| 摘要 |
PROBLEM TO BE SOLVED: To increase torque and prevent uneven rotation, by controlling the difference between the content of the third harmonic component and the content of the fifth harmonic component to a specified value or below. SOLUTION: Hall signals U and V are synthesized by a signal synthesizing means comprising an adder circuit 1 and a non-linear converting means 2, and the signal synthesizing means outputs a synthesized signal W. At this time, the driving magnetic pole waveform is of trapezoidal wave containing a third harmonic component and a fifth harmonic component; therefore, the synthesized signal W is obtained as triangular-wave-shaped signal. A triangular-wave-to-trapezoidal-wave conversion means 3 converts the synthesized signal W into a trapezoidal-wave-shaped conversion signal W', and supplies it to a drive circuit means 7. The stator coil 6 of the drive rotating means 7 produces rotating magnetic fields corresponding to the rotation of a rotor, and generates rotational driving force through interaction with driving magnetic poles. However, as the fifth harmonic component of the driving magnetic poles is eliminated and only the third harmonic component is increased, the trapezoidal waveform is distorted and uneven rotation results. To cope with this, the value obtained by subtracting the content of the third harmonic component is controlled to 16% or below. |
