Patent ID: 7405527
Filing Date: 2008-07-29
Classification: H02P

Abstract:
1. A method of controlling an electronically commutated d.c. motor having a permanent-magnet rotor and a wound stator, the d.c. motor being used as a driving motor for a wear adjusting device of a pneumatically actuated disc brake, the method comprising the acts of: providing a first method for determining a position of the rotor from electrically measurable parameters without sensing the rotor position by measuring an inductance; providing a second method for determining the rotor position from electrically measurable parameters without sensing the rotor position by measuring an induced voltage; and combining the first and second methods to detect the rotor position in order to control the electronically commutated d.c. motor so that, for all rotational speed values below a limit value rotational speed both the first and the second methods are used contemporaneously in a parallel manner to determine the rotor position.