System for comparing a reference signal with a filtered signal to detect pressure discontinuity

A pressure discontinuity analysis system, applicable to a fluid pressure which, except for small magnitude fluctuations, is normally substantially constant or within a narrow range, comprising:

• pressure transducer means for converting pressure changes into time-varying electrical signals;
• low-pass filter means, said signals being applied to said low-pass filter means for suppressing high-frequency oscillations, thereby producing a filtered signal;
• direct current (DC) blocking means, coupled to the output of said low-pass filter means for substantially removing the direct current component of said filtered signal;
• alternating current (AC) amplifying means, coupled to the output of said DC blocking means for amplification of the alternating current component of said filtered signal thereby producing an output AC signal;
• reference signal producing means coupled to the output of said AC amplifying means for generating a time-varying reference signal proportional to an average magnitude of said filtered signal during normal continuous variation of said pressure;
• comparator means having a first input coupled to said AC amplifying means and a second input coupled to said reference signal producing means, for comparing the output AC signal of said AC amplifying means with said reference signal of the reference signal producing means, said comparator means also for producing an output pulse when a significant pressure discontinuity occurs;
• bistable switch means for providing an on-off signal, coupled to the output of said comparator, and providing an on-off signal when an output pulse is received from said comparator;
• and
• detection use means coupled to said bistable switch means for providing a detection use signal upon operation of said bistable switch means.

A pressure discontinuity analysis system, applicable to a fluid pressure which, except for small magnitude fluctuations, is normally substantially constant or within a narrow range, comprising:

• pressure transducer means for converting pressure changes to time-varying electrical signals;
• signal conditioning means for suppressing direct current (DC) components while amplifying alternating current (AC) components of said signals, thereby producing a conditioned signal;
• reference signal producing means coupled to the output of said conditioning means for generating a reference signal proportional to the average magnitude of said conditioned signal during normal continuous variation of said pressure;
• circuit means, including a comparator having two inputs, including a first input coupled to said signal conditioning means and a second input coupled to said reference signal producing means, for comparing the conditioned signal of said signal conditioning means of said conditioning means with said reference signal, said circuit means further including a bistable switch comparator means for producing an output on-state signal when a significant pressure discontinuity occurs, and wherein said circuit means is insensitive to minor pressure and corresponding signal variations but produces an output on-state signal upon major pressure discontinuities;
• and
• detection use means coupled to said circuit means for providing a detection use signal upon reception of said output on-state signal from said circuit means.