Abstract: A DC-DC converter includes: a DC-AC conversion circuit that converts a DC input voltage into a primary AC voltage; a transformer including a primary coil to which the primary AC voltage is applied and generates a secondary AC voltage at a secondary coil; a rectifier circuit that outputs a rectified voltage obtained by full-wave rectifying the secondary AC voltage; a smoothing circuit that smooths the rectified voltage; and a control circuit that causes the rectifier circuit to perform rectification by a diode such that, in a free-wheeling period in which power of the input voltage is not transmitted to the transformer, a current does not flow via the rectifier circuit from a first intermediate terminal to a second intermediate terminal, the first and second intermediate terminals connected to the smoothing circuit, and a current flows via the rectifier circuit from the second intermediate terminal to the first intermediate terminal.

Abstract: In a switching power supply device, a control circuit controls a first thyristor, a second thyristor, and a switching element according to an input voltage. The control circuit maintains the first thyristor in an on state while maintaining the second thyristor and the switching element in an off state in a first period in which the absolute amplitude value is equal to or less than a first threshold value within the latter half of a first half-cycle of the input voltage at startup, and maintains the second thyristor in an on state while maintaining the first thyristor and the switching element in an off state in a second period in which the absolute amplitude value is equal to or less than a second threshold value within the latter half of a second half-cycle of the input voltage at startup. The second half-cycle is the half-cycle following the first half-cycle.

Abstract: In a switching power supply device, a control circuit controls a first thyristor, a second thyristor, and a switching element according to an input voltage. The control circuit maintains the first thyristor in an on state while maintaining the second thyristor and the switching element in an off state in a first period in which the absolute amplitude value is equal to or less than a first threshold value within the latter half of a first half-cycle of the input voltage at startup, and maintains the second thyristor in an on state while maintaining the first thyristor and the switching element in an off state in a second period in which the absolute amplitude value is equal to or less than a second threshold value within the latter half of a second half-cycle of the input voltage at startup. The second half-cycle is the half-cycle following the first half-cycle.

Abstract: A noise reduction device according to one embodiment includes a noise reduction circuit and a failure diagnosis circuit. The noise reduction circuit generates an offset signal with reverse polarity of a noise component generated in a load. The failure diagnosis circuit detects a level of the offset signal. The failure diagnosis circuit determines whether or not a detected level of the offset signal deviates from an appropriate range. The failure diagnosis circuit diagnoses, on the basis of a determination result, whether or not a failure has occurred in the noise reduction circuit.

Abstract: A power converter according to the present disclosure includes a cooling plate and a plurality of circuit elements. The cooling plate includes a first cooling surface and a second cooling surface on an opposite side from the first cooling surface. The cooling plate is provided with a through hole passing through between the first and second cooling surfaces. The circuit elements convert AC power supplied from an external power source into DC power of a certain voltage and output the DC power. The circuit elements at least include first and second circuit elements. The first circuit element includes a first terminal and is thermally connected to the first cooling surface. The second circuit element includes a second terminal electrically connected to the first terminal and inserted into the through hole, and is thermally connected to the second cooling surface.

Abstract: Disclosed is a high-temperature operating fuel cell system including: a fuel cell stack; a combustor that combusts a cathode off-gas and an anode off-gas; a heat insulator that covers at least part of the fuel cell stack and at least part of the combustor; a first preheater that covers at least part of the heat insulator and preheats an oxidant gas; an oxidant gas feeder that supplies the oxidant gas to the first preheater; a vacuum heat insulator that covers at least part of the first preheater; a sensor that detects information indicating stopping of a power generation operation; and a controller. When a determination is made that the power generation has stopped, the controller controls the oxidant gas feeder to supply the oxidant gas to the first preheater so that the temperature of the vacuum heat insulator is equal to or lower than a prescribed temperature.

Abstract: In a switching power supply device, a control circuit controls a first thyristor, a second thyristor, and a switching element according to an input voltage. The control circuit maintains the first thyristor in an on state while maintaining the second thyristor and the switching element in an off state in a first period in which the absolute amplitude value is equal to or less than a first threshold value within the latter half of a first half-cycle of the input voltage at startup, and maintains the second thyristor in an on state while maintaining the first thyristor and the switching element in an off state in a second period in which the absolute amplitude value is equal to or less than a second threshold value within the latter half of a second half-cycle of the input voltage at startup. The second half-cycle is the half-cycle following the first half-cycle.

