JPS5742263A - Power feeding and two/four wire conversion system - Google Patents

Power feeding and two/four wire conversion system

Info

Publication number
JPS5742263A
JPS5742263A JP11813380A JP11813380A JPS5742263A JP S5742263 A JPS5742263 A JP S5742263A JP 11813380 A JP11813380 A JP 11813380A JP 11813380 A JP11813380 A JP 11813380A JP S5742263 A JPS5742263 A JP S5742263A
Authority
JP
Japan
Prior art keywords
circuit
reception signal
inputted
transmitted
line
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
JP11813380A
Other languages
Japanese (ja)
Other versions
JPS6230546B2 (en
Inventor
Takashi Tabu
Shuichi Ashihara
Hitoshi Shirai
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP11813380A priority Critical patent/JPS5742263A/en
Publication of JPS5742263A publication Critical patent/JPS5742263A/en
Publication of JPS6230546B2 publication Critical patent/JPS6230546B2/ja
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
    • H04M19/005—Feeding arrangements without the use of line transformers

Abstract

PURPOSE:To make small the size of power feeding circuit and two/four wire conversion circuit incorporatingly and to achieve high circuit integration, by cancelling the reception signal and outputting only the transmission signal, in a differential amplifier. CONSTITUTION:An inverted reception signal is inputted to an addition circuit of a power feeding circuit SP, for example, and it is added with an output voltage of a voltage division circuit VD and inputted to a current conversion circuit VI. Thus, the reception signal is transmitted to the line constituting the 2 wire type line through superimposition on the call current and transmitted to a telephone set Tel. On the other hand, the transmission signal delivered from the telephone set Tel to a line constituting the two wire line, is transmitted from the circuit SP to the line. The output is inputted to one input terminal of differential amplifiers DA1, DA2 together with the reception signal transmitted in an opposite direction, and the reception signal is inputted to another input terminal of the amplifier DA1. The reception signal is cancelled at the amplifiers DA1, DA2 and only the transmission signal is outputted to a transmission signal transmitter SEN.
JP11813380A 1980-08-27 1980-08-27 Power feeding and two/four wire conversion system Granted JPS5742263A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11813380A JPS5742263A (en) 1980-08-27 1980-08-27 Power feeding and two/four wire conversion system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11813380A JPS5742263A (en) 1980-08-27 1980-08-27 Power feeding and two/four wire conversion system

Publications (2)

Publication Number Publication Date
JPS5742263A true JPS5742263A (en) 1982-03-09
JPS6230546B2 JPS6230546B2 (en) 1987-07-02

Family

ID=14728857

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11813380A Granted JPS5742263A (en) 1980-08-27 1980-08-27 Power feeding and two/four wire conversion system

Country Status (1)

Country Link
JP (1) JPS5742263A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60210092A (en) * 1984-03-30 1985-10-22 Fujitsu Ltd Data transmission system in pushbutton telephone set
JPS6242695A (en) * 1985-08-20 1987-02-24 Fujitsu Ltd Two-line/four-line converting circuit
US4935960A (en) * 1987-06-17 1990-06-19 Fujitsu Limited Battery feed circuit
EP0639021A1 (en) * 1993-07-31 1995-02-15 DeTeWe - Deutsche Telephonwerke Aktiengesellschaft & Co. Circuit arrangement for a transformerless subscriber line interface circuit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5537046A (en) * 1978-09-06 1980-03-14 Nec Corp Subscriber's circuit
JPS5599874A (en) * 1979-01-23 1980-07-30 Nec Corp Communication current supply circuit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5537046A (en) * 1978-09-06 1980-03-14 Nec Corp Subscriber's circuit
JPS5599874A (en) * 1979-01-23 1980-07-30 Nec Corp Communication current supply circuit

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60210092A (en) * 1984-03-30 1985-10-22 Fujitsu Ltd Data transmission system in pushbutton telephone set
JPS6242695A (en) * 1985-08-20 1987-02-24 Fujitsu Ltd Two-line/four-line converting circuit
JPH0439957B2 (en) * 1985-08-20 1992-07-01 Fujitsu Ltd
US4935960A (en) * 1987-06-17 1990-06-19 Fujitsu Limited Battery feed circuit
EP0639021A1 (en) * 1993-07-31 1995-02-15 DeTeWe - Deutsche Telephonwerke Aktiengesellschaft & Co. Circuit arrangement for a transformerless subscriber line interface circuit

Also Published As

Publication number Publication date
JPS6230546B2 (en) 1987-07-02

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