Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M3/00—Automatic or semi-automatic exchanges
  • H04M3/08—Indicating faults in circuits or apparatus
  • H04M3/12—Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/71—Substation extension arrangements
  • H04M1/715—Substation extension arrangements using two or more extensions per line
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M19/00—Current supply arrangements for telephone systems
  • H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
  • H04M19/04—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20307662

Family Applications (1)

Country Status (4)

• 0
  • BE BE519670D patent/BE519670A/xx unknown
  • NL NL83319D patent/NL83319C/xx active
  • NL NLAANVRAGE7904096,B patent/NL178068B/xx unknown
• 1953
  • 1953-05-01 CH CH313062D patent/CH313062A/de unknown
  • 1953-05-05 FR FR1076687D patent/FR1076687A/fr not_active Expired

Also Published As

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