Control device for controlling the power supply to a continuous-rotation motor which is formed by a stator and a rotor, the stator comprising at least one supply coil (B1, B2) and the rotor carrying at least one magnet (12a, 12b) arranged so as to be magnetically coupled to said at least one supply coil when the rotor is rotating, this control device being arranged to be supplied with electrical power by a power supply unit, supplying a first supply voltage (Vdd), and comprising a voltage divider (22, 24) arranged such that it can divide the first supply voltage and supply the stator with a second supply voltage that is lower than the first supply voltage, this control device being arranged such that it can generate, in a given operating mode or regime of the motor, electrical pulses which are driving pulses supplied to the stator with said second supply voltage for driving the rotor, the number of these electrical pulses per defined time interval being variable as a function in particular of the load applied to the motor; characterised in that the voltage divider (22, 24) is arranged such that it can supply said second supply voltage with a plurality of different values and thus said electrical pulses with a variable voltage; in that the control device comprises a logic circuit which is arranged such that it can count the numbers of electrical pulses in successive time periods; such that it can periodically select a voltage value, from among said plurality of different values provided for the second supply voltage, as a function of a counted number of electrical pulses or of a succession of counted numbers of electrical pulses; and such that it can control the voltage divider so that this voltage divider supplies the second supply voltage with the selected voltage value when generating electrical pulses after the selection of this voltage value; and in that the logic circuit is arranged such that, with each new selection: - the value of the second supply voltage is reduced, if this value is greater than a given low value, when a last calculated number of electrical pulses or a first increasing function of this last number is below a first determined threshold, or when the succession of calculated numbers of electrical pulses including the last number or of the first increasing function of each of these numbers satisfies a first selection criterion for which at least one number among the succession of numbers or the first increasing function of this number is below a first determined threshold; - the value of the second supply voltage is increased, if this value is less than a given high value, when a last calculated number of electrical pulses or the first increasing function of this last number is above a second determined threshold, or when the succession of calculated numbers of electrical pulses including the last number or of the first increasing function of each of these numbers satisfies a second selection criterion for which at least one number among the succession of numbers or the first increasing function of this number is above a second determined threshold. - the value of the second supply voltage is reduced, if this value is greater than a given low value, when a last calculated number of electrical pulses or a first increasing function of this last number is below a first determined threshold, or when the succession of calculated numbers of electrical pulses including the last number or of the first increasing function of each of these numbers satisfies a first selection criterion for which at least one number among the succession of numbers or the first increasing function of this number is below a first determined threshold; - the value of the second supply voltage is increased, if this value is less than a given high value, when a last calculated number of electrical pulses or the first increasing function of this last number is above a second determined threshold, or when the succession of calculated numbers of electrical pulses including the last number or of the first increasing function of each of these numbers satisfies a second selection criterion for which at least one number among the succession of numbers or the first increasing function of this number is above a second determined threshold.