Equivalent Circuit Analysis of a WT-2 Piezoelectric Transducer.

An equivalent circuit is invaluable in the design of a sound source and in the prediction of its behavior when subject to an acoustic load. A piezoelectric transducer may actually be represented by means of two different equivalent circuits each of which will have the same impedance characteristics as the source. The attached computations show in detail how to compute the parameters of the two equivalent circuits for the WT-2 1200 piezoelectric transducer designed by P. Weber. The impedance of one of the two equivalent circuits is evaluated at various frequencies for the unloaded condition and the impedance loop thus obtained is compared with the source in-air measurements. Adjustments are made in the circuit to make its impedance match the actual source characteristics as closely as possible. The circuit is then modified by the addition of the theoretical acoustic water load and the impedance of this circuit are compared with measurements on the source in water.