A DC-DC converter includes an induction coil cooperating with two switches, which operate alternately, to supply output voltage of a determined level relative to input voltage. The converter control method includes, in each cycle, a first phase of first duration with first switch controlled to make it conductive, and to increase current in the induction coil, and a second phase with second switch controlled to be conductive and to decrease current in the induction coil during a second adjustable time period. Detection device detects, at the end of the second phase, sign of overvoltage across one terminal of the induction coil connected to the switches, and supplies a detection signal kept in a high or low state, depending upon sign of detected overvoltage. Timing device receives detection signal for adapting, in each successive cycle, the second duration of the second phase to cancel out current in the induction coil.