Abstract
The article describes new operating principles of ultrasonic actuators. The technical limitations of driving the piezoelectric actuators using the pulse-width modulation (PWM) will be discussed. The limitations caused by parameters of high-speed switching transistors (namely ultra-fast MOSFETs), by speed of the field-programmable gate arrays (FPGA) and by parameters of piezoceramic actuators will be examinated. Further, usage possibilities of resonant converters for the driving of piezoceramic actuators with travelling acoustic wave will be analysed. The aim is to find such courses of driving signals as to minimize requirements for switching transistors and computing performance of FPGA. In conclusion a methodology for measurement of the dynamic properties of piezoceramic actuators will be introduced. The measuring system developed at the Technical University of Liberec will be presented.
Acknowledgments
This work was supported by the Ministry of Education of Czech Republic (Project Code MSM 242200002) and in part by the IST-2000-30193 Grant (Reason-EU).