Abstract: A power converter according to the present disclosure includes a cooling plate and a plurality of circuit elements. The cooling plate includes a first cooling surface and a second cooling surface on an opposite side from the first cooling surface. The cooling plate is provided with a through hole passing through between the first and second cooling surfaces. The circuit elements convert AC power supplied from an external power source into DC power of a certain voltage and output the DC power. The circuit elements at least include first and second circuit elements. The first circuit element includes a first terminal and is thermally connected to the first cooling surface. The second circuit element includes a second terminal electrically connected to the first terminal and inserted into the through hole, and is thermally connected to the second cooling surface.

Abstract: A high-temperature operating fuel cell system includes: a fuel cell stack that generates electric power through an electrochemical reaction of an oxidant gas and a reformed gas; a combustor that combusts a cathode off-gas and an anode off-gas; a reformer that generates the reformed gas from a raw material by utilizing heat of an exhaust gas generated by the combustor; a first preheater; a second preheater that preheats the oxidant gas through heat exchange with the exhaust gas and supplies the preheated oxidant gas to the cathode of the fuel cell stack; a casing that contains these components; and a first heat insulator that covers at least part of the casing, wherein the first preheater covers the first heat insulator and preheats the oxidant gas by heat transferred from the casing through the first heat insulator before the oxidant gas is supplied to the second preheater.

Abstract: A fuel cell device includes: a reformer that generates a reformed gas; a fuel cell; a combustor that combusts off-gas of the reformed gas and air for power generation, and generates a combustion exhaust gas; a first air heat exchanger that has a combustion exhaust gas path and a first air supply path, and that performs heat exchange between the combustion exhaust gas and the air for power generation; a fuel cell storage which stores the fuel cell; a second air heat exchanger that has a second air supply path that supplies the air for power generation to the fuel cell, and that performs heat exchange between the off-gas of the air for power generation and the air for power generation; and a housing that stores members. The first air supply path and the second air supply path are disposed to cover whole members stored in the housing.

Abstract: A fuel cell system includes a hydrodesulfurizer that removes a sulfur compound from raw material and that is heated with heat of exhaust gas flowing in the fuel cell system; a fuel cell that generates power through an electrochemical reaction using fuel and oxidant gas, the fuel being obtained by reforming raw material from which the sulfur compound has been removed by the hydrodesulfurizer; an introduction passage through which the exhaust gas that is to heat the hydrodesulfurizer passes; a first heat exchanger disposed in the introduction passage and that preheats, with heat of the exhaust gas passing through the introduction passage, the oxidant gas to be supplied to the fuel cell; and a second heat exchanger that preheat, with heat of exhaust gas passing through a passage other than the introduction passage, the oxidant gas to be preheated by the first heat exchanger.

Abstract: An aircraft includes: a plurality of rotor units each of which includes a propeller, and a motor which drives the propeller; and a balloon to which the plurality of rotor units are connected and in which a gas less dense than air is contained. At least one rotor unit among the plurality of rotor units generates downward thrust.

Abstract: A high-temperature operating fuel-cell module includes a fuel-cell stack; a fuel-cell stack container in which the fuel-cell stack is contained and cathode off-gas discharged from the fuel-cell stack flows; a cathode off-gas collector that is provided in the fuel-cell stack container and in which the cathode off-gas is collected; an anode off-gas passage through which anode off-gas discharged from the fuel-cell stack flows; and a combustor that combusts the cathode off-gas collected in the cathode off-gas collector and the anode off-gas flowing through the anode off-gas passage, the combustor comprising: a combustion chamber in which the anode and cathode off-gas are mixed and combusted, an ejector that is connected to the anode off-gas passage and ejects the anode off-gas into the combustion chamber, and a diffusion plate that surrounds the ejector so that the ejector is located at the center of the diffusion plate, and ejects the cathode off-gas into the combustion chamber.

