BURGLAR ALARM CODER Russian patent published in 1996 - IPC

FIELD: burglar alarm systems for transportation facilities, such as motor cars. SUBSTANCE: device has two constructionally isolated parts: lock and switch. Lock has synchronizing generator 1, synchronizing unit 2, coder 3, OR gate 4, pulse generator 5, antenna circuit 6, pulse shaper 20, code comparison unit 21, final unit 22. Switch has antenna circuit 7 connected to anodes of rectifier diode 8 and isolating diode 9, storage capacitor 10, pulse shaper 11, pulse length selector 12 whose output is connected to second input of counter 13, commutator 14, code dialing unit 15, switch power bus 16, pulse generator 17, chopper 18, loading resistor 19, and flip-flop 23. Bringing switch to ac magnetic field region of antenna circuit 6 of lock compares codes dialed on coder 3 provided in lock and in code dialing unit 15 incorporated in switch. In case of coincidence, final unit 22 is switched off. EFFECT: improved functional reliability of coder. 2 cl, 2 dwg