| 摘要 |
<p>A circuit arrangement is described for commutating a collectorless direct current motor without a commutation sensor, the motor comprising at least two windings (608, 609, 610), in which arrangement the motor current is caused to commutate from one winding to the next winding in the direction of motion of the direct current motor by a pulse-shaped shift signal (sh) which signal is derived from an induced voltage (ui) in the direct current motor reaching a reference voltage (Ur). Such a circuit arrangement is to be improved in that erroneous commutations with diode pulses having flat trailing edges are avoided. According to the invention this is achieved in that the shift signal (sh) has adjustable pulse intervals (td1, td2) which depend on the speed of the direct current motor, in that the pulses of the shift signal (sh) cover at least the time intervals in which transient effects caused by the commutation occur in the induced voltage (ui), and in that the pulses of the shift signal (sh) are used for suppressing transient effects caused by the commutation and occurring in the induced voltage (ui).</p> |
