Smart card reader system for credit, cheque, access, telephone cards - using external power source and switched tuned circuits to transmit data by modifying coupling

摘要

Card reader (2) has card (1) inserted in slot (17). Card (1) contains microchip (3) with resonant circuit drawing external power for circuit operation. High frequency oscillator (8) drives tuned resonant circuit (5), coupled to resonant circuit (7). A detector circuit (9) generates signal (16). In operation, microchip (3) generates a pulse sequence according to internal stored data and modulates the signal coupled from (5) to (7) by switching its own resonant circuit. Signal (16) is then passed to evaluation circuitry. USE/ADVANTAGE - Card functions without internal power source, data storage on chip renders card duplication difficult and improves system security.