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GB1149118A - Intercommunication telephone set - Google Patents

Intercommunication telephone set

Info

Publication number
GB1149118A
GB1149118A GB1615367A GB1615367A GB1149118A GB 1149118 A GB1149118 A GB 1149118A GB 1615367 A GB1615367 A GB 1615367A GB 1615367 A GB1615367 A GB 1615367A GB 1149118 A GB1149118 A GB 1149118A
Authority
GB
United Kingdom
Prior art keywords
receiver
diode
crosstalk
called party
opc2
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.)
Expired
Application number
GB1615367A
Inventor
George Ronald Gunson
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.)
Ericsson Telephones Ltd
Original Assignee
Ericsson Telephones 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 Ericsson Telephones Ltd filed Critical Ericsson Telephones Ltd
Priority to GB1615367A priority Critical patent/GB1149118A/en
Publication of GB1149118A publication Critical patent/GB1149118A/en
Priority to MY6900415A priority patent/MY6900415A/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)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

1,149,118. Intercommunication systems. ERICSSON TELEPHONES Ltd 16 Feb. 1968 [7 April, 1967], No. 16153/67. Heading H4K. In an intercommunication system in which calls are set up over the home line of the called party, the effects of crosstalk are prevented by inserting a diode in series with the calling party's permanent magnet type receiver until such time as the called party replies. When station A calls station B by lifting his handset (thus operating CS1 and CS2) and actuating cb and hence OPC1 (but not OPC2), CO1 and CO2, negative battery n is extended to B's home line b. At this time diode MR which is connected in series with receiver R is non conductive since there is an open circuit condition and consequently it prevents any crosstalk that may be occurring on the b wire from affecting the receiver. When B replies (CS1, CS2 operated) the diode becomes conductive so that speech signals from B can now influence the receiver, crosstalk being no longer present due to the removal of the open circuit condition. In an alternative embodiment, contacts OPC1 and OPC2 are monostable so that brief operation thereof causes ringing current to be applied over r to the called party and ringing " tone " (produced by the fluctuating voltage developed in r during the operation of B's buzzer BZ) to be applied via the short-circuited diode to the receiver.
GB1615367A 1967-04-07 1967-04-07 Intercommunication telephone set Expired GB1149118A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB1615367A GB1149118A (en) 1967-04-07 1967-04-07 Intercommunication telephone set
MY6900415A MY6900415A (en) 1967-04-07 1969-12-31 Intercommunication telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1615367A GB1149118A (en) 1967-04-07 1967-04-07 Intercommunication telephone set

Publications (1)

Publication Number Publication Date
GB1149118A true GB1149118A (en) 1969-04-16

Family

ID=10072137

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1615367A Expired GB1149118A (en) 1967-04-07 1967-04-07 Intercommunication telephone set

Country Status (2)

Country Link
GB (1) GB1149118A (en)
MY (1) MY6900415A (en)

Also Published As

Publication number Publication date
MY6900415A (en) 1969-12-31

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