Piëzo-elektrische transformator met een structuur met vier aansluitingen

In a piezoelectric transformer, a piezoelectrically inactive region 11 is provided between a driving portion 22 and a power generating portion 31. The power generating portion 31 extends longitudinally of the piezoelectric body 1 and is provided with a pair of top and bottom electrodes 7T and 7B on its major surfaces. The driving portion 22 is provided with a side electrode 5 on a side surface perpendicular to the width direction. Other electrodes 50T and 50B are also provided so as to be parallel to the electrodes 7T and 7B. The power generating portion 31 is polarized in the width direction and the thickness direction of the piezoelectric body and the driving portion 22 is polarized in the width direction of the piezoelectric body 1. By regulating width of the piezoelectrically inactive region 11 provided between the electrode 50T (50B) of the driving portion 22 and the electrode 7T (7B) of the power generating portion 31, the transforming ratio can be regulated.