motor 34 comprises an output shaft 48 on which there is fixed a gear wheel 49 arranged to cooperate with the gear wheel 15 via an idle gear wheel 49a the output shaft rotates within a bearing 70 the idle gear wheel 49a being associated with a shaft 71 rotating within a bearing 72 the bearings 71 and 72 are contained in seats 73 and 74 provided in that face 8 of the bracket 3 opposite the face 2 in correspondence with which the knob 1 is positioned the unit 23 is connected to four pushbuttons 50 51 52 and 53 arranged on a control panel 54 provided on the face 8 of the bracket 3 preferably to the side of the knob this latter comprises three concentric angular quadrants namely a first quadrant 1a comprising a plurality of markings 58 relative to the various programs which can be effected by the washing machine or the like a second quadrant 1b showing the maximum duration of the various programs which can be executed by the machine and a third quadrant 1c which is a usual clock quadrant the various quadrants are to be used jointly with the pushbuttons 50 51 52 and 53 on choosing the desired wash program in this respect it will be assumed that a washing machine provided with the described device is to be operated after loading the usual machine drum the user firstly rotates the knob 1 in the direction w of fig3 to position that marking 58 of the quadrant.