Command generator for electric positioning drives

摘要

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.