US1501735A - Wireless signaling system - Google Patents

Description

July 15, 1924. 1,501,735

W. C. WHITE WIRELESS SIGNALING SYSTEMv Filed June 5, 1915 I y 2/ q; g w

Inventor: William CWhite,

H is Attorney.

Patented July 15, 1924.-

UNITED STATES WILLIAM c. WHITE,

PATENT OFFICE.

- COMPANY, A. CORPORATION OF NEW YORK.

WIRELESS SIGNALINIG, SYSTEM.

Applicatioh filed June 5, 1915. Serial No. 82,367.

To all whom it may concern: A

Be it known that I, WILLIAM C: WHITE, a citizen of the United States, residing at Schenectad in the county of-Schenectady,

State of Nzw York, have invented certain new and useful Improvements iI I Wireless SignalingSystems, 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 beenproposed 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. Difficulty 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 of my invention is to overcome this difficulty by providing an organization whichwill 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 sametime provide a system which is easy of adjustment and which is simple and efficient in its operation. I The novel features of my invention are pointed out with particularity. in the ap pended claims, the invention itself, however, with further objects and advantages will best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig.

1 illustrates diagrammatically one way of carrying my invention into effect and Fig. 2 ShOWS'B. modification thereof.

As shown in Fig. 1 of the drawing .the antenna 1 is grounded as usual. nected thereto a source of high frequency oscillations which in this case consists of a high frequency alternator 2. This may be inductively connected to sthe antenna by means of a transformer 3, or may be connected directly thereto if desired.- An inductance 4 which may be varied to tune the It has conantenna circuit to the desired frequency may be placed in serles with the antenna. In some cases it may be desirable to connect the source of energy to the antenna by loosely v coupling the primary'of the transformer 3' to this inductance. It is a well known fact that with 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 potential between different points in the antenna circuit. In carrying my inventions into effect I select two such points and connect between these points an energy consuming device .6, which in the case illustrated is an electron discharge relay comprising an exhausted envelope containing trode of the electron discharge relay to the extreme end of the antenna as indicated in Fig. 2. In the present illustration the anode 7 is connected to the point 5 at the top of the tuning inductance 4. I prefer to connect the cathode to earthpin order to prevent high potentials being impressed upon the telephone transmitter, transformers and batteries employed. I

The 'cathode 8 is of filamentary form, preferably of tungsten, andis provided with current for heating it to incandescence by the secondary, 10 of the transformer 11 which may be supplied with a low frequency alternating current from the mains 12. The temperature of the cathode may be adjusted by means of the variable resistance 13 in the primary circuit of the transformer. The electron discharge device in the present case is one which is adapted for use with high potentials and in order to adapt it to such use it is necessary that the envelope containing the electrodes should be eX-. .hausted to such a high degree that when high potentials are impressed upon the electrodes the flow of current between the elec trodes is "not accompanied by any visible manifestation of gas ionization. When connected in this way to the antenna and when the grid the flow of current will decrease.

Hence if the grid potential be varied in accordance wth potential variations produced by sound. waves the amount of energy radiated by the antenna may be varied accordingly. As a means for thus varying the 7 grid potential I have indicated in the present case an ordinary telephone transmitter; 14 provided with the usual battery 15 consistin of a few cells and preferably connecte to grid9 through the transformer 16 as indicated, one terminal of the transformer being connected directly to the grid while the other is connected to the middle point of the secondary 10 of the transformer 11 as indicated. In order to secure the best results it will usually be found desirable to adjust the current flowing through relay 6 so that about half of the energy of the source 2 is normally diverted from the antenna circuit. This may be done by impressing an extra potential on the grid 9 in addition to that produced by the trans; former 16. This extra potentia'l may be derived from the battery 17 and by varying the potential of battery 17 the normal current through relay 6 may be adjusted to the desired value. By this arrangement both thepositive and negative half waves of the alternating current produced in the secondary of transformer 16 are effective in varying the amount of energy diverted from the antenna circuit. In order that the currents produced in the secondary of the transformer 16 may not be com elled to flow through the battery 17a con enser 18 may be inserted in shunt to this battery. In case the potential variations produced in the secondary of transformer 16 are not great enough to produce the desired variat1on in the amount of energy diverted from the antenna any suitable amplifying means may be employed to secure larger potential variations.

