Frequency regulation method for series tuned piezoelectric transducer

摘要

The frequency regulation method involves using a phase measuring signal obtained between a polarity signal for the primary current of the piezoelectric transducer and an orthogonal signal proportional to the frequency of the piezoelectric transducer, generated in synchronism with the base oscillation. The phase signal is used to obtain a frequency signal for which the phase signal is zero at the transmission minimum. The resulting frequency-proportional rectangular signal is used for providing a control signal for the series tuned piezoelectric transducer.