Abstract: The present control device is used in connection with a diphase or polyphase stepper motor in which the coils of two phases (b.sub.i, b.sub.j) are not simultaneously supplied with driving current. A commutation circuit CC is adapted to connect the coils to a voltage source V or to a detection circuit CD. A logic control circuit CL.sub.1, CL.sub.2, CL.sub.3, itself controlled by a clock signal source G.sub.1 and by a generator of programmed control pulses PG, supplies control signals to said circuits CC and CD. The control device provides a feedback control of the motor as a function of the speed and the position of the rotor at various instants of the control cycle in accordance with a predetermined program so as to assure perfectly reliable operation of the motor with a minimum of electric energy even for motors manufactured with rather wide manufacturing tolerances.

Abstract: Device for controlling a monophase rotary step-by-step motor supplying electric control pulses to the winding of the motor, comprising means for detecting the variation of the current passing through the motor winding at each control pulse, this detection means including means of interrupting the control pulse when a minimum appears in the current passing through the winding.