GB1277188A - Telephone conference circuit - Google Patents

Telephone conference circuit

Info

Publication number
GB1277188A
GB1277188A GB57456/70A GB5745670A GB1277188A GB 1277188 A GB1277188 A GB 1277188A GB 57456/70 A GB57456/70 A GB 57456/70A GB 5745670 A GB5745670 A GB 5745670A GB 1277188 A GB1277188 A GB 1277188A
Authority
GB
United Kingdom
Prior art keywords
circuit
subscriber
dec
common
conference circuit
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
GB57456/70A
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.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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 International Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB1277188A publication Critical patent/GB1277188A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/42—Systems providing special services or facilities to subscribers
    • H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
    • H04M3/568—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/42—Systems providing special services or facilities to subscribers
    • H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
  • Amplifiers (AREA)

Abstract

1277188 Automatic exchange systems; antiside tone circuit INTERNATIONAL STANDARD ELECTRIC CORP 3 Dec 1970 [5 Dec 1969] 57456/70 Headings H4K and H4R A conference circuit for up to ten or more subscribers comprises a common amplifier to the input of which each subscriber's transmitter is connected and to the output of which an individual receive amplifier for each subscriber is connected. The common and individual amplifiers are each operational amplifiers of the integrated circuit type and they each have a variable feedback circuit, for example resistances formed by printed circuit techniques, for adjusting the degree of sidetone whereby singing in the current talker's subset is prevented. (For Figure see next page) 6
GB57456/70A 1969-12-05 1970-12-03 Telephone conference circuit Expired GB1277188A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US88280269A 1969-12-05 1969-12-05

Publications (1)

Publication Number Publication Date
GB1277188A true GB1277188A (en) 1972-06-07

Family

ID=25381362

Family Applications (1)

Application Number Title Priority Date Filing Date
GB57456/70A Expired GB1277188A (en) 1969-12-05 1970-12-03 Telephone conference circuit

Country Status (3)

Country Link
ES (1) ES386184A1 (en)
GB (1) GB1277188A (en)
ZA (1) ZA707784B (en)

Also Published As

Publication number Publication date
ZA707784B (en) 1971-08-25
ES386184A1 (en) 1973-03-16

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees