Piezoelectric transformer circuit using a piezoelectric transformer unit of a thickness extensional vibration mode

摘要

In a piezoelectric transformer circuit which is operable as a d.c./d.c. converter for a d.c. input voltage into a plurality of d.c. output voltages and which has a piezoelectric block divided into first and second partial blocks having first and second principal surfaces coated with first and second electrode units and a third electrode unit extended from the piezoelectric block between the first and the second electrode units, a selected one of the first and the second electrode units is divided into a plurality of subdivided electrodes. A plurality of a.c. output voltages are developed between each of the subdivided electrodes and the third electrode unit and are converted into the d.c. output voltages. Alternatively, the second partial block is composed of a plurality of piezoelectric layers stacked with one another via at least one intermediate electrode to derive a plurality of the a.c. output voltages between the third electrode unit and at least one intermediate electrode and between the third electrode unit and the second electrode which is not divided into subdivided electrodes. Furthermore, each of the first and the second electrode units is divided into main and subsidiary electrode members to develop an a.c. output voltage across the main electrode members and to induce a self-excited vibration by the use of the subsidiary electrode members.