US1436252A - System for producing modulated waves - Google Patents

Description

R. A.-HEISING.

SYSTEM-FOR PRODUCING MODULATED WAVES.

APPLICATION FILED 050.27, 1918.

1 4362520 mama Nov. 21, 1922 ?atented Nov, 2i, i922,

warren stares intern PATENT carton RAYMOND A. HEIQING, OF EAST ORANGE, JIEBSEY, ASSIGNOB TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, H. Y., A CORPORATION OF NEW YORK.

SYSTEM FOR PRODUCTNG MODULA'IYE WAVE To all it may concern Be it known that l, RAYMOND A. HEISING,

a citizen of the United States, residing at is produced by uniformly recurring disvention, reference is made, to the accompanying drawings wherein Fig. 1'" represents. a system having a discharge device in series charges of amounts of electricity which vary in accordance with signals (2) To provide such means which are adapted for the transmission of speech: (3) To provide systems in which large currents, modulated in accordance with signals, may be efliciently generated by an arc: (4:) To provide systems in which the frequency of arc discharges is maintained constant independently of variations in their amplitude: (5) To provide ellicient variable impedance means for as- Consideration of the following descrip' tion will an gest other objects and advanta he variation in voltage of the vcurrent supplied to the arc is caused by a variable impedance either in shunt to, in series with the are or otherwise suitably related thereto. The variable impedance preferably consists of a deviceof the electrondischarge type. For telephony the discharge device is controlled by a microphone or equivalent element. Use is made of a third of auxiliary electrode ofthe are for controlling the main arc dischar e. B adjustingt'he constants in the auxifiary e ectrode'circuit, the frequency can tie-controlled indeendw ently, in a large degree, of the amptude variation due to the signals. a For more definite explanation; of the in- -tudes of'inductance 13 and capacity s of the invention.

with an arc; Fig. 2 a system having a discharge device in parallel with an arc; Figs. 3 and 4 are other modified forms, while F 1g. 5 .discloses an arrangement which may be utilized in connection with any of the pre ceding arrangements.

Re erring-particularly to Fi l, a generator 5 constitutes a source 0 )direct current for supplying an arc circuit which comprises the anode-cathode path of the electron discharge device 6, the high frequency choke coil 7 the electrode 8, electrode 9 and conductors 10 and 11. The device 6 typifies either a single vacuum tube or a suit able system of such tubes in parallel or series relation. The material of which the electrodes 8 and 9 are composed, the space therebetween, and themaximum voltage across the electrodes, are so chosen that normally the discharge will not occur except as it is controlled, triggered, primed or tripped oil by the discharge across the electrodes 12 and 9. The frequency of the discharges across elec trodes 9 and 12is controlled by the magni- 14 in the control circuit 15, which circuit includes electrodes 12 and 9. The control circuit is energized by the source 5 but it is optional to provide a'separate control source. The electromagnet l7 malntams a field across the space between. electrodes 8, 12 and 9 which" serves to extinguish the are after each dis- 19 and a grid. or impedance controlling clement 20. Gonnected to the grid and the cathode is the input circuit 21 comprising resistance 22, shunted by the secondary 23 of a transformer to which is coupled the inary 24, said primary 2% being located in series with the controlling microphone or equivalent device 26 in the circuit 25. The usual sources 27 and 28 are rovided for heating the cathode and mai taining the grid netive' with respect thereto respectively. The are across'the electrodes 8 and 9 is included in the path to ground or the antenna circuit which com rises inductance 29' 'andthe serial 30. Wit "proper adjustmentsthe radiated fre uency will be an approximatesine waveo the same frequency ice microphone 26, will cause negligible change of current through coil 31, due to its high inductance. The generator 0 may be regarded as a source of current which is maintained constant by coil 31, or the generator 5 and coil 31 together may be regarded as a source of constant current.

In Fig. 3 the out-put circuit of device 6 comprises primary 32 and a suitable source of direct current, such as a generator 33 or a battery. (oil 32 is coupled to coil 34 which thereby serves to impress low frequency variations of voltage across the path comprising the arc electrodes 8 and 9 which correspond to variations across the anodecathode circuit of device 6. Coil 7 serves to prevent the shunting of high frequency oscillations around the arc to ground. This arrangement difiers from that of Fig. 1 in that the device 6, instead of being in series with the current supply path of the arc is coupled to this path by means of a transformer 32, 34.

