JPS5553950A - Multi-telephone device - Google Patents

Multi-telephone device

Info

Publication number
JPS5553950A
JPS5553950A JP12742778A JP12742778A JPS5553950A JP S5553950 A JPS5553950 A JP S5553950A JP 12742778 A JP12742778 A JP 12742778A JP 12742778 A JP12742778 A JP 12742778A JP S5553950 A JPS5553950 A JP S5553950A
Authority
JP
Japan
Prior art keywords
telephone
electric conduction
telephones
circuit
handset
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
JP12742778A
Other languages
Japanese (ja)
Inventor
Hachishiro Kawamura
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to JP12742778A priority Critical patent/JPS5553950A/en
Publication of JPS5553950A publication Critical patent/JPS5553950A/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
    • H04M1/715—Substation extension arrangements using two or more extensions per line

Landscapes

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

Abstract

PURPOSE:To avoid occurrence of the trouble caused by taking off other telephones while using a certain telephone, by providing the electric conduction blocking circuit which blocks the electric conduction to other telephones to each telephone set. CONSTITUTION:Primary windings 18 of transformers 15 and 16 are connected in series to telephone sets 12 and 13, and the electric conduction blocking circuit is provided to block the electric conduction to other telephones 13 and 12 via the output of secondary windings 19. Now if the handset of telephone 12 is taken off from the telephone main body, the breakdown voltage is applied to Zener diode 26 at privacy circuit 20. Thus silicon control rectifying device 25 conducts. Under these conditions, no breakdown voltage is applied to diode 26 of privacy circuit 21 even though the handset of other telephone 13 is taken off from the main body, thus blocking the conduction to be applied to device 25.
JP12742778A 1978-10-18 1978-10-18 Multi-telephone device Pending JPS5553950A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12742778A JPS5553950A (en) 1978-10-18 1978-10-18 Multi-telephone device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12742778A JPS5553950A (en) 1978-10-18 1978-10-18 Multi-telephone device

Publications (1)

Publication Number Publication Date
JPS5553950A true JPS5553950A (en) 1980-04-19

Family

ID=14959682

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12742778A Pending JPS5553950A (en) 1978-10-18 1978-10-18 Multi-telephone device

Country Status (1)

Country Link
JP (1) JPS5553950A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60181952U (en) * 1984-05-15 1985-12-03 松下電工株式会社 phone secret device
EP0182393A2 (en) * 1984-11-12 1986-05-28 Amper S.A. Excluder device for telephones installed in parallel

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60181952U (en) * 1984-05-15 1985-12-03 松下電工株式会社 phone secret device
EP0182393A2 (en) * 1984-11-12 1986-05-28 Amper S.A. Excluder device for telephones installed in parallel

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