JPS56128062A - Branch and coupling amplifier circuit - Google Patents

Branch and coupling amplifier circuit

Info

Publication number
JPS56128062A
JPS56128062A JP3091780A JP3091780A JPS56128062A JP S56128062 A JPS56128062 A JP S56128062A JP 3091780 A JP3091780 A JP 3091780A JP 3091780 A JP3091780 A JP 3091780A JP S56128062 A JPS56128062 A JP S56128062A
Authority
JP
Japan
Prior art keywords
branch
gain
coupling
amplifier
circuits
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.)
Pending
Application number
JP3091780A
Other languages
Japanese (ja)
Inventor
Yoshiji Furuya
Masaru Aoyanagi
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.)
NEC Corp
Nippon Telegraph and Telephone Corp
Original Assignee
NEC Corp
Nippon Telegraph and Telephone Corp
Nippon Electric 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 NEC Corp, Nippon Telegraph and Telephone Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP3091780A priority Critical patent/JPS56128062A/en
Publication of JPS56128062A publication Critical patent/JPS56128062A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/42—Systems providing special services or facilities to subscribers
    • H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To enable to execute a simultaneous mutual service of plural subscribers without deteriorating the quality, by constituting a coupled circuit of a branch amplifier having low output impedance and gain 0dB, and a coupling amplifier having low input impedance and gain 0dB. CONSTITUTION:Coupled circuits 131-13n are constituted of branch amplifiers 201-20n having low output impedance and gain 0dB, to which a transmission input terminal of a 4-wire circuit has been connected, and coupling amplifiers 211- 21n having low input impedance and gain 0dB, to which a receiving input terminal of a 4-wire circuit has been connected. Loss circuits 161-16n and 171-17n are provided in order to insert a loss of gain by a detour due to branch and coupling of (n) circuits, into a part of those which constitute a 4-wire loop. The output terminals of n-1 pieces of the amplifiers 201-20n are connected to one input terminal of the coupling amplifier in other branch and coupled circuits. Accordingly, the signal line passes through one branch amplifier and one coupling amplifier, the constitution can all be made symmetrical, and deterioration of the quality can be made minimum.
JP3091780A 1980-03-13 1980-03-13 Branch and coupling amplifier circuit Pending JPS56128062A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3091780A JPS56128062A (en) 1980-03-13 1980-03-13 Branch and coupling amplifier circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3091780A JPS56128062A (en) 1980-03-13 1980-03-13 Branch and coupling amplifier circuit

Publications (1)

Publication Number Publication Date
JPS56128062A true JPS56128062A (en) 1981-10-07

Family

ID=12317045

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3091780A Pending JPS56128062A (en) 1980-03-13 1980-03-13 Branch and coupling amplifier circuit

Country Status (1)

Country Link
JP (1) JPS56128062A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59134966A (en) * 1983-01-24 1984-08-02 Fujitsu Ltd Conference call circuit
JPS6041360A (en) * 1984-02-10 1985-03-05 Fujitsu Ltd Loudening conference telephone system
JPS6058757A (en) * 1983-09-10 1985-04-04 Fujitsu Ltd Mixing circuit connecting system of plural lines in voice remote conference system
JPS60114059A (en) * 1983-11-25 1985-06-20 Fujitsu Ltd Conference telephone system
JPH0327656A (en) * 1989-06-23 1991-02-06 Nec Corp Hybrid circuit

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59134966A (en) * 1983-01-24 1984-08-02 Fujitsu Ltd Conference call circuit
JPS6058757A (en) * 1983-09-10 1985-04-04 Fujitsu Ltd Mixing circuit connecting system of plural lines in voice remote conference system
JPH0224427B2 (en) * 1983-09-10 1990-05-29 Fujitsu Ltd
JPS60114059A (en) * 1983-11-25 1985-06-20 Fujitsu Ltd Conference telephone system
JPS6041360A (en) * 1984-02-10 1985-03-05 Fujitsu Ltd Loudening conference telephone system
JPH0427746B2 (en) * 1984-02-10 1992-05-12 Fujitsu Ltd
JPH0327656A (en) * 1989-06-23 1991-02-06 Nec Corp Hybrid circuit

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