Experimental investigation of a piezoelectric ceramic transformer using radial vibration of disks combined with a coupling element

In this paper a new type of piezoelectric ceramic transformer using radial vibration of disks, combined with a coupling element is proposed. The specific merit of this piezoelectric ceramic transformer is that its electrical input impedance is effectively reduced by the radial vibration of disks with a high electromechanical coupling factor. First, the structure of the new piezoelectric ceramic transformer is presented. Next, the experimental results of the input admittance characteristics, gain of step-up voltage and power transmission efficiency of the piezoelectric ceramic transformer which were measured by varying the length of the coupling element are presented. The experimental results proved that the newly proposed piezoelectric ceramic transformer possessed a vibration mode that could realize a low input impedance and power transmission with efficiency of not less than 90% for a high-voltage step-up application.