In Fig. 4 the-device 6, instead of being in a path parallel to the arc supply circuit,

as in Fig. 2, is coupled by means oftransformer 35, 36'to a shunt path 37 which comprises capacity 38 and secondary 36. The microphone acts upon device 6 to vary the space current therethrough, and these variations in turn cause corresponding voltages to be induced in path 37. The electromagnet 17 may be supplied by aseparate source 38. The control circuit may also be energized by separate source 5 in series with which aninductance 40 may be placed, if necessary.

The function of those-elements of Figs. 2, 3 and 4 which are not given in detail, may be readily understoodby reference to the description of the correspondingly numbered elements of Fig.4?

Fig. 5 illustrates a modified arrangement which may be utilized in connection with any of the preceding. The main oscilla tioncircuit 29, 30 is here substituted for the antenna circuit of the preceding figures. The antenna circuit 39 is coupled to the oscillation circuit by coil 29. By means of this arrangement the oscillations existing in the antenna will have a smaller proportion of harmonic frequencies. Intermediate tuned circuits may be placed between the oscillation circuit and the antenna 39 to more eifectively eliminate the harmonics. Such tuned circuits are well known and therefore need no description... By substituting a transmission line for the antenna,

this invention may be utilized-for transmitting intelligence over conductive. circuits.

Operation: The generator 5 supplies a direct voltage to the circuit 15 andcondenser 14. which periodically discharges across the electrodes 9 and 12 and causes amount of energy, it may serve to control the discharge of a much larger amount of energy across the electrodes 8, 9. The device 6 acts as an amplifier and reproduces in amplified form the impedance changes in or the current changes through the device 26. The antenna capacity or the equivalent capacity 30' is continually being charged by the source 5, butthe rate of charge varies in accordance with the condition of device 6.'

Novel features inherent in; the invention are defined in the appended claims.

lVhat is claimed is: 1. system comprising an arc generator, a direct current supply source for saidgenerator, means for varying in accordance with sound waves the potential supplied by said source at' a rate lower than the frequency generated by said generator, and

means to prevent the operation of said first- I mentioned means from materially changing the frequency generated by said generator. 2. A system comprising an arc generator, adirect current supply source therefor, and a non-periodic path including a signal controlled dischargedevice in shunt to said generator for Varying at a low frequency rate the potential supplied by said source. 3. A system comprising an arc generator, a direct current energy source therefor, and an untuned path including a discharge device for shunting from said generator in accordance with sound Waves the energy supplied by said source.

' 4. A system comprising an arc generator,

-a direct current supply' source therefor, a

iii

nreaeea source of constant current for supplying said devices.

6. A system comprising a source of electric current, an are for transforming the energy from said source into high frequency alternating current Whose amplitude is dependent upon the instantaneous magnitude of the voltage supplied by said source, a discharge device for controlling the voltage supplied by saidsource, and means for supplying said device with current from said source.

7. A system comprising an are for transforming electrical energy into high frequency alternating current energy, an energy supply for said are varying at a signaling frequency, and means operable without substantial time lag for preventing variations in said energy supply from ailecting the frequency generated by said arc.

8. A. system comprising anarc for transforming electrical current energy into high frequency oscillations, a current supply source for said arc, a speech controlled electric device for varying the current supply oi said are, and means operable with a time lag measurably less than the period of an audible sound wave for preventing variations in the current supply from varying til? the period of said oscillations.

9. A system comprising an arc generator, a signal conductor in which said generator produces high frequency waves, a current supply line for said generator, a unidirectionally conducting electron discharge device operatively connected to and energized by current transferred through said line, and signal controlled means for varying the impedance of said discharge device.

lil. A system for generating modulated high frequency waves, comprising an arc generator, a current supply source therefor, means adapted to be varied at a rate within the range of audibility for varying the current supplied from said source, and means for preventing variations at said rate in said current supply from varying the frequency of said generator.

11. A system comprising a main oscillation-circuit, an arc device for generating oscillations in saidcircuit, a current supply means for said are device, means adapted to be controlled in accordance with sound signals for varying the-current supplied from said source, a control circuit for said are, and means associating said circuit with said are whereby the tendency of signaling variations in current supply to said are to change the frequency of oscillations is counteracted.

12. A system comprising a main oscillation circuit, anarc device for generating oscillations in said circuit, a current sup ly means for said arcdevice, an-electron ischar e device for varying the current supphe from said means, and a tr1gger control circuit including inductance and capacity for said are.

