Abstract: The method of regulation includes:starting to measure the rectified voltage at the output of the alternator during each period T of this voltage,performing this measurement by sampling over a predetermined period T.sub.e,comparing this measured value of the rectified voltage with a calculated reference value, anddeducing from this comparison the duration of the first phase T.sub.1 for the next following period T, this first phase being the one in which the battery voltage of the vehicle is applied to the alternator rotor winding. The sampling measurement of period T.sub.e ends, in each period T, at an instant T-.epsilon., where .epsilon. is a period of time which is very short by comparison with the length of the period T.