FR680025A - Improvements to telephone systems - Google Patents

Improvements to telephone systems

Info

Publication number
FR680025A
FR680025A FR680025DA FR680025A FR 680025 A FR680025 A FR 680025A FR 680025D A FR680025D A FR 680025DA FR 680025 A FR680025 A FR 680025A
Authority
FR
France
Prior art keywords
telephone systems
telephone
systems
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.)
Thales SA
Original Assignee
Le Materiel Telephonique Thomson CSF
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 Le Materiel Telephonique Thomson CSF filed Critical Le Materiel Telephonique Thomson CSF
Application granted granted Critical
Publication of FR680025A publication Critical patent/FR680025A/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

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
FR680025D 1928-07-20 1929-07-18 Improvements to telephone systems Expired FR680025A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB21064/28A GB324328A (en) 1928-07-20 1928-07-20 Improvements in telephone systems

Publications (1)

Publication Number Publication Date
FR680025A true FR680025A (en) 1930-04-24

Family

ID=10156588

Family Applications (1)

Application Number Title Priority Date Filing Date
FR680025D Expired FR680025A (en) 1928-07-20 1929-07-18 Improvements to telephone systems

Country Status (5)

Country Link
US (2) US1763013A (en)
BE (1) BE362519A (en)
DE (1) DE636403C (en)
FR (1) FR680025A (en)
GB (1) GB324328A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2601302A (en) * 1941-05-02 1952-06-24 Int Standard Electric Corp Two-way wire telephone repeater circuit
US2564084A (en) * 1946-11-02 1951-08-14 Automatic Elect Lab Telephone system having repeater insertion on long distance lines
US2550755A (en) * 1947-09-24 1951-05-01 Automatic Elect Lab Toll switching telephone system

Also Published As

Publication number Publication date
DE636403C (en) 1936-10-13
BE362519A (en)
USRE19741E (en) 1935-10-22
US1763013A (en) 1930-06-10
GB324328A (en) 1930-01-20

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