' In the preferred construction of the electron discharge relay 6 the anode 7 is made up of one or more plates of considerable area and the 9 consists of a number of turns of e wire wound on a supporting framework and located in parallel relation to the anode plate or plates; The cathode located in a plane paralanode. The distance be- 8 is also preferabl lel to the grid and noon-res tween. these members is preferably small and as a result there is an appreciable capacity between them. It will be seen that with the arrangement indicated the anode 7 is alternately positive; and negative with respect to the cathode and that as a result the grid 9 will have inducedthereon by electrostatic induction positiv andnegativecharges. Altho the grid and cathode are connected electrically the reversals in polarity in these induced charges are so rapid that the potential difference between the two at times may become very large, the secondary of the transfhrmer 16 offering a high impedance to the flow of high frequency charging current between grid and cathode. As a result the positive potential which may be induced on the grid "9 when the anode is also positive may become so great as to allow a large enough current to flow through the relay 6 to divert from the antenna nearly all of the energy from the high frequency source even when no potential is induced-upon the grid by means of the telephone transmitter. Also the potentials produced by the secondary of the transformer 16 arein most cases small in com- 1 flowing throu h relay 6. In order to overcome this di culty I employ a tuned circuit comprising a condenser 19 and a variable inductance 20 between the grid 9 and vcathode 8. If this circuit is tuned to the frequency of the source 2 it will offer a low impedance to the high frequency charges induced on the grid and in so far as these induced charges are concerned will have the same effect as a short circuit between grid and cathode. Hence the grid and cathode willnormally be at substantially the same potential except for the comparatively small difference of potential produced 'by battery 17. The condenser 19 should preferably be of small capacity so as to offer a high impedance to the comparatively low frequency current produced by the sound waves.

While I have described only two ways 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. While I have illustrated and described an organization in as sound waves by substituting a telegraflr or key 21 shunted by a high resistance 22 thetransformer 16 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 system for the transmission of wireless signals of an electron discharge relay comprising an anode, a cathode and a grid, means for impressing an alternating potential of high frequency upon the anode of said relay and a connection between the cathode and grid of said relay which offers a low impedance to high frequency current whereby large high frequency potential diiferences between grid and cathode are prevented.

2. The combination in a system for the transmission of wireless signals of an antenna, a source of high frequency energy connected to said antenna, an electron discharge relay comprising a cathode an anode and a grid, direct'electrical connections be-' tween said cathode and said anode and points in the antenna circuit between which there is a large difference of potential and a connection between the cathode and grid of said relay which offers a low impedance to high frequency current whereby large high frequency potential differences between grid and cathode are prevented.

3. The combination in a system for the transmission of wireless signals of an anv tenna, .a source of high frequency energy connected to said antenna, an electron discharge relay comprising an anode, a cathode and a grid enclosed in a highly exhausted envelope, a connection ween'the anode of said relay and a point in the antenna circuit. at which a high potential exists, a connection between the cathode and earth and a connection between the cathode and grid of said relay which offers a low impedance to high frequency current whereby large high frequency potential differences between grid and cathode are prevented.

4. The combination in a wireless signaling systemof an antenna, a source of high frequency energy connected to said antenna, an electron discharge relay comprising a cathode, an anode and a grid enclosed in ahighly .exhausted envelope, connections between said cathode and said-anode and points in the antenna circuitbetween which there is a large difference .of potential, means for varying the potential of said grid inaccordance with signals to be transmitted, and

a connection between thecathode and grid of said relay which offers a low impedance to hi h frequency current but offers high impe ance to current of the frequency employed for varying the grid potential .to transmlt signals whereby large high frequency potential differences between grid and cathode are prevented.

