US1855601A

US1855601A - Impulse and wave transmission system

Info

Publication number: US1855601A
Application number: US477880A
Authority: US
Inventors: William S Gorton
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1930-08-26
Filing date: 1930-08-26
Publication date: 1932-04-26
Anticipated expiration: 1949-04-26

Description

April 26, 1932. s GQRTON 1,855,601

IMPULSE AND WAVE TRANSMISSION SYSTEM Filed Aug. 26, 1930 2 Sheets-Sheet l a: ll mm T0 RE CE/VERS r13 125w UP I III 190' /N VEN TO/P By WSGORTON' )kJM , TTO/PNEY April 26, 1932. w. s. G ORTON IMPULSE AND WAVE TRANSMISSION SYSTEM Filed Aug. 26, 1950 2 Sheets-Sheet 2 By W5. GORTON ATTORNEY Patented Apr. 26, 1932 UNITED sr was PAIENT j wILnIA'Ms: eonron, oFiEAs'r-omnen NEW JERSEY; ASSIGNdItTOBEnnf-rmnPHoNEi- LABORATORIES, INCOR-PORATED," FNEW' YORK? N; A3 OORPORAT'ION on NEW YORK IMPULSE'AND'WAVE TRANSMISSION SYSTEM Application-filed smudge, 1930. Serial No ;-47-7,8802

Thisinvention relates: to communication range than can'be done Where the transmis sion'is carried on exclusively bymeans'ofwro tary distributor apparatus.-

Another. ob ect is to provide. for the" syn-- chronization of carrier frequency scircuits Without the transmission of any carrier fre frequencies: e'xtendingrfrom to 125'ucyclesv 5? thev modulating 3 quency currentover;the -'line.-

From a generlcaspect: Waves of the carrier portion of the system may have any Wave form: andmay-represent signals by any desired signallinglcode; How- Y ever, ,in the system herein described carrier Wavesare modulated bytelegraph-impulsesfrom printinghtelegraphr senders Which-impulses: are: transmitted-over rotary" distribu tOIS'.

with the-accompanying drawings; In; the. drawings,

Fig. 1 represents-a? schematic" circuittdiaegram of a transmittingfstation;

Fig. 1"-A annodification thereof; and. Fig; 2, a similardiag-ramof a receiv'ingzsta tion.

The circuit of l is representediasi transmitting to the stationoof'i 2.i=over. a

duplex line; but the essentialiprinciples of the: invention v may be :practicediii: onewvay systems aswell as-duplex systems.

; In Fig:11 the rotatingishaft'l isrdriven' 'byu a La Cour. motor 12 havingiits terminal a; a

connected to'any suitablesource of constant frequency current such; as is known: 1mm: art. The shaft lzdrives ithe'brush armiof the: 451 synchronous distributor- 3; The contact's of" a I group of: printing; telegraph sendersi T1;

Further objects and==feati1res-ofi the: invention will appear-:from-a: p-erusal o-f the follow: ing detailed description read in connections mita range of frequencies-appropriate:t-o the telegraph" signals transmitted from the .tra ns-- mit-ter's Tl',v 1 2,1 etc The linerin thisgcase isv indicated as asubmarine cable- 4: The ratio arms 5: and; the balancing network Gare of:v the usual type. 'Elieyimay be Dmifitdgim a system 1 wherein transmissiom takes place in onlylone direction at a'time. The -apparatus" so far described is of a more or lessvconve'n tional'type. Leeitnow be supposed tlfatithe 1, signals transmitted from thetransmitters? T1,; T2, do not occupy the: total frequency rangeravailab le on the cable-A. Foraexample; s: let itbe assumedthat they occupy; a ran'geof:

and thata range of -a" few hundred? cycl'es;.: more or lessyabovethis: range'is available fora telegraph transmission.- (Alb frequen'--' cies *given herein 1 are incomplete cycles: pen secondly. The=- apparatus-about to horde scribed is intended to make use of'i'therest" of the available frequency range: v

