Drive arrangement with collectorless D.C. motor

摘要

Drive arrangement comprising a collectorless d.c. motor and a rpm-regulating arrangement. The motor comprises a permanent-magnet rotor and a stator winding arrangement. The latter is connected to a current source in dependence upon angular-position signals by means of an electrical commutation arrangement. The rpm-regulating arrangement produces a regulator signal that is a function of the deviation of the rotor's actual rpm from a desired rpm. There is provided an arrangement for modulating the regulator signal in synchronism with the rotation of the rotor. As a result of the action of the modulation arrangement, the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs, and the drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs.