the anode current supply of the electron discharge device 48 and its secondary winding to the coupling device 51 which may be a choke coil or a resistance unit or other form of conductive or inductive coupling. The phase shifting apparatus 49 is connected into the circuit of the auxiliary electrode 4861. A variable connection is provided between the voltage divider 52 and the coupling device 51 whereby a variable positive potential which is equal to a fraction of the anode potential may be applied to the auxiliary grid electrode 4861. The phase shifting apparatus 49 is employed in conjunction with the variable coupling transformer 50 and the potentiometer 53 to provide means whereby the proper phase relation between the maxima. of the anode current, the cathode current, the grid electrode potential and the auxiliary electrode potential may be maintained. Current supply sources 54 and 55 which are of the same type as are employed in the form of this invention illustrated. in Fig. 8 are associated with the circuits of the grid electrode and the cathode respectively.

A modified form of this invention in which a transformer 56. having provision for adjustin the coupling between the primary and secondary, employed to impress an alternating potential upon the cathode circuit of the electron discharge device 51' from the source of pulsating anode potential, is illustrated in Fig. 11 of the drawings. Phase shifting apparatus 58 similar to the apparatus 49 of Fig. 10 is connected to the secondary of the transformer 56 and to the coupling device 59, which may be in the form of a transformer, choke coil or resistance. A potentiometer 60 is connected across the cathode of the device 57 Current supply sources 61. and G2 are COIHIQCt-GQ into the cathode and grid electrode circuits, respectively, oi the device 57. In operating the pat sating anode current is caused to energize the transformer 56 and induce an alternating electromotive force into the secondary thereof. An alternating current is caused to flow in the circuit of the secondary of the trans former 56, the phase adjusting apparatus 58 and the coupling device 59. r he current flowing in the cathode circuit of the device 57 is varied in accordance with the alternating current component flowing in the circuit including the phase shifting apparatus 58. By adjusting the coupling of the transformer 56, the phase shifting apparatus 58 and the potentiometer 60 so that the maxima of the anode current, the cathode current and the grid electrode biasing potential are in cor-- rect phase relation, the modulating effect of the pulsating character of the anode potential may be neutralized.

While I have described my invention in several of its preferred embodiments it is understood that various modifications thereof may be made without departing from the scope and spirit of this invention and that therefore I do not desire to limit this invention to the exact details set forth in the foregoing specification, except in so far as these details may be defined by the appended claims.

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

1. In a power supply system for electron tubes, an electron tube having a cathode, anode, grid and shielding grid, a source of pulsating direct current for energizing said anode, a source of pulsating direct current for energizing said shielding grid, and a current source for energizing said cathode, said source for energizing said shielding grid being connected to said shielding grid and to the circuit of said cathode, the pulsations applied to said shielding grid being of magnitude and phase for neutralizing in the circuit of said anode the pulsations of the potential directly applied by said source for energizing said anode, whereby a smooth continuous anode current is produced.

2. In a power supply system for electron tubes, an electron tube having a cathode, anode, grid and shielding grid, a source of pulsating direct current for energizing said anode, a current source for energizing said cathode, a source for energizing said shielding grid, an anode circuit connecting said anode to said source for energizing said anode, a shielding grid circuit connecting said shielding grid to the circuit of said cathode through said source for energizing said shielding grid, a coupling circuit coupled to said anode circuit and to said shielding grid circuit for impressing pulsations in said anode circuit upon said shielding grid circuit, and phase adjusting means for varying the phase of the pulsations impressed upon said shielding grid in desired relation, whereby the effect upon the current in said anode circuit of the pulsations impressed upon said shielding grid neutralizes the pulsations in potential directly impressed upon said anode from said source for energizing said anode and a smooth continuous anode current is produced.

ERNEST R. HENTSCHEL.

DISCLAIMER 1,87 7,128.-Emest R. Hentschel, Washington, D. C. ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT. Patent dated September 13, 1932. Disclaimer filed September 6, 1934, by the assignee, Wired Radio, Inc.

Hereby enters this disclaimer to that part of the claims in said specification which are designated as claims 1 and 2 of said patent.

[Oficial Gazette October 2, 1934.]

DISCLAIMER 1,877,128.Ernest R. Hentschel, Washington, D. O. ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT. Patent dated September 13, 1932. Disclaimer filed September 6, 1934, by the assignee, Wired Radio, Inc. Hereby enters this disclaimer to that part of the claims in said specification which are designated as claims 1 and 2 of said patent.

[Ofiicz'al Gazette October 2, 1934.]

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