US1877129A - Electron discharge device circuit arrangement - Google Patents

Description

Sept; 13, 1932. E. R. HENTSCHEL ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT Original Filed July 5, 1929 2 Sheets-Sheet nun A TTORNEY Sept. 13, 1932. E. R. HENTSCHEL ELECTRON DISCHARGE DEVICE CIRCUIT ARRANGEMENT Original Filed July 5, 1929 2 Sheets-Sheet WAQ/ MM WaW A T TORNEY Patented Sept. 13, 1932 FUNITED ISTA ERNEST R. HENTSOIIEL, DECEASED, LATE 0F SPRiNGFIELD, MISSOURI, BY JOHN OLSON, ADIWILTIS'I.RA'IOR, OE SPRINGFIELD,,MISSOURI, ASSIGNOR T0 WIRED RADIO, INC., OF NE'W YORK, N. Y., A CORPORATION OF DELAWARE Emerson DISCHARGE ronvron omcurr ARRANGEMENT Original application filed July 5, 1929, Serial No. 376,181. Divided and this 1931. Serial 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.

This application is a division of application Serial No. 376,181, filed July 5, 1929.

One of the objects of this invention is to provide an arrangement in which the effect of the pulsating character of the cathode'current supply of an electron discharge device is caused to neutralize the eflect produced upon the output oscillations of the electron discharge device by the pulsating character of the anode current supply. 7 I

Another object of this invention is to provide 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 developed in the circuits thereof is substantially neutralized.

Stillanother object of this invention is to provide an arrangement associated with an electron discharge device, in which undesirable modulation of the output'oscillations developed or amplified by the electron disdevice.

" charge device is neutralized through the counter-modulation of the electrical energy supplied to a low potential electrode other than the cathode of the electron discharge A further object of this invention is to provide an arrangement associated with an electron discharge device in which undesirable modulation by anode current ofa 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 phase opposition with the undesirable application filed vJuly 31, No. 554,345. A

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 os-" cillations of an. electron discharge device caused 'by the pulsating character of-electrical energy employed for energizing the circuits of an electrode of the electrondischarge device is neutralized by causing the undesirable modulation to ,modulate the electrical energy employed for energizing the circuits of another electrode of the electron discharge device in 1809' phase opposition with the undesirable modulations. i 7

Other and further'objects 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, by reference to .the accompanying drawings, wherein: V A Y Figure '1 illustrates an embodiment of this invention; F i gs..2, 3, 4, 5, 6, and 7 are graphs illustrating principles of operation ofthis in vention and Fig. 8 illustrates a further modification of this invention.

According to this invention the modulatng 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-inven tion 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 currentimpressed upon the other electrodenmay be varied so that the neutralization of the un'-' desirable modulations may be properly adjusted. Reference numeral 1 of Fig. 1 of thedraw lngs, designates an electron discharge device TES PATENT OFFICE 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 1b 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 1b 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 4 on potentiometer 5 for impressing a biasing potential upon the grid electrode 15. The potentiometer '5 has a portion thereof shunted across the oathode 10. High frequency oscillation by-pass condenser '6 is connected across the cathode. Another by-pass condenser 7 is provided 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 I frequency transformer. High frequency oscillation by-pass condenser 8 is pro vided 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 conden-sens 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 combination with the vari able potential secured by movement of contactor 4 may be obtained on the grid 15.

A filter system 10 which may consist of any suitable combination of inductance and capacity units is connected into the circuit of 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 second.-

ary windings 13a and 13b and a primary winding 130. The anodes of the tubes 11 and 12 are connected to the terminals of the sec-- 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 14Iand the output circuit 9 to prevent high frequency currents of large magnitude from flowing through the circuits of the filter 14. The anodes of pair of rectifier tubes 19 and 20 are connected to the terminals of the secondary winding 24 of the transformer 21. Where it is more convenient, a single 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 supplying the cathode heating current for the rectifier tubes. The primary windings 13c and 25 of the transformers 13 and 21, respectively, are connected to the source of alternating current supply 257. A phase shifting device 26 is connected into the primary circuit of the transformer 13 whereby the phase of the secondary cur-' rent of transformer 13 may be shifted with respect to the phase of the secondary currents of the transformer 21 at will. Secondary windings 13a and 13b 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 13a, 13b, 23 and 24 are wound upon a single core the phase shifting device .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 full 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 pulsating nature of a wave form similar 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 10 from the output of the filter 10 is illustrated in Fig.3 of the drawings. A negative biasing potential of apulsating 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 4 between the potenti ometer 5 and the source of grid biasing potenial 65 is adjusted as explained belowso 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. ,This "increase in the negativebiasing potential ap- I the right terminal of potentiometer 5 is posiill:

