Patent ID: 7944183

Claim:
An output voltage controller for an AC vehicle generator including an armature coil and a field coil and driven by a motor equipped in the vehicle so that an AC output voltage is generated in the armature coil, the output voltage controller comprising: a rectifier that rectifies the AC output voltage to produce a rectified output voltage; an excitation circuit that excites the field coil by using the rectified output voltage; a circulation element provided in the excitation circuit and connected in parallel to the field coil; a semiconductor switch element provided in the excitation circuit and connected in series with the field coil; a voltage adjustment circuit that turns the semiconductor switch element on and off based on the rectified output voltage and adjusts the rectified output voltage to a level within a predetermined range; an inductor provided in the excitation circuit and connected in series with the field coil and the semiconductor switch element; and transient voltage absorption means provided in the excitation circuit, the transient voltage absorption means absorbing a transient voltage generated in the inductor in association with the switching of the semiconductor switch element between ON and OFF.