Patent ID: 7683588

Claim:
A device for controlling power generated in a vehicle provided with an engine, a power generator generating power to an electrical load mounted on the vehicle, the power generator having an excitation winding through which an excitation current is supplied such that the excitation current is intermittently controlled and an output voltage outputted from the power generator is regulated at a predetermined value, the device comprising: a power generation controlling circuit that controls the excitation current by driving the excitation winding using a variable duty cycle, wherein the power generation controlling circuit increasingly changes the duty cycle so as to increase the excitation current when the output voltage from the power generator is less than the predetermined value, and decreasingly changes the duty cycle so as to decrease the excitation current when the output voltage from the power generator is equal to or more than the predetermined value; duty cycle control means for controlling the duty cycle to be changed based on an amount of the electrical load and a rotation status of the engine; first changing means for changing an increase rate of the duty cycle by setting a gradual excitation duty that limits the duty cycle which is changed increasingly; and second changing means for changing a decrease rate of the duty cycle by setting the gradual excitation duty that limits the duty cycle which is changed decreasingly.