JPS5373009A - Privacy call circuit of button telephone device - Google Patents

Privacy call circuit of button telephone device

Info

Publication number
JPS5373009A
JPS5373009A JP14960976A JP14960976A JPS5373009A JP S5373009 A JPS5373009 A JP S5373009A JP 14960976 A JP14960976 A JP 14960976A JP 14960976 A JP14960976 A JP 14960976A JP S5373009 A JPS5373009 A JP S5373009A
Authority
JP
Japan
Prior art keywords
telephone device
button telephone
call circuit
privacy call
privacy
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
JP14960976A
Other languages
English (en)
Japanese (ja)
Other versions
JPS5536223B2 (cs
Inventor
Koichi Sekiguchi
Juichi Takano
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
Original Assignee
Iwatsu 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 Iwatsu Electric Co Ltd filed Critical Iwatsu Electric Co Ltd
Priority to JP14960976A priority Critical patent/JPS5373009A/ja
Publication of JPS5373009A publication Critical patent/JPS5373009A/ja
Publication of JPS5536223B2 publication Critical patent/JPS5536223B2/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)
JP14960976A 1976-12-13 1976-12-13 Privacy call circuit of button telephone device Granted JPS5373009A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14960976A JPS5373009A (en) 1976-12-13 1976-12-13 Privacy call circuit of button telephone device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14960976A JPS5373009A (en) 1976-12-13 1976-12-13 Privacy call circuit of button telephone device

Publications (2)

Publication Number Publication Date
JPS5373009A true JPS5373009A (en) 1978-06-29
JPS5536223B2 JPS5536223B2 (cs) 1980-09-19

Family

ID=15478937

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14960976A Granted JPS5373009A (en) 1976-12-13 1976-12-13 Privacy call circuit of button telephone device

Country Status (1)

Country Link
JP (1) JPS5373009A (cs)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61220552A (ja) * 1985-03-26 1986-09-30 Nec Corp 秘話方式

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4996604A (cs) * 1973-01-13 1974-09-12

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4996604A (cs) * 1973-01-13 1974-09-12

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61220552A (ja) * 1985-03-26 1986-09-30 Nec Corp 秘話方式

Also Published As

Publication number Publication date
JPS5536223B2 (cs) 1980-09-19

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