Abstract: A control circuit 6 determines whether a difference between an input/output potential difference V11 and an input/output potential difference V13 when bypass switches SW1 and SW2 are again turned on is equal to or smaller than a threshold value Vth2 in a case where the control circuit 6 determines, at normal times other than an engine restart after being idle-stopped, that a difference between the input/output potential difference V11 of a bypass circuit when the bypass switches SW1 and SW2 are turned on and an input/output potential difference V12 when the bypass switch SW1 is turned on and the bypass switch SW2 is turned off is equal to or larger than a threshold value Vth1 and that the bypass switch SW1 has an open fault, and validates the determination of the open fault of the bypass switch SW1 in a case where the control circuit 6 determines that the difference between the input/output potential differences V11 and V13 is equal to or smaller than a the threshold value Vth2.

Abstract: A power source circuit for idling-stop vehicles is provided whereby at normal times other than a restarting of an engine after being idling-stopped, a first voltage detected by a current detection circuit when a bypass switch is turned off is acquired, and a second voltage detected by the current detection circuit when the bypass switch is turned on is also acquired, and an electric current flowing from a battery to a load via the bypass switch is obtained on the basis of a difference between the first voltage and the second voltage.

Abstract: A control circuit 6 determines whether a difference between an input/output potential difference V11 and an input/output potential difference V13 when bypass switches SW1 and SW2 are again turned on is equal to or smaller than a threshold value Vth2 in a case where the control circuit 6 determines, at normal times other than an engine restart after being idle-stopped, that a difference between the input/output potential difference V11 of a bypass circuit when the bypass switches SW1 and SW2 are turned on and an input/output potential difference V12 when the bypass switch SW1 is turned on and the bypass switch SW2 is turned off is equal to or larger than a threshold value Vth1 and that the bypass switch SW1 has an open fault, and validates the determination of the open fault of the bypass switch SW1 in a case where the control circuit 6 determines that the difference between the input/output potential differences V11 and V13 is equal to or smaller than a the threshold value Vth2.

Abstract: At normal times other than a restarting of an engine after being idling-stopped, a voltage Va1 detected by a current detection circuit 5 when a bypass switch SW2 is turned off is acquired, and a voltage Va2 detected by the current detection circuit 5 when the bypass switch SW2 is turned on is also acquired, and an electric current I1 flowing from a battery B to a load Lo via the bypass switch SW2 is obtained on the basis of a difference between the voltage Va2 and the voltage Va1.

Abstract: A power circuit includes a boost circuit having a boost switching element, a coil provided between a battery and the boost switching element and a rectifier element provided between the coil and a load, a first switch connected to the boost circuit in parallel, a current detection circuit detecting current flowing through the first switch and a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop and turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load. The control circuit determines based on the current detected by the current detection circuit during the normal state whether or not the first switch has an open fault.

Abstract: A power-supply circuit 1 includes a booster circuit 4, a bypass switch 15, and a controlling circuit 13. The controlling circuit 13 controls the driving of a boosting switching element 6 in a manner such that, at a predetermined timing during an ordinary period, the bypass switch 15 is put and maintained in the off state and then such that an output voltage of the booster circuit 4 becomes equal to an input voltage of the booster circuit 4 before the predetermined timing. While the controlling circuit 13 is controlling the driving of the boosting switching element 6 in a manner such that the output voltage of the booster circuit 4 becomes equal to the input voltage of the booster circuit 4 before the predetermined timing, the controlling circuit 13 detects, as a bypass current flowing through the bypass switch 15, a current detected by a current detecting circuit 14.

Abstract: A power-supply unit has an electric connection box operable to supply an electric power of a battery to loads and a power supply operable to control first voltage supplied from the battery and outputted through the electric connection box and supply second voltage into which the first voltage is controlled in the power supply to the loads through the electric connection box. The electric connection box includes an electric connection box side input terminal connectable to the battery and an electric connection box side output terminal connectable to the loads. The power supply includes a power supply side input terminal that is directly connected to the electric connection box side input terminal and a power supply side output terminal that is directly connected to the electric connection box side output terminal. The power supply is directly supported by and fixed to the electric connection box.

Abstract: A power control device for a vehicle includes a first battery, a second battery, the voltage of which is lower than the voltage of the first battery, and a transformer. The transformer includes a primary coil, to which an alternating-current power source is connected, a first secondary coil, to which the first battery is connected, and at least one second secondary coil, to which the second battery is connected. A rectification circuit is located between the second secondary coil and the second battery. A voltage adjustment circuit is located between the rectification circuit and the second battery. A control section charges the first battery using the alternating current power source, and, simultaneously supplies electrical power to the second battery.

Abstract: A power circuit includes a boost circuit having a boost switching element, a coil provided between a battery and the boost switching element and a rectifier element provided between the coil and a load, a first switch connected to the boost circuit in parallel, a current detection circuit detecting current flowing through the first switch and a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop and turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load. The control circuit determines based on the current detected by the current detection circuit during the normal state whether or not the first switch has an open fault.

Abstract: A power-supply unit has an electric connection box operable to supply an electric power of a battery to loads and a power supply operable to control first voltage supplied from the battery and outputted through the electric connection box and supply second voltage into which the first voltage is controlled in the power supply to the loads through the electric connection box. The electric connection box includes an electric connection box side input terminal connectable to the battery and an electric connection box side output terminal connectable to the loads. The power supply includes a power supply side input terminal that is directly connected to the electric connection box side input terminal and a power supply side output terminal that is directly connected to the electric connection box side output terminal. The power supply is directly supported by and fixed to the electric connection box.

Abstract: A power control device for a vehicle includes a first battery, a second battery, the voltage of which is lower than the voltage of the first battery, and a transformer. The transformer includes a primary coil, to which an alternating-current power source is connected, a first secondary coil, to which the first battery is connected, and at least one second secondary coil, to which the second battery is connected. A rectification circuit is located between the second secondary coil and the second battery. A voltage adjustment circuit is located between the rectification circuit and the second battery. A control section charges the first battery using the alternating current power source, and, simultaneously supplies electrical power to the second battery.