Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04Q—SELECTING
  • H04Q1/00—Details of selecting apparatus or arrangements
  • H04Q1/18—Electrical details
  • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
  • H04Q1/38—Signalling arrangements; Manipulation of signalling currents using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/02—Constructional features of telephone sets
  • H04M1/23—Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/26—Devices for calling a subscriber
  • H04M1/515—Devices for calling a subscriber by generating or selecting signals other than trains of pulses of similar shape, or signals other than currents of one or more different frequencies, e.g. generation of dc signals of alternating polarity, coded pulses or impedance dialling

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19750459

Family Applications (1)

Country Status (2)

• 0
  • NL NL73107D patent/NL73107C/xx active
• 1949
  • 1949-10-28 FR FR998330D patent/FR998330A/fr not_active Expired

Also Published As

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