The shaft 1 carries an alternating: currentgenerator 6=whichsupplies -t he?input circuit v V of a harmonic generat'or' H'Gir Tha -generator? 73* 6 andzthe'harmonic generator tiypifyaany 1' suitable": apparatus driven by: the: shaft ilxt'o supply snitablefcarrier frequencies as wiilibei described in What followse- Acrfrequencyiof? I cycles is "supplied" through the circuit'fl to the carrierssuppression vacuum: tube modu'lator circui-t 8.- A suitableifilter EQ selectsatlfezfrequency of 125 cycles-from? the outputzof' the harmonic generatorHGi Asuit'able otlier selective circuit: F9'a 1 selects another suitable? as carrier: frequency; for example-p cycles; transmitted-throughthe circuit7a to aearrierf suppression modulatingi'circuit 8a; Gircuits 8 vand'f8a may besupplied with modulating: v impulses on signals zfrom any. desired signal- '6 ingr source; In the-present system impulses from a suitable q l rality of transmitters GT1 and' GTQ are transmitted over v a rotary" distributor l0 'toithe input circuit" of th'e modulating circuitfii. A condenser lids-pref; 9'5 erably included in the circuit i'conne'ctin' the rotary distributor 1 0 itO th'e circuit '82 3 15am; r output :circuit' 0f the circuit 8 is ear new de signed F to: transmit a: range of frequencies from 125cycles:tozl90 cyclesb Thisir ange is 100 the upper side-band which results from modulation of a 125 cycle wave with impulses proceeding from the transmitter GT1 and GT2. The lower side-band is assumed to be suppressed by thefilter F12.

Other filters F12a etc. serve to pass the waves proceeding from other modulators 8a, etc. which are supplied with modulating impulses from other series of transmitters CTlct, Urea, etc. overrotary distributors 10a etc. A filterF 13 is connected between the filter F12, F12a, etc. and the line. Filter F13. serves to tra'nsmit'all frequencies essential to the system above 125 cycles. Filter F 13 is not essential and may be omitted.

In the modified form of circuit illustrated in Fig. 1A the generator 6 is a multi-fre quency generator of a type well known in the art. It supplies currents of the frequencies of 125 cycles, 190 cycles etc. to a plurality of amplifiers A, A1 which in turn apply them to the carrier suppression modulators 8, 8a etc. The rest of the system is the same as that of Fig. 1.

At the receiving end of thesystem shown in Fig. 2 waves of frequencies between Oand 125 cycles are selected by the filter F1 1- and transmitted to a shaping and amplifying circuit 15. Theoutput circuit of the circuit 15 is connected to a polar relay 16 whose contacts control the application of positive and negative battery to the ring and associated seg ments of a distributor 17. To the segments of distributor 17 are connected the printer magnets of the series of receivers R1, R2,

P1, P2, etc.

The polar relay 18 is a synchronizing relay corresponding in function to the relay 13 of Knoop Patent 1,747,248 February 18, 1930.

; The La. Cour motor 19 drives the shaft 1. It

is assumed that the-relay 18 is connected to synchronizing apparatus for driving and synchronizing the La Cour motor 19 in the same manner as the relay 13 in Patent1,747,-

I 248 is connected to the motor 5 in that patent.

Conductor C18 corresponds to conductor 56 of the'patent and relay R19 corresponds to relay 43 of the patent.

The elements 18 and R19 typify any suitable sort of driving and synchronizing mechanism. If the means for maintainin synchronism consists ofa Corrector working on a differential gear, arrangement it is considered essential for the purpose of the inven- I tion that thedifferential gear be not located between the enerator 6 and the rotary dis tributor l7. it should be connected between the La Cour motor 19 and the apparatus driven thereby. With this limitation in mind practically any sort of correcting or synchronizing arrangement keeping the rotary distributor 17- of the receiving station in synchronism with the rotary distributor 3 of the transmitting station may be employed.

The shaft 1 drives the generator 6.. The

generator 6 supplies a harmonic generator HG in the same manner as the corresponding generator at the transmitting station to produce waves of 125 cycles, 190 cycles, etc. These waves are selected by suitable selecting circuits F9, and F9a and supplied to demodulating circuits D, D1, etc. which are of a well known character.

Waves of frequencies above 125 cycles arriving over the cable 4 are conveyed by the circuit 20 to a series of selective filters. F12, F12a, F126, etc. Filter F12 selects a range of frequencies of from 125 to 190 cycles, filter F12a selects a range of frequencies of from 190 to 265 cycles, other filters select other suitable ranges of frequencies for application to their respective demodulating circuits D1, D2, etc.

