Abstract: A drive and control device for sewing machines, automatic sewing installations, and the like, with a recognition unit which responds for the purpose of end recognition when the sewing tools have approached a predetermined spacing from the desired seam end. The drive and control device also includes a preselection stitch counting unit, which can be triggered by means of the recognition unit, for the presetting of a predetermined number of remaining stitches still to be executed subsequently to the end recognition, and a correction unit for the performance of a stitch correction in dependence on the respective needle position at the instant of end recognition. The correction unit serves for automatically varying the length of at least one of the remaining stitches.

Abstract: A method and an apparatus for controlling and regulating an electrical motor, especially a reactive motor for time-keeping devices such as clocks. The motor has a permanent-magnetic rotor with at least two poles, and a stator with at least two coils. In a normal speed mode one of coils is supplied with driving pulses whereas the second coil senses the rotational speed of the rotor. If the rotational speed of the rotor falls below a predetermined value, a self-starting mode is initiated wherein the first and second coils are alternately supplied with driving pulses. In this self-starting mode the frequency of the pulses supplied to the first and second coils is increased until normal speed has been reached wherein the self-starting mode is switched off and the normal speed mode regulation is switched on.

Abstract: A control circuit for driving an electric motor at a substantially constant speed, the motor including a rotor with at least one pair of permanent magnetic poles and a stator provided with a first and second coil, the control circuit including a control element for supplying energizing pulses to the coils dependent upon a detected rotor speed, the control element having a normal speed mode wherein the rotor speed is detected by the first coil and wherein only the second coil is supplied with energizing pulses at a frequency corresponding to single coil driving and a self-starting mode wherein the energizing pulses are supplied alternately to the first and second coils to accelerate the rotor to a desired speed, the control element including rotor acceleration and braking circuitry operable during the normal speed mode and including a desired frequency pulse generator, an actual frequency pulse generator, a phase comparator for comparing the widths and phases of the desired and actual frequency pulses, and an