In this study, a new disk-type piezoelectric transformer design is proposed. The input side of the transformer has a crescent-shaped electrode and the output side has a focused poling direction. The electrodes and poling directions on commercially available piezoelectric ceramic disks were designed so that the planar or shear mode coupling factor (kp or k15) becomes effective rather than the transverse mode coupling factor (k31). ATILA finite element code was used to analyze transformer behavior and to optimize electrode and poling configurations. The voltage step-up ratio of the proposed transformer has been markedly improved in comparison with that of the equivalent rectangular type. A single layer prototype transformer, 25.4 mm in diameter and 1.0 mm thick, operated at 92.8 kHz, was fabricated and its characteristics, such as step-up ratio and power transformation efficiency were measured. While the transformer was driving a cold cathode fluorescent lamp (CCFL), the temperature field of the transformer was also observed.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)