US1696233A - Energizing vacuum discharge device by alternating current - Google Patents

Description

Dec. 25, 1928. 1,696,233

R. A. HEIESING ENERGIZING VACUUM DISCHARGE DEVICE BY ALTERNATING CURRENT Filed Nov, 6. 1922 //7Ve/1f0/ Raymond A Hal's/k7 y z-l k framed Dec. a5, 192s.

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'mw'xonn A. imismo, or MILLIBUBN, NEW mnsn'r, nssmnon 'ro wns'mrm unc- TRIO COII'AN Y, INCORPORATED, 015 NEW YORK, N. Y., A CORPORATION 01' NEW mmnexz'me vacuum mscnnnen nnvrcn BY ALTERNATING cmmmrr.

I Application filed November 6, 1822. Serial No. 599,200.

I I ]This; invention lirelates to methods of operating electric discharge devices from an a alternating current "supply source and to systems operating in accordance with said methods.

An object of the invention is to reduce the number of tubes needed in the modulating systemsupplied with alternating energizing current for producing and modulating high frequency waves.

Another object is to increase the efiiciency of systems wherein modulated high frequency waves are produced at relatively low power and then amplified and radiated at high power.

Another object is to so organize such a i system that tubes ofa single kind only, or

of a very small number of kinds of tubes, maybe utilized whereby interchange of tubes is facilitated and the necessity for de' signing numerous types of tubes is avoided.

A further object is to reduce to a minimum the necessary number of phases of alternating current supplied to a system of as possible the disturbances introduced into the system by the utilization of alternating current supply instead of direct current.

The invention is particularly illustrated in connection with a radio system which consists in general of a modulator and an amplifier for amplifying the energy of the high frequency waves produced by the modulating system. The amplifying system is supplied with alternating current and serves not only to rectify its own operating current, but also servesto rectify the current supply for the modulating system.

Various advantageous and novel features of an arrangement of this sort will occur to those skilled in the art from a perusal of the following detailed description taken in connection with the accompanying drawing which is a circuit diagram of an arrangement embodying the invention.

i In thissystem four power-amplifying and rectifying tubes 1 are supplied with space current from two phases 2 and 3 of alternating current supply which are preferably 90 out of phase. A quarter-phase generator is illustrated as theprimary source of ower.

Although four tubes andtwo phases are chosen for purposes of illustration, it will be obvious that two of the tubes and one phase might be omitted or that three, six, or systems having any other number of phases might be used. Each of the different phase supply circults is divided into two parts by means of a transformer 4 having its secondar tapped at the middle point which in e 'ect gives four phases of current 90 apart, each supplying one tube.

The rectified current path for a single one of these four phases will now be traced. Beginning at the central tap of the secon ary of the transformer 4 positive current passes in a direction as indicated by the arrows from the anode to the cathode of a tube 1 through the secondary winding of transformer 36, conductor 5, and choke coil 6 to a point 7.- At point 7 the current divides, part passing through the conductor 8 and the variable impedance tube 9 to the cathode of the tube, thence returning to the.

point of beginning along conductor 10. From the point 7 the other portion of the current passes through choke coil 11 and the tube 12 to the cathode thereof, thence returning likewise through the conductor 10 to the point of beginning.

The coil 6 is designed to prevent the passage of current variations of speech frequency and hence has a large inductance.

The coil 11 is designed to pass current variations of speech frequency and prevent the passage of high or radio frequency current variations,

The tube 12 has associated with itself.

. alternative path from the anode .to the cathode of tube 12 extends from the anode through condenser 19 to a point on the con ductor 5. Condensers 19 and 15 are of such capacity as to be of highimpedance to speech frequency currents. From a point between the condensers 14 and 15, there is a connection to the grid of the tube 12 through a stopping condenser 20. p

The arrangement of elements just described when r0 erly adjusted acts as a enerator of ig 1 frequency oscillations. This is an oscillator of the type illustrated in Figs. 3 (f) on page 69 of the proceedings of the I. R. E. vol. 6, No. 2 April 1918. Any convenient oscillating circuit might be used instead, The oscillations are modulated in amplitude in accordance with signals in a manner now to be described.

Choke coil 6 tends to maintain constant the flow of the total direct current supplied to the tubes 9 and 12. Consequently when the impedance of the tube 9 is increased or decreased the current flowing through the tube 12 is accordingly increased or decreased and the amplitude of the oscillations varies simultaneously.

A speech or other signaling frequency circuit is represented by a microphone circuit 21 coupled by means of a transformer 22 to the input orgrid-filament circuit of the tube 9. As sound waves impressed upon the microphone through the circuit 21 vary the impedance of the tube 9, the am litude of the oscillations produced by the tu e 12 will vary accordingly.

A leak path for direct current extends from the grid of the tube 12 through a high resistance 24 to the middle point of a resistance 25 which is connected across the cathodes of the tubes 9 and 12. When the tube 12 is oscillating, direct current will flow in the grid circuit through resistance 24. By means of the variable tap on the resistance 24 the grid of the tube 9 is caused to have a suitable average negative potential with respect to its associated cathode for the purpose of preventing distortion by the tube 9 and increasing its efficiency. A choke coil 23 designed to have high impedance to speech frequency currents prevents such currents, induced in the microphone circuit 21, from producing speech frequency voltage variations on the grid of tube 12. A condenser 23 is of low impedance to speech frequencies and permits currents of such frequencies to flow in the grid-filament circuit of tube 9.

The high frequency waves produced by the oscillation generator are impressed across a combination of impedance elements 26, 27 and 28 which are included in the gridfilament circuit of the amplifier tubes 1. A stopping condenser 29 separates the grids of the tubes 1 from any other direct current source in the oscillation generating system.

The elements 26, 27 and 28 may be adjusted to regulate the input impedance and the grid potential of the amplifiers 1. The grid potential is determined by the value of the resistance 28 and the impedance to high frequency is determined chiefly by the adjustments of inductance 26 and capacity 27. The grid potential determines the efiiciency of the tubes 1, and the high frequency impedance is adjusted to ive efiective ener transfer from the osci lator circuit to tie amplifier circuit.

Direct current flows through inductance element 26 and the high resistance 28 which consequently constitute a leak path for direct current between the grids and the oathodes of the tubes 1.

The path for the high frequency waves in the anode-cathode circuit of the tubes 1 is from the anodes through the capacities 30, and an adjustable high frequency transformer primar 31 and condensers 32 and 33 to the catho es. The energy of the high frequency waves is thus impressed upon any suitable load circuit, as for example, the radiating antenna circuit 34, which includes the coil 35 clectromagnetically coupled to the coil 31.

The cathodes of all the tubes may be heated from any suitable current source, but preferably from one of the phases 2, 3. As illustrated, a connection is made across the conductors of the phase 2 to the transformers 36 and 37. The secondary of transformer 37 is connected across the cathodes of the tubes 9 and 12 and the secondary of transformer 36 is connected across the cathodes of the tubes 1.

In order to reduce the effect of the alternating current variations in the anode circuits of the tubes, the anodes and grids are connected to the midpoints of impedance elements connected across the cathodes. In the case of low frequency tube 9, this impedance element is preferably a resistance 25, but for the other tubes capacities 17, 18 and 32, 33 are provided. Choke coils 41 prevent the passage of high frequency currents through the windings of transformers 4.

In the operation of the system, each tube 1 will be rectifying current for about onehalf the time. The several impulses of rectified current will overlap so as to produce a practically continuous space current sup- 3 ply for the tubes 9 and 12. This current will be smoothed out by the action of the condensers 30 which are selected in capacity not only with a view to passing high frequency waves, but also to exercise a maxi- 3 mum smoothing effect upon the rectified current.

Since the four tubes 1 are each operating approximately one-half the time, the total current supplied to the tubes 9 and 12 will be about that which would be required for two tubes 9 and 12 similar in design to the tubes 1 because the tubes 9 and 12 are continuously operating. Howcver, if it is desired to use more tubes 1 or tubes of greater power capacity the variable resistance 38 may be shunted across the space current supply leads to the tubes 9 and 12 and adjusted to shunt off such portion of the current, rectified by the tubes 1, as may be desirable.

If the current supplied by the tubes 1 is exactly that requisite forthe tubes 9 and 12 the resistance 38may be omitted or adjusted to a very high value. The resistance 38 may beany resistance device, or a direct current operated "device, which will not interfere with the 0 ration of the rest of the system and there ore the ener y dissipated in the f rent supply source, by opening the primary circuits of transformers 4 and operating the 39to connect the battery 40 into circuit.

- The system above described is typical of various possible'iarrangements operating in accordance with the same general prlnclples which may be devised and therefore the invention is not limited to the exact arrangements illustrated, but only in accordance with the sco 'of the appended claims. The

system is o viously a plicable to energy transmission. over. con uctive circuits for which purpose a line is substituted for the antenna 34.

Having described one'form of the invention, the novel features believed to be in- 'herent therein are now set forth in the appended claims.-

-- What is claimed is:

1. In combirtion, a modulating system, a svstem for amplifying the'waves produced .thereby, an alternating current supply, and

free the energizing current for the modulating system. I e 2. In comb'nat1on,a constant current modmeans whereby the amplifying system rectiulating system. in combination with an amplifier for amplifying the modulated waves produced thereby and also for rectifying the current, to be supplied to said I modulating system.

