Mechatronic system, comprising: a single-strand 1-phase synchronous motor, wherein the motor has a rotor with different preferred orientations in the energised and de-energised states; a frequency converter for connecting to an alternating line voltage at a predetermined frequency, having a rectifier, a direct voltage intermediate circuit comprising a capacitor, and an inverter; a voltmeter; and a control device that is set up to control the frequency converter in order to: align the rotor using direct current, superimposed direct current or one or more direct voltage pulses; start the motor by applying an alternating voltage generated by modulation from the rectified alternating line voltage, which alternating voltage has a different frequency and optionally a different amplitude than the alternating line voltage; and let the motor run up to an operating speed by increasing the frequency and optionally the amplitude of the applied alternating voltage; control the frequency converter in order to specify the applied alternating voltage in at least one period by changing the duty cycle so that a voltage-time integral results in order to start the motor in a desired direction of rotation; interrupt the applied alternating voltage for a time interval; measure the electromotive force in the time interval with the voltmeter; and detect a rotation of the rotor based on the measured electromotive force. a single-strand 1-phase synchronous motor, wherein the motor has a rotor with different preferred orientations in the energised and de-energised states; a frequency converter for connecting to an alternating line voltage at a predetermined frequency, having a rectifier, a direct voltage intermediate circuit comprising a capacitor, and an inverter; a voltmeter; and a control device that is set up to control the frequency converter in order to: align the rotor using direct current, superimposed direct current or one or more direct voltage pulses; start the motor by applying an alternating voltage generated by modulation from the rectified alternating line voltage, which alternating voltage has a different frequency and optionally a different amplitude than the alternating line voltage; and let the motor run up to an operating speed by increasing the frequency and optionally the amplitude of the applied alternating voltage; align the rotor using direct current, superimposed direct current or one or more direct voltage pulses; start the motor by applying an alternating voltage generated by modulation from the rectified alternating line voltage, which alternating voltage has a different frequency and optionally a different amplitude than the alternating line voltage; and let the motor run up to an operating speed by increasing the frequency and optionally the amplitude of the applied alternating voltage; control the frequency converter in order to specify the applied alternating voltage in at least one period by changing the duty cycle so that a voltage-time integral results in order to start the motor in a desired direction of rotation; interrupt the applied alternating voltage for a time interval; measure the electromotive force in the time interval with the voltmeter; and detect a rotation of the rotor based on the measured electromotive force.