High-power characteristics of piezoelectric materials

A measuring method of the high-power characteristics of the piezoelectric transducers and some experimental results are described. The vibrational velocity dependences of the equivalent circuit constants and the temperature rise were measured under the constant vibrational velocity control. In addition, when a high-power ultrasonic device such as an ultrasonic motor is practically used, the maximum efficiency is obtained at the antiresonance frequency, not at the resonance frequency. These phenomena are caused by the increase of the dielectric loss related to the vibrational velocity. In the paper, a measuring method and the experimental results of the dielectric loss under the high vibrational velocity are also described