A disk type piezoelectric transformer with crescent shape input electrodes

摘要

For most PZT based piezoelectric materials the shear mode coupling constant is twice as large as the transverse mode coupling. From this motivation, a new circular piezoelectric transformer was designed. Non-concentric input electrodes and non-uniform output poling lead to the usage of shear mode piezoelectric effect at (3,0) radial mode resonance frequency. A prototype three layered transformer with 25.4-mm in diameter and 1.5 mm in thickness, operating at 153 kHz, was fabricated and its characteristics were measured. Characteristics, such as efficiency, step-up ratio and temperature rise of the propoed transformer are presented.