An alternating current generator of the invention has three armature windings, which are wound from a winding start end connected to a neutral point to winding finish ends, and a stator that is connected to the neutral point in Y-connection at a phase difference of 120 degrees, respectively, and configures a three-phase power source, wherein the generator comprises two taps provided at predetermined positions from the winding start end to the winding finish ends of two armature windings out of the three armature windings, and wherein one terminals of the two armature windings are connected to relevant ones of the two taps and the other terminals of the two armature windings are made single-phase output terminals.