Vibration detection apparatus

Claim 1

IN SIGNAL DETECTION AND TRIP APPARATUS OPERATIVE WITH ALTERNATING SIGNALS PROPORTIONAL EITHER TO THE AMPLITUDE OR TO THE AMPLITUDE AND FREQUENCY OF A DETECTED VIBRATION THE COMBINATION OF: DEMODULATOR MEANS TO RECEIVE SAID ALTERNATING SIGNALS AND BEING OPERATIVE TO CONVERT SAID ALTERNATING SIGNALS INTO UNIDIRECTION SIGNALS PROPORTIONAL TO THE AMPLITUDE OF SAID ALTERNATING SIGNALS, SAID DEMODULATOR MEANS HAVING DIFFERENT TIME CONSTANTS FOR INCREASING AND DECREASING AMPLITUDES OF SAID ALTERNATING SIGNALS, SAID DEMODULATOR MEANS INCLUDING A CAPACITIVE ELEMENT HAVING AN INPUT AND AN OUTPUT END TO RECEIVE SAID ALTERNATING SIGNALS AT THE INPUT THEREOF, A UNIDIRECTION DEVICE COUPLED TO THE OUTPUT END OF SAID CAPACITIVE ELEMENT TO PERMIT SAID CAPACITIVE ELEMENT TO CHARGE TO A VOLTAGE OF A GIVEN POLARITY IN PROPORTION TO THE AMPLITUDE OF SAID ALTERNATING SIGNALS AT A RELATIVELY SHORT TIME CONSTANT, AND AN IMPEDANCE ELEMENT COUPLED TO SAID CAPACITIVE ELEMENT AT THE OUTPUT END TO PERMIT SAID CAPACITIVE ELEMENT TO DISCHARGE AT A RELATIVELY LONG TIME CONSTANT WHEN THE AMPLITUDE OF SAID ALTERNATING SIGNALS DROPS BELOW THW PREVIOUS CHARGING LEVEL ON SAID CAPACITIVE ELEMENT, ACTIVE ELEMENT MEANS COUPLED AT AN INPUT THEREOF TO THE OUTPUT END OF SAID CAPACITIVE ELEMENT TO PREVENT THE DISCHARGE OF SAID CAPACITIVE ELEMENT THROUGH SAID ACTIVE ELEMENT MEANS AND TO PROVIDE UNIDIRECTIONAL SIGNALS PROPORTIONAL TO THE AMPLITUDE OF SAID ALTERNATING SIGNALS AND AN OUTPUT THEREOF, AND A FEEDBACK IMPEDANCE ELEMENT COUPLED BETWEEN THE OUTPUT OF SAID ACTIVE ELEMENT MEANS AND THE INPUT END OF SAID CAPACITIVE ELEMENT TP COMPENSATE FOR CLIPPING AT THE MAXIMUM EXCURSIONS OF SAID ALTERNATING SIGNALS CAUSED BY NON-IDEAL CHARACTERISTICS OF SAID UNIDIRECTION DEVICE; COMPARING MEANS COUPLED TO SAID DEMODULATOR MEANS TO COMPARE SAID UNIDIRECTION SIGNALS WITH A PREDETERMINED REFERENCE LEVER TO PROVIDE DIFFERENCE SIGNALS WHEN SAID UNIDIRECTIONAL SIGNALS REACH A PREDETERMINED LEVEL; SWITCHING MEANS HAVING TWO OPERATIVE STATES COUPLED TO SAID COMPARING MEANS AND BEING RESPONSIVE TO SAID DIFFERENCE SIGNALS TO CHANGE OPERATIVE STATES; OUTPUT MEANS CONNECTED TO SAID SWITCHING MEANS TO BE ACTIVATED WHEN SAID COMPARING MEANS CHANGES STATE; AND HOLDING MEANS COUPLED BETWEEN SAID OUTPUT MEANS AND SAID COMPARING MEANS TO MAINTAIN SAID SWITCHING MEANS IN ITS CHANGED STATE UNTIL RESET.