| 摘要 |
<p>PROBLEM TO BE SOLVED: To charge a secondary battery by effectively utilizing a DC power supply source with a different rated current, such as an AC adapter.SOLUTION: In a power supply part 30 of a composite device 1, when an AC adapter 50 is attached to a DC jack I/F 12, a switching/shunt circuit 32 detects the attachment, and an AC adapter rated current detection circuit 34 detects a rated current of the AC adapter 50. A CPU 21 extracts an operation current required at an operation mode of the composite device 1, and notifies the switching/shunt circuit 32 of a current obtained by subtracting the operation current from the rated current as a charging current. The switching/shunt circuit 32 supplies the notified charging current of a DC current from the AC adapter 50 to the charging circuit 33, and supplies the remaining current to DC/DC converters 36 and 37. The charging circuit 33 charges a secondary battery 10 and an auxiliary secondary battery 41 with the charging current, and the DC/DC converters 36 and 37 generate an operation current and supply it to a control board 20.</p> |
