US1501664A - Wireless signaling system - Google Patents

Description

Witnesses July 15, 1924. 1,501,664

A. HUND WIRELESS S IGNALING SYSTEM Filed Sept 18. 1914- His Attorneg.

Patented July 15, 1924.

UNITED STATES AUGUST QHUND, OF SCHENECTADY, NEW YORK, ASSIGNO'R T0 COMPANY, A CORPORATION or new YORK.

GENEEAL saws-m WIRELESS SIGNALING SYSTEM.

Application filed September 18, 1914.

To all whom it may concern:

Be it known that I, AUGUST HUND, a sub ject of the Emperor of Germany, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in \Vireless Signaling Systems, of which the following is a specification.

My present invention relates to wireless signaling systems and more especially to the wireless transmission of speech or other sound waves, such, for example, as those produced by musical instruments.

It has heretofore been proposed to connect a source of continuous high frequency oscillations to an antenna and to modify the waves sent out in accordance with the signals to be transmitted without interrupting their continuity. U. S. Patents #706,747 and 7 53,863 to Fessenden describe systems of this character. Difliculty has been ,experienced, however, in the practical operation of such systems in providing suitable apparatus for controlling a sufficient amount of energy and for producing large enough energy variations in the transmitted waves to reproduce the sound waves at a distant point.

The object ofmy invention is to overcome this difficulty by providing an organization which will produce continuous waves which are capable of radiating large amounts of energy and which have a large variation in amplitude in accordance with the signals to be transmitted and at the same time provide a system which is easy of adjustment and which is simple and eflicientin itsoperation.

In carrying my invention into efiect Iconnect a source of high frequency oscillations to an antenna and also connect to suitable points in the antenna circuit an energy consuming device which ,willabsorb more or less energy from the antenna in accordance with the signals to be transmitted. The device which I prefer to use for this purpose is one which is especially. adapted for use with high voltages and comparatively small currents. It is a well known fact thatwith a properly tuned antenna to which is connected a source of high frequency oscillations there exists,

because of certain resonance phenomena, a large difference of potentialbetween-different points in .the antenna circuit. vBy connecting an energy consuming device of the preferred type in parallel Wltllthe antenna which Fig.

former 3 to .tential between the Serial No. 862,325.

circuit between two points between which there is a large difference of potential and by suitably varying the amount of energy consumed by said device it is possible to vary the amount of energy which will be radiated by the antenna, the larger the amount of energy consumed by this device the smaller will be the amount radiated.

The novel features of my invention are pointed out with particularity in the appended claims. The invention itself, however, will best be understood by reference to the following description taken in connection with the accompanying drawing in l illustrates diagrammatically one way of carrying my invention into effect and Fig. 2 shows a modification.

Asshown in the drawing the antenna 1 is grounded as usual and hasconnected thereto a source of high frequency oscillations which in this case consists of the high frequency alternator 2. This may be inductively connected to theantennaby means of frequency is placed in series with the antenna. In some cases itmay be desirable to connectthe source of energy to the antenna by loosely coupling the primary of transthis inductance. Ifthe antenna is comparatively smallthe value ofthis inductance required to givethe proper tuning will be correspondingly large and as aresult .there will be a large difference of poterminals ofthe inductance. The terminals of this inductance may be connected directly tothe anodes-50f an electrondischarge relay 6 while the mid dle point of the inductance is connected {to the cathode 7 of the relay. These electrodes are enclosed in an envelope exhausted to such a high degree that when highpotentials are impressed upon theelectrodes the flow of currentbetween the electrodes is not .ac

companied by any visible.manifestationof gas ionization. lVhile the current which will flow through a relay of this type is 'limited the voltage which may be employed is practically unlimited except by difficultiesof insulation. The cathode 7 is. of filamentary form and is provided with a battery ,8,or

other suitable means for heating. A consurrounds the cathode 7.

ducting body ,9' in the form of a grid also With the arrangement thus far described it will be seen that when energy is supplied to the antenna there is a high potential impressed upon the electrodes of the relay 6. Hence there will be a flow of current from the cathode 7 to the anodes During onehalf wave of the oscillation current will flo W to one of the anodes and during the next half wave current will flow to the other anode. As a result there will be a continual consumption of energy in the device. If now a positive potential be impressed upon the grid the flow of current will be increased while if a negative potential is impressed on the grid the flow of current will decrease. Hence by varying the grid potential the amount of energy consumed by the relay may be varied as desired and as a result the amplitude of the current wave and the amount of energy radiated by the antenna may be varied accordingly. If it is desired to transmit speech or other sound waves the grid potential may be varied in accordance with potential variations produced by a telephone transmitter 10. The transmitter is provided with the usual battery 11 and is preferably connected to the grid 9 through the transformer 12 as indicated, one terminal of the transformer being connected to the grid through the potentiometer 13 while the other terminal is connected to the cathode. In order to secure the best results it will usually be found desirable to impress an extra potential upon the grid 9 in addi tion to that produced by the transformer 12. This extra potential may be derived from a battery 14. and may be given the proper value by adjusting the potentiometer 18. In order to increase the amount of energy which may be consumed withoutoverheating the relay 6 it may be desirable to insert series resistances 15 as indicated.

