FR687997A - Improvements to telephone devices - Google Patents

Improvements to telephone devices

Info

Publication number
FR687997A
FR687997A FR687997DA FR687997A FR 687997 A FR687997 A FR 687997A FR 687997D A FR687997D A FR 687997DA FR 687997 A FR687997 A FR 687997A
Authority
FR
France
Prior art keywords
telephone devices
telephone
devices
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
Other languages
French (fr)
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.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
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 Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Application granted granted Critical
Publication of FR687997A publication Critical patent/FR687997A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/40—Applications of speech amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/42—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Structure Of Telephone Exchanges (AREA)
FR687997D 1929-01-12 1930-01-10 Improvements to telephone devices Expired FR687997A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE1819685X 1929-01-12

Publications (1)

Publication Number Publication Date
FR687997A true FR687997A (en) 1930-08-18

Family

ID=20423702

Family Applications (1)

Application Number Title Priority Date Filing Date
FR687997D Expired FR687997A (en) 1929-01-12 1930-01-10 Improvements to telephone devices

Country Status (4)

Country Link
US (1) US1819685A (en)
BE (1) BE366860A (en)
FR (1) FR687997A (en)
GB (1) GB360354A (en)

Also Published As

Publication number Publication date
GB360354A (en) 1931-10-22
US1819685A (en) 1931-08-18
BE366860A (en) 1930-02-28

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