. waves, and a source of space current, said rcpeater being in series with sa1d source 0 3. In combination, a repeating device, a

- device for producing modulated waves, a device of varlable impedance for cooperating with said device in producing modulater space current, and said modulating device and variable impedance device constitutlng .aparallel combination in series with the i ."scries combination thus formed.

4. In combination, a source of a number ofyphases of alternating current, a rectifying device supplied by each phase 1n comd 'bination with a constant current modulating system COIIIPI'lSIIIg dGVICGS similar to sa1d rectifying devices and having one-half the total power -capacity thereof.

,5. In combination, a space discharge device 'havingJa-plate or anode, a grid and a cathode, a source supplying alternating current to said device, in combinat on with a repeatingsystem of discharge devices for repeatrn system rectifies the current supplied to sa'i space discharge device.

6. In a system for modulating and amplifymg carrier waves, a device for producing modulated waves, a variable impedance device and an amplifying device, each of said devices having an anode-cathode circuit, a rid-cathode circuit and a filament circuit, 1n combination with a sin le source of alternating current for supplyin filament heating current, space current rom the anode to the cathode, and current to maintain the grid of each device negative with respect to its associated cathode.

7. In combination, a wave amplifier a device for supplying waves to be amplified to the input clrcuit of said amplifier, said device during operation requiring a supply of energizing current, an alternating current source, and means whereby said amplifier rectifies and supplies current from said source to said device.

8. In combination, a high frequenc' discharge device and a low frequenc disc arge device each having a heated. lamentary cathode in combination with a transformer for supplying heating current to said cathodes in parallel, said high frequency device having its cathode shunted by a divided capacity to the middle point of which its anode connection is made, and said low frequency device having its cathode shunted by a divided resistance to the middle pointof which its grid circuit connection is made. 9. In a high frequency amplifier, a series of repeating tubes individual to phases of alternating current for supplying each tube, said tubes having a common output impedance element, and individual condensers connecting them to said impedance element.

10. In combination, a high frequency amplifying system arranged in series with respect to a modulating system which is supplied with energizing current through a circuit connecting said modulating system to said amplifying system, and a shunt element f across the'circuit connecting said systems for regulating the current supplied to said modulating system.

11. A transmission circuit comprising a constant current system, including space discharge devices, for producing a signal modulated carrier wave, a plural-phase alternating current source, and a space discharge system for amplifying the modulated carrier wave and for rectifying the phases of said alternating current to supply energizing current to the discharge devices of said modulating system.

12. A system for generating high power high frequency electrical currents comprising a source of low frequency alternating currents, means for impressing sa1d low frequency currents upon a vacuum tube with which are associated self-oscillation producin circuits, means for impressing said low requency currents upon a pair of vacuum tubes with which rectifying and amplifying circuits are associated, means associated with the said air of vacuum tubes for impressing the said rectified currents upon the circuits of the first mentioned vacuum tube and means for impressing the oscillations in the circuits of said tube on the circuits of the said pair of vacuum I tubes.

13. A system for generating high power high frequency electrical currents comprising a source of low frequency alternating currents, means for impressing said currents upon the plate-filament and filament circuits of a vacuum tube with which are associated self-oscillation producing circuits, means for impressing said low frequency currents upon a pair of vacuum tubes, means associated with said pair of vacuum tubes for the simultaneous rectification of said low fre uency currents and amplification of osci ations produced in the first mentioned vacuum tube.

14. A system for generating and radiating high power radio signals comprising a source of low frequency alternating currents, means for impressing said currents upon a vacuum tube with which are associated selfoscillation producing circuits, means for impressing said low frequency currents upon a pair of vacuum tubes with which rectifying and amplifying circuits are associated, means ass ciated with said pair of vacuum tubes for impressing the said rectified currents cuits of said tubes upon a radiating system.

15. In combination two space discharge tubes in tandem whereby output waves supplied by the first tube are impressed upon the second tube and repeated thereby withbut change of frequency, a source of alternating current, and connections of the space paths of said tubes to said source, whereby the second tube serves to rectify alternatin current from said source to sup ly ung-directional space current to thefi rst tu e. 1

16. In combination two space discharge tubes in tandem whereby output waves supplied by the first tube are im ressed u on the second tube and repeated t ereby without change of frequency, a source of alternating current, and connections of the space paths of said tubes to said source, whereby the second tube serves to rectify alternating current from said source to supply unidirectional space current to both said tubes.

In witness whereof, I hereunto subscribe my name this 3rd day of November A. D.,

RAYMOND A. HEISING.

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