JPS57157669A - Key telephone system - Google Patents

Key telephone system

Info

Publication number
JPS57157669A
JPS57157669A JP4243181A JP4243181A JPS57157669A JP S57157669 A JPS57157669 A JP S57157669A JP 4243181 A JP4243181 A JP 4243181A JP 4243181 A JP4243181 A JP 4243181A JP S57157669 A JPS57157669 A JP S57157669A
Authority
JP
Japan
Prior art keywords
control
signal
telephone set
signal line
tel8
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
JP4243181A
Other languages
Japanese (ja)
Inventor
Chuta Aikawa
Masaru Kasuya
Kenji Etsuno
Noboru Kanzaki
Masateru Kuroda
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.)
Tamura Electric Works Ltd
Original Assignee
Tamura Electric Works 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 Tamura Electric Works Ltd filed Critical Tamura Electric Works Ltd
Priority to JP4243181A priority Critical patent/JPS57157669A/en
Publication of JPS57157669A publication Critical patent/JPS57157669A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems
    • H04M9/005—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems with subscriber controlled access to an exchange line

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

PURPOSE:To use a signal line in common by transmitting control information by using the signal line common to a main device and each telephone set and adjusting the voltage of an encoded signal transmitted from each telephone set so as not to be received to other telephone sets. CONSTITUTION:A main device KSU is provided with a switch unit SWU, which performs switching connection between respective telephone sets through a trunk unit TKU. A control line LS connects between a control unit CTU and respective telephone sets TEL1-TEL8 and transmits only a control signal. Each telephone set TEL1-TEL8 is provided a receiving part to receive a control signal and a transmitting circuit to transmit an encoded signal to the signal line LS as the voltage which can be received only by the control unit CTU.
JP4243181A 1981-03-25 1981-03-25 Key telephone system Pending JPS57157669A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4243181A JPS57157669A (en) 1981-03-25 1981-03-25 Key telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4243181A JPS57157669A (en) 1981-03-25 1981-03-25 Key telephone system

Publications (1)

Publication Number Publication Date
JPS57157669A true JPS57157669A (en) 1982-09-29

Family

ID=12635872

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4243181A Pending JPS57157669A (en) 1981-03-25 1981-03-25 Key telephone system

Country Status (1)

Country Link
JP (1) JPS57157669A (en)

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