A direct-current bus power supply as a power supply device supplies power to a load capable of switching a state between a driving state in which driving is performed by receiving power supply and a standby state in which driving is stopped while receiving power supply. The power supply device includes: a diode bridge circuit and capacitors as a rectifier circuit that enables an alternating-current voltage to be rectified by respective rectification systems of full-wave rectification and voltage doubler rectification; and a switching unit that perform switching between the full-wave rectification and the voltage doubler rectification on the basis of a voltage value of the alternating-current voltage and the state of the load.

A motorized hand tool, such as a cordless ratchet wrench, that has a motor, one or more electronic components and/or integrated circuits, and a step-up converter that are housed or disposed in a housing of the tool. The step-up converter is adapted to prevent a voltage of a battery of the tool from dropping below a threshold voltage of a component or integrated circuit when current draw from the battery increases, thus preventing a “brownout” condition.

A cooler includes a heat radiating member and a cover member that form a coolant flow path. The heat radiating member has a first surface on which an object to be cooled is disposed. The heat radiating member includes multiple fin members protruding into the coolant flow path from a second surface of the heat radiating member. The second surface of the heat radiating member is a part of a surface of the coolant flow path. The cover member includes a trap part in which multiple recesses are formed in a portion of an inner surface of the cover member being another part of the surface of the coolant flow path outside a protruding direction of the fin members.

An electric device is provided which can reduce risk of malfunction. This electric device is provided with a motor (31), an inverter circuit (30) which has switching elements (S1-S6) and which drives the motor (31), and a charge pump circuit (22) which generates the drive voltage of the switching elements (S1-S6). A discharge circuit (a discharge resistor R and a capacitor C1) is provided between a power line to which a drive voltage (VM) of the motor (31) is supplied and an output terminal (a VGT terminal) of the charge pump circuit (22). Energy of the surge voltage (Vs) generated in a parasitic inductance (Ls) when the switching elements (S4-S6) are turned off is absorbed by the discharge circuit (the discharge resistor R and the capacitor C1).

A sensor unit includes a bus bar and a magneto-electric conversion device. The bus bar connects a plurality of switch elements constituting a part of a power conversion circuit and a motor. The magneto-electric conversion device is disposed to face a middle portion of the bus bar across a clearance in a predetermined direction to detect a magnetic field caused by an electric current flowing through the bus bar, to thereby detects the electric current. The bus bar includes a first end and a second end. The first end of the bus bar is connected to one of a switch terminal extending from the switch elements and a motor terminal extending from the motor, and the second end of the bus bas is connected to the other of the switch terminal and the motor terminal.

A motor control device includes an optimal voltage calculation part configured to calculate an input voltage that is a lowest total of electric power losses generated by an inverter, a motor and a converter, a lowest voltage calculation part configured to calculate a lowest value of the input voltage required at a motor operating point, and a target value setting part configured to set any one of the optimal input voltage and the lowest input voltage as the target input voltage, and the target value setting part sets the lowest input voltage lower than the optimal input voltage to the target value when the element temperature of the inverter and the converter is equal to or greater than a predetermined value.

According to one embodiment, the controller configured to, when an operation of the boosting circuit is in the boosting mode, and if an instantaneous value Ia of a current flowing through the reactor lowers to a value smaller than or equal to a set value Ias, switch the operation of the boosting circuit from the boosting mode to the non-boosting mode.

Selective efficiency multi-phase traction inverters and chargers as heat sources for thermal conditioning of electric vehicles is provided. The traction inverter comprises a plurality of phases, each of the plurality of phases having at least one semiconductor switching device, the at least one semiconductor switching device configured to switch between at least three differing states, for thermal management of the electric vehicle components and compartments. The traction inverter includes a controller coupled to the plurality of phases, to operate the plurality of phases in a first mode of the traction inverter to drive the electric motor as a traction motor. The controller operates the plurality of phases in a second mode of the traction inverter as a first type of converter. The controller to operate the plurality of phases in a third mode of the traction inverter as a second type of converter.

A direct-current bus power supply as a power supply device supplies power to a load capable of switching a state between a driving state in which driving is performed by receiving power supply and a standby state in which driving is stopped while receiving power supply. The power supply device includes: a diode bridge circuit and capacitors as a rectifier circuit that enables an alternating-current voltage to be rectified by respective rectification systems of full-wave rectification and voltage doubler rectification; and a switching unit that perform switching between the full-wave rectification and the voltage doubler rectification on the basis of a voltage value of the alternating-current voltage and the state of the load.

A fuel cell module has: a first stacked body including a plurality of unit cells stacked on each other; and a second stacked body including a plurality of magnetic body sheets stacked on each other. The magnetic body sheets includes a coil. The first stacked body is superposed on the second stacked body so as to be electrically connected to the coil. A conductor serving as a part of the coil is embedded in each magnetic body sheet. The conductor has a first end portion and a second end portion exposed from surfaces of each magnetic body sheet on opposite sides from each other. The first end portion of the conductor of one of a set of magnetic body sheets adjacent to each other, among the magnetic body sheets, contacts the second end portion of the conductor of the other of the set of magnetic body sheets.