STALL SURGE DETECTOR

摘要

In a pressure measuring system which includes a pressure transducer for generating an analogue signal as a function of pressure, circuitry for generating a nonlinear error signal as a function of the difference between the input signal and a feedback signal, a feedback circuit which generates the feedback signal as a function of said error signal to null the error signal and generates a digital output signal as a function of the pressure, a pressure surge detecting circuit having an amplitude detector connected to said pressure measuring system to receive the error signal and generating an output signal when the error signal is equal to and greater than a predetermined magnitude: a timer circuit connected to receive said output signal and generate an alarm signal when the output signal continues for a predetermined period of time, a digital computing circuit connected to receive the digital output signal for computing the rate of change of pressure and the change in pressure, a memory circuit storing predetermined maximum and minimum values of the rate of change and change of pressure, respectively, the computing circuit effecting comparison of the computed values of rate of change and change in pressure to stored values to generate first and second computed output signals when both are in excess of the stored values, the timer means being connected to receive at least one of the computed output signals to generate the alarm signal when the computed output signals continue for a predetermined period of time.