Abstract: An apparatus for the control of variable speed electrical positioning drives, especially for sewing machine positioning drives, is disclosed in two exemplary embodiments. The apparatus provides a preset nominal value of speed and a range of adjustment for additional signals in digital form, thus making possible a continuous or incremental change in the nominal value as well as additional digital signals. The apparatus includes lamellar contact elements of a potentiometer arranged on a base element in the path of a slider for the nominal value of speed and at least one low resistance lamellar contact element arranged in the slider path for producing an additional digital signal.