JPS54122012A - Ringing-signal detection circuit - Google Patents

Ringing-signal detection circuit

Info

Publication number
JPS54122012A
JPS54122012A JP2924178A JP2924178A JPS54122012A JP S54122012 A JPS54122012 A JP S54122012A JP 2924178 A JP2924178 A JP 2924178A JP 2924178 A JP2924178 A JP 2924178A JP S54122012 A JPS54122012 A JP S54122012A
Authority
JP
Japan
Prior art keywords
terminal
diode
constant
detection circuit
series
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
JP2924178A
Other languages
Japanese (ja)
Inventor
Isamu Ueki
Yuichi Morikawa
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
NTT Inc
Original Assignee
NEC Corp
Nippon Telegraph and Telephone 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 Telegraph and Telephone Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP2924178A priority Critical patent/JPS54122012A/en
Publication of JPS54122012A publication Critical patent/JPS54122012A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/02—Calling substations, e.g. by ringing

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

PURPOSE:To obtain a detection circuit of simple constitution which can detect a ringing signal by making use of two constant-voltage diodes. CONSTITUTION:The anode of 1st constant-voltage diode 26 and that of 2nd constant-voltage diode 25 are connected together and the cathode of diode 25 is connected in series to one terminal of light emission diode 23; and diodes 23 and 24 are connected together in parallel with polarities opposite and the other terminal of light emission diode 23 is connected in series to resistance 22. Further, the other terminal of resistance 22 is connected in series to capacitor 21, the other terminal of which constitutes the input terminal together with the cathode of constant-voltage diode 26. Consequently, a ringing signal can be detected under no switching control of a switch without damping a call signal.
JP2924178A 1978-03-16 1978-03-16 Ringing-signal detection circuit Pending JPS54122012A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2924178A JPS54122012A (en) 1978-03-16 1978-03-16 Ringing-signal detection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2924178A JPS54122012A (en) 1978-03-16 1978-03-16 Ringing-signal detection circuit

Publications (1)

Publication Number Publication Date
JPS54122012A true JPS54122012A (en) 1979-09-21

Family

ID=12270740

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2924178A Pending JPS54122012A (en) 1978-03-16 1978-03-16 Ringing-signal detection circuit

Country Status (1)

Country Link
JP (1) JPS54122012A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5967432U (en) * 1982-10-29 1984-05-07 三洋工業株式会社 Kasagi mounting structure
JPH01168149A (en) * 1987-12-24 1989-07-03 Oki Electric Ind Co Ltd Subscriber line polarity detection circuit for telephone exchange
JPH02150891U (en) * 1989-05-19 1990-12-27

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5361905A (en) * 1976-11-16 1978-06-02 Tokyo Rokuon Kougiyou Kk Telephone calling signal detector

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5361905A (en) * 1976-11-16 1978-06-02 Tokyo Rokuon Kougiyou Kk Telephone calling signal detector

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5967432U (en) * 1982-10-29 1984-05-07 三洋工業株式会社 Kasagi mounting structure
JPH01168149A (en) * 1987-12-24 1989-07-03 Oki Electric Ind Co Ltd Subscriber line polarity detection circuit for telephone exchange
JPH02150891U (en) * 1989-05-19 1990-12-27

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