US2184835A - System for transmitting communications - Google Patents

System for transmitting communications Download PDF

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Publication number
US2184835A
US2184835A US153074A US15307437A US2184835A US 2184835 A US2184835 A US 2184835A US 153074 A US153074 A US 153074A US 15307437 A US15307437 A US 15307437A US 2184835 A US2184835 A US 2184835A
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US
United States
Prior art keywords
exchange
high frequency
frequency
telephone
station
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US153074A
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English (en)
Inventor
Hahnemann Walter Max
Wiessner Alfred
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcatel Lucent Deutschland AG
C Lorenz AG
Original Assignee
Standard Elektrik Lorenz AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Standard Elektrik Lorenz AG filed Critical Standard Elektrik Lorenz AG
Application granted granted Critical
Publication of US2184835A publication Critical patent/US2184835A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/78—Circuit arrangements in which low-frequency speech signals proceed in one direction on the line, while speech signals proceeding in the other direction on the line are modulated on a high-frequency carrier signal

Definitions

  • This invention relates to new and useful improvements in highand low-frequency transmission of intelligence, particularly over cables.
  • the invention has for its object so to construct the subscribers stations that the subscribers may use them without any circuit change whether it is desired to employ highor low-frequency.
  • Subscribers stations as provided by the invention present the advantage that the high frequency generators may be disposed in the exchange stations without requiring feed-back suppressors.
  • Fig. l is a wiring diagram illustrating the fundamental idea of the invention, that is, the arrangement of the talking paths.
  • Figs. 2 to 4 each show a wiring diagram of the subscribers station.
  • Fig. 5 is a wiring diagram representing a special construction of the exchanges.
  • Fig. 6 is a View similar to Fig. 5 and shows a slight modification of the arrangement illustrated there.
  • the relay contacts are shown at rest.
  • a and B denote the subscribers stations while VI and V2 indicate the exchanges.
  • the arrows n designate low frequency whilst the arrows h denote modulated high frequency.
  • the trafiic outgoing from A passes in low frequency fashion to the exchange VI.
  • the low frequency acts to modulate the carrier high frequency wave.
  • the modulated high frequency however does not only pass to the exchange V2 but flows to the subscribers station B.
  • the reverse applies for the traific outgoing from B that is to say, the transmission from B td V2 is by low frequency whilst the transmission from V2 to subscriber's station A is by high frequency.
  • the high frequency carrier waves are different from each other. No feed-back suppressors are here 5 necessary.
  • Microphone and. telephone are for clearness shown separately in Figs. 2 to 4.
  • the two talking wires are designated a, b.
  • th microphone M is located between the wires a, h, high frequency chokes H being connected in advance thereof which however are not absolutely necessary to provide.
  • the telephone T is on the 15 one hand connected directly to the wires a, b, only high frequency chokes likewise designated H being if desired-interposed between T and the wires on, b, and is-on the other hand connected to the output terminals of a rectifier G.
  • This recti- 20 bomb which may be a dry rectifier, is joined to the wires a, I; over condensers C. Whenever low frequency is supplied to this subscribers station, disclosed in Fig.
  • a split circuit I in which a microphone M is included and which is connected to the wires a, b over high frequency blocking means H, acts to energize 40 winding I of the telephone T.
  • the intercommunication is effected in the usual manner.
  • the blocking means H On changing from low frequency traflic to high frequency trafiic arriving over a, b the high fre- 5 quency will be prevented by the blocking means H from entering the split circuit I and will pass over low frequency arresters Nand rectifier G to the Winding 2 of the telephone T.
  • the windings I, 2 are so designed. that no transmission shall 5 occur between them.
  • the voice current is completely converted into sound en'- ergy, being prevented in this way from returning to line a, b over thewindings 2, l and circuit I.
  • a split cir- 55 cuit with microphone M and telephone T is in the case of low frequency traffic likewise connected to the wires a, b.
  • 0n changing to high frequency trafiic a relay AA is in well known manner energized over a condenser Q by continuous currents arriving from the exchange.
  • Relay AA closes its contact a3 and thus remains energized as long as continuous voltage is acting on it.
  • Relay AA also has a break contact al and an alternate contact a2. Therefore on the response of relay AA contact a! is opened while contact a2 is switched over.
  • the microphone shall be joined to the talking wires a, b with the avoidance of that attenuation which would be caused by the split circuit, whilst the switched contact a2 acts to connect telephone T to the wires a, I) over a high frequency rectifier G and low frequency arresters N.
  • This arrangement thus allows of changing from high frequency service to low frequency service without the subscriber having to do anything in this regard, and also acts to avoid an unwelcome attenuation of the microphone currents.
  • Figs. 5 and 6 each show an example of an arrangement by which preferably in the case of long distance service the communications shall arrive in the subscribers station in high frequency fashion even if in the exchange they arrive in low frequency fashion, for example along repeatered two-wire or four-wire circuits. This does away with the necessity for a split circuit on the exchange side and subscriber side and also avoids a balancing network having to be provided on the exchange side.
  • a modulator M In the incoming direction of a four-wire long distance circuit F, Fig. 5, that serves for the low frequency transmission of communications a modulator M is located after an amplifier V.
  • This modulator receives its carrier frequency from a generator disposed in the exchange, for instance, and common to several junction circuits.
  • a side band with carrier passes over the 7 low frequency arresters N to the exchange jack K and thus over the local line to the subscribers station.
  • the voice currents arriving from the subscribers station pass over the high frequency blocking means H into the outgoing toll line direction.
  • a repetition by relays is provided instead of the jack K.
  • the carrier frequency is so chosen that in the local cable the difference of attenuation between high frequency and low frequency shall be as small as possible and that further the symmetry and avoidance of cross-talk shall be sufficiently great.
  • connection of a long distance circuit having two line wires D is according to Fig. 6 made with the aid of a split connection P. In other respects the arrangement is here the same as that shown in Fig. 5.
  • a system for transmitting communications comprising in combination with talking wires and subscribers stations having each a telephone and a microphone, a split circuit including the microphone, high frequency blocking means connecting said circuit to the talking wires, a winding in the telephone by which the latter is joined to said split circuit, a second winding in the telephone, a high frequency rectifier connected in circuit with said second winding, and a low frequency arrester connecting said rectifier 15 to the talking wires.
  • a system according to claim 1 having an exchange and a relay under control of said exchange, contacts controlled by said relay to open that part of the said split circuit in which the microphone is not included and at the same time to connect the telephone to the circuit of the high frequency rectifier.
  • a system according to claim 1 having an exchange and a relay adapted to be energized by continuous currents arriving from said exchange, and contacts controlled by said relay to open that part of the said split circuit in which the microphone is not included and at the same time to connect the telephone to the circuit of the high frequency rectifier.
  • a system for transmitting communication comprising a first and a second telephone exchange, wires for low frequency transmission in both directions between said exchanges, a first subscribers station connected to said first exchange and including means for generating speech frequency currents for transmission to said first exchange and then over said wires to said second exchange, a second subscribers station connected to said second exchange and including means for generating speech frequency currents for transmission to said second exchange and then over said wires to said first exchange, means in said second exchange for generating high frequency currents, means in said second exchange for modulating said high frequency currents with the speech frequency currents arriving over said wires from said first exchange and. for transmitting said modulated high frequency currents to said second subscribers station, and means at said second subscribers station for demodulating said modulated high frequency currents and reproducing therefrom speech frequency sound waves.
  • a system according to claim 6, wherein the means to modulate the high frequency currents is a modulator included in the wires that serve for the incoming low frequency transmission, and a low frequency arrester between said modulator and a subscribers station.
  • twowire telephone subscribers lines each having a subscribers telephone station, a central telephone exchange with which said lines are associated, means for transmitting speech forming one side of a two way conversation from said exchange to a subscribers station at carrier frequency, and means for transmitting speech forming the other side of said same conversation to said exchange from the same station at speech frequency.
  • connection between a station and the associated line including a low-pass filter, and a second connection between said station and line including a high-pass filter and a rectifier.
  • a microphone at each station and a high-frequency blocking means between each microphone and the associated line.
  • a system for transmitting communication comprising a first telephone exchange, a second telephone exchange, connecting means for transmitting high frequencies in both'directions between said exchanges, a first subscribers station connected to said first exchange and having means for generating speech frequency currents and transmitting them to said first exchange, means at said first exchange for converting said speech frequency currents received from said first subscribers station into high frequency currents and transmitting them to said second exchange, means at said second exchange for transmitting such high frequency currents received from said first exchange directly to said second subscribersstation without demodulation, means at said second subscribers station for demodulating said received high frequency currents, means at said second subscribers station for generating and transmitting to said second exchange speech frequency currents, means at said second ex- I change for converting such speech frequency currents received from said second subscribers station into high frequency currents and transmitting them to said first exchange, means at WALTER MAX HAHNEMANN. ALFRED WIESSNER.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephonic Communication Services (AREA)
  • Prepayment Telephone Systems (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Interface Circuits In Exchanges (AREA)
US153074A 1934-03-14 1937-07-10 System for transmitting communications Expired - Lifetime US2184835A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DEL85522D DE708943C (de) 1934-03-14 1934-03-14 Verfahren zur UEbertragung von Nachrichten mit Verlagerung der Sprechstroeme auf Teilstrecken der UEbertragungsleitung in verschiedene Frequenzbereiche
DEL90279D DE726045C (de) 1934-03-14 1936-05-01 Anordnung zur UEbertragung von Nachrichten
NL82857A NL50600C (no) 1934-03-14 1937-06-10
FR823122T 1937-06-15
GB18436/37A GB501915A (en) 1934-03-14 1937-07-02 Telephone exchange systems

