Classifications

• • 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
  • H04M1/21—Combinations with auxiliary equipment, e.g. with clocks or memoranda pads
  • H04M1/215—Combinations with auxiliary equipment, e.g. with clocks or memoranda pads by non-intrusive coupling means, e.g. acoustic couplers
  • H04M1/2155—Acoustic coupling
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
  • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M1/00—Substation equipment, e.g. for use by subscribers
  • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
  • H04M1/62—Constructional arrangements

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Coils Or Transformers For Communication (AREA)
• Details Of Audible-Bandwidth Transducers (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10038122

Family Applications (1)

Country Status (3)

• 0
  • BE BE499477D patent/BE499477A/xx unknown
• 1948
  • 1948-01-23 GB GB207648A patent/GB646589A/en not_active Expired
• 1950
  • 1950-06-08 GB GB1427050A patent/GB684633A/en not_active Expired
  • 1950-11-22 CH CH288283D patent/CH288283A/de unknown

Also Published As

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