| 摘要 |
PROBLEM TO BE SOLVED: To prevent an onboard apparatus from being malfunctioned for avoidance of system failure by mounting an auxiliary power supply which compensates voltage drop to prevent power supply voltage supplied to the onboard apparatus from dropping below the voltage of the auxiliary battery when the backup power supply voltage of a vehicle drops. SOLUTION: This onboard power supply system 1 is provided with a main power supply circuit 101 for supplying the power supply to an onboard apparatus 7 from a vehicle battery 3 through a backup power supply line (A), an auxiliary power supply charge circuit 103 for charging an auxiliary power supply 5 from the battery 3 through a charging line (B), and an auxiliary power supply discharge circuit 105 for discharging the auxiliary power supply 5 through a discharge line (C) to compensate for voltage drop if the backup power supply voltage from the backup power supply line (A) drops. It is thus possible to compensate the backup power supply voltage applied to the onboard apparatus 7 by means of the auxiliary power supply 5 so as to maintain 9.6 V, even if the voltage of the backup power supply drops below 9.6 V; for example, below the voltage of the auxiliary power supply 5. |
