| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a vehicle mounted power supply in which a fuse, a mechanical relay, and the like, can be omitted and the current from a sub-battery is controlled appropriately while detecting the state efficiently. <P>SOLUTION: With regard to a sub-battery 31 for driving a load 33 as a backup power supply when the voltage of a main battery 41 lowers, its current is controlled through a power MOSFET 35. From the joint of the sub-battery 31 and the power MOSFET 35, a sense MOSFET 43 shunts the current at a specified ratio and on/off control or chopping control of the power MOSFET 35 is performed by detecting the current shunted by the sense MOSFET 43. Current of the power MOSFET 35 can thereby be controlled appropriately even if a fuse, a mechanical relay, and the like, are omitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