Abstract: A fuel cell system includes a hydrodesulfurizer configured to remove a sulfur compound in a raw material; a fuel cell configured to generate power by electrochemical reaction using a fuel gas and an oxidizing gas, the fuel gas being obtained by reforming the raw material desulfurized with the hydrodesulfurizer; a heater configured to heat the hydrodesulfurizer by utilizing the heat of an exhaust gas circulated in the fuel cell system including the fuel cell; an introduction passage disposed to guide the exhaust gas to the heater; and a gas supply unit configured to supply a cooling gas to the exhaust gas, the cooling gas being not utilized in the power generation in the fuel cell system, wherein a mixture gas of the exhaust gas and the cooling gas supplied from the gas supply unit is passed through the inside of the heater.

Abstract: Disclosed is a high-temperature operating fuel cell system including: a fuel cell stack; a combustor that combusts a cathode off-gas and an anode off-gas; a heat insulator that covers at least part of the fuel cell stack and at least part of the combustor; a first preheater that covers at least part of the heat insulator and preheats an oxidant gas; an oxidant gas feeder that supplies the oxidant gas to the first preheater; a vacuum heat insulator that covers at least part of the first preheater; a sensor that detects information indicating stopping of a power generation operation; and a controller. When a determination is made that the power generation has stopped, the controller controls the oxidant gas feeder to supply the oxidant gas to the first preheater so that the temperature of the vacuum heat insulator is equal to or lower than a prescribed temperature.

Abstract: A heat exchanger, in which heat is exchanged between first and second mediums, includes a housing that includes a first inlet and a first outlet, an internal member that divides a space in the housing into first and second chambers, and first and second external channels, through which the first medium flows, in the respective first and second chambers. The internal member includes a diverging hole that divides the first medium into flows through the first and second external channels, a converging hole that allows the divided first medium to converge, a second inlet, a second outlet, and an internal channel through which the second medium flows. The first and second external channels each include a first bent portion bent inwardly at a peripheral portion of the first or second chamber. The internal channel includes a second bent portion bent inwardly at a peripheral portion of the internal member.

Abstract: A high-temperature operating fuel cell system includes: a fuel cell stack that generates electric power through an electrochemical reaction of an oxidant gas and a reformed gas; a combustor that combusts a cathode off-gas and an anode off-gas; a reformer that generates the reformed gas from a raw material by utilizing heat of an exhaust gas generated by the combustor; a first preheater; a second preheater that preheats the oxidant gas through heat exchange with the exhaust gas and supplies the preheated oxidant gas to the cathode of the fuel cell stack; a casing that contains these components; and a first heat insulator that covers at least part of the casing, wherein the first preheater covers the first heat insulator and preheats the oxidant gas by heat transferred from the casing through the first heat insulator before the oxidant gas is supplied to the second preheater.

Abstract: Provided is a video surveillance technique of preventing erroneous detection.

Abstract: A fuel cell device includes: a reformer that generates a reformed gas; a fuel cell; a combustor that combusts off-gas of the reformed gas and air for power generation, and generates a combustion exhaust gas; a first air heat exchanger that has a combustion exhaust gas path and a first air supply path, and that performs heat exchange between the combustion exhaust gas and the air for power generation; a fuel cell storage which stores the fuel cell; a second air heat exchanger that has a second air supply path that supplies the air for power generation to the fuel cell, and that performs heat exchange between the off-gas of the air for power generation and the air for power generation; and a housing that stores members. The first air supply path and the second air supply path are disposed to cover whole members stored in the housing.

Abstract: A high-temperature operating fuel-cell module includes a fuel-cell stack; a fuel-cell stack container in which the fuel-cell stack is contained and cathode off-gas discharged from the fuel-cell stack flows; a cathode off-gas collector that is provided in the fuel-cell stack container and in which the cathode off-gas is collected; an anode off-gas passage through which anode off-gas discharged from the fuel-cell stack flows; and a combustor that combusts the cathode off-gas collected in the cathode off-gas collector and the anode off-gas flowing through the anode off-gas passage, the combustor comprising: a combustion chamber in which the anode and cathode off-gas are mixed and combusted, an ejector that is connected to the anode off-gas passage and ejects the anode off-gas into the combustion chamber, and a diffusion plate that surrounds the ejector so that the ejector is located at the center of the diffusion plate, and ejects the cathode off-gas into the combustion chamber.