High-Power Characteristics of Multilayer Piezoelectric Ceramic Transducers

In this report, the behavior of the mechanical quality factor Qm for multilayer piezoelectric transducers which operate at a low to high vibratory velocity is described. It has long been known that the Qm of multilayer piezoelectric devices, such as transformers and actuators, decreases when the number of ceramic layers in the devices is increased. In such devices, the output power converges to a saturated value with heat generation much lower than that which the value of Qm measured at low vibration velocity would suggest. This fact implies that the Qm strongly depends not only on the number of ceramic layers, but also on vibratory velocity and temperature. It appears that high-power and vibratory velocity characteristics of the Qm for multilayer piezoelectric transducers have not been studied sufficiently. Taking the temperature factor into consideration, we used the electrical transient response method and equivalent circuit analysis to investigate the vibratory velocity characteristics of the Qm for multilayer piezoelectric transducers.