US1669448A - Multiplex signaling system - Google Patents

Description

- May 15,1928. 1,669,448

5. BRAND MULTIPLEX SIGNALING SYSTEM Filed May 1. 1925 2 sneeze-sham 1 L72 i v i urn- I 5? W V IN VEN TOR 7' 2 54211146 firm/ad A T] ORA E Y May 15, 1928. 1,669,448

5. BRAND MULTIPLEX SIGNALING SYSTEMi Filed May 1. 19 26 2 sheets-sum 2 :l

5 R :k 859 E Ky/5% 1! 3F 5 I L Smart finmai siifa'ii'rniihiing s aeeeaa aaaw reaa ssmaoa fro anrnn oafi Taearaoaa min TELEGRAPH COMPANY, A CORPORATION on NEW Y'oRK.

MULTIPLEX SIGNALING SYSTEM.

Application filed May 1,

It is an object of my invention to proyi de a new and improved system of multiplex carrier current signaling. Another oloject of my invention is to provide insuch asysteinfor operating a special station on only one ora limited number otthe carrier fi e;

quencie s. A i'urther object is to provide alocal source in connection with such a; tatiq i o n at n a .Pui' 1mm,. in. proper synchronisrn and phase relation with ei ele Car fillers 2, s mpone t j system. These ,o'bjects and other objects of my invention, will become apparent on a diagram of a sending station, for multi-.

plexs gnahng. Fig. 21s a dlagramgo't a corresponding reoeiving station,and Fig. 3

is .a-i iee m sh in s at- 9 aden t d nd QPT YQ on a si e, ewir r equencyi in connection with a system such as disclosed in Figs. 1 and 2.

he ni'otor M in 1 drives the various n r or G12aG2ill lWG3 1 9 iz qe e 1 1, rents of difierent frequencies wh ch are preferably harmonics oi" a fundamental he 1 13 2 5?: T mir fi r m ie 'es ii 'e mt such" as G goes to phase splitter from which two components of the same frequency 9O apart in phase g0 tovth e respective transformers whose primary wind ings are 37 and S. Current of one phase transmitted through the winding 37v is'coin trolled b the keys K and K The key K reverses the phase oi'this component of,

e i n 'c o t r W t its Amen ties as the lre'y K changes the magnitude without affecting the phase. V p Thetwo components of current 90 apart" in phase and each affectediby phase reversals and magnitude changes as deten mined bythe operation of the tour keys "K K K; and K are superposed in the input to the filter F from which they pass to theline Z I c 1 l At the receiving end, these currents pass through the adjustable artificial line N's and the amplifier A and are separated through 1926, Serial No. 106,098.

respective band filters such passes only the current of thesame fre q e'n'cy a P e by efilte F3 at the sending end. Accordingly, the output fro in fi er c mp s .two mpons i 9 f on par i p' sei a h re rsed in pha e-iron me t m -e a rv riei l in mag i de; m im i .t i.a deter ne by' h p Q o e-t ssndi'ns eyslin Ki,

sI- Ki- Th se'. ec i d, c r ntee maoa modifications, in the I received current, so

that the output from the network: SQ Pur u m dified r -Q1 1 oi the an mia a r qu n y to which h iba d lte il l is approp e T is utpntnur eat m i n rk r itesft esy s mmaus.v

mo or S ni yns wn' m ith. t eim e zi M iii e ndi gend', it m qrfiM. iv s l the ge to s rl, i-i at eason, oies corresponding/to those of the genera;

e 1, e ma lt e ng e qAQ Ql'dff lyr h gen ra or T3 del st lurrent hese eque yies pa s d. by; eiband, filter. flTh sicurr nt cfr m the sea ater; T3 goe hroug e ph s s i t endnh se;

pli wn and .p qd ce twqlj le t s s Ineitive f apar in Pha 91i which is applied in the grid circuits of th e e e rs. 1 a d Dina-I i the ot r na grid circuits of the detectors D and D e. detesto jDl h pola iz d r lay, 1. .31, 0

in i s plate rc hose armature. st nds one way when the received electromotive force a d e ocally; g ne ated e ebtrema-g re f c i p a e g e t, d stand the Opp e-W y w e they ii ii phaseenr;

p si o .Hfi e th re ay lBi, ism ee'ml si slve to reversals of phase on one component of received current.

