US932111A - Producing high-frequency oscillations. - Google Patents

Description

R. A. PESSENDEBL, PRODUCING HIGH FREQUENCY OSGILLATIONS. APPLICATION FILED DEO.14,1905.

.932, 1 1 1 Patented Aug. 24, 1909.

FIELI- F|B-2 WITNESSES:

. V I M I r EQJNVENTGR BEGINAILD A. FESSENDEN, OF WASHINGTON, FIS'IRIGT OF COLUMBIA.

{PRODUCING HIGH-FEE QUENCY OSCILLAT IONS.

Specification 6: Letters Patent.

Patented Aug. 24', 1909.

Application filed lieoember 14, 1905. SerialNo. 291,739.

.To all whom it may concern: H

Be it'known that I, REGINALD A. FEssEN- DEN, a citizen of the United States, and resident of Washington, Districtof Columbia, have invented certain new and useful Imrovements in Producin High-Frequency scillations, of which t e following is a specification. J

' The invention described herein relates to production of high frequency oscillating currents, the currents 'so produced being especially adapted for the generation of electromagnetic waves for transmission of energy, particularly in wireless telegraphy and telephony. I

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification, Figure 1 is a sectional elevation of a condenser havin a member movable relative to the other; ig. 2 is a transverse section of the same; Flgs. 3, 4, 5 illustrate modifications in the construction of the condenser, and Fig. 4 is a section of the structure of Fig. 4 on' line 4* therein. Fig. 6 illustrates a form of sending apparatus embodying my improved condenser, and Fig. 7 illustrates another formof sending a 'paratus.

It has eretofore been generally assumed as necessary for electromagnetic or Wireless transmission of signals, to use a s ark-gap for producing oscillations, but I ave developed a system for the wireless transmission of ener y in which a spark gap is not used and which has been found to be not only more efficient as regards the use of power, but also entirely free from disturbing electrical effects, such as are produced by 40 atmospheric electricity or otherv stations and is capable of the very highest degree of selectivity.

In the practice of my invention provision is made for bausing variations in the amount of current flowing inan oscillating circuit by varying the capacity of the circuit. This can e, effected by employing a condenser capab e-of having its capacity altered very ra idl thereby roducing very sudden P Y P changes ,lIlllhB amountpf current flowing in the oscillating circuit. Any suitable means may be employed for producin the desired I rapid change of capacity, and

" inthe drawin s forillustration several means suitable or that purpose.

have shown In the construction shown in Figs. 1 and 2,

m'ay' be employed, consistin there is a condenser having one of its parts or elements formed by a drum or cylinder, 1, having av series of suitably spaced projections, 2, arranged at an angle to the direction of rotation of the drum, which is mounted on a shaft, 3, driven by a suitable motor, 4. 'A shell, 5, which may artially, but preferably wholly surround t e drum, is provided with a series of inward rojections,'6, and is arranged concentric with the drum. Any suitable dielectric ma be employed as a solid insulating materia or compressedv air, or a vacuum may be maintained etween the two parts or elements of the condenser. It is preferred, however, to employ a cylinder, 7, of mica, referably secured inside of the shell, 5. his mica acts as an insulator and ermits a higher potential to be maintained between the two parts or elements.

It will be understood by those skilled in the art, that members of the condenser may both be rotated, in opposite directions,

thereby doubling the variations or changes of ca acity in-a given time. In-lieu ofxmaking t e condenser elements in the form of rojections on concentric cylindrical suraces, the construction shown in Fig. 3, of two disks or plates, ,8, provided with ra( ial ribs or projections, 9. One or both of these disks are provided with shafts, 10, whereby they may e rotated in o osite directions as by bands 10*, 10 Wgfle any suitable dielectric may be employed, it is preferred to secure sheets, 11, of mica on the adjacent faces of the disks for the double purpose of avoiding air friction and furnishing a highly eificient insulation.

As shown in Fig. 4, I may use in lieu of one of the disks, 8, a sheet, 29, of mica or glass, rubber or other suitable material, coated with metal, as silver, and the coating or silvering is partially removed so as toform radial conducting strips corresponding to the radial ribs or projections, 9, on the disk, 8 (see Fig. 4

It will be understood thattwo disks or plates of mica, etc.,"may be employed advantageously, mounted to rotate as in Fig. 3, as on account of their slight weight, they can be rotated at very highspeed.

