A generating apparatus includes a generator, a first and a second rectifiers, and a voltage regulator. The generator has three-phase star-connected armature windings which generate three-phase high-output voltage at phase-terminals and low-output voltage at a neutral point. The first rectifier is a three-phase full-wave rectifier connected between the phase-winding and a high-voltage load, and the second rectifier is a diode connected between the neutral point and a low-voltage load with a battery. The regulator regulates the high output voltage to energize the high-voltage load and, at the same time, the low-output voltage to become an optimum voltage level for charging battery. MOSFETs may be used for the first rectifier to short-circuit the armature windings thereby supplying them with leading currents which are respectively ahead of the high-output voltages, so as to increase the generator output power.