Vhile I have described only one way in which my invention may be carried into effect it will be apparent to one skilled in the art that many modifications thereof may be made without departing from the scope of the appended claims. The essential thing required in practicing my invention is the selection of two points in the antenna circuit between which large difference of potential exists. In case the antenna itself possesses such a high inductance that but little tuning inductance is required one of these points may be found in the antenna itself and it may be desirable to connect one electrode of the electron discharge relay to the extreme end of the antenna. Also while I have illustrated and described an organization in which energy is abstracted from both half waves 1 have found in actual practice that speech may be efficiently transmitted when the connections are so modified that energy is absorbed from only one-half wave of current. This may be done by merely connecting the cathode to one terminal of the induc- 1 tance and connecting the two anodes in parallel to the other terminal as indicated in Fig. 2.

What I claim as new and desire to secure by Letters Patent of the United States is 1. The combination in a wireless signaling system of an antenna, a source of energy con-- nected to said antenna, a tuning inductance in series with said antenna, a relay comprising a plurality of electrodes enclosed in a highly evacuated envelope, direct electrical connections from said electrodes to points in said inductance between which there is a lar e difference of potential and means cooperating with said relay whereby the ampli tude of the current flow in said antenna may be varied in accordance with the signals to be transmitted.

2. The combination. in a wireless signaling system of an antenna, a high frequency source of energy connected to said antenna, a tuning inductance in series with said antenna, .an electron discharge relay having a plurality of, electrodes, direct electrical con nections from said electrodes to points in the inductance between which there is a large difference of potential, and means for varying the current through said relay in accordance with the signals to be transmitted, thereby producing a similar variation in the amplitude of the current flowing in the antenna.

8. The combination in a wireless signaling system of an antenna, a source of energ connected to said antenna, a relay comprising a cathode and two anodes enclosed in a highly exhausted envelope, a tuning inductance in series with said antenna, electrical connections between said anodes and the terminals of said inductance, an electrical connection between said cathode and an in-- termediate point in said inductance. a. conducting grid surrounding said cathode and means for varying the potential of said grid in accordance with the signals to be transmitted to produce a similar variation in the amplitude of the current flow in the antenna.

4. The combinationin a wireless signaling system of an antenna, a high frequency source of energy connected to said antenna, a tuning inductance in series with said antenna, means for diverting a variable amount of energy from said antenna comprising an energy consuming device having a plurality of electrodes, direct electrical connections from said electrodes to points in the inductance between which there is a large difference of potential, a conducting grid surrounding one of said electrodes and means for varying the potential of said grid in accordance with the signals to be transmitted to produce a variation in the amplitude of the current flow in the antenna.

5. The combination in a wireless signaling system of an antenna, a high frequency source of energy connected to said antenna, means for diverting a variable amount of energy from said antenna comprising a relay having a plurality of electrodes enclosed in a highly evacuated envelope, a tuning inductance in series with said antenna, direct electrical connections between said electrodes and points in said inductance between which there is a large difference of potential, a conducting grid surrounding one of said electrodes, a telephone transmitter and means for varying the potential of said grid in accordance with variations in current through the telephone transmitter to produce a variation in the amount of energy directed from said antenna.

6. The combination in a wireless signaling system of an antenna, a high frequency source of energy connected to said antenna,

means for diverting a Variable amount of energy from said antenna in order to vary the amplitude of the current flowing therein, said energy diverting means comprising a relay device having an anode, an electron emitting cathode and a current controlling grid enclosed in a highly exhausted receptacle, a tuning inductance in series with said antenna, direct electrical connections between the anode and cathode of said relay device and points in the inductance between which there is a large difference of potential, and means for varying the potential of the current controlling grid in accordance with the signals to be transmitted.

In witness whereof, I have hereunto set my hand this 17th day of September, 1914.

AUGUST HUN D. Witnesses:

BENJAMIN B. HULL, BENJ. H. WEISBROD.

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