JPS54154202A - Talking protective circuit for multi-telephone - Google Patents

Talking protective circuit for multi-telephone

Info

Publication number
JPS54154202A
JPS54154202A JP6363678A JP6363678A JPS54154202A JP S54154202 A JPS54154202 A JP S54154202A JP 6363678 A JP6363678 A JP 6363678A JP 6363678 A JP6363678 A JP 6363678A JP S54154202 A JPS54154202 A JP S54154202A
Authority
JP
Japan
Prior art keywords
telephone
relay
talking
protective circuit
line
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
JP6363678A
Other languages
Japanese (ja)
Inventor
Masayasu Chiba
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 JP6363678A priority Critical patent/JPS54154202A/en
Publication of JPS54154202A publication Critical patent/JPS54154202A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/71—Substation extension arrangements

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)

Abstract

PURPOSE:To prevent the mutual interference for the multiple connection of telephones by providing such circuit that cuts off completely the other telephone when one telephone is used for connection at the originating and incoming time each. CONSTITUTION:The telephone line led from the exchange is connected to terminal LA and LB of subscriber's private protective circuit 4, and the earth and -48V are supplied to the LA and LB side each. With arrival of the call signal of 16 Hz from the exchange, the bells of both telephone A and B ring. Then relay A and then relay C operate with the answer of telephone A, and furthermore relay AA operates to secure the self-holding. Thus, the A-line is cut to have switching to the B-line side of telephone B in order to eliminate the effect of telephone B. Then the loop breaking is given by photo coupler P and with end of the talking to relay C which has hitherto operation while taking, and thus relay C and then relay AA have release. For originating, telephone B has off-hook to actuate relay B, C and BB, giving the same operation as incoming thereafter.
JP6363678A 1978-05-26 1978-05-26 Talking protective circuit for multi-telephone Pending JPS54154202A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6363678A JPS54154202A (en) 1978-05-26 1978-05-26 Talking protective circuit for multi-telephone

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6363678A JPS54154202A (en) 1978-05-26 1978-05-26 Talking protective circuit for multi-telephone

Publications (1)

Publication Number Publication Date
JPS54154202A true JPS54154202A (en) 1979-12-05

Family

ID=13235029

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6363678A Pending JPS54154202A (en) 1978-05-26 1978-05-26 Talking protective circuit for multi-telephone

Country Status (1)

Country Link
JP (1) JPS54154202A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5947866A (en) * 1982-09-10 1984-03-17 Nippon Telegr & Teleph Corp <Ntt> Main wire common use system of telephone exchange and terminal device
JPS59178851A (en) * 1983-03-30 1984-10-11 Toshiba Corp Telephone set circuit
JPS63179655A (en) * 1987-01-21 1988-07-23 Hitachi Denshi Service Kk Line switching device for terminal equipment using telephone line in common
JPS63217758A (en) * 1987-03-05 1988-09-09 Nec Corp Branching telephone set
JPH01177758A (en) * 1988-01-08 1989-07-14 Canon Inc Communication equipment

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5947866A (en) * 1982-09-10 1984-03-17 Nippon Telegr & Teleph Corp <Ntt> Main wire common use system of telephone exchange and terminal device
JPS59178851A (en) * 1983-03-30 1984-10-11 Toshiba Corp Telephone set circuit
JPS63179655A (en) * 1987-01-21 1988-07-23 Hitachi Denshi Service Kk Line switching device for terminal equipment using telephone line in common
JPS63217758A (en) * 1987-03-05 1988-09-09 Nec Corp Branching telephone set
JPH01177758A (en) * 1988-01-08 1989-07-14 Canon Inc Communication equipment

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