| 摘要 |
<p>A power supply control section 62 calculates a target charge/discharge current of a secondary power supply apparatus 50 on the basis of an actual charged amount and a target charged amount of the secondary power supply apparatus 50, and feedback-controls the stepped-up voltage of a step-up circuit 40 such that an actual charge/discharge current detected by a secondary current sensor 51 coincides with a target charge/discharge current. When the actual charged amount is equal to or greater than the target charged amount, the target charge/discharge current is set to zero so as to prevent overcharging. When the actual charged amount is less than the target charged amount, a target charge current corresponding to a capacity margin of the step-up circuit 40 is set so as to quickly charge the secondary power supply apparatus 50. When the output of the step-up circuit 40 has no margin, the target charge/discharge current is set to zero so as to supply electric power from the secondary power supply apparatus 50 by an amount corresponding to the deficiency of the capacity of the step-up circuit 40. Thus, charging of the secondary power supply apparatus 50 is performed well.</p> |
