Патент USA US2105809код для вставки
"J'Qäs, i938. R. D. DUNCAN, JR CARRIER SUPPLY 'SYS TEM Filed Aug. l, 1936 .ai \I l|_ _ wrm». , 2,105,809 Patented Jan. 18, 1938 ~ 2,105,809 " Í UNlTED STATES 'PATENT ol-‘l-‘lclsl-> 2,105,809 CARRIER SUPPLY SYSTEM Robert D. Duncan, Jr., East orange, N. J., as; \ signor to Wired Radio, Inc., -New York, N. Y., a - corporation of Delaware Application _august 1, i936, sel-inl Nogjsaeos 2 claims’. (Cl. 179-15) 'I‘his invention pertains in general to the trans _auxiliary high 4range carrier frequency which nlission of programs and specifically relates to operates through means for producing 'the desired such systems for transmitting programs in which lower frequencies for carrier replacement pur _the-carrier frequency is substantially eliminated poses. 'This replacement carrier isvthen incor 5 'during transmission and replaced upon reception. ` porated with the received program energy to re- 5 The principal object of the invention con? place the suppressed carrier for audible reproduc sists in providing a transmission system having tion of the transmitted program. . means' for impressing modulated carrier fre Referring to the drawing in detail, there is pro ’ quency energy upon a transmission medium with vided a commercial power transmission network I l0 the carrier frequency itself substantially elimi connected with power equipment 2. This power 10 nated; said energy being received at a remote equipment 2," may be located in the commercial point with local replacement of the carrier ire power substation 3. The lines I, equipment 2. ` y and sub-station _3 are indicative of a power trans A. Vfurther object of the invention comprises ‘ mission network in general. In the present in quenoy. lo providing a suppressed carrier _transmission sys tem in which an auxiliary higher ,carrierfre quency is transmitted to the point of recep tion for incorporation with the received energyfor carrier frequency replacement purposes. stance, the lines I are of the three phase 60-cycle 15 alternating current type and operate through a step down transformer 4 to supply commercial voltages to the consumer’s local transmission cir cuit 5. These and other objects will be apparent from the following, reference being >had to the accom panying drawing which represents one embodi cillator 8 develops high frequency oscillations of a standard frequency, such as 13 kilocycles.- The ment of the system of my invention. *_ , My invention contemplates the provision of a In accordance with the invention, a master os'- ' '20 ' oscillator 8 may be of a. type known in the art, such as a crystal controlled thermior'lic oscillator transmission system for developing a plurality circuit.- 'I'he output of the oscillator 8 is directedr ‘25 of related» carrier frequencies from a master os to a harmonic generator 9 which develops, from cillator. These carrier frequencies, having a the master frequency, a plurality of harmonically multiple relationship, are each subjected to in dividual program modulation. Concomitantly, 30 each- of. the‘carrier frequencies is eliminated so' that the energy impressed uponthe transmission medium comprises program modulated’l carrier related multiple frequencies. vFor example, these ' energy in the side band regions, the side band4 multiple frequencies may be 26, 39 and 52 kilo cycles, respectively, and correspond to diüerent '30 program channels. These different carrier fre quencies are respectively. directed to transmitters III, II and I2. ‘ ' The transmitters I0, ~II' and I2 each comprise regions corresponding to the related carrier fre ,35 quencies being, of course, discretely situated along ~ known means for respectively producing ampliñed 35 the frequency spectrum 'to'produce independent three phase carrier frequency energy. 'I‘he high frequency energy for each transmitter is modu program channels; In. the- embodiment illus trated, I employ _a commercial power network as lated in accordance with the individual source of ' the transmission medium, although the invention modulation" energy` associated with that trans-_40 ls not to be strictly limited thereto, since other _ mitter. _In addition, each carrier frequency it- ¿o media may be employed` without departing from the intended scope of the ing out the invention, 'the energy may be restricted 45 band of frequencies, when inventiomv In carry transmitted program tobut a single side desired. self is eliminatedifrom the modulated carrier energy so that the output at the transmitter com prises three-phase modulated carrier-energy in the side band „range with the carrier frequency itself substantially eliminated.` \ v. _ _ 45 lin accordance with the invention',- means are`-> , The circuits for such transmission`\ equipment provided for developing,-from the master oscilla >are known in the art.> A' special form 'of such y tor, an additional carrier frequency arranged'sub stantially higher than those .of the program chan carrier elimination and transmission circuits may be seen in my copendinlg application, _Serial No. 50 nels. This high carrier frequency is then trans 40,526,'as well as in the copending applications 50 ' or E; A. Laport, serial No. 52,751; and serial No. mitted over the transmission medium in an un modulated condition. At the point _of reception, , 50,491. The harmonic generator als'ocom'prlses the receiving equipment selectively receives any means knownfin the art, such as 'electron -tube one of the program channels. At the same time, circuits of standard form, for producing such ' u 55 equipment _is provided for the reception of the harmonically related' carrier frequencies. / y 2 2,105,809 The outputs of"transmitters IIJ, II and I2 are directed respectively through filters I4, I5 and I6. ceiver 20. The circuits of the receiver 20 selec tively receive the program modulated carrier fre These filters limit the output of the transmitters to discrete carrier frequency ranges comprising the different program channels. The output cir quency energy with the carrier frequency itself suppressed while the output of amplifier 21 sup plies this carrier frequency.