A Novel Ultrasonic Motor Driver Based on Two Phase PWM Signals
An ultrasonic motor (USM) has been widely used in many applications since it has several advantages over the conventional electromagnetic motor, such as high torque at low speeds, no electromagnetic interference, and high holding torque without power supply. However, in order to achieve high efficiency, its electrical drive system presents unique challenges, especially in producing two-phase signal (high frequency, high voltage, phase difference of two-phase signal) input to a low impedance capacitive motor. In this paper, a novel drive system based on microcontroller (ATmega16) has been proposed for ultrasonic motor. Drive system includes power drive circuit and control system. Power drive circuit is combined from Push-Pull Inverter to provide high-frequency two-phase voltages. A microcontroller was used to control ultrasonic motor drive system. PWM signals were generated and then directly applied to the MOSFET drivers for speed control of ultrasonic motor. The frequency and phase difference of two phase PWM signals can be directly changed by microcontroller. Detailed experimental results are provided to demonstrate the successful of the proposed drive system.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
T. M. Zhang et al., "A Novel Ultrasonic Motor Driver Based on Two Phase PWM Signals", Advanced Materials Research, Vols. 189-193, pp. 1543-1546, 2011