A Novel Driver with Adjustable Frequency and Phase for Traveling-Wave Type Ultrasonic Motor

A mode conversion rotary traveling-wave ultrasonic motor (TWUSM) has potential applications in miniature robotics. However, its electrical drive circuit presents some unique challenges, particularly in producing a high frequency, high voltage signal into a low impedance capacitive motor, while achieving high efficiency. A novel driving circuit is proposed to provide two-phase balance voltage for TWUSM. This paper describes the design of such a drive circuit, intended for use with phase-modulation control strategy. The operating principle and detail analysis of the proposed driving circuit are introduced. Detailed experimental results are provided to demonstrate the effectiveness of the proposed driving circuit.