The relayNR is a neutral es egs in magni u e, d? the for t responds only to magn tude changes on one of the two componentsot rece ved current Thus it Will-be seen-that each otthe four relays PR NR 1 1R and NR; answers only no fiuence d by phase reversals, but. responsive 10.3

to the operation of a corresponding key at i the sending stat-ion.

r The attenuation on the line may vary somewhat. from time to time, and to compensate for this a voltmeter relay V is bridged across the outputifrom the network SC and operates automaticallyto adjust the artificial line N. so as to maintain the voltage on the said voltmeter relay V substantially constant. Since the artificial line N is in the path of allthe received current components, they willall be held at substantially a constant level as they come into the various receiving networks.

Fig. 3 shows two sending stations SS, and

SS like that shown iniFig. 1, and two re ceiving stations RS, and RS like that shown in Fig. 2, and Fig. also shows a way station adapted for sending and recelvlng on one only of the multiple frequencies employed in the system of the foregoing mentioned four stations. i

By means of the branch conductors115, signal modified currents from the sending station SS of one particular frequency are taken off and passed through the band filter 116 and the adjustable artificial line N". These signal modified currents go to a re- V ceiving network like that shown in Fig. 2

where they are indicated respectively in the receiving relays PR N R PR and NR The received currents through the band filter 116andthe artificial line i also go over a multiple branch circuit to the delay network D andthence to the signal compensator SC shown at the bottom-of Fig. 3. This network SC consists of resistances and reactance elements provided with switches I controlled by the relays 94, 95, 96 and 97.

These relays in turn are controlled by armature contacts associated respectively with the receiving relays PR PR NR, and The arrangementis such that as the signaling changes in the received current operate therespective relays of the receiving network they cause OlFClllll changes in the network SC toc'ompensate, so that the output current from the network SCfover the conductors 86 is a purecurrent of the carrier frequency unmodified by the signal changes. Thiscurrent goes through the amplifier 87 to the input for the receiving network across the points '51 and 52, the same as in Fig. 2.

Current of the same frequency goes through the'phase shifterPSh over the conductors 118 through the phasesplitter PS7) for varying attenuationby the adjustable artificial line N, the same as in Fig. 2.

It will be seenthat the system of Fig. 3 is designed for co-operation in amultiplex signaling system at only one of'itsinany he quencies. At the station shown in this figure, there is no requirement for generating the fundamental frequency of the multiplex f system, nor anyother harmonic than the harmonic current of the single frequency statio I'claimr i H I 1. In a multiplex carrier current signaling system, the method of operating at a station at one ofthe various carrier current mployed for receiving and sending at this i frequencies independentlyof the other such" frequencies, which consists in filtering the current of that frequency to .a "receiving network, compensating the signalmodifiers tions in such current and applying it. to cooperate with the receivedcurrent in the re- I ceiving network. I

2. In a multiplex carrier current 'signaling system, the method of operating a station at one of the variouscarrier current frequencies, which consists in filteringthe current of that frequency to a receiving network, compensating the signal modifications in such current and applying it to coop erate with the received current in the receiving network, and also applying it for 'send ing on that same frequency.

In a multiplex carrier current signal-' ing system, the method of operating a station at one ofthe various 0&11161 current frequencies, which consistsin filtering-the said cur- 1 rent of that frequency with its signal modifications to the said station, determining thereby a local current of the same frequency freed from signal modifications and-:comblnlng thereceive'd signal modlfied current with the said local current freed from sig nal modifications to operate detectors to dis- .criminate a plurality cally of a current of the same frequency but unaffected by signal modifications and combining this current with the received current,,to detect the signals conveyed by the first named current of firstwmentioned fre g quency.

of message channels -in the said received current. p I

4. T he method of receiving on acurrent of a single frequency, which consists in determining by said current the generation 10 5. The method of receivingon a current of a single frequency, which consists in deter mining by said current the generation locally of a current of the samefrequency, but unaffected by signalmodifications and combining this current with the received current .to discriminate among a plurality of message channels on said current and detectthe signal 1nd1cat1ons n the; respectlve channels. 6. In a multiplex carrier current slgnal' ing system, a station adapted to operate on a a single carrier frequency comprising a retion at one of these carrier current frequencies without the need for developing the fundamental for such operation which consists in filtering the'current of that frequency to a receiving network, compensating the signal modifications in such current and applying it to co-operate with the received current 1n the receiving network.

In testimony whereof, I have signed my name to this specification this 29th day of April, 1926.

' SMART BRAND.

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