SECURITY CODE-LOCK DEVICE Russian patent published in 1997 - IPC

FIELD: emergency alarm systems, which protect against intrusion, fire and so on. SUBSTANCE: device has lock and key. Lock is designed as synchronization unit, OR gate, pulse oscillator, pulse generator, code comparison circuit, encoder, antenna circuit, final-control unit, synchronization generator, asynchronous RS flip-flop which has two NOR gates. Key has load resistor, circuit breaker, accumulating capacitor, clock oscillator, rectifying diode, pulse edge generator, counter, commutator, code input unit, antenna circuit, preliminary frequency divider, digit divider, unit of gates. This results in possibility to increase number of codes to be entered, to eliminate gaps in pulse generation during switch from one digit of code to another, to exclude generation of false codes. EFFECT: increased safety, increased sensitivity. 11 dwg