| 摘要 |
PROBLEM TO BE SOLVED: To allow each electric load of a power supply object to be driven, even when a voltage conversion circuit fails.SOLUTION: In a first power supply path 1 from a low voltage battery 10 to electrical equipment 18, a power supply changeover switch 4 is provided, and in a second power supply path 2 from a high voltage battery 20 to a connection point 8 of the first power supply path 1, a DC-DC converter 3 is provided for converting a direct current high voltage of the high voltage battery 20 into a direct current low voltage. During an operation of the DC-DC converter 3, the power supply changeover switch 4 is turned on, and also, in this state, when a starter 11 connected to an electrical path between the low voltage battery 10 and the power supply changeover switch 4 is operated, the power supply changeover switch 4 is turned off. Then, when abnormality of the DC-DC converter 3 is detected by an abnormality detection part 9, the operation of the DC-DC converter 3 is stopped, and irrespective of the operation state of the starter 11, the power supply changeover switch 4 is brought into an ON state.SELECTED DRAWING: Figure 5 |