13. A system comprising asource of direct current, an arc, and an electron discharge device, said are and said discharge device being in paths conductive to direct current which are in parallel with respect to said source.

14. A system comprising a source of enerizing current, an arc, an electron discharge device and means for varying the impedance or said discharge device, said are and said discharge device being in paths conductive to direct current which are in parallel with respect to said source.

15. A system comprising a source of direct current, an arc, an-electron discharge device, said are and said discharge device being in paths conductive to direct current which are in parallelwith respect to said source, and means to maintain the current through said source substantially constant.

16. in combination, a source of substantially constant current, an arc, and an electron discharge device, said are and said device being in paths conductive to direct current which are in parallel with respect to said source. a 1?. A system comprising an are, an electron discharge device, the terminals of said are and said device being connected by conductors or" negligible impedance for direct and speech frequency current, and a common source of electrical energy for supplying current to said are and said device.

18. A system comprising an are, a unidirectionally conducting electron discharge device having a space current path, and a common source oi current supply for said are and said path.

19.. A system comprising a source of direct current, a speech irequency choke coil, ahigh "frequency choke coil, and main arc electrodes, said aforementioned elements being located in a series irouit, a conductive path shunted across the high frequency choke coil and the are, an electron dischar e device operatively associated with said path, means including a microphone and an input circuit for controlling the impedance of said device, a high frequency oscillation circuit shunted around said electrodes, acontrol circuit includin inductance and capacity shunted around said source of di= rect current, an auxiliary electrode for said are, one portion of said control circuit being connected to one of said main electrodes and another portion to said auxiliary electrode, and means for maintaining a mag netic field across the space between said main and-auxiliaryelectrodes.

20. i l-system comprising an arc, a source of current therefor, an electron discharge device having an anode, an electron emltting cathode, and an impedance controlling element, said are and said device being in non-periodic paths which are in parallel with respect to said source.

21. A system comprising a source of cur-. rent, means to vary the voltage supplied by said source at a low frequency rate, a dis charge path for said source, and means operating independently of discharges across said path to cause discharges across said path at a high frequency rate which is substantially independent of the instantaneous voltage supplied by said source.

22. In combination, an arc, means for impressing thereon "an electric potential varying in accordance withsignals, means for extinguishing said are, and means for priming said are at a constant frequency rate.

23. The method of producing modulated oscillations in a circuit which comprises charging a capacity in the circuit, varying at a low frequency rate the charging current for said capaclty, and causing the dischar e of the capacity at a constant and relative y high rate. v

24. The method which comprises causing a current to continuously flow tocharge a capacity, varying the amperage of said current in accordance with speech, and periodically priming a discharge path to cause the capacity to discharge therethrough at a frequency which is high as compared with speech frequencies.

25. The method which comprises forcing a continuous current into a capacity, varying the rate of flow of the current at a comparatively low frequency, and priming a dlscharge path to cause the capacity 'to' discharge therethroughat a radio frequency rate.

26. The method which comprises forcing a continuous current into .a capacity vari ably impeding a shunt path around said capacity at a comparatively low frequency and dischar 'ng the capacity at a constant and relatively high frequency rate.

27. A system comprising an arc, a source of current therefor, highly evacuated unidirectionally conducting electron discharge device, an anode-cathode discharge pathwithin said devlce, and means for varying the comprising an arc and a space discharge device having an anode-cathode path, with means for controlling the impedance of said path, which comprises maintaining constant the sum of the currents through said are and said device.

.29. A system comprising an arc device, a space discharge device having an anode and an electron emitting cathode comprising terminals of a discharge path, a common source of electrical energy for said path and saidv arc, and means for varying the current to said are by, variably dissipating energy in said device.

30. A system comprising an arc, a s ace discharge device having an anode an an electron emittin cathode comprising terminals of a disc arge path, means for energizing said cathode, a common source of current for said are and device, and means for preventing variations in current supply from said source.

31. An are system having main electrodes and means forimpressing a variable voltage thereaoross, an auxiliary electrode, a priming circuit connected to said auxiliary electrode, and a steady current supply for said priming circuit, said priming circuit and auxiliary electrode being arranged to prime said are at regular intervals irrespective of voltage variations across said main electrodes.

In witness whereof, I hereunto subscribe my name this 20th day of December A. D.,;

RAYMOND A. HEISING. I

Images