Abstract: An automotive power control system which delivers a regulated voltage to a load circuit during normal operation and which delivers maximum power when the demand exceeds the alternator's ability to supply adequate current to the load. A duty-cycle- controlled DC-to-DC voltage converter reduces the alternator voltage to a level appropriate for charging the system battery and supplying low voltage loads. When the rotational speed of the alternator is adequate to generate sufficient load current, the voltage converter operates under the control of a first feedback circuit which compares the converter's output load voltage with a reference potential to generate an error signal which regulates the output voltage to a desired level.