FR2320672A1 - Constant current circuit for supplying telephone terminals - has high symmetry AC attenuation without complex symmetry restoring controls - Google Patents

Constant current circuit for supplying telephone terminals - has high symmetry AC attenuation without complex symmetry restoring controls

Info

Publication number
FR2320672A1
FR2320672A1 FR7623559A FR7623559A FR2320672A1 FR 2320672 A1 FR2320672 A1 FR 2320672A1 FR 7623559 A FR7623559 A FR 7623559A FR 7623559 A FR7623559 A FR 7623559A FR 2320672 A1 FR2320672 A1 FR 2320672A1
Authority
FR
France
Prior art keywords
symmetry
constant
attenuation
telephone terminals
controls
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
FR7623559A
Other languages
French (fr)
Other versions
FR2320672B3 (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.)
Tenovis GmbH and Co KG
Original Assignee
Telefonbau und Normalzeit GmbH
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 Telefonbau und Normalzeit GmbH filed Critical Telefonbau und Normalzeit GmbH
Publication of FR2320672A1 publication Critical patent/FR2320672A1/en
Application granted granted Critical
Publication of FR2320672B3 publication Critical patent/FR2320672B3/fr
Granted 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

The constant current circuit, for supplying telephone terminals from a central exchange, achieves high symmetry AC attenuation without using complex controls to maintain symmetry. A transistorised constant DC current source (T1) is connected into one wire (a) of the loop circuit and acts also as a constant AC current source. The second wire (b) contains a transistorised constant DC voltage source (T2) that also acts as a constant AC current source. The transistors are IGFETs. The advantage lies in the stability achieved by using only one constant DC current source - and thereby preventing asymmetry arising from any opposite regulation that might occur with two sources in series.
FR7623559A 1975-08-02 1976-08-02 Constant current circuit for supplying telephone terminals - has high symmetry AC attenuation without complex symmetry restoring controls Granted FR2320672A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19752534609 DE2534609C3 (en) 1975-08-02 1975-08-02 Circuit arrangement for the central supply of subscriber stations in telecommunication systems, in particular telephone systems

Publications (2)

Publication Number Publication Date
FR2320672A1 true FR2320672A1 (en) 1977-03-04
FR2320672B3 FR2320672B3 (en) 1979-07-06

Family

ID=5953091

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7623559A Granted FR2320672A1 (en) 1975-08-02 1976-08-02 Constant current circuit for supplying telephone terminals - has high symmetry AC attenuation without complex symmetry restoring controls

Country Status (2)

Country Link
DE (1) DE2534609C3 (en)
FR (1) FR2320672A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2441303A1 (en) * 1978-11-13 1980-06-06 Labo Cent Telecommunicat Electronic bridge power supply for telephone line - employs feedback comparator to provide constant output current and voltage to drive transistor which provides circulating current
EP0185213A2 (en) * 1984-12-19 1986-06-25 Siemens Aktiengesellschaft Circuit arrangement for overcharge protection of a subscriber current supply circuit, especially in a digital telephone exchange

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1159706B (en) * 1978-06-02 1987-03-04 Cselt Centro Studi Lab Telecom USER LINE ELECTRONIC TELEPHONE CIRCUIT
DE2850905C2 (en) * 1978-11-24 1985-11-14 Felten & Guilleaume Fernmeldeanlagen GmbH, 8500 Nürnberg Circuit arrangement for feeding a subscriber terminal
DE3234209C2 (en) * 1982-09-15 1986-03-20 kabelmetal electro GmbH, 3000 Hannover Circuit arrangement for the separation of DC and AC components in line-bound signal transmission
DE3436903A1 (en) * 1984-10-08 1986-04-10 Horst Dipl.-Ing. Kopetzky (FH), 8025 Unterhaching Circuit arrangement to limit the feed current supplied via a feed circuit of a line-individual subscriber connection circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2441303A1 (en) * 1978-11-13 1980-06-06 Labo Cent Telecommunicat Electronic bridge power supply for telephone line - employs feedback comparator to provide constant output current and voltage to drive transistor which provides circulating current
EP0185213A2 (en) * 1984-12-19 1986-06-25 Siemens Aktiengesellschaft Circuit arrangement for overcharge protection of a subscriber current supply circuit, especially in a digital telephone exchange
EP0185213A3 (en) * 1984-12-19 1988-09-21 Siemens Aktiengesellschaft Berlin Und Munchen Circuit arrangement for overcharge protection of a subscriber current supply circuit, especially in a digital telephone exchange

Also Published As

Publication number Publication date
DE2534609B2 (en) 1977-09-22
FR2320672B3 (en) 1979-07-06
DE2534609C3 (en) 1978-05-18
DE2534609A1 (en) 1977-02-03

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Legal Events

Date Code Title Description
ST Notification of lapse