JPS5679565A - Subscriber circuit - Google Patents

Subscriber circuit

Info

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
Application number
JP15661479A
Other languages
Japanese (ja)
Inventor
Tadashi Nakanishi
Akira Tanaka
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
Original Assignee
NEC 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 Electric Co Ltd filed Critical NEC Corp
Priority to JP15661479A priority Critical patent/JPS5679565A/en
Publication of JPS5679565A publication Critical patent/JPS5679565A/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
    • H04M19/02—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.
JP15661479A 1979-12-03 1979-12-03 Subscriber circuit Pending JPS5679565A (en)

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)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4514595A (en) * 1982-06-10 1985-04-30 Northern Telecom Limited Active impedance line feed circuit

Cited By (1)

* Cited by examiner, † Cited by third party
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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