Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04M—TELEPHONIC COMMUNICATION
  • H04M17/00—Prepayment of wireline communication systems, wireless communication systems or telephone systems
  • H04M17/02—Coin-freed or check-freed systems, e.g. mobile- or card-operated phones, public telephones or booths
  • H04M17/023—Circuit arrangements

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Computer Security & Cryptography (AREA)
• Signal Processing (AREA)
• Interface Circuits In Exchanges (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20308758

Family Applications (1)

Country Status (6)

• 0
  • BE BE378410D patent/BE378410A/xx unknown
  • NL NL34614D patent/NL34614C/xx active
• 1931
  • 1931-03-13 US US522461A patent/US1855087A/en not_active Expired - Lifetime
  • 1931-03-18 FR FR713494D patent/FR713494A/fr not_active Expired
  • 1931-03-19 DE DET38565D patent/DE583068C/de not_active Expired
  • 1931-03-19 GB GB8512/31A patent/GB355181A/en not_active Expired

Also Published As

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