Abstract: The invention relates to a yarn feeding device (F) for weaving or knitting machines whose winding element (W) is driven by an electric motor (M) controlled by an electronic speed control device (CU). According to the invention, the electric motor (M) is a synchronous motor, in particular, a permanent magnet (PM) motor with the speed control device (CU) provided for effecting a permanent vector control with the stator being sinusoidally acted upon. Continuously determined information pertaining to the relevant rotational position of the rotor (R) of the motor (M) is used in the speed control device (CU), which serves to perform permanent vector control, in order to adjust at least one predetermined rotational position (X1, X2) of the winding element (W).

Abstract: A thread feed system having a measuring feeder, a supply bobbin supplying thread to the measuring feeder and a textile machine which withdraws the thread from the measuring feeder so as to perform a weaving operation. The measuring feeder includes a storage drum and a winding element which removes the thread from the supply bobbin and winds the thread onto the storage drum. A control device is provided for monitoring the operating conditions of the thread system so as to identify increases in thread tension. The control device is operatively connected to an auxiliary conveyor device having a drivable friction roll which is frictionally engaged with the thread between the supply bobbin and the storage drum. The auxiliary conveyor device is operable so as to provide an increased frictional action on the thread so as to advance the thread at an increased rate to the storage drum so as to preparatorily counteract the thread tension increase and eliminate short picks of the thread in the textile machine.