tive and the left terminal is negative. Since the midpoint of the. cathode isat zero potential, the point ofthe 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. It 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 reference to the midpoint of the cathode, and will include pulsations or ripples present in the current supplied to the 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 or the potentiometer 5 to the return connection 4 is added to the negative'voltagesupplied by source 65. At the instant when the pulsations of the voltage impressed on pctentiometer 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 instantaeous value of anode current, so that the two ellects oppose each other. The grid return connection 4 on potentiometer 5 can be adjusted so that the effects on the anode current will be equal and opposite, and the anode current will then be without pulsations due to the source of cathode potential. The source can then be adjusted to the proper val no 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 vfrom plusations.

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. l/Vhen the cathode 1c of the. electron discharge device 1 is energized bya steady current and the anode circuit ofthe device 1 is supplied with partially filtered rectified alternating current it has been found that the wave. formoi the Fig.5. j

nder the conditions of operation in which anode currentisof the type illustrated in a steady source of anode current supplyand' supplied with pulsating voltage from rectifier 1920, it is necessary to make further adjustments to secure anode current free By properly adjusting the phase shifting device26 so that the phase relations between the maxima of the cathode energizing current and the maxima of the anode current arein phase and by properly adjusting the variable connections of the. potentiometer 5 so that the'maxima of the cathode current are in 180 phase opposition with respect to the maxima of the grid electrode biasing potential and the maxima of the grid bias potentialare in 180 phase opposition with respect to the anode potential, and so that the magnitude of the pulsations impressed.

on the grid are ofproper magnitude, the pulsating character of the anode current] is eliminated andthe anode currentis caused to assume a steady character as illustrated in Fig. 7, which isa curve of substantially the same character. as is obtained byaddin the curves of Figs. 5 and 6..

A modified form of this invention in which a transformer 56.'having provision for adjusting the coupling between the primary secondary, isemployed to impress an alternating potential upon the cathode circuit ofthe electron discharge device 57 from the source of pulsating anode potential, is illustrated, in'Fig.,:8 of the drawings. Phase shifting apparatus 58 is connected to the sec of the device 57.. In operation the pulsatinganode current iscausedto energize the transformer 56 and induce an alternating electro- .motive force into the secondary thereof. An

alternating current is caused to flow in the circuit of the secondary ofthe transformer 56, the phase adjusting apparatus 58 and the coupling device 59. The 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 po tentiometer 60 so that the DlZtXlHll/ 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 this invention has been described 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 it is not desired 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 is claimed as new and desired to be secured 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 and grid, a source of continuous current for energizing said cathode, a source of pulsating direct current for energizing said anode, a potentiometer connected to said source for energizing said cathode, a variable tap on said potentiometer connected to said grid, a connection on said potentiometer connected to said source of pulsating direct current for energizing said anode, an anode circuit comprising a connection between said anode and said source for energizing said anode, a coupling circuit coupled to said anode circuit and the circuit of said cathode for impressing pulsations in the anode circuit upon the circuit of the cathode, and phase adjusting means connected in said coupling circuit for controlling the phase of pulsations of said anode current impressed upon said cathode and said grid, whereby the pulsations of energy impressed uponsaid grid and the pulsations of energy impressed upon said cathode may be adjusted in magnitude and polarity to oppose the pulsations in energysupplied to said anode and cause a smooth continuous current to flow in said anode circuit.

2. In a power supply system for an electron tube using pulsating direct current supply for energizing the cathode and anode, the method of obtaining smooth continuous anode current which consists in applying the pulsating current to the anode in phase with the pulsating current applied to the cathode, and applying to the grid of the electron tube a portion of the pulsating supply impressed upon the cathode of the electron tube in such phase re- July, JOHN OLSON, Administrator of the Estate 0 Ernest R.

Hcntsclwl, Deceased.

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