Generation of music scale from brushless DC motor with surface permanent magnets

The authors propose a method for generating a music scale from a brushless DC motor with surface permanent magnets by introducing d-axis current with a desired frequency. The paper begins by theoretically verifying the proposed method by analyzing the vibration emitted from the motor, which is the cause of an acoustic noise and/or musical sounds. The calculated results approximately agree with the measured ones. Moreover, the vibration characteristics are clarified by changing the desired frequency, the motor speed and the output power. Finally, this paper shows a method of generating desired musical sounds by sequentially emitting the musical scales.