| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce dedicated wires connected between a vehicular power supply device and a battery for feeding power. <P>SOLUTION: This vehicular power supply device 25 includes a selection circuit 34 for inputting thereto a voltage VB1 of a first power wire 22 connected to a battery 5 via an ignition switch 2, a voltage VB2 of a second power wire 23 connected to the battery 5 via a normally-open contact 4a of a main relay 4, and a voltage VB3 of a third power wire 24 connected to the battery 5 via a coil 4b of the main relay 4 to select the highest voltage out of them. The selection circuit 34 can always supply a battery voltage VB or a voltage close thereto to a power wire 35 regardless of the condition of the ignition switch 2, and can continuously operate circuits always requiring power feed such as an RAM 10, a soak timer 54 and a battery disconnection detection circuit 60. <P>COPYRIGHT: (C)2012,JPO&INPIT |
