Abstract: So as to permit operating a shunt-wound motor with the series characteristic without the use of electronic armature current adjusters, it is proposed to start the motor (1) with the connection of start-up resistances (R.sub.1 -R.sub.4) and to control each step added by means of a comparator by a minimum armature current value (I.sub.A min o -I.sub.A min 4) specifically predetermined for each step. After said minimum value specific to each step has been reached, the comparator (7) actuates a guide and a regulating switch (S.sub.w, S.sub.x), whereby the minimum armature current value so reached specific to the step is kept constant by means of adjusting the excitation (I'.sub.E), and a limiting unit (17) prevents the exciting current (I'.sub.E) from dropping below a predetermined minimum value (I'.sub.E mn), which, at higher numbers of revolution (n), again leads to the shunt characteristic, now with reduced excitation (I'.sub.E min) and the resistances (R.sub.1 -R.sub.