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GB2012521A - Feed bridge for a telephone line - Google Patents

Feed bridge for a telephone line

Info

Publication number
GB2012521A
GB2012521A GB7900252A GB7900252A GB2012521A GB 2012521 A GB2012521 A GB 2012521A GB 7900252 A GB7900252 A GB 7900252A GB 7900252 A GB7900252 A GB 7900252A GB 2012521 A GB2012521 A GB 2012521A
Authority
GB
United Kingdom
Prior art keywords
transistor
feed
telephone line
gyrators
gyrator
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.)
Granted
Application number
GB7900252A
Other versions
GB2012521B (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.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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 International Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB2012521A publication Critical patent/GB2012521A/en
Application granted granted Critical
Publication of GB2012521B publication Critical patent/GB2012521B/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)
  • Telephone Function (AREA)

Abstract

In an electronic feed bridge, such as used in a telephone exchange for supplying direct current to the line, it is known to use transistor gyrators between each "leg" of the line and the power supply terminals. However, such transistor gyrators are liable to act as amplifiers for any noise which originates on the d.c. supply. To overcome this each gyrator's transistor (T, T', Fig. 5) has an inverter feed to its emitter circuit from the other gyrator's transistor. By suitable proporting of these inverse feed connections, the noise due to the d.c. supply is substantially eliminated. <IMAGE>
GB7900252A 1978-01-13 1979-01-04 Feed bridge for telephone line Expired GB2012521B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7800970A FR2414832A1 (en) 1978-01-13 1978-01-13 SUPPLY BRIDGE FOR TELEPHONE LINE

Publications (2)

Publication Number Publication Date
GB2012521A true GB2012521A (en) 1979-07-25
GB2012521B GB2012521B (en) 1982-01-20

Family

ID=9203442

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7900252A Expired GB2012521B (en) 1978-01-13 1979-01-04 Feed bridge for telephone line

Country Status (4)

Country Link
BE (1) BE873459A (en)
BR (1) BR7900101A (en)
FR (1) FR2414832A1 (en)
GB (1) GB2012521B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2438394A1 (en) * 1978-10-06 1980-04-30 Philips Nv SUPPLY BRIDGE FOR SUBSCRIBER LINE
GB2117590A (en) * 1981-12-18 1983-10-12 Telefongyar Active resistance circuit
FR2526183A1 (en) * 1982-04-29 1983-11-04 Motorola Inc REGULATOR CIRCUIT
EP0330961A1 (en) * 1988-02-24 1989-09-06 Bell Telephone Manufacturing Company N.V. Telephone line interface circuit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1290202B (en) * 1966-09-30 1969-03-06 Merk Gmbh Telefonbau Fried Circuit arrangement for the supply of telephone subscriber stations
CH586984A5 (en) * 1974-12-23 1977-04-15 Ibm
US4007335A (en) * 1975-11-12 1977-02-08 Bell Telephone Laboratories, Incorporated Telephone line battery feed circuit

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2438394A1 (en) * 1978-10-06 1980-04-30 Philips Nv SUPPLY BRIDGE FOR SUBSCRIBER LINE
GB2117590A (en) * 1981-12-18 1983-10-12 Telefongyar Active resistance circuit
FR2526183A1 (en) * 1982-04-29 1983-11-04 Motorola Inc REGULATOR CIRCUIT
GB2120498A (en) * 1982-04-29 1983-11-30 Motorola Inc Regulator circuit
EP0330961A1 (en) * 1988-02-24 1989-09-06 Bell Telephone Manufacturing Company N.V. Telephone line interface circuit
US4910769A (en) * 1988-02-24 1990-03-20 Alcatel Nederland B.V. Telephone line interface circuit

Also Published As

Publication number Publication date
GB2012521B (en) 1982-01-20
FR2414832A1 (en) 1979-08-10
BR7900101A (en) 1979-08-07
BE873459A (en) 1979-07-16

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Legal Events

Date Code Title Description
746 Register noted 'licences of right' (sect. 46/1977)
PCNP Patent ceased through non-payment of renewal fee