PURPOSE: To obtain a brushless self-excited generator which is constituted of a single winding and of a single pole and whose output voltage can be regulated without installing a special exciting circuit and without a need of an exciting current from the outside.

CONSTITUTION: Armature windings NA, PB, NC of three phases are installed on the side of a stator 2 for a generator 1. The number of turns of the winding NA of one phase out of them is made smaller than that of the other two phases. A capacitor 5 and a voltage regulator 8 in which a reactor 6 and a triac 7 have been connected in series are installed in parallel with the winding NA of one phase. In addition, a field winding 12 with which a diode 11 has been connected in series is installed on a field core 9 on the side of a rotor 3.