JPS5279705A - Privacy circuit in key telephone unit - Google Patents

Privacy circuit in key telephone unit

Info

Publication number
JPS5279705A
JPS5279705A JP15672475A JP15672475A JPS5279705A JP S5279705 A JPS5279705 A JP S5279705A JP 15672475 A JP15672475 A JP 15672475A JP 15672475 A JP15672475 A JP 15672475A JP S5279705 A JPS5279705 A JP S5279705A
Authority
JP
Japan
Prior art keywords
key telephone
telephone unit
privacy circuit
privacy
circuit
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.)
Granted
Application number
JP15672475A
Other languages
English (en)
Japanese (ja)
Other versions
JPS5440403B2 (enrdf_load_stackoverflow
Inventor
Koichi Sekiguchi
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.)
Iwatsu Electric Co Ltd
Iwasaki Tsushinki KK
Original Assignee
Iwatsu Electric Co Ltd
Iwasaki Tsushinki KK
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 Iwatsu Electric Co Ltd, Iwasaki Tsushinki KK filed Critical Iwatsu Electric Co Ltd
Priority to JP15672475A priority Critical patent/JPS5279705A/ja
Publication of JPS5279705A publication Critical patent/JPS5279705A/ja
Priority to US05/967,017 priority patent/US4254306A/en
Publication of JPS5440403B2 publication Critical patent/JPS5440403B2/ja
Granted 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
    • H04M1/68—Circuit arrangements for preventing eavesdropping

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)
JP15672475A 1975-12-26 1975-12-26 Privacy circuit in key telephone unit Granted JPS5279705A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP15672475A JPS5279705A (en) 1975-12-26 1975-12-26 Privacy circuit in key telephone unit
US05/967,017 US4254306A (en) 1975-12-26 1978-12-06 Key telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15672475A JPS5279705A (en) 1975-12-26 1975-12-26 Privacy circuit in key telephone unit

Publications (2)

Publication Number Publication Date
JPS5279705A true JPS5279705A (en) 1977-07-05
JPS5440403B2 JPS5440403B2 (enrdf_load_stackoverflow) 1979-12-03

Family

ID=15633935

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15672475A Granted JPS5279705A (en) 1975-12-26 1975-12-26 Privacy circuit in key telephone unit

Country Status (1)

Country Link
JP (1) JPS5279705A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52104008A (en) * 1976-02-27 1977-09-01 Taiko Denki Seisakusho:Kk Connecting method of button telephone apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4926241A (enrdf_load_stackoverflow) * 1972-07-12 1974-03-08
JPS4996604A (enrdf_load_stackoverflow) * 1973-01-13 1974-09-12

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4926241A (enrdf_load_stackoverflow) * 1972-07-12 1974-03-08
JPS4996604A (enrdf_load_stackoverflow) * 1973-01-13 1974-09-12

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52104008A (en) * 1976-02-27 1977-09-01 Taiko Denki Seisakusho:Kk Connecting method of button telephone apparatus

Also Published As

Publication number Publication date
JPS5440403B2 (enrdf_load_stackoverflow) 1979-12-03

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