Abstract: The present invention is directed to an apparatus and method for a measurement system for the testing of transducers, and more particularly to the testing of piezoelectric transducers. The measurement system includes a transducer, a feedback amplifier coupled to the transducer and a signal processing circuit coupled to the output of the amplifier. The method of testing the transducer includes coupling the test signal to the transducer, disabling the amplifier, and measuring the response of the transducer to the test signal with the test processing circuit.

Abstract: The present invention is directed to an apparatus and method for a measurement system for the testing of transducers, and more particularly to the testing of piezoelectric transducers. The measurement system includes a transducer, a feedback amplifier coupled to the transducer and a signal processing circuit coupled to the output of the amplifier. The method of testing the transducer includes coupling the test signal to the transducer, disabling the amplifier, and measuring the response of the transducer to the test signal with the test processing circuit.

Abstract: An autonomous sensor system is provided for powering sensors using thermoelectric modules driven by thermal energy. The system includes solid-state thermoelectric (TE) modules for the conversion of thermal energy to electrical energy. The TE modules are composed of p-type and n-type semiconductors that are interdigitated so that the p-type and n-type elements form thermocouples. The TE modules derive electrical power from thermal energy available in the immediate environment. The system also includes sensors that are powered by the TE module, wherein a corresponding free space signal is generated.

Abstract: The present invention provides an apparatus and method for in-situ testing of transducers, and more particularly to the testing of piezoelectric transducers including piezoelectric accelerometers. Circuits, measurement techniques, and interpretative algorithms to enable in-situ testing of piezoelectric accelerometers are described. Accelerometers that employ a piezoelectric material to convert mechanical strains into electronic signals are reciprocal electromechanical transducers. In such transducers the electrical output impedance of the sensor is dependent upon the electrical and mechanical parameters of the sensor. The procedure described in this disclosure includes methods of measuring the transducer electrical output impedance as a function of frequency and the extraction of the electrical and mechanical transducer parameters from the measured data. The measured values of the transducer parameters may be interpreted to provide an indication of the operational status of the transducer.

Abstract: The present invention provides an apparatus and method for in-situ testing of transducers, and more particularly to the testing of piezoelectric transducers including piezoelectric accelerometers. Circuits, measurement techniques, and interpretative algorithms to enable in-situ testing of piezoelectric accelerometers are described. Accelerometers that employ a piezoelectric material to convert mechanical strains into electronic signals are reciprocal electromechanical transducers. In such transducers the electrical output impedance of the sensor is dependent upon the electrical and mechanical parameters of the sensor. The procedure described in this disclosure includes methods of measuring the transducer electrical output impedance as a function of frequency and the extraction of the electrical and mechanical transducer parameters from the measured data. The measured values of the transducer parameters may be interpreted to provide an indication of the operational status of the transducer.