High-efficiency driving circuit to realize small AC-DC converter by using mechanical resonance of piezoelectric single crystal

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420239
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Power engineering/Power conversion/Electric machinery
• Research Institution: Yamagata University
• Principal Investigator: HIROSE SEIJI 山形大学, 理工学研究科, 名誉教授 (70007201)
• Co-Investigator(Kenkyū-buntansha): TAMURA Hideki 東北工業大学, 工学部, 准教授 (90396581)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ACアダプタ / 圧電トランス / 圧電単結晶 / スイッチング / 駆動回路 / 高効率

Outline of Final Research Achievements

Driving circuit and other additional circuits of LiNbO3 piezoelectric transformer have been studied for achieving small sized-high efficiency AC-DC power supply. Switching device MOSFET has capacitances between each two electric terminals, where the terminals are Gate, Source and Drain. Because of these capacitances, switching efficiency of MOSFET becomes very low at the frequency of several hundred kHz for driving piezoelectric transformer. In this study, switching circuit which is little influenced by these capacitances has been invented. By the experiment, it has been shown that newly developed switching circuit gives useful results. To realize further improvement on efficiency and miniaturization of piezoelectric transformer application circuit, the effect of additional inductance and charging battery as smoothing device of rectifier circuit have been examined, and some improvements have been achieved.

Free Research Field

超音波エレクトロニクス