JPS5679565A - Subscriber circuit - Google Patents
Subscriber circuitInfo
- Publication number
- JPS5679565A JPS5679565A JP15661479A JP15661479A JPS5679565A JP S5679565 A JPS5679565 A JP S5679565A JP 15661479 A JP15661479 A JP 15661479A JP 15661479 A JP15661479 A JP 15661479A JP S5679565 A JPS5679565 A JP S5679565A
- Authority
- JP
- Japan
- Prior art keywords
- fed
- signal
- call
- call current
- transistors
- 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
- H04M19/00—Current supply arrangements for telephone systems
- H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
- H04M19/04—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
PURPOSE:To reduce the mounting area of suabscriber circuit, by detecting a call current and removing the audio component with a low pass filter from the call current detected and controlling the call current control circuit with the signal. CONSTITUTION:The call current fed to subscriber lines 6A, 6B through transistors 10, 11 and a resstor 12 is detected at a call current detection circuit 16 to produce the control signal according to the magnitude of call currnet. This signal is fed to a low pass filter 21 to reject the audio component and the result is fed to a call current control circuit 22. Thus, resistors 23, 24 in the control circuit 22 dividing the battery voltage convert the impedance of operational amplifiers 17, 18 and determine the base potential of the transistors 10, 11. Thus, the signal to the subscriber fed from a reception circuit 16 is signal-amplified with the amplification factor determined with resistors 19, 20, and fed to the base of the transistors 10, 11, and transmitted to a subscriber line 6 with current amplification.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15661479A JPS5679565A (en) | 1979-12-03 | 1979-12-03 | Subscriber circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15661479A JPS5679565A (en) | 1979-12-03 | 1979-12-03 | Subscriber circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5679565A true JPS5679565A (en) | 1981-06-30 |
Family
ID=15631574
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15661479A Pending JPS5679565A (en) | 1979-12-03 | 1979-12-03 | Subscriber circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5679565A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4514595A (en) * | 1982-06-10 | 1985-04-30 | Northern Telecom Limited | Active impedance line feed circuit |
-
1979
- 1979-12-03 JP JP15661479A patent/JPS5679565A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4514595A (en) * | 1982-06-10 | 1985-04-30 | Northern Telecom Limited | Active impedance line feed circuit |
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