GB1560922A - Telephone systems - Google Patents

Telephone systems Download PDF

Info

Publication number
GB1560922A
GB1560922A GB3984/77A GB398477A GB1560922A GB 1560922 A GB1560922 A GB 1560922A GB 3984/77 A GB3984/77 A GB 3984/77A GB 398477 A GB398477 A GB 398477A GB 1560922 A GB1560922 A GB 1560922A
Authority
GB
United Kingdom
Prior art keywords
transistor
subscribers
transistor means
feed bridge
telephone
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
GB3984/77A
Other languages
English (en)
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.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
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 Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB3984/77A priority Critical patent/GB1560922A/en
Priority to AU32673/78A priority patent/AU514376B2/en
Priority to FR7802170A priority patent/FR2379210A1/fr
Priority to ZA00780513A priority patent/ZA78513B/xx
Priority to NZ186342A priority patent/NZ186342A/xx
Priority to IT19856/78A priority patent/IT1092555B/it
Priority to CA000296101A priority patent/CA1116767A/en
Publication of GB1560922A publication Critical patent/GB1560922A/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)
  • Devices For Supply Of Signal Current (AREA)
GB3984/77A 1977-02-01 1977-02-01 Telephone systems Expired GB1560922A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
GB3984/77A GB1560922A (en) 1977-02-01 1977-02-01 Telephone systems
AU32673/78A AU514376B2 (en) 1977-02-01 1978-01-24 Subscribers feed bridge
FR7802170A FR2379210A1 (fr) 1977-02-01 1978-01-26 Circuit electronique d'alimentation en pont, pour un poste telephonique d'abonne
ZA00780513A ZA78513B (en) 1977-02-01 1978-01-27 Improvements in or relating to telephone systems
NZ186342A NZ186342A (en) 1977-02-01 1978-01-30 Transistorised subset feed bridge
IT19856/78A IT1092555B (it) 1977-02-01 1978-01-31 Ponte elettronico di alimentazione per sistemi telefonici
CA000296101A CA1116767A (en) 1977-02-01 1978-01-31 Electronic bridge circuit for supplying dc power and tone signals to subscriber line

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3984/77A GB1560922A (en) 1977-02-01 1977-02-01 Telephone systems

Publications (1)

Publication Number Publication Date
GB1560922A true GB1560922A (en) 1980-02-13

Family

ID=9768612

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3984/77A Expired GB1560922A (en) 1977-02-01 1977-02-01 Telephone systems

Country Status (7)

Country Link
AU (1) AU514376B2 (it)
CA (1) CA1116767A (it)
FR (1) FR2379210A1 (it)
GB (1) GB1560922A (it)
IT (1) IT1092555B (it)
NZ (1) NZ186342A (it)
ZA (1) ZA78513B (it)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1074662B (de) * 1957-10-10 1960-02-04 Pye Limited, Cambridge (Grossbritannien) Automatisches Telefonsystem mit elektronischer Schaltung des Rufstromes zu einem Teilnehmer
US3065307A (en) * 1959-10-12 1962-11-20 Automatic Elect Lab Electronic telephone systems and ringing arrangements therefor
FR2216733B1 (it) * 1973-01-31 1978-05-12 Labo Cent Telecommunicat

Also Published As

Publication number Publication date
AU3267378A (en) 1979-08-02
IT1092555B (it) 1985-07-12
IT7819856A0 (it) 1978-01-31
ZA78513B (en) 1978-12-27
NZ186342A (en) 1981-02-11
FR2379210A1 (fr) 1978-08-25
AU514376B2 (en) 1981-02-05
CA1116767A (en) 1982-01-19

Similar Documents

Publication Publication Date Title
US4079211A (en) Protection device for a subscriber's telephone set
US4300023A (en) Hybrid circuit
US4088843A (en) Electronic current feed circuit
DE2826851C3 (de) Schaltungsanordnung zum Einschalten eines örtlichen Rufsignalerzeugers
GB1489143A (en) Subscriber line interface circuit
US4322586A (en) Transformerless line interface circuit
US4360710A (en) Telephone circuit
EP0163308B1 (en) Battery feed circuit for a pair of subscriber lines
US4577064A (en) Auto-balance circuit for battery feed in a telephone circuit
EP0134229B1 (en) Borsht/slic auto balancing technique
GB1481750A (en) Subscriber line interface circuit
US4110636A (en) Feeding bridge
CA1138138A (en) Line circuit
GB1560922A (en) Telephone systems
US4400588A (en) Electronic voice network for a telephone subscriber's substation
US4429187A (en) Audio distributing system
SE7902832L (sv) Abonnentanslutningskrets innefattande en symmetrisk effektforsterkare for matning av en abonnentledning
US4267408A (en) Arrangement for applying a signal to a transmission line
US4133986A (en) Subscriber's line equipment for a telephone exchange
JP2000307767A (ja) 給電線方式変調回路における歪みを減少させる方法および装置
US4414435A (en) Interface circuit with flux cancelling transformer circuit
EP0713320B1 (en) Ring generator circuit
US4809324A (en) Subscriber line interface circuit (SLIC) isolation from lighting-induced ground overshoots
JPS61214655A (ja) 定電流ライン回路
US4302636A (en) Subscriber's electronic line equipment comprising a two-wire-four-wire conversion circuit for a telephone exchange

Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee