Abstract: In an AC generator having a plurality of claw-shaped magnetic pole portions in a rotor, a pair of projected portions which extend toward an outer circumference from both ends of boss portions on an outer circumference of a shaft are provided, and permanent magnets are also provided so as to abut against the projected portions so that magnetic flux is applied in the same direction as the magnetic flux applied to the projected portions when an electric current is applied to a field winding which is wound around the boss portions. With a magnetic path thus constructed, it is possible that the magnetic flux if permanent magnets is put on the magnetic flux produced by a field winding, thus applying much magnetic flux to the stator. As a result, the output per weight can be increased.

Abstract: A voltage regulating system for an automotive vehicle having a switching transistor connected to a field winding of an alternating current generator and a regulator for comparing a battery voltage with a reference value and for driving the transistor into a conductive state when the battery voltage is lower than the reference value. A current limiting circuit is provided for limiting the field current when the switching transistor is going to be driven into the conductive state over a predetermined interval, so that a maximum charging current can be obtained and an unfavorable heating of the switching transistor can be avoided.