GB1530089A - Telephone line circuit - Google Patents

Telephone line circuit

Info

Publication number
GB1530089A
GB1530089A GB36417/77A GB3641777A GB1530089A GB 1530089 A GB1530089 A GB 1530089A GB 36417/77 A GB36417/77 A GB 36417/77A GB 3641777 A GB3641777 A GB 3641777A GB 1530089 A GB1530089 A GB 1530089A
Authority
GB
United Kingdom
Prior art keywords
line
circuit
line circuit
telephone line
differential amplifier
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
Application number
GB36417/77A
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.)
Thales SA
Original Assignee
Thomson CSF SA
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 Thomson CSF SA filed Critical Thomson CSF SA
Publication of GB1530089A publication Critical patent/GB1530089A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/001—Current supply source at the exchanger providing current to substations
    • H04M19/005—Feeding arrangements without the use of line transformers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

1530089 Telephone line circuits; hybrid circuits THOMSON-CSF 31 Aug 1977 [3 Sept 1976] 36417/77 Headings H4K and H4R A line circuit for 2/4 wire conversion between a line L1, L2 and the transmitting E and receiving means R of an exchange (not shown) includes differential amplifiers A1, A2, A3 and power amplifiers A4, A5 having biasing inputs, for connecting E to the two wires L1, L2, a differential amplifier A6 which through another differential amplifier A7 connects the line L1, L2 to R. A7 is also connected to E so that signals from E to L1, L2 are not retransmitted on R. A common unit (not shown) controls the operation of the line circuit through FET switches S1-S7 so that the circuit provides line feed, ringing, reversing polarity of the line, compensation for differences in line impedances and loop detection. The line circuit may be formed as an IC.
GB36417/77A 1976-09-03 1977-08-31 Telephone line circuit Expired GB1530089A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7626614A FR2363952A1 (en) 1976-09-03 1976-09-03 TELEPHONE LINE CIRCUIT

Publications (1)

Publication Number Publication Date
GB1530089A true GB1530089A (en) 1978-10-25

Family

ID=9177355

Family Applications (1)

Application Number Title Priority Date Filing Date
GB36417/77A Expired GB1530089A (en) 1976-09-03 1977-08-31 Telephone line circuit

Country Status (8)

Country Link
JP (1) JPS5332605A (en)
BE (1) BE858262A (en)
DE (1) DE2739718A1 (en)
FR (1) FR2363952A1 (en)
GB (1) GB1530089A (en)
IT (1) IT1084094B (en)
NL (1) NL7709578A (en)
SE (1) SE7709758L (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5531358A (en) * 1978-08-28 1980-03-05 Nec Corp Subscriber circuit
JPS5537046A (en) * 1978-09-06 1980-03-14 Nec Corp Subscriber's circuit
FR2437123A1 (en) * 1978-09-19 1980-04-18 Thomson Ericsson Telephones So Electronic power supply for telephone lines - comprises operational amplifier with feedback followed by transistor stage
NL7810086A (en) * 1978-10-06 1980-04-09 Philips Nv POWER BRIDGE FOR A SUBSCRIBER FLOW.
JPS5593392A (en) * 1979-01-10 1980-07-15 Nec Corp Subscriber circuit
NL7904159A (en) * 1979-05-28 1980-12-02 Philips Nv DEVICE FOR SUPPLYING SIGNALS TO A TELEPHONE LINE.

Also Published As

Publication number Publication date
FR2363952B1 (en) 1981-09-25
DE2739718A1 (en) 1978-03-09
JPS5332605A (en) 1978-03-28
BE858262A (en) 1977-12-16
SE7709758L (en) 1978-03-04
IT1084094B (en) 1985-05-25
FR2363952A1 (en) 1978-03-31
NL7709578A (en) 1978-03-07

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee