Abstract: A method, and a corresponding device, for controlling a power switch in a system with variable structure includes at least a switch capable of being actuated to deliver a given electric signal corresponding to an electric system, based on a control signal taking into account a reference input signal and a feedback signal sampled at the electric system output. The method applies to the control signal an oscillation at a controllable frequency, resulting from the application of a filtering on the feedback signal, the filtering being defined in such a way as to induce a phase shift of −180° between the filtered feedback signal and the electric system input signal, to the controllable frequency.