Patent RU-94028114-A (RU)
Inventor: JAZOVTSEV V I
IPC: G08B13/00
Filed: 1994-07-27
Abstract: FIELD: security systems. SUBSTANCE: device has key and lock. Lock has synchronization unit 2, OR gate 5, pulse oscillator 6, pulse generator 10, code comparison unit 3, encoder 26, antenna circuit 8, final-control unit 7, synchronization oscillator 1 and asynchronous RS-flip-flop 4, which has two NOR gates. Output of synchronization oscillator 1 is connected to first input of code comparison unit 3. Second group input of code comparison unit 3 is connected to group output of decoder 26, its first output is connected to input of final-control unit 7, its third input is connected to output of pulse generator 10. Input of pulse generator 10 is connected to first input of pulse oscillator 6, which input is connected to output of OR gate 5, its second output is connected to lock antenna circuit 8. Direct input of asynchronous RS-flip-flop 4 is connected to first input of OR gate 5, which second input is connected to second output of code comparison unit 3. third input of code comparison unit 3 is connected to "one" setting input of asynchronous flip-flop 4, which "zero" setting input is connected to fourth input of code comparison unit 3 and to first input of synchronization unit 2. second input of synchronization unit 2 is connected to second output of pulse generator 6. Key has load resistor 23, circuit breaker 22, accumulating capacitor 13, circuit clock 12, rectifying diode 11, gate 15, which generates pulse leading edge, counter 18, commutator 19, code entering unit 20, antenna circuit 9, preliminary frequency divider 16, digital frequency divider 17, tuning resistor 25, code signal generator 21 and logical gate unit 24. Output of key antenna circuit 9 is connected to input of circuit clock 12 and to common line of key through serial circuit which has load resistor 23 and current circuit of circuit breaker 22. Common line of key is connected to key power supply line 14 through accumulating capacitor 13. Key power supply line 14 is connected to output of antenna circuit 9 through rectifying diode 11 and to first input of counter 18 through gate 15, which generates pulse leading edge. Group output of counter 18 is connected to first group input of commutator 19, which second group input is connected to group output of code entering unit 20. First input of key entering unit 20 is connected to key common line. First input of logical gate unit 24 is connected to key common line, its group output is connected to second group input of key entering unit 20, its second group input is connected to group output of digital frequency divider 17. One line that belongs to said group input is connected to second input of counter 18. First input of counter 18 is connected to first input of preliminary frequency divider 16 and to first input of digital frequency divider 17, which second input is connected to first output of preliminary frequency divider 16. Second output of preliminary frequency divider 16 is connected to output of circuit clock 12, its second output is connected to first input of code signal generator 21. Output of code signal generator 21 is connected to control input of circuit breaker 22, its second input is connected to output of commutator 19 and to key power supply line 14 through tuning resistor 25. Device provides possibility to detect emergency situations such as penetration of intruders to guarded object, fire, and so on. EFFECT: increased cryptographic reliability, increased sensitivity.