JPS556999A - Privacy circuit of key telephone system - Google Patents

Privacy circuit of key telephone system

Info

Publication number
JPS556999A
JPS556999A JP8510079A JP8510079A JPS556999A JP S556999 A JPS556999 A JP S556999A JP 8510079 A JP8510079 A JP 8510079A JP 8510079 A JP8510079 A JP 8510079A JP S556999 A JPS556999 A JP S556999A
Authority
JP
Japan
Prior art keywords
relay
privacy
key telephone
winding
telephone system
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
JP8510079A
Other languages
Japanese (ja)
Other versions
JPS593913B2 (en
Inventor
Minoru Sasai
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.)
Kanda Tsushin Kogyo Co Ltd
Original Assignee
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 Kanda Tsushin Kogyo Co Ltd filed Critical Kanda Tsushin Kogyo Co Ltd
Priority to JP8510079A priority Critical patent/JPS593913B2/en
Publication of JPS556999A publication Critical patent/JPS556999A/en
Publication of JPS593913B2 publication Critical patent/JPS593913B2/en
Expired 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

Landscapes

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

Abstract

PURPOSE:To obtain a privacy circuit for the key telephone system in order to secure the use of two pieces of control lines for other purposes than the privacy talk. CONSTITUTION:The key telephone sets TEL0 and TEL1 consist of connection terminals l1, l2, h1 and h2to main unit 1; telephone circuit network N; fixed switches HS<0> and HS<1>; winding S for the privacy-use relay; relay K comprising contacts s<0> and s<1> of relay S, primary winding K(P), secondary winding K(S) plus contact k; diodes D1-D5; transistor Tr1, resistances R1-R4; and capacitors C1 and C2. While unit 1 consists of detection circuit DET, primary winding H(D), secondary winding H(S), relay H for polarity inversion comprising contacts h<0>- h<3>, transistor Tr0, resistances R0 and R10, diode D0 and capacitor C0 respectively.
JP8510079A 1979-07-06 1979-07-06 Confidential relay drive circuit in button telephone equipment Expired JPS593913B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8510079A JPS593913B2 (en) 1979-07-06 1979-07-06 Confidential relay drive circuit in button telephone equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8510079A JPS593913B2 (en) 1979-07-06 1979-07-06 Confidential relay drive circuit in button telephone equipment

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP8967375A Division JPS5213707A (en) 1975-07-23 1975-07-24 Privacy system in key telephone system

Publications (2)

Publication Number Publication Date
JPS556999A true JPS556999A (en) 1980-01-18
JPS593913B2 JPS593913B2 (en) 1984-01-26

Family

ID=13849184

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8510079A Expired JPS593913B2 (en) 1979-07-06 1979-07-06 Confidential relay drive circuit in button telephone equipment

Country Status (1)

Country Link
JP (1) JPS593913B2 (en)

Also Published As

Publication number Publication date
JPS593913B2 (en) 1984-01-26

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