摘要 |
PURPOSE: To provide a brushless motor to which sine wave driving currents are supplied by using a simple rotation detector. CONSTITUTION: A field part consisting of rotor permanent magnets, the 3-phase driving windings 20A, 20B and 20C of a stator, a group of driving transistors supplying power to the driving windings, a driving command unit 43 which generates sine wave command signals and a driving unit which supplies sine wave driving currents to the driving windings are provided. The driving command unit is composed of a time measuring instrument 42 which measures a timing interval inversely proportional to the revolution of a rotor by the pulse signal of a rotation detector 41 and a driving command generating unit 45 which changes an estimated electric angle at every timing interval in response to the measured result of the time measuring instrument and generates a sine wave driving command signal corresponding to the estimated electrical angle. |