A device for producing electricity, the device comprising a three-phase alternator comprising three windings, a rectifier for converting the AC delivered by the alternator into rectified current, and a voltage-raising chopper using the self-inductance of the alternator to raise the voltage. The device includes a switch unit enabling the three windings to be connected either in a star configuration when the alternator is being rotated to produce electricity, or else to the respective phases of a three-phase network when the alternator is stopped.