A drive device for a brushless motor, a brushless motor, and a medical handpiece using the brushless motor.

摘要

PROBLEM TO BE SOLVED: To provide a drive method for operating a sensorless brushless DC motor smoothly.;SOLUTION: A driver for controlling a three-phase brushless motor includes drive means for energizing three-phase, control means of the drive means, voltage detection means for detecting terminal voltage of a phase, and storage means for storing the detection value of the voltage detection means. In a first state where two phases out of three phases are energized, the voltage detection means detects the first voltage of the non-energized phase out of the three phases and stores in the storage means, and in a second state where all phases are not energized, the voltage detection means detects the second voltage of the phase that was the non-energized phase in the first state and stores in the storage means, and the control means switches the phase to be energized by the drive means, on the basis the first and second voltages.;SELECTED DRAWING: Figure 2;COPYRIGHT: (C)2019,JPO&INPIT