| 摘要 |
<p>A piezoelectric transformer (21) comprising a rectangular piezoelectric body (23) divided into first to fourth regions (A1, A2, A3, and A4) in the longitudinal direction, planar electrodes (24, 25, 26, and 27) provided in the first and fourth regions (A1 and A4) as input electrodes, and belt-like electrodes (30 and 31) provided at the boundary between the second and third regions (A2 and A3) as output electrodes and polarized in the thickness direction. The piezoelectric body (21) is vibrated in a two-wavelength resonance mode by applying an AC input voltage having the frequency corresponding to the wavelength equal to half the length of the piezoelectric body to the input electrodes, and the voltage generated by the piezoelectric effect resulting from the vibration is taken out of the output terminal. This transformer has a small size, generates little vibration speed heat, and is efficient. In a modification of the transformer, the input electrodes can be installed, not in the first and fourth regions, but in two or three regions in which the displacement distributions are opposite to each other in the two-wavelength resonance mode, and the output electrodes are installed in the other regions.</p> |
