Classifications

• • 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
  • H04M1/30—Devices which can set up and transmit only one digit at a time
  • H04M1/50—Devices which can set up and transmit only one digit at a time by generating or selecting currents of predetermined frequencies or combinations of frequencies
• • 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
  • H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
  • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
  • H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
  • H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04Q—SELECTING
  • H04Q3/00—Selecting arrangements

Landscapes

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

Applications Claiming Priority (1)

Publications (1)

Family

ID=6833991

Family Applications (1)

Country Status (2)

• 0
  • BE BE448132D patent/BE448132A/xx unknown
• 1942
  • 1942-11-16 FR FR887937D patent/FR887937A/fr not_active Expired

Also Published As

Similar Documents