US2265067A - Transmission system - Google Patents

Transmission system Download PDF

Info

Publication number
US2265067A
US2265067A US372977A US37297741A US2265067A US 2265067 A US2265067 A US 2265067A US 372977 A US372977 A US 372977A US 37297741 A US37297741 A US 37297741A US 2265067 A US2265067 A US 2265067A
Authority
US
United States
Prior art keywords
section
line
currents
metallic
grounded
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
US372977A
Other languages
English (en)
Inventor
Irwin M Ellestad
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.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
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
Priority to BE442706D priority Critical patent/BE442706A/xx
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Priority to US372977A priority patent/US2265067A/en
Application granted granted Critical
Publication of US2265067A publication Critical patent/US2265067A/en
Priority to FR888196D priority patent/FR888196A/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/28—Reducing interference caused by currents induced in cable sheathing or armouring
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/0123—Frequency selective two-port networks comprising distributed impedance elements together with lumped impedance elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1758—Series LC in shunt or branch path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults

Definitions

  • This invention relates to transmission systems and more particularly to a means for coupling together two or more sections of a transmission line wherein one of said sections is exposed to interference from neighboring power or communication lines.
  • This line may be composed of two sections, a metallic section 3 and a grounded section 4.
  • the metallic section and grounded section are connected together in the following manner.
  • a split-Winding repeat coil [4 is provided having its windings 5 connected to the tip and ring conductors of metallic section 3 and also having its windings connected to ground 8 through condensers 6 and 1.
  • the windings !2 of the repeat coil I4 are interconnected by condenser 13.
  • the upper winding is connected to the line of grounded section 4 and the lower winding connected to ground.
  • An impedance 9, which may be a repeat coil, is provided connected to the ring conductor of section 3 and the line of section 4.
  • a similar impedance coil I0 is connected to the tip conductor of section current.
  • the arrangements of the invention are particularly desirable for inter connecting a grounded section of line with a metallic section of line when the metallic section is exposed to inductive interference from a neighboring power line. Hence a portion of a power line H is shown in the vicinity of the metallic section 3 of the line.
  • the invention may be more fully understood from the following description of its operation.
  • the currents which are to be transmitted between the subscribers station I and the central OfllCB 2 include not only the voice currents but also alternating current for signaling and direct current for dialing purposes.
  • the location of the metallic section 3 in the vicinity of the power line II will cause so-called longitudinal currents to flow over the tip and ring conductors of the metallic section 3 as indicated by the arrows. These longitudinal currents might interfere with voice transmission and signaling or dialing on the line if connection were made in the usual manner between the metallic and grounded sections.
  • the windings 5 of the split-winding repeat coil l4 and condensers 6 and 1 have their constants so chosen that they constitute a low impedance shunt to ground for the longitudinal currents induced in the metallic section 3 due to its exposure to the neighboring power line H.
  • the impedances 9 and ID are so designed that they will have a high impedance to longitudinal currents and voice currents and a low impedance to direct Accordingly the longitudinal currents will neutralize each other in the windings 5 of repeat coil I4 and will not be repeated through coil l2 to the subscribers station I. They will not be transmitted through impedance 9 to station I. Direct current signals will be transmitted between the station I and the central office 2 through impedance 9. The voice currents will be transmitted in the normal manner through the transformer comprising repeat coils 5 and I 2.
  • a transmission line comprising a grounded section and a metallic section, a split winding repeating coil having two pairs of windings,
  • the first mentioned repeating coil windings and the circuit interconnecting them being adapted to constitute a low impedance shunt to ground for longitudinal currents induced in said metallic section, and an impedance coil connecting a conductor of said grounded section to a conductor of said metallic section, said last mentioned impedance coil having high impedance to longitudinal and voice currents and a 10 low impedance to direct currents.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Communication Cables (AREA)
US372977A 1941-01-03 1941-01-03 Transmission system Expired - Lifetime US2265067A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE442706D BE442706A (en, 2012) 1941-01-03
US372977A US2265067A (en) 1941-01-03 1941-01-03 Transmission system
FR888196D FR888196A (fr) 1941-01-03 1942-01-10 Systèmes de transmission d'ondes électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US372977A US2265067A (en) 1941-01-03 1941-01-03 Transmission system

Publications (1)

Publication Number Publication Date
US2265067A true US2265067A (en) 1941-12-02

Family

ID=23470414

Family Applications (1)

Application Number Title Priority Date Filing Date
US372977A Expired - Lifetime US2265067A (en) 1941-01-03 1941-01-03 Transmission system

Country Status (3)

Country Link
US (1) US2265067A (en, 2012)
BE (1) BE442706A (en, 2012)
FR (1) FR888196A (en, 2012)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2754482A (en) * 1949-01-29 1956-07-10 Emi Ltd Band-pass circuit arrangements
US3731234A (en) * 1971-12-27 1973-05-01 Bell Telephone Labor Inc Combined voice frequency transmission and dc signaling circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2754482A (en) * 1949-01-29 1956-07-10 Emi Ltd Band-pass circuit arrangements
US3731234A (en) * 1971-12-27 1973-05-01 Bell Telephone Labor Inc Combined voice frequency transmission and dc signaling circuit

Also Published As

Publication number Publication date
BE442706A (en, 2012)
FR888196A (fr) 1943-12-06

Similar Documents

Publication Publication Date Title
US1762775A (en) Inductance device
US2265067A (en) Transmission system
US2026308A (en) Balanced inductance device
US2338405A (en) Protective system
US1803453A (en) System for communicating with moving vehicles
US1812624A (en) Telephone and telegraph signaling system
US2113708A (en) Transmission system
US1362613A (en) Means for neutralizing interfering disturbances
US2046050A (en) Noise suppression system for telephone lines
US1579931A (en) Transmission circuits
US2116172A (en) Composite set
US2283891A (en) Prevention of interference in telephone circuits
US940658A (en) System for nullifying inductive disturbances.
US1474430A (en) Telephone bepeatee
US2099800A (en) Shielded circuits for open wire lines
US2101243A (en) Telegraph signal repeating system
US1840434A (en) Conductor system for signaling currents
US1539902A (en) Carrier transmission over power circuits
US1222810A (en) Protective system for composite circuits.
US2117835A (en) Telephone signaling system
US1984062A (en) Telephone set
US1516519A (en) Electrical transformer
Slaughter et al. Carrier telephony on power lines
US1697462A (en) Wired-wireless system
US2077899A (en) Electrical signaling system