Vibration detection vault alarm system

Claim 1

AN ELECTRICAL PROTECTION SYSTEM FOR DETECTING PHYSICAL ATTACKS ON A VAULT OR LIKE STRUCTURE, COMPRISING VIBRATION TRANSDUCER MEANS DISPOSED IN CLOSE PROXIMITY TO THE INSIDE SURFACE OF THE STRUCTURE TO BE PROTECTED SO AS TO BE SUBJECT TO ACCELERATION RESULTING FROM VIBRATORY ENERGY IN THE STRUCTURE WALLS AND ARRANGED TO PRODUCE AN ALTERNATING SIGNAL VOLTAGE PROPORTIONAL TO THE MAGNITUDE OF THE ACCELERATION TO WHICH IT IS SUBJECTED, MEANS TO FILTER SAID SIGNAL VOLTAGE TO SUPRESS FREQUENCY COMPONENTS THEREIN BELOW A PREDETERMINED VALUE, A FIRST AMPLIFIER, MEANS TO SUPPLY THE FILTERED SIGNAL VOLTAGE OUTPUT OF SAID FILTER MEANS TO THE INPUT CIRCUIT OF SAID FIRST AMPLIFIER, A RECTIFYING CIRCUIT COUPLED TO THE OUTPUT OF SAID FIRST AMPLIFIER AND ARRANGED TO PRODUCE A PULSATING DIRECT CURRENT FROM THE AMPLIFIED SIGNAL VOLTAGE OUTPUT OF SAID FIRST AMPLIFIER, AN INTEGRATING NETWORK HAVING A RELATIVELY LONG TIME CONSTANT AND COUPLED TO THE OUTPUT OF SAID RECTIFIER CIRCUIT TO INTEGRATE SAID PULSATING DIRECT CURRENT, A DIFFERENTIATING NETWORK HAVING A TIME CONSTANT SUBSTANTIALLY LONGER THAN SAID RELATIVELY LONG TIME CONSTANT AND COUPLED TO THE OUTPUT OF SAID INTERGRATING NETWORK TO DIFFERENTIATE THE INTEGRATED PULSATING DIRECT CURRENT OUTPUT OF SAID INTERGRATING CIRCUIT, A DETECTOR ARRANGED TO PRODUCE AN ALARM SIG-