Publications (1)

Publication Number Publication Date
US2184835A true US2184835A (en) 1939-12-26

Family

ID=7285923

Family Applications (1)

Application Number Title Priority Date Filing Date
US153074A Expired - Lifetime US2184835A (en) 1934-03-14 1937-07-10 System for transmitting communications

Country Status (5)

Country Link
US (1) US2184835A (no)
DE (4) DE708943C (no)
FR (1) FR823122A (no)
GB (1) GB501915A (no)
NL (1) NL50600C (no)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2932694A (en) * 1954-09-10 1960-04-12 Bell Telephone Labor Inc Rural carrier telephone transmission system
DE1112549B (de) * 1955-12-30 1961-08-10 Gen Electric Co Ltd Fernsprechteilnehmerschaltung fuer den Parallelanschluss zweier Teilnehmer an eine Zweidrahtleitung
DE1028625B (de) * 1957-03-14 1958-04-24 Telefonbau Schaltungsanordnung zum Einsatz von Traegerfrequenz auf Teilnehmeranschlussleitungen in Fernsprechanlagen mit Waehlerbetrieb
NL266047A (no) * 1960-07-21
DE3802088C2 (de) * 1987-01-26 1996-12-12 Dirr Josef Verfahren für die Codierung und Decodierung von Information in Endstellen von Vermittlungseinrichtungen und Übertragung über Anschlusswege/Leitungen zu und von den Vermittlungseinrichtungen

Also Published As

Publication number Publication date
DE726045C (de) 1942-10-05
FR823122A (fr) 1938-01-14
NL50600C (no) 1941-06-17
DE730055C (de) 1943-01-12
GB501915A (en) 1939-03-02
DE708943C (de) 1941-08-01
DE726511C (de) 1942-10-15

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