| 摘要 |
PROBLEM TO BE SOLVED: To assure higher reliability to easily generate an AC of optimum frequency and control generation of noise as much as possible. SOLUTION: A switching element 3 controls a DC element from a DC power supply 2 flowing through a primary winding of a transformer 5 with the timing pulses P1, P2, P3, P4 from a CPU 6. Consequently, boosted high frequency voltage AC elements Φ0, Φ90 are generated on the secondary winding side of the transformer 5 to generate high frequency voltage AC elements of two phases including the phase difference of 90 deg. from the DC element. These AC elements of two phases are impressed to an ultrasonic motor 4 to operate this motor. In this case, the earth side of switching element 3, earth side of the secondary side of transformer 5 and the side of ultrasonic motor 4 are isolated within the ultrasonic motor drive circuit 1 and the closed circuit of earth is not formed. Therefore, generation of noise while the ultrasonic motor 4 drives is controlled and influence on the other electronic devices of this noise can be prevented. |
