JPS5475205A - Line supervisory system - Google Patents
Line supervisory systemInfo
- 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
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.
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)
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 |
-
1977
- 1977-11-29 JP JP14294577A patent/JPS5475205A/en active Pending
Cited By (1)
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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