It is evident that when the ribs or projections on the members of the condenser are directly opposite each other, the capacity of the disks with respect to each other, will be mum, and from minimum to maximum, as

The primaryy15, of the transformer is m the other member. members is fixed and the other movable, the

capacity will vary from maximum to. mini,-

many times per revolution, as there are ribs or projections on the fixed or movable mem-' her. If the ribs or projections on' the monk bers, for example, are one-tenth of an'inch. wide and the spaces between adjacent ribs also one-tenth of an inch wide, and thedisk in many ways, and the ribs may be so shaped moves at a peripheral speed of twenty miles per minute, which I have ascertained is ob.- tainable, the ca acity be changed through a comp ete cycle, one hundred thousand (100,000) times per second and the electrical oscillations so reduced will be of that frequency. If bot members be retated one opposite the other, at the periphe Ilephony. The mica disk, 29, with its eon ducting segments, is attached to a resilient- -diaphragm, 30, by fine platinum rods, 31. .On talking into the .mouth piece, 32, the

oral speed stated, the freriluency will be doubled, there being two 7 undred thousand (200,000) cyclesper'second. I have ascertained that, contrary to what has been held by many experimenters, wireless t-elegra by can be carried on very efi1.-. ciently wit fre uenciesas low as twenty thousand (20,000 or second. This. corree s onds to a perip eral speed when both Isks are rotatlng, of two miles er minute, and hence with my improved mot ed, a very wide range of frequencies can be obtained. By the means described herein, it is possible to obtain more than five hundred thousand (500,000) difierent fro ueneies, alLof which could act independent y ahd in close imity. I

Any convenient form: or arrangementof apparatus can be employed for utilizing the oscillations, As for eXample*,-in Fi 6, is shown a form of a paratus in which the aerial, 12, is 'groun ed and is opcratively connected to the secondary, 13, of the transformer, and to the variable condenser, 14.

circuit of the source; 16, of voltage (prefers ably constantlwhich may have a number of dry or stor'a e cells. A capacity changer, '17, such as liereinbefore described, is also arranged in the circuit of the source of Y012. tage and the primary, 15. A condenser, 26, and an -inductance, .27, may also be usedif desired, in accordance with methods well known in the art. In operation, when-the ribs on one member of the capacit changer, are op osite the spaces between t e ribs on the v0t er 'member, the capacity will be; a minimum. When, during the movement of one or both members, the ribs on the two members are opposite each other, the capace 1ty will be maximum and the cur-rent flow into the disks and produce an oscillation in the aerial.

When one of the condenser In 7, is shown another form of apps-.-

' mately sine form in the fluctuations. .is best done empirically, especially if the material.

grounded. .A continuous current generator,

as a dynamo, 28, is connected to the aerial and als to. ground. By the operation of the capacity changer 17 in this arrangement,

the capacity of the aerial to ground is. i

changed every time the ribs on one member kpass the ribs on. the other member of'the changer, and thereby set up an oscillation in the aerial- The capacity changer may lie constructed and proportioned as, to give an approxi- This members are formed of coated insulating In Fig. 4, is. Shawna form of capacity changer especially adapted to wireless te disk, 29, is caused to approach and recede from the rotating disk, 8, thereby changing the capacity and the strength of the oscillas tions in accordance with the sound Waves vibrating the. diaphragm, 30.. I

In some cases, it. is preferred to arrange one part or member eccentric to the other, as

- shown in Fig. 5, in which the conducting ribs orportions are arranged to be parallel or approximately so with the ribs or conduct-. ing portions on the other disk, when such ribs are moving adjacent. to the first disk.-

I claim herein as my invention:-

i 1. A capacity changer for electromagnetic electric circuits comprising a condenser and means to rapidly move its, eflective eodperate ing members relative to each other, to produce oscillations in the circuit.

2. A high frequency oscillation producer comprising a condenser and means to very rapidly vary the relative distances apart of its effective condensing surfaces.

3. device for producing oscillations in a circuit comprising a condenser and means-to regularly and continuously vary its ca .a city at a very high frequency, substantia as described. I

4. A wireless telegraph sending circuit including as a ca acity two conductors separated by a die ectric, ,and means for .veryrapidly varying the distance between the effective areas of said ca acity conduct tors whereby to produce oscillations in the circuit by varying the-capacity.

5. An ap aratus forproducing high fr 'quency'osc ations in a circuit, comprising two condenserparts or elements movable relative to each other whereby to vary the.

current and oduce oscillations. B. An apparatusfor producing high frequency oscillations in a circuit comprising a condenser and means to move the effect ve .areas of one of its members rapidly with tions.

7. In an apparatus for producing high freuency oscillations, a circuit and a capacity hanger therein comprising a condenser With its members movable relative to each other, and means for moving said members with sufiiciently highfrcquency to produce electric oscillations.

8. A condenser comprising two members having on their adjacent faces'a series of conandinsulated surfaces, a second member;

having alternate conducting and insulated portions, means to move one member wlth respect to the.other, and means actuated by sound waves to move the other member relativelyto the first, substantially as described.

10. In Wireless telephone apparatus the combination with a condenser and means to rapidly move one of its members with respect to the other, of a sound actuated element attached to and adapted to move one of the elements of the condenser with respect to the other, whereby to produce oscillations in a circuit and at the same time vary the strength of said oscillations in accordance with sound waves substantially as described.

11. Means for' producing sustained electrical oscillations, of definite frequency, comprising a circuit including a capacity, means for changing the ca acity, and means for periodically altering the value of the capacity very rapidly, substantially as described.

In testimony whereof I have hereunto set my hand.

. REGINALD A. FESSENDEN. Witnesses;

HELEN M. FEssENDEN, Jnssrn E. BENT.

Images