Abstract: A controller with at least one switch or a plurality of switches e.g. in the form of a power switchgroup for controlling an electric drive motor in a vehicle wherein a set point selector consists of a mask that is rigidly connected or interchangeably attached to an actuating member of the controller, the mask is adapted to provide a predetermined set point characteristic in cooperation with control elements that are connected to an input of an electronic circuit which includes a second input to which are connected means for varying a reference voltage at the output of the electronic circuit and the control range of the set point characteristic. The control elements cooperating with the mask may consist of an opto-electronic transmitter-receiver device.