| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric transformer with less spuriousness by varying the thickness of the piezoelectric transformer of a part having an electrode from that of a peripheral part which does not have the electrode in the piezoelectric transformer using energy containment vibration. SOLUTION: A pair of input electrodes 32 and 33 confronted in a thickness direction, and the plural pairs of output electrodes 34 and 35 exist in the center part of a square board constituted of piezoelectric ceramic. Then, thickness differs in the parts of the inner electrodes and a peripheral part. Thus, a difference occurs in a transmission frequency at the peripheral part and the electrode parts. When AC voltage which is almost equal to the resonance frequency of energy containment vibration at a thickness vertical vibration mode in the electrode parts of the piezoelectric board is applied between the input electrodes 32 and 33, the energy containment vibration of the thickness vertical vibration mode is excited near the confronted electrodes 32 and 33. Output voltage is generated between the output electrodes 34 and 35 by piezoelectric effect.
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