摘要 |
<p>A piezoelectric stepping motor including a stator and a rotor each provided with radial regions of reduced rigidity periodically alternated with radial regions of normal rigidity, the step positions being those where the regions of normal rigidity of the stator are in register with the regions of reduced rigidity of the rotor. A control circuit excites the stator at two successive frequencies (f2, f1) to switch each step, and the two excitation frequencies correspond to the resonant frequency (2) of the stator/rotor assembly outside a step position, and to the resonant frequency (1) of the stator/rotor assembly in a step position, respectively, the first (f2) of said two excitation frequencies being selected in such a way that the stator is insufficiently excited in the area adjacent to the step positions.</p> |