Main circuit of an electric power generating apparatus for dispersed power supply, having a permanent magnet type electric power generator driven by windmill or waterwheel and having three windings, each inducing a different value of induced voltage, AC outputs of the generator rectified by rectifiers, and DC outputs of the rectifiers summed in parallel for output. First and second reactors are respectively connected in series between first and second rectifiers and output terminals of first and second windings, the first winding inducing the lowest induced voltage among the three windings, the second winding inducing the second lowest. A capacitor is connected between a third rectifier and an output terminal of a third winding inducing the highest induced voltage. The sum of inductive impedance by internal inductance of the third winding and capacitive impedance by the capacitor is capacitive impedance within a range of rotational speed of the generator.