High Power Transformer Employing Piezoelectric Ceramics

Abstract

0.10Pb(Mn_1/3Sb_2/3)O₃–0.47PbZrO₃–0.43PbTiO₃ piezoelectric ceramics in a single-layer transformer successfully produces a maximum available power of 11 W. This 42×10×1 mm piezoelectric transformer operates in a third order length expansion vibration mode, with a load impedance of 100 k Ω at the output terminal. Two types of ceramic fabrication have been tested: one using 5.5 m²/g specific surface area calcined powder sintered at 1100° C, the other using 2.0 m²/g specific surface area calcined powder sintered at 1300° C. While such ceramics are expected to be especially useful in multilayered structure transformers, as well, sintering at 1100° C would be preferred for multilayer designs because relatively low cost metals, such as Ag–Pd alloys, could be employed for the internal electrodes. With ceramics sintered at 1300° C, however, high cost metals such as Pt would have to be used.