| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a vehicle power supply device adapted to ensure electric power for starting an engine by reducing power consumption even while the engine is stopped, and by suppressing power generation by a generator to improve power consumption. <P>SOLUTION: The vehicle power supply device includes a capacitor 12 connected in parallel to the generator 4 through a first switch 11; a voltage switching means 5 for switching the output voltage of the generator 4 to a first voltage for charging a battery 15 or a second voltage higher than the first voltage; a step-down voltage circuit 13 for lowering the output voltage of the generator 4 switched to the second voltage and/or the output voltage of the capacitor 12 charged by the second voltage to the first voltage; and a second switch 14 for switch-connecting the positive pole side terminal of the battery 15 to the output terminal of the step-down voltage circuit 13 or the generator 4. Based on a vehicle speed signal and an on/off signal of the engine 1, a part or all of the first switch 11, the second switch 14, the step-down voltage circuit 13 and the voltage switching means 5 are operated to suppress the power generation of the generator 4, thereby ensuring a predetermined remaining capacity of the battery 15. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
