Abstract: The actuation system including a control system, an actuator comprising a drive part and a step motor comprising a rotor and a stator with at least one electric phase, an actuated system comprising a controlled element coupled to the drive part, and an elastic part capable of generating an elastic return force on the rotor of the motor or on the drive part. The control system comprises means for measuring an induced electric parameter on the phase of the stator after switching off the current of said at least one phase of the stator to detect a return of the rotor resulting from elastic return force when a mechanical clearance is overtaken.

Abstract: The actuation system including a control system, an actuator comprising a drive part and a step motor comprising a rotor and a stator with at least one electric phase, an actuated system comprising a controlled element coupled to the drive part, and an elastic part capable of generating an elastic return force on the rotor of the motor or on the drive part. The control system comprises means for measuring an induced electric parameter on the phase of the stator after switching off the current of said at least one phase of the stator to detect a return of the rotor resulting from elastic return force when a mechanical clearance is overtaken.

Abstract: A stepping motor with an electrical activation circuit for electrical control of its exciter windings, is made as a driving motor and also as a braking motor with an adjustable braking action. The predefinable braking action is achieved passively without any current feed into the exciter windings. For this purpose a stipulated impedance with an adjustable duty factor can be connected to each exciter winding. One such stepping motor that is controlled in its braking action is used in an arrangement in which a strip or filament material can be transported braked from a storage.