Patent ID: 8198861

Claim:
An electronic device comprising: an external device connecting connector which is connected to a power supplying connector of an external device having a power supplying function and receives power supplied from said external device; an electronic circuit which performs predetermined operation upon reception of the power supplied from said external device through said external device connecting connector; and an electromagnet which is provided to said external device connecting connector and electrically connected between said external device connecting connector and said electronic circuit, generates a magnetic force when a power supply current supplied from said external device flows therethrough, and attracts a predetermined portion formed of a magnetic body of said power supplying connector, to maintain a fitting state between said external device connecting connector and said power supplying connector, wherein said electronic circuit comprises a rechargeable battery and a charging circuit to charge said rechargeable battery, and when said charging circuit receives power supplied from said external device through said external device connecting connector to charge said rechargeable battery, during a trickle charging period in which a voltage difference between a power supply and said rechargeable battery becomes smaller than a predetermined value, said charging circuit drives said electromagnet with a charging current having a current value corresponding to the voltage difference to gradually weaken the fitting state between said power supplying connector and said external device connecting connector.