JPS5475205A - Line supervisory system - Google Patents

Line supervisory system

Info

Publication number
JPS5475205A
JPS5475205A JP14294577A JP14294577A JPS5475205A JP S5475205 A JPS5475205 A JP S5475205A JP 14294577 A JP14294577 A JP 14294577A JP 14294577 A JP14294577 A JP 14294577A JP S5475205 A JPS5475205 A JP S5475205A
Authority
JP
Japan
Prior art keywords
line
display device
terminal equipment
generated
transistor
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
JP14294577A
Other languages
Japanese (ja)
Inventor
Hideo Fukazawa
Eishi Ikeda
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.)
HASEGAWA DENKI SEISAKUSHO
HASEGAWA DENKI SEISAKUSHO KK
Fujitsu Ltd
Original Assignee
HASEGAWA DENKI SEISAKUSHO
HASEGAWA DENKI SEISAKUSHO KK
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 HASEGAWA DENKI SEISAKUSHO, HASEGAWA DENKI SEISAKUSHO KK, Fujitsu Ltd filed Critical HASEGAWA DENKI SEISAKUSHO
Priority to JP14294577A priority Critical patent/JPS5475205A/en
Publication of JPS5475205A publication Critical patent/JPS5475205A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/2272—Subscriber line supervision circuits, e.g. call detection circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

PURPOSE:To economize this system dependently upon the application of an electronic circuit by detecting call signals and loop closing by photo coupling in a telephone line. CONSTITUTION:When call signals are applied to terminals A0 and B0, PD-LED is generated by the current which flows to a bell, etc., in the terminal equipment side and is made incident onto a PT photo transistor, and transistor Tr is turned on to communicate incoming signals to a display device. Meanwhile, when the terminal equipment makes the loop closed, PD is generated by the line current to display a line busy state on the display device through PT.
JP14294577A 1977-11-29 1977-11-29 Line supervisory system Pending JPS5475205A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14294577A JPS5475205A (en) 1977-11-29 1977-11-29 Line supervisory system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14294577A JPS5475205A (en) 1977-11-29 1977-11-29 Line supervisory system

Publications (1)

Publication Number Publication Date
JPS5475205A true JPS5475205A (en) 1979-06-15

Family

ID=15327293

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14294577A Pending JPS5475205A (en) 1977-11-29 1977-11-29 Line supervisory system

Country Status (1)

Country Link
JP (1) JPS5475205A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58152052U (en) * 1982-04-07 1983-10-12 株式会社ナカヨ通信機 Simple telephone switching device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58152052U (en) * 1982-04-07 1983-10-12 株式会社ナカヨ通信機 Simple telephone switching device

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