US2326584A - Multiplex telephony system - Google Patents

Multiplex telephony system Download PDF

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Publication number
US2326584A
US2326584A US321342A US32134240A US2326584A US 2326584 A US2326584 A US 2326584A US 321342 A US321342 A US 321342A US 32134240 A US32134240 A US 32134240A US 2326584 A US2326584 A US 2326584A
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United States
Prior art keywords
impulses
transmission line
transmitted
voltage
pulses
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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
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US321342A
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English (en)
Inventor
Johannes Jacobus Zaalber Zelst
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Filing date
Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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Publication of US2326584A publication Critical patent/US2326584A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/10—Arrangements for reducing cross-talk between channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems

Definitions

  • - lvlyinvention relates to multiplex telephony systems in which a plurality of telephonic conversations are simultaneously transmitted over a common transmission medium for instance a common transmission line.
  • the object of my invention is to overcome the above diificulty and for this purpose I provide means to make the transmission medium or the speech channel impassable, at least for voltages below a definite threshold value, during the time periods between successive impulses.
  • the distortion introduced in the first part of the cable must be removed ordecreased before they can be transmitted to the next part of the cable.
  • Fig. 1 shows the impulses as they are emitted at the beginning ofthe cable and Figure 4 shows them as they reach the first intermediate station.
  • the distortion has now proceeded to a much smaller extent than in Fig. 2 so that, for
  • Figures 1 to 9 are voltage-time graphs for use penetrated the impulse 2.
  • the first intermediate station may comprise a suppressor which is controlled by the voltage in describing the principle of the invention, and 5 illustrated in Fig. 3.
  • Fig. 1 shows a series of impulses I, 2, 3, 4 and I5 as they are transmitted and corresponding to the the impulses I, 2, 3, 4 and 5 shown in Fig. 4 occur the suppressor receives, for instance the impulses II, I2, I3, l4 and I5 of Fig. 3.
  • the suppressor is passable, whereas it is imfirst, second, third, fourth and fifth conversation passable betweenthese impulses. Consequently,
  • the impulses shown in Fig. 1 are More resonance phenomena may occur so that the impulses shown in Fig. '7 are distorted as shown in Fig. 8 when they reach the first intermediate station.
  • a resonance phenomenon occurs at the beginning and at the end of each impulse, the resonance phenomena associated withimpulse I being denoted by reference numerals 8 and 8 in Fig. 8.
  • the resonance phenomenon 8 may at the moat only slightly alter the average height feature of the invention is that the device provided for the above purpose has a threshold value of such a value that the disturbing voltages, which occur during the time elapsing between two impulses, do not exceed this threshold value. In Fig. 8 this threshold value is indicated by a dotted line It and only the voltages above this threshold voltage are transmitted to the second intermediate station.
  • a threshold voltage is used again at this station so that the disturbing voltages between the impulses are made inoperative.
  • This threshold voltage is indicated by the dotted line I! in Fig. 9.
  • the last-mentioned method may also be used for eliminating the distortion illustrated in Fig. 4.
  • the circuit arrangement illustrated in Fig. 10 comprises a discharge tube 20 having two control grids 2
  • the impulses are received over a transmission line 23 and supplied to the control grid 2
  • Periodical suppression of the electronic stream in-tube 20 may be eifected, for instance by supplying to the control grid 22 a pulse-shaped voltage as shown in Fig. 3.
  • an alternating voltage may be supplied to the control grid 22 by a transformer 21, which has its secondary winding connected between cathode 4
  • the control grid 22 is made negative relatively to the cathode by the alternating voltage, the anode current is suppressed.
  • a grid current fiows inthe other half elapsing between two successive impulses so that the tails or the oscillation phenomena directly behind each impulse are not transmitted.
  • impulses received over a transmission line 23 are supplied to an amplifying tube 30 having a cathode 45, an anode 46 and a control grid 3
  • the transmission .line has one conductor connected through a grid bias battery 32 to grid 3
  • the impulses After being amplified the impulses are transmitted through a transmission line 38.
  • is negative biased by means of the battery 32, which bias has such a valuethat voltages below a predetermined value are not amplified and that the resonance phenomena, which occur at the end of each impulse, are not transmitted.
  • a common transmission line adapted to transmit a train of elementary pulses each representing the signal in one of a pulrality of channels, and suppressor means in said transmission line to block the transmission line, only during the periods between successive pulses, against the passage of disturbing voltages which lie below a predetermined threshold value, said means comprising a controlled discharge tube, and a control circuit for said tube including a source of voltage which varies in synchronism with the pulses to thereby make the tube operative in the rhythm of the pulses.
  • a common. transmission line adapted to transmit a train of elementary pulses each representing the signal in one of a plurality of channels, and suppressor means in said transmission line to block the transmission line, only during the periods between successive pulses, against the passage of disturbing voltages which lie below a predetermined threshold value, said means comprising a controlled discharge tube having a plurality of control grids, a control circuit for one of said grids and connected to the transmission line, and a control circuit for another of said grids and including a source of voltage which varies in synchronism with the frequency of the pulses to thereby make the tube operative in the rhythm of the pulses.
  • a common transmission line adapted to transmit a train of elementary pulses each representing the signal in one of a, plurality of channels, and suppressor means in said transmission line to block the tarnsmission line, only during periods between successive pulses, against the passage of disturband connected to the transmission line, and a 10 control circuit for another or said grids and including a source or voltage varying in synchronism with the frequency or the pulses to thereby make the tube operative in the-rhythm of the pulses and a resistance element interposed between the said latter grid and the said voltage source.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Electrostatic Separation (AREA)
  • Radio Relay Systems (AREA)
US321342A 1939-02-20 1940-02-28 Multiplex telephony system Expired - Lifetime US2326584A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE537091X 1939-02-20

