FR475417A - Improvements to telephone systems - Google Patents

Improvements to telephone systems

Info

Publication number
FR475417A
FR475417A FR475417A FR475417DA FR475417A FR 475417 A FR475417 A FR 475417A FR 475417 A FR475417 A FR 475417A FR 475417D A FR475417D A FR 475417DA FR 475417 A FR475417 A FR 475417A
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
FR475417A
Other languages
French (fr)
Inventor
George Larkin Hughes
Robert Emmet Cooper
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.)
Individual
Original Assignee
Individual
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of FR475417A publication Critical patent/FR475417A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/04—Telephonic communication systems specially adapted for combination with other electrical systems with alarm systems, e.g. fire, police or burglar alarm systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Fire Alarms (AREA)
  • Alarm Systems (AREA)
FR475417A 1914-07-18 Improvements to telephone systems Expired FR475417A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE292956T

Publications (1)

Publication Number Publication Date
FR475417A true FR475417A (en) 1915-05-12

Family

ID=6076350

Family Applications (1)

Application Number Title Priority Date Filing Date
FR475417A Expired FR475417A (en) 1914-07-18 Improvements to telephone systems

Country Status (2)

Country Link
DE (1) DE292956C (en)
FR (1) FR475417A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE864103C (en) * 1949-10-29 1953-01-22 Normalzeit G M B H Circuit arrangement for telephone extension systems

Also Published As

Publication number Publication date
DE292956C (en)

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