A method includes receiving a signal associated with one or more sensors. The method also includes examining one or more parameters of a signal conditioning circuit to determine whether clipping of the signal has occurred. The method further includes, upon a determination that clipping of the signal has occurred, decreasing a gain of the signal conditioning circuit. In addition, the method includes, upon a determination that clipping of the signal has not occurred, determining whether a cut-off frequency of the signal conditioning circuit is within a range of a frequency response of an object measured by the one or more sensors. The method can further include changing the cut-off frequency of the signal conditioning circuit and increasing a resistance or a capacitance of the signal conditioning circuit.

The present invention provides a method of surely detecting a crack in piezoelectric elements regardless of size of the crack. The method includes applying voltage to a first piezoelectric element of a pair of piezoelectric elements to cause deformation in the first piezoelectric element, forcibly deforming a second piezoelectric element of the pair of the piezoelectric elements to generate voltage from the second piezoelectric element according to the deformation of the first piezoelectric element, finding a transfer function of the pair of the piezoelectric elements based on values of the applied voltage and the generated voltage, and detecting presence or absence of a crack in the pair of the piezoelectric elements based on an objective value obtained from the found transfer function.

There is provided a print apparatus including: a piezoelectric member; an individual electrode formed in the piezoelectric member; a first common electrode formed in the piezoelectric member so that the first common electrode is opposed to the individual electrode; a second common electrode formed in the piezoelectric member so that the second common electrode is opposed to the individual electrode, a voltage to be applied to the second common electrode being different from a voltage to be applied to the first common electrode; and a detection circuit configured to detect a capacitance of a first capacitor configured by the piezoelectric member, the individual electrode, and the first common electrode and a second capacitor configured by the piezoelectric member, the individual electrode, and the second common electrode. The detection circuit includes an oscillation circuit configured to be connected to the individual electrode.

There is provided a print apparatus including: a piezoelectric member; an individual electrode formed in the piezoelectric member; a first common electrode formed in the piezoelectric member so that the first common electrode is opposed to the individual electrode; a second common electrode formed in the piezoelectric member so that the second common electrode is opposed to the individual electrode, a voltage to be applied to the second common electrode being different from a voltage to be applied to the first common electrode; and a detection circuit configured to detect a capacitance of a first capacitor configured by the piezoelectric member, the individual electrode, and the first common electrode and a second capacitor configured by the piezoelectric member, the individual electrode, and the second common electrode. The detection circuit includes an oscillation circuit configured to be connected to the individual electrode.

A method for measuring equivalent circuit parameters and resonant frequency of a piezoelectric resonator, by which the phase-frequency curve of the piezoelectric resonator is measured, and the resonant frequency and the anti-resonant frequency are obtained. Then, the slopes of the phase-frequency curve at the resonant frequency and the anti-resonant frequency are respectively measured. The resonant angular frequency and the anti-resonant angular frequency are also calculated. Finally, the equivalent circuit parameters of the piezoelectric resonator are obtained by solving a system of nonlinear equations.

A method for measuring equivalent circuit parameters and resonant frequency of a piezoelectric resonator, by which the phase-frequency curve of the piezoelectric resonator is measured, and the resonant frequency and the anti-resonant frequency are obtained. Then, the slopes of the phase-frequency curve at the resonant frequency and the anti-resonant frequency are respectively measured. The resonant angular frequency and the anti-resonant angular frequency are also calculated. Finally, the equivalent circuit parameters of the piezoelectric resonator are obtained by solving a system of nonlinear equations.

Activity of piezoelectric material dimension and electrical properties can be changed with an applied stress. These variations are translated to a change in capacitance of the structure. Use of capacitance-voltage measurements for the extraction of double piezoelectric thin film material deposited at the two faces of a flexible steel sheet is described. Piezoelectric thin film materials are deposited using RF sputtering techniques. Gamry analyzer references 3000 is used to collect the capacitance-voltage measurements from both layers. A developed algorithm extracts directly the piezoelectric coefficients knowing film thickness, applied voltage, and capacitance ratio. The capacitance ratio is the ratio between the capacitances of the film when the applied field in antiparallel and parallel to the poling field direction, respectively. Piezoelectric bulk ceramic is used for calibration and validation by comparing the result with the reported values from literature. Extracted values using the current approach match well values extracted by existing methods.

A method for testing a drug delivery device including a piezoelectric transducer, a microcontroller, and a DC power source, with the piezoelectric transducer having an operative state and inoperative state. The method includes providing a drive signal to the piezoelectric transducer of the drug delivery device, determining an actuation voltage value or an actuation current value, and comparing the actuation voltage value or the actuation current value to a baseline value to determine whether the piezoelectric transducer is in the operative state or the inoperative state.

A method for testing a drug delivery device including a piezoelectric transducer, a microcontroller, and a DC power source, with the piezoelectric transducer having an operative state and inoperative state. The method includes providing a drive signal to the piezoelectric transducer of the drug delivery device, determining an actuation voltage value or an actuation current value, and comparing the actuation voltage value or the actuation current value to a baseline value to determine whether the piezoelectric transducer is in the operative state or the inoperative state.

A diagnostic device includes: a generation circuit that generates an inspection signal that is an alternating current signal of a single frequency, a conversion circuit that converts, into a direct current signal, a response signal of a piezoelectric element in response to the inspection signal, and a controller that analyzes the direct current signal and determines whether the piezoelectric element operates normally based on the analysis of the direct current signal.