5. The combination in a system for the transmission of wireless signals of an electron. discharge relay comprising an anode, a cathode and a grid, means forimpressing an alternating potential of high frequency upon the anode of said relay and a circuit including the cathode and grid of said relay which is resonant to the frequency of the potential impressed upon the anode whereby large .high frequency potential differences between, grid and cathpde are prevented.

6. The combination 1n a wireless signaling system of an antenna, a source of high frequency energy connected to said antenna, an electron discharge relay comprising a cathode, an anode 'and a grid, electrical connections between said cathode and said anode and points in the antenna circuit between which-there is a large difference of poten tial and a connection between the cathode and grid of said relay which is resonant to the frequency of the source of energy connected to said antenna whereby large high frequency potential differences between grid and cathode are prevented.

7. The combination in a wireless signaling system of an antenna, a source of high fre quency energy connected to said antenna, an electron discharge relay comprising a cathode, an anode and a id, a connection between the cathode of said relay and earth, a connection between the anode of said relay and a point in said antenna electrically remote from earth and a circuit including the cathode and grid of said relay which is resonant to the frequency of the source of energy connected to said antenna whereby large highfrequency potential differences between grid and cathode are prevented.

8. The combination in a wireless signaling system of an-electron discharge relay comprising -an anode, a cathode and a grid, means for impressing an alternating potential of high frequency upon the anode of i said relay, means for impressing potential variations of comparatively lowfrequency upon said grid for transmitting signals and a connection between the cathode and grid of said relay which is resonant to the highfrequency potential impressed on the anode but which offers a high impedance to potential of the lower frequency impressed -upon, the',grid whereby large frequency poa highly exhausted envelope, connections between said cathode and earth and between said anode and the end of said antenna electrically remote from earth, and means for varying the potential of said id in accordance with signals to be transmitted.

10. The combination in a wireless signaling system of an antenna, a source of high frequency energy connected to. said antenna, an electron discharge relay coin rising a cathode an anode and a grid, enc osed in a tween said cathode and said anode and points in the antenna circuit between which there is a large difference of potential, means for varying the potential of said grid in accordance with current variations produced by sound waves, and a connection between the cathode and grid of said relay which offers a low impedance to high frequency current but offers a high impedance to the current produced by sound waves whereby large high frequency potential differences between grid and cathode grid of said relay which ofi'ers a low impedance to high frequency current but which offers a high impedance to the-current which is-varied by soundwaves whereby large high frequency potential differences between grid and cathode are prevented.

12. The combination in a wireless si nalingsystem 'of an antenna, a source of igh frequency energy connected ,to said antenna, an energy consuming device comprising a cathode, an anode and a grid, electrical connections between said cathode and sa d anode, and points in the antenna circult between which there is a large difierence of potential and a connection between ences between cathode the cathode and a grid of said energy consuming device which offers a low impedance to high frequency current whereby large high frequency potential differences vbetween grid and cathode are prevented. highly exhausted envelope, connections be- 13. The combination in a wireless signaling system of an antenna, a source of high frequency energy connected to said antenna,

means for diverting a variable amount of energy from said antenna comprising an electron discharge relay having a cat ode, an anode and a grid, direct electrical con nections between said cathode and said anode andpoints in the antenna circuit between which there is a large difference of potential and a connection between the cathode and grid of said relay which offers a low impedance to high frequency current whereby large high frequency potential difi'erand grid are prevented. g

14-. The combination in a wireless signalin s 'stem of an antenna a source. of hi h;

g a h frequency energy connected to said antenna, means for diverting a variable amount of energy from said antenna. comprising an electron discharge relay having a cathode, an anode and a grid, electrical connections between said cathode and said anode and.

points in the antenna circuit between which there is a large difference of potential, a connection between the cathode and grid of said relay which oflers a low impedance to high frequency current wherebylarge high frequency potential differences between cathode and grid are prevented, and means for varying the potential between cathode and grid in accordance with variations in a comparatively low frequency signaling current.

In witness whereof, I have hereunto set my hand this 4th day of June, 1915.

WrLL AM 0., WHITE.

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