The invention relates to methods and systems for modulating the supply voltage of an electric load, particularly an electric motor, fed by a bridge circuit, wherein the load is switched as a function of a predetermined setpoint value for the input current or the input power by means of power electronics to an intermediate circuit voltage. A modulation method is disclosed in which, instead of the winding current (or the winding currents in the case of multi-strand motors), the intermediate circuit current or the input power of the motor is used as the actual value for regulation. The switch-on times for the modulation of the motor voltage are predetermined at a set frequency by a controller, such as a microcontroller or a timer. The switch-off times are determined such that the average value of the intermediate circuit current corresponds to a predetermined setpoint value.