JPS555522A - Supply circuit for communication current - Google Patents

Supply circuit for communication current

Info

Publication number
JPS555522A
JPS555522A JP7803678A JP7803678A JPS555522A JP S555522 A JPS555522 A JP S555522A JP 7803678 A JP7803678 A JP 7803678A JP 7803678 A JP7803678 A JP 7803678A JP S555522 A JPS555522 A JP S555522A
Authority
JP
Japan
Prior art keywords
trq1
current
ground
telephone set
passes
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
JP7803678A
Other languages
Japanese (ja)
Inventor
Yoichiro Sano
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.)
Iwatsu Electric Co Ltd
Original Assignee
Iwatsu 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 Iwatsu Electric Co Ltd filed Critical Iwatsu Electric Co Ltd
Priority to JP7803678A priority Critical patent/JPS555522A/en
Priority to BR7904073A priority patent/BR7904073A/en
Publication of JPS555522A publication Critical patent/JPS555522A/en
Pending 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)

Abstract

PURPOSE:To make samll the communication current supply source in size through the use of transistors and to avoid mutual interferrnece. CONSTITUTION:The DC current for communication of the telephone set EXT passes through, ground-resistor R2-pnp trnasistor TrQ2-terminal L1-L2-npn TrQ1- R1-DC power supply E-ground. The bias current of TrQ1,Q2 passes through, ground -R2-Q1-R0-Q2-R2-E-ground. The diodes D1,D2 and D3,D4 determine the telephone set supply current, and the resistors R1,R2,R0 control the bias current to keep TrQ1,Q2 at the active region. In practice, since TrQ1,Q2 in active region have very high impedance from the collector side, the audio signal from the telephone set can be delivered to the opposing telephone set without passing through the DC power supply side. Since the base current of TrQ1,Q2 passes through one resistor R0, the bias can be made to one state to keep the balance for the terminals L1 and L2.
JP7803678A 1978-06-29 1978-06-29 Supply circuit for communication current Pending JPS555522A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP7803678A JPS555522A (en) 1978-06-29 1978-06-29 Supply circuit for communication current
BR7904073A BR7904073A (en) 1978-06-29 1979-06-27 SPEECH CURRENT POWER SUPPLY CIRCUIT

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7803678A JPS555522A (en) 1978-06-29 1978-06-29 Supply circuit for communication current

Publications (1)

Publication Number Publication Date
JPS555522A true JPS555522A (en) 1980-01-16

Family

ID=13650584

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7803678A Pending JPS555522A (en) 1978-06-29 1978-06-29 Supply circuit for communication current

Country Status (2)

Country Link
JP (1) JPS555522A (en)
BR (1) BR7904073A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51100618A (en) * 1975-03-03 1976-09-06 Nippon Telegraph & Telephone Denwakokankiniokeru chokuryudenryukyokyuhoshiki

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51100618A (en) * 1975-03-03 1976-09-06 Nippon Telegraph & Telephone Denwakokankiniokeru chokuryudenryukyokyuhoshiki

Also Published As

Publication number Publication date
BR7904073A (en) 1980-04-01

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