| 摘要 |
Provided is a power supply device in which, when the difference between the input/output potential difference (V11) of a bypass circuit when bypass switches (SW1, SW2) are turned on and the input/output potential difference (V12) when the bypass switch (SW1) is turned on and the bypass switch (SW2) is turned off becomes equal to or greater than a threshold value (Vth1) at a normal time other than when restarting an engine after an idle stop, a control circuit (6) determines that the bypass switch (SW1) is suffering from an open fault, determines whether the difference between the input/output potential difference (V11) and the input/output voltage potential difference (V13) when the bypass switches (SW1, SW2) are turned on again is equal to or less than a threshold value (Vth2), and when the difference between the input/output potential differences (V11) and (V13) is determined to be equal to or lower than the threshold value (Vth2), validates the determination of an open fault in the bypass switch (SW1). |