- As a result, the re cuits of filters I4, I5 and I6 are directed through capacitive couplings to the lines I. ceiver 20 replaces this carrier frequency as sup plied from the amplifier 21 so that the desired program can be intelligibly reproduced by the A harmonic generator I1 is also connected with the master oscillator 8 for developing high fre 10 quency oscillations within a range higher than loud speaking device 2|. ` - In another arrangement of the system of the 10 invention, a frequency sub-divider of any type might besubstituted for the multivibrator 25. Again, a harmonic generator may be substituted for the >iilter 26 for producing a selected _fre quency vfrom the sub-divided frequency. 15 In another embodiment of the invention, the harmonic generators 9 and I1 may be combined in a single unit so that one harmonic generator serves to produce the carrier frequencies `for the transmitters III-I2, as well as the auxiliary car 20 the carrier frequencies `associated with the trans mitters I0, II and> I2. For example, the har monic generator I1 may develop a frequency of the order of 78 kilocycles. In suitably amplified 15 form, the output of the harmonic generator I1 is directed through ñlter I8 which limits the output of the harmonic generator I1 to the de sired high frequency, such as '18 kilocycles. The output of the filter I 8 is then directed through capacitive couplings to the power lines I. The consumer’s dwelling including the circuit rier frequency passed through filter I8. 5 is provided with a receiver 20 and loud speaker Although I have .shown a preferred embodi unit 2I for audibly reproducing the programs ment of my carrier supply system, it will be transmitted over the lines I.l The receiver 20 understood that various changes can be made 25 embraces suitable selection, amplification and without-'departing from the intended scope of detection circuits known in the art for repro Imy invention. Therefore, I do not desire to ducing desired programs. 'I‘he circuits of re limit myself to the foregoing except as may be ceiver 20 include electron tubes energized through pointed out in the appended claims. power connections 22 extending to the circuit 5. What I claim as new and original and desire 30 The signal input circuit for the receiver 20 is to secure by United States Letters Patent is: 30 directed through capacitive couplings 23 and also 1. In a transmission system in which a plu connected with the power circuit 5. rality of modulated suppressed-carrier high A further circuit is provided from the capacitive frequency bands and carrier replacement high couplings 23 to direct signaling energy through frequency waves are transmitted to a receiving a filter 24 >to a multivibrator 25. The filter point as discrete frequencies, receiving appara 35 24 comprises a selective circuit corresponding to the ñlter I8 and restricted to the range of high frequency auxiliary carrier such as 78 kilocycles developedby the harmonic generator I1. The 40 multivibrator 25 comprises circuits known in the art for producing a sub-multiple of the oscilla tions of a given high frequency. In the present instance, the multivibrator 25 produces a 13 kilo cycle frequency which is the sixth sub-multiple of 45 the 78 kilocycle auxiliary carrier frequency, as well as other frequencies which are harmonics thereof. 'I'he output of the multivibrator 25 is directed tus comprising, a receiver selectively operable to receive any one of said plurality of modulated suppressed-carrier high-frequency bands, means responsive to said replacement carrier waves for supplying to said receiver any one of several re placement carrier frequencies corresponding to the carrier suppressed from said modulated high frequency bands received by said receiver, and 40 common control means for operating said last mentioned means and said receiver so that when 45 a particular modulation band is received by said receiver, said last mentioned means operates to supply thereto a corresponding replacement car rier frequency for intelligibly reproducing the desired modulation by said receiver. A50 quencies directed thereto from the multivibrator. 2. In a transmission system in which a plu The circuits of the filter 26 are selectively ad-> rality of modulated suppressed-carrier high f to a selective filter 26 having a circuit known in 50 the art for producing a selection among the fre justable for passing any one of several harmonic frequencies,.as for-example, 26 kilocycles, 39vkilo-l 55 cycles, or 52 kilocycles, it being remembered that, in the present embodiment of, the invention, the frequency bandsfand a carrier replacement wave , are transmitted at different frequencies to a re ceiving point, a receiver selectively operable to 55 receive any one of said plurality~ of modulated ' selection circuits of the receiver 20 are adjust suppressed-carrier high-frequency bands, a re able for the selective reception of carrier fre placement carrier means for receiving said re quency energy within similar ranges. Accord . placement wave and adapted to generate there insly. a common control knob 28 is mechanically from a plurality of replacement carrier waves connected with the adjustable _elements of the corresponding to the carriers suppressed from selection circuits of receiver 2D and the adjust said bands, and common control means for con able elements of the circuits of the filter 26 so jointly operating said receiver to receive a se that the output of the filter 26 always 'corre lected band and said replacement means to sup sponds in frequency with the selection of the ply thereto a corresponding carrier wave of the 65 receiver 20. ' _ proper frequency for replacement purposes. The output circuit of the filter 26 is directed through an amplifier 21 and thence to the re ROBERT n. DUNCAN, Jn.