High power piezoelectric transformers - Their applications to smart actuator systems

Piezoelectric transformers with power capability of < 10 W have successfully been commercialized for the backlight inverters of laptop computers. For further high power applications, our approaches in new piezoelectric materials, new designs and new connection technologies are introduced in this paper. PZT based piezoelectric ceramics with the maximum vibration velocity of 1.0 m/sec have been developed by rare-earth ion doping. Multi-stacked disk type transformers have significant advantages over the conventional Rosen type in terms of high power and isolation resistance. Also the connection technology helps to enhance the power capability. New applications of the piezoelectric transformers have been demonstrated in an integrated ultrasonic motor and a piezoelectric actuator drive system for active vibration control on helicopters.