A lead-free piezoelectric transformer in radial vibration modes

Mingsen Guo, D. M. Lin, K. H. Lam, S. Wang, Helen L. W. Chan, X. Z. Zhao
2007 Review of Scientific Instruments  
In this study, a disk-shaped piezoelectric transformer was fabricated using lead-free ͑K,Na͒NbO 3 -based ceramics with high mechanical quality factor. The transformer can operate in the fundamental or the third radial vibration mode. The transformer is poled along the thickness direction. The top surface is covered by ring/dot silver electrodes separated by an annular gap which serve as the input and output parts of the transformer, respectively. The bottom surface, fully covered with a silver
more » ... lectrode, is grounded as a common electrode. The dimensions of the top ring/dot electrodes are designed such that the third radial vibration mode can be strongly excited. The electrical properties of the transformer with diameter of 34.2 mm and thickness of 1.9 mm were measured. For a temperature rise of 35°C, the transformer has a maximum output power of 12 W. With the matching load, its maximum efficiency is Ͼ95%, and maximum voltage gains are 6.5 and 3.9 for the fundamental and the third radial vibration modes, respectively. It has potential to be used in power supply units and other electronic circuits.
doi:10.1063/1.2712795 pmid:17411212 fatcat:um44px7ccneh3dbtu2kb2oja2a