Sumitomo Electric Industries, Limited

Sumitomo Wiring Systems, Limited

Autonetworks Technologies, Limited

Tsuguo Nishimura

Shigeki Yamane

Seiji Takahashi

Manabu Hashikura

Takanori Itou

Yutaka Kakuno

Kazuhide Kitagawa

Youzou Nishiura

An in-vehicle power supply device includes a first voltage conversion unit for performing at least a step-down operation to lower a voltage applied to a first conductive path electrically connected to an in-vehicle power storage unit, and apply the lowered voltage to a second conductive path; a second voltage conversion unit for performing at least the step-down operation to lower a voltage applied to a first conductive path and apply the lowered voltage to a second conductive path, a second voltage conversion unit having a smaller power capacity than the first voltage conversion unit; a driving unit that drives the first voltage conversion unit and the second voltage conversion unit, and a capacitor that is electrically connected to the second conductive path and is charged with a current flowing through the second conductive path.

In-vehicle power supply device

A voltage converter performs a step-up operation and step-down operation in parallel. The step-up operation raises an input voltage to a voltage that is N (N&#x2265;1) times the input voltage. The step-down operation lowers the input voltage to a voltage that is M (0&#x2264;M&#x2264;1) times the input voltage. The voltage converter outputs the voltage transformed through the step-up operation and the step-down operation from output terminals. A current detection circuit detects an output current. A step-up adjustment circuit decreases N if the output current is higher than a reference current, and increases N if the output current is lower than the reference current. A step-down adjustment circuit decreases M if the output current is higher than a reference current, and increases M if the output current is lower than the reference current. The reference current is higher than the reference current.

Voltage converter having a step-up and step-down adjustment circuit

In a converter, the source of a first FET and the drain of a second FET are connected to one end of an inductor while the source of a third FET and the drain of a fourth FET are connected to the other end of the inductor. The sources of the first FET and the second FET are connected to each other. The cathode and the anode of a diode are connected respectively to the drain and the source of the third FET. Then, the first FET, the second FET, the third FET and the fourth FET are turned ON/OFF individually so that a voltage applied by a battery is converted. When voltage conversion is to be terminated, OFF-state of the third FET is maintained. Then, during the time that the OFF-state of the third FET is maintained, an electric current is reduced that flows from the drain of the third FET through a storage battery to the source of the fourth FET.

Converter

A converter having an inductor, a first switch, a second switch, a third switch, and a fourth switch connected between the other ends of the inductor and the second switch. The converter is adapted to turn ON/OFF individually the first switch, the second switch, the third switch and the fourth switch so as to convert a voltage applied between the other ends of the first switch and the second switch. Also included is a diode, a maintaining device and a release device. The generating device generates small/large output electric current in correspondence with high/low of a voltage of a connection node between the semiconductor transistor and the resistor, and increases the output electric current by switching a voltage applied on the third end from a first voltage to a second voltage lower than the first voltage.

Disclosed is a power-supply device configured to supply an operating voltage from an external battery to a control circuit via a voltage terminal. The power-supply device is also configured to supply an operating voltage from an output terminal to a driving circuit of the power-supply device via a switch. The control circuit that has received the operating voltage compares the voltage of the output terminal with a predetermined voltage, and makes a determination. If the voltage of the output terminal is not higher than the predetermined voltage, a predetermined notification is sent outside the power-supply device.

Power-supply device

A DC-DC converter is provided with a transformer provided with a primary coil and a secondary coil; switching elements connected to the primary coil for switching the flow of electrical current to the primary coil; rectifying elements connected to the secondary coil; a case having a first accommodating portion in which the transformer is accommodated and a second accommodating portion in which the switching elements and the rectifying elements are accommodated; and a metal heat sink mounted on the case, the metal heat sink being thermally connected to the switching elements and the rectifying elements and having a radiator portion exposed on the outer surface of the case.

DC-DC converter

A switching power supply is provided including a transformer that transforms an AC voltage converted by a bridge circuit, and outputs the transformed voltage from a center tap between secondary coils, and two second switches that respectively cause both ends of the secondary coils to be brought in contact with and be separated from a fixed electrical potential. By the second switches being switched on/off, the switching power supply outputs the rectified DC voltage from the center tap. The switching power supply further includes two diodes connected to the both ends of the secondary coils, and cause the currents to flow from the both ends, a capacitor that stores the currents caused to flow, and a third switch that is connected between the capacitor and the center tap, in which, by the third switch being turned on, the capacitor is discharged to the smoothing circuit.

Switching power supply

Semiconductor relays switch power supplied from a power source to drive loads, and further detect current values of electric currents flowing through the loads. A control section intermittently turns ON the semiconductor relays via driving circuits, thereby limiting electric power consumption of the loads. Further, the control section calculates, based on the current values detected by the semiconductor relays, load electric power consumption of the loads, and estimated electric power consumption of the loads when the semiconductor relays are continuously ON, and allows a display section to display, as a value indicative of an energy-saving effect, an electric power amount difference i.e. a saved electric energy that is based on an electric power difference obtained by subtracting the load electric power consumption from the estimated electric power consumption.

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Yokkaichi, Japan

Tsuguo Nishimura