Electrical Properties of Step-down Multilayer Piezoelectric Transformer for AC-DC converter

Multilayer piezoelectric transformers (MPT) were manufactured using PZN-PMN-PZT ceramics and their electrical properties were then investigated according to frequency and load resistance. The voltage step-up ratio of multilayer piezoelectric transformer showed the maximum value in the vicinity of 73 kHz and increased according to the increase of load resistance. When the output impedance coincided with the load resistance, the piezoelectric transformer showed the temperature rise of about 21 at the output power of 15W. The multilayer piezoelectric transformer manufactured at low cofiring temperature of 940 using PZN-PMN-PZT ceramics could be stably driven as the step-up or down transformers.