'Each demodulating circuit has its output connected to receiving apparatus suitable for receiving demodulated waves. Thus, the circuit D has in its output a polar relay 21 which controls the application of positive and negative impulses over a rotary distributor 22 to printer magnets of a series of printers CP, CPl, etc. Another suitable series of printers CPa and CPla is connected over distributor 22a to the output circuit of the demodulator D1, and still other series to the output circuits of other demodulating demodulators if other demodulators are provided in the system.

Generator 6 in the'arrangement illustrated is driven at the same number of revolutions per unit of time as the brush arm of its associated distributor 3 or 17, as the case may be. However, if the generator 6 does not revolve sufficiently rapidly a gear may be introduced between the generator and the distributor brush to increase the relative speed of revolution of the generator to any desired amount. The La Cour motor, the generator 6, and the distributor may be'located in any desired order along the shaft so that the gear will not be interposed between the La Cour motor and the distributor. The power produced by the generator 6 may be quite small because this power can be increased to any desired amount in the output circuit of the harmonic generator HG.

In the operation of the system the brush of distributor 17 is kept in synchronism with the brush of distributor 3 except for small phase variations. By the use ofmodern correction systems thisphase variation may be reduced to quite infinitesimal proportion. A correcting system suitable for doing this is illustrated, for example, in Patent 1,747,248 referred to above. Consequently,-the generator 6 at the transmitting and receiving stations respectively are kept in synchronism. This results in the various sources of carrier oscillation being likewise kept in synchronism with the corresponding sources at the opposite end of the system. Thus, for example, the 125 cycle carrier wave supplied to the demodulating circuit D is in synchronism with the 125 cycle carrier wave supplied to the modu lating circuit 8 at the transmitter. The dis tributor 22 is synchronized with the distributor 10, and the distributor 22a with distributor 10a by the signal impulses passing beplurality of transmitters T1, T2 be employed, although in practice this may be the most convenient way of utilizing the available frequency range. Likewise, it is not essential that the input circuit, or any particular modulating circuit such as the circuit 8, be supplied by a plurality of printing telegraph transmitters TTl, TT2, etc. Single synchronized or unsynchronized transmitters of any suitable known kind may take the place of each of the series of transmitters.

What is claimed is:

1. In a system for the communication of intelligence, an impulse transmitter at a transmitting station, an impulse receiver at a receiving station, each of said stations being provided with a rotary distributor for distributing the impulses to be transmitted or received respectively, and synchronizing means whereby the distributor at the receivr ing station is kept in synchronism with the distributor at the transmitting station, in combination with a carrier wave transmission system, said system comprising a source of carrier frequency oscillations at each terminal, one of said sources at one terminal being controlled in frequency and phase by one of said distributors located at the station whereat the source is located, and the other of said sources being controlled by the distributor located at the other end of the system whereat the other distributor is located.

2. In a multiplex telegraph system, distributors at remote points in the system, driving means and synchronizing means for said distributors, carrier current generators one located at each distributor, a signaling source associated with one of said generators, signal receiving means associated with the other of said generators, and mechanical cou- V pling means for maintaining a definite periodic relation between the waves produced by each of said generators and the driving means of the distributor located thereat.

3. A communication system comprising synchronized rotary distributors at opposite lating means for modulating the carrier waves with waves or impulses representing signals to be transmitted at the transmitting end and demodulating apparatus for demodulating the modulated waves at the receiving end.

4:. A submarine cable system comprising a synchronous distributor communication channel consisting of elements for transmitting over a line'di'rect current impulses representing messages and elements for receiving the impulses, a carrier wave communication channel, said carrier wave communication channel including devices for producing one or more carrier waves, one or more separate sets of apparatus for producing signaling impulses, devices for modulating the one or more carrier waves with the signaling impulses and transmitting them over said signaling line, and elements whereby a distributor of said synchronous distributor communication channel and said devices for producing carrier waves are maintained in a fixed phase relation.

5. In a communication system a device for generating carrier waves driven by a shaft upon which is mounted a rotating element of a synchronous distributor, mechanism, for transmitting signaling impulses to said synchronous distributor, and separate means uncontrolled by saidmechanism for transmitting over a path other than said distributor, other signaling waves or impulses to said carrier waves, and devices for modulating said carrier waves by said other signaling waves or impulses.

In witness whereof, I hereunto subscribe my name this 25 day of August, 1930.

WILLIAM S. GORTON.

terminii of the system, sources of carrier waves at opposite terminii of the system, each controlled in phase and frequency by associated synchronous distributors, andmodu-