| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the manufacturing cost, by simplifying a circuit constitution by using a load FET as an FET of an N channel. <P>SOLUTION: The power supply device comprises a secondary battery 1; a boosting circuit 2 which boosts a power supply voltage, feeds it to the secondary battery 1, and charges the battery; the load FET 3, connected between the secondary battery 1 and a load 12; and a control circuit 4 which controls the load FET 3 so as to be turned on/off. In the boosting circuit 2, there exists a voltage difference between a negative input side 2c and a negative output side 2d, the negative input side 2c is connected to the negative side of a power supply 5, and the negative output side 2d is connected to the negative side of the secondary battery 1. Furthermore, the load FET 3 is connected, between the negative output side 2d and the negative input side 2c of the boosting circuit 2, and the load FET 3 is made to serve as the FET of the N channel. The control circuit 4 switches the load FET 3 to an off-state in an uninterruptive state, and to an on-state in an interruptive state, blocks the application of electricity from the load FET 3 in the uninterruptive state, and feeds power to the load 12 from the secondary battery 1 in the interruptive state. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
