A drive unit is provided including a synchronous machine, a pulse counter
unit for detecting a rotor position during the running operation of the
synchronous machine, and a control unit. The control unit is constructed
such that, with the start of the operation of the synchronous machine,
the stator winding of the synchronous machine is energized such that the
rotor aligns itself corresponding to a magnetic preference direction
parallel to the direction of the magnetic stator field generated by the
energizing. In addition, the pulse counter unit is set to a defined
starting value.