Abstract: A non-linearly operating control arrangement for driving units, such as those of damping devices of printing machines, includes a plurality of parallel resistance-diode bridges having two inputs and two outputs, a pair of resistors interposed between one of the inputs and the respective outputs, and a potentiometer interposed between the outputs and having a wiper connected to the other input via a diode. The first outputs of all bridges are connected to the input of a summation member and the output of the latter, together with the second outputs of all bridges, is connected to the input of an amplifier whose output voltage controls the driving unit speed of rotation. Comparison potentials of different magnitudes are supplied to the second inputs of the bridges from a series of additional potentiometers respectively associated with the bridges. Another potentiometer is provided which supplies additional potential to the input of the amplifier.