FR847280A - Improvements to telephone systems - Google Patents

Improvements to telephone systems

Info

Publication number
FR847280A
FR847280A FR847280DA FR847280A FR 847280 A FR847280 A FR 847280A FR 847280D A FR847280D A FR 847280DA FR 847280 A FR847280 A FR 847280A
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.)
Associated Electric Laboratories Inc
Original Assignee
Associated Electric Laboratories Inc
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 Associated Electric Laboratories Inc filed Critical Associated Electric Laboratories Inc
Application granted granted Critical
Publication of FR847280A publication Critical patent/FR847280A/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L15/00—Indicators provided on the vehicle or train for signalling purposes
    • B61L15/0018—Communication with or on the vehicle or train
    • B61L15/0036—Conductor-based, e.g. using CAN-Bus, train-line or optical fibres
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/001—Two-way communication systems between a limited number of parties

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
FR847280D 1937-12-10 1938-12-08 Improvements to telephone systems Expired FR847280A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US179125A US2168881A (en) 1937-12-10 1937-12-10 Telephone system

Publications (1)

Publication Number Publication Date
FR847280A true FR847280A (en) 1939-10-05

Family

ID=22655326

Family Applications (1)

Application Number Title Priority Date Filing Date
FR847280D Expired FR847280A (en) 1937-12-10 1938-12-08 Improvements to telephone systems

Country Status (3)

Country Link
US (1) US2168881A (en)
FR (1) FR847280A (en)
GB (1) GB521879A (en)

Also Published As

Publication number Publication date
GB521879A (en) 1940-06-03
US2168881A (en) 1939-08-08

Similar Documents

Publication Publication Date Title
FR865522A (en) Improvements to telephone systems
FR856153A (en) Improvements to telephone systems
FR831620A (en) Improvements to telephone systems
FR847855A (en) Improvements to aerial systems
FR951758A (en) Improvements to telephone systems
FR840325A (en) Improvements to telephone systems
FR50906E (en) Improvements to telephone systems
FR833176A (en) Improvements to telephone systems
FR838511A (en) Improvements to telephone systems
FR847279A (en) Improvements to telephone systems
FR835343A (en) Improvements to electrical systems
FR819791A (en) Improvements to telephone systems
FR846979A (en) Improvements to television systems
FR836908A (en) Improvements to telephone systems
FR847280A (en) Improvements to telephone systems
FR49556E (en) Improvements to telephone systems
FR833254A (en) Improvements to telephone systems
FR49014E (en) Improvements to telephone systems
FR832760A (en) Improvements to telegraph systems
FR931904A (en) Improvements to telephone systems
FR853385A (en) Improvements to telephone systems
FR844408A (en) Improvements to telecommunication systems
FR848213A (en) Improvements to telecommunications systems
FR931429A (en) Improvements to radio-telegraph systems
FR50504E (en) Improvements to telephone systems