JPS5781754A - Improved double-telephone set - Google Patents

Improved double-telephone set

Info

Publication number
JPS5781754A
JPS5781754A JP55137440A JP13744080A JPS5781754A JP S5781754 A JPS5781754 A JP S5781754A JP 55137440 A JP55137440 A JP 55137440A JP 13744080 A JP13744080 A JP 13744080A JP S5781754 A JPS5781754 A JP S5781754A
Authority
JP
Japan
Prior art keywords
telephone
circuit
telephone circuit
voltage
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
JP55137440A
Other languages
English (en)
Japanese (ja)
Other versions
JPH029743B2 (enrdf_load_stackoverflow
Inventor
Akinobu Sekiguchi
Tokuji Yamada
Minoru Sasai
Yoshio Nagasaki
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.)
Nippon Telegraph and Telephone Corp
Kanda Tsushin Kogyo Co Ltd
Original Assignee
Nippon Telegraph and Telephone Corp
Kanda Tsushin Kogyo 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 Nippon Telegraph and Telephone Corp, Kanda Tsushin Kogyo Co Ltd filed Critical Nippon Telegraph and Telephone Corp
Priority to JP55137440A priority Critical patent/JPS5781754A/ja
Publication of JPS5781754A publication Critical patent/JPS5781754A/ja
Publication of JPH029743B2 publication Critical patent/JPH029743B2/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
    • H04M1/71—Substation extension arrangements
    • 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
    • H04M1/70—Lock-out or secrecy arrangements in party-line systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)
JP55137440A 1980-10-01 1980-10-01 Improved double-telephone set Granted JPS5781754A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55137440A JPS5781754A (en) 1980-10-01 1980-10-01 Improved double-telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55137440A JPS5781754A (en) 1980-10-01 1980-10-01 Improved double-telephone set

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP51037307A Division JPS597254B2 (ja) 1976-04-05 1976-04-05 改良形親子電話装置

Publications (2)

Publication Number Publication Date
JPS5781754A true JPS5781754A (en) 1982-05-21
JPH029743B2 JPH029743B2 (enrdf_load_stackoverflow) 1990-03-05

Family

ID=15198668

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55137440A Granted JPS5781754A (en) 1980-10-01 1980-10-01 Improved double-telephone set

Country Status (1)

Country Link
JP (1) JPS5781754A (enrdf_load_stackoverflow)

Also Published As

Publication number Publication date
JPH029743B2 (enrdf_load_stackoverflow) 1990-03-05

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