Abstract: A failure in the activation, of a motor, caused by external noise superimposed on an induced voltage is reduced. A detection circuit is connected to a connection node provided between an upper-arm switching element and a lower-arm switching element, and detects the induced voltage of a fan motor before activation. The switching controller activates the fan motor in accordance with a result of detection by the detection circuit. While the detection circuit detects the induced voltage, the switching controller performs switching control which involves alternately turning ON and OFF of the lower-arm switching element.

Abstract: A refrigerant jacket includes a refrigerant cooling member, a cover member and a strength member. The cooling member is constructed of aluminum or aluminum alloy that thermally contacts a heat emitting electrical part, and has a groove portion. A refrigerant tube of a refrigerant circuit fits into the groove portion. The cover member covers the refrigerant cooling member in a state where the refrigerant tube has been fitted into the groove portion. The strength member is higher in strength than the cooling member, and is fixed to the cooling member. The cover member has a cover-side through hole opposing the strength member. The strength member has a cover member fixing screw hole opposing the cover-side through hole. The cover member is fixed to the strength member by a cover member fixing screw that passes through the cover-side through hole and screws into threads of the cover member fixing screw hole.

Abstract: A refrigeration device includes a high-voltage electrical parts group having reactors and cooled elements, a low-voltage electrical parts group, a printed wiring board with the electrical parts groups mounted, and a refrigerant jacket that uses refrigerant flowing through the refrigerant circuit to cool the cooled elements. The high-voltage electrical parts group form an interleaved power supply circuit. The cooled elements are placed in an order conforming to a power supply path of the power supply circuit. The power supply circuit has a rectifier circuit, a power factor improvement circuit, smoothing capacitors, and an inverter circuit. The power factor improvement circuit has the reactors connected to each other in parallel and diodes and switching elements serving as the cooled elements connected to each of the reactors. The reactors are placed on an opposite side of the smoothing capacitors, with the diodes and the switching elements sandwiched in between.

Abstract: Reduced is occurrence of hunting in which a power factor corrector continuously turns on and off alternately for a short period of time. A power factor correction controller turns on a power factor corrector if a parameter value for an input current into the power factor corrector is greater than or equal to a first threshold, and turns off the power factor corrector if the parameter value is smaller than or equal to a second threshold below the first threshold. Through a predetermined time period from a moment when the power factor corrector is switched either from on to off or from off to on, the power factor correction controller maintains a state of the switched power factor corrector, regardless of the parameter value.

Abstract: Disclosed herein is a technique for substantially preventing, in a power converter including a boost power factor correction section, the power factor correction section from starting an intermittent operation even if the ripple voltage of its smoothing capacitor has increased. The converter includes: a power factor correction section including a booster circuit boosting an input voltage supplied from a rectifier section and a smoothing capacitor smoothing an output of the booster circuit; and a control section correcting a power factor by controlling the booster circuit. The control section makes correction to the amount of boost of the booster circuit such that an output voltage of the smoothing capacitor does not become lower than the input voltage.

Abstract: Malfunctions of a switching device included in a power factor corrector are reduced when an instantaneous voltage drop or an instantaneous power failure occurs. If the instantaneous voltage drop or the instantaneous power failure occurs in an AC power source while the power factor corrector is performing a power factor correction operation by boosting an input voltage, an instantaneous power failure controller turns off the switching device included in the power factor corrector so that the power factor correction operation stops. When the commercial power source recovers, too, the power factor corrector suspends the power factor correction operation.

Abstract: A motor driving apparatus includes a boosting section, a drive voltage output section, a detecting section, a storage section and a determining section. The boosting section generates a post-boosting voltage by boosting an input voltage. The drive voltage output section generates a drive voltage to drive a motor using the post-boosting voltage. The detecting section detects a value of the input voltage or a variation width relative to a reference value of the input voltage as variation power source variation information when there is power source variation. The storage section stores target value association information associating the power source variation information and a boosting target value of the post-boosting voltage. The determining section determines the boosting target value based on the power source variation information and target value association information. The target value association information is determined based on a range of operations of the drive voltage output section.

Abstract: A refrigerant jacket includes a refrigerant cooling member, a cover member and a strength member. The cooling member is constructed of aluminum or aluminum alloy that thermally contacts a heat emitting electrical part, and has a groove portion. A refrigerant tube of a refrigerant circuit fits into the groove portion. The cover member covers the refrigerant cooling member in a state where the refrigerant tube has been fitted into the groove portion. The strength member is higher in strength than the cooling member, and is fixed to the cooling member. The cover member has a cover-side through hole opposing the strength member. The strength member has a cover member fixing screw hole opposing the cover-side through hole. The cover member is fixed to the strength member by a cover member fixing screw that passes through the cover-side through hole and screws into threads of the cover member fixing screw hole.

Abstract: A voltage smoothing circuit is configured to smooth a voltage outputted from a power supply portion. The voltage smoothing circuit includes first and second smoothing capacitors, a first balancing resistor, and a second conduction regulating portion. The first smoothing capacitor and the second smoothing capacitor are connected in series to each other and are connected in parallel to the power supply portion. The first balancing resistor is connected in parallel to the first smoothing capacitor. The second conduction regulating portion is connected on a current path in parallel with the second smoothing capacitor and conducts current in one direction on the current path in a case where a voltage equal to or greater than a second predetermined voltage has been applied.

Abstract: A converter receives input of an AC voltage, converts the AC voltage into a DC voltage, and applies the DC voltage between a first power line on a positive electrode side and a second power line on a negative electrode side. A snubber circuit has a capacitor provided between the first and the second power lines, and a diode connected in series with the capacitor between the first and the second power lines, and including an anode on a side close to the first power line on the positive electrode side in a series path with the capacitor. An inverter converts the DC voltage into an AC voltage, and applies the AC voltage to an inductive load. An inverter-side current detection unit detects a current that flows through the first power line on the positive electrode side or the second power line on the negative electrode side between the inverter and the snubber circuit.

Abstract: A voltage smoothing circuit is configured to smooth a voltage outputted from a power supply portion. The voltage smoothing circuit includes first and second smoothing capacitors, a first balancing resistor, and a second conduction regulating portion. The first smoothing capacitor and the second smoothing capacitor are connected in series to each other and are connected in parallel to the power supply portion. The first balancing resistor is connected in parallel to the first smoothing capacitor. The second conduction regulating portion is connected on a current path in parallel with the second smoothing capacitor and conducts current in one direction on the current path in a case where a voltage equal to or greater than a second predetermined voltage has been applied.