| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure stable operation when power voltage is low, while suppressing the cost increase. SOLUTION: A body ECU 10 is activated by electric power supply from a battery power 21 and carries out various plurality of processings. A power retaining circuit 11 consisting of a capacitor is placed on a power line from the battery power 21, and the power retaining circuit 11 alleviates changes in the battery voltage. A switch input circuit 15 regularly inputs (samples) on/off status of an external switch 22 in accordance with an instruction from a microcomputer 13. On the body ECU 10, the microcomputer 13 judges a decrease in the battery voltage and stops input sampling of the external switch 22 by the switch input circuit 15 when the battery voltage is on the decrease. Thus voltage decrease can be delayed during the battery voltage fall right after a collision of a vehicle, and processing time of collision memory on a collision memory circuit is fully secured.</p> |