Publications (1)

Publication Number Publication Date
US2326584A true US2326584A (en) 1943-08-10

Family

ID=6557579

Family Applications (1)

Application Number Title Priority Date Filing Date
US321342A Expired - Lifetime US2326584A (en) 1939-02-20 1940-02-28 Multiplex telephony system

Country Status (4)

Country Link
US (1) US2326584A (fr)
BE (1) BE438046A (fr)
GB (1) GB537091A (fr)
NL (1) NL60289C (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428118A (en) * 1944-04-07 1947-09-30 Standard Telephones Cables Ltd Pulse multiplex system
US2429613A (en) * 1943-10-19 1947-10-28 Standard Telephones Cables Ltd Pulse multiplex communication system
US2431577A (en) * 1945-03-14 1947-11-25 Philco Corp Synchronizing system
US2434921A (en) * 1944-11-02 1948-01-27 Standard Telephones Cables Ltd Pulse amplitude selective system
US2434922A (en) * 1944-11-02 1948-01-27 Standard Telephones Cables Ltd Pulse amplitude selector system
US2438902A (en) * 1943-10-04 1948-04-06 Standard Telephones Cables Ltd Pulse multiplex system employing fixed pulse-time displacement for signaling
US2438903A (en) * 1943-10-11 1948-04-06 Standard Telephones Cables Ltd Pulse communication system employing pulse frequency reduction for signaling
US2468058A (en) * 1943-11-23 1949-04-26 Standard Telephones Cables Ltd Blocking system for multichannel operation
US2474244A (en) * 1944-05-19 1949-06-28 Standard Telephones Cables Ltd Amplitude modulated time modulated pulse system
US2507176A (en) * 1945-03-15 1950-05-09 Hartford Nat Bank & Trust Co Receiver for pulse modulated waves
US2579071A (en) * 1947-07-16 1951-12-18 Rca Corp Time division multiplex system
US2580421A (en) * 1944-12-23 1952-01-01 Radio Patents Corp Cross-talk compensation in pulse multiplex system
US2725470A (en) * 1951-02-28 1955-11-29 Rca Corp Time division multiplex gating arrangements
US2801281A (en) * 1946-02-21 1957-07-30 Bell Telephone Labor Inc Communication system employing pulse code modulation

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2438902A (en) * 1943-10-04 1948-04-06 Standard Telephones Cables Ltd Pulse multiplex system employing fixed pulse-time displacement for signaling
US2438903A (en) * 1943-10-11 1948-04-06 Standard Telephones Cables Ltd Pulse communication system employing pulse frequency reduction for signaling
US2429613A (en) * 1943-10-19 1947-10-28 Standard Telephones Cables Ltd Pulse multiplex communication system
US2468058A (en) * 1943-11-23 1949-04-26 Standard Telephones Cables Ltd Blocking system for multichannel operation
US2428118A (en) * 1944-04-07 1947-09-30 Standard Telephones Cables Ltd Pulse multiplex system
US2474244A (en) * 1944-05-19 1949-06-28 Standard Telephones Cables Ltd Amplitude modulated time modulated pulse system
US2434921A (en) * 1944-11-02 1948-01-27 Standard Telephones Cables Ltd Pulse amplitude selective system
US2434922A (en) * 1944-11-02 1948-01-27 Standard Telephones Cables Ltd Pulse amplitude selector system
US2580421A (en) * 1944-12-23 1952-01-01 Radio Patents Corp Cross-talk compensation in pulse multiplex system
US2431577A (en) * 1945-03-14 1947-11-25 Philco Corp Synchronizing system
US2507176A (en) * 1945-03-15 1950-05-09 Hartford Nat Bank & Trust Co Receiver for pulse modulated waves
US2801281A (en) * 1946-02-21 1957-07-30 Bell Telephone Labor Inc Communication system employing pulse code modulation
US2579071A (en) * 1947-07-16 1951-12-18 Rca Corp Time division multiplex system
US2725470A (en) * 1951-02-28 1955-11-29 Rca Corp Time division multiplex gating arrangements

Also Published As

Publication number Publication date
GB537091A (en) 1941-06-09
BE438046A (fr) 1940-03-30
NL60289C (fr)

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