Abstract: An object is to provide a technology to suppress temperature unevenness in a semiconductor device while suppressing deterioration in productivity. A semiconductor device includes a heat sink having heat radiating fins on one surface side thereof, a plurality of semiconductor modules arranged on an other surface side of the heat sink, and a plurality of heat radiation members provided between the plurality of semiconductor modules and the heat sink, respectively, in which of the plurality of heat radiation members a thickness of the heat radiation member provided between the semiconductor module susceptible to temperature rise and the heat sink is thinner than a thickness of the heat radiation members other than thereof.

Abstract: A three-level I-type inverter includes first to fourth switching devices between first and second potentials, first to fourth diodes, and fifth and sixth diodes. The first to fourth diodes are respectively connected to the first to fourth switching devices in anti-parallel. Between a connection node of the first and second switching devices and a connection node of the third and fourth switching devices, the fifth and sixth diodes are connected in series and in anti-parallel with series connection of the second and third switching devices. A connection node of the fifth and sixth diodes is connected to an input node having intermediate potential. A connection node of the second and third switching devices is connected to an output node. The second switching device and diode are formed of a first reverse conducting IGBT. The third switching device and diode are formed of a second reverse conducting IGBT.

Abstract: A three-level I-type inverter includes first to fourth switching devices between first and second potentials, first to fourth diodes, and fifth and sixth diodes. The first to fourth diodes are respectively connected to the first to fourth switching devices in anti-parallel. Between a connection node of the first and second switching devices and a connection node of the third and fourth switching devices, the fifth and sixth diodes are connected in series and in anti-parallel with series connection of the second and third switching devices. A connection node of the fifth and sixth diodes is connected to an input node having intermediate potential. A connection node of the second and third switching devices is connected to an output node. The second switching device and diode are formed of a first reverse conducting IGBT. The third switching device and diode are formed of a second reverse conducting IGBT.

Abstract: A gas appliance judgment apparatus and method by which a type of gas appliance in use and the existence of a gas leak can be identified. In operation, noise is removed from measured instantaneous flow volume, whereupon the “length”, “initial flow volume” and “sequence of transited regions” of the variable portion of the flow volume and the “length”, “average value” and “gradient” of the flat portion of the flow volume are extracted. A rule having characteristics data which matches the characteristics of the variable portion and the flat portion of the flow volume is then searched, and points are added respectively for the type of gas appliance and for the existence of a gas leak. When the added points are not less than a previously established threshold value, then the type of gas appliance in use is determined, and appliance type information is output as a judgment result.

Abstract: A gas appliance judgment apparatus and method by which a type of gas appliance in use and the existence of a gas leak can be identified. In operation, noise is removed from measured instantaneous flow volume, whereupon the “length”, “initial flow volume” and “sequence of transited regions” of the variable portion of the flow volume and the “length”, “average value” and “gradient” of the flat portion of the flow volume are extracted. A rule having characteristics data which matches the characteristics of the variable portion and the flat portion of the flow volume is then searched, and points are added respectively for the type of gas appliance and for the existence of a gas leak. When the added points are not less than a previously established threshold value, then the type of gas appliance in use is determined, and appliance type information is output as a judgment result.

Abstract: According to the present invention, mistaken detection of a gas leak can be prevented even when using an appliance which has been newly installed in a dwelling receiving a gas supply, and whereby a gas leak can be detected rapidly, efficiently and accurately. The characteristics extraction means 5 extracts characteristics of a gas flow including a combination of the instantaneous flow volume data and the instantaneous flow volume time differential value, on the basis of the data obtained by the flow volume measurement means 1, pressure measurement means 2, instantaneous flow volume time differential operation means 3 and pressure time differential operation means 4.

Abstract: A gas appliance judgment apparatus and method by which a type of gas appliance in use and the existence of a gas leak can be identified. In operation, noise is removed from measured instantaneous flow volume, whereupon the “length”, “initial flow volume” and “sequence of transited regions” of the variable portion of the flow volume and the “length”, “average value” and “gradient” of the flat portion of the flow volume are extracted. A rule having characteristics data which matches the characteristics of the variable portion and the flat portion of the flow volume is then searched, and points are added respectively for the type of gas appliance and for the existence of a gas leak. When the added points are not less than a previously established threshold value, then the type of gas appliance in use is determined, and appliance type information is output as a judgment result.

Abstract: According to the present invention, mistaken detection of a gas leak can be prevented even when using an appliance which has been newly installed in a dwelling receiving a gas supply, and whereby a gas leak can be detected rapidly, efficiently and accurately. The characteristics extraction means 5 extracts characteristics of a gas flow including a combination of the instantaneous flow volume data and the instantaneous flow volume time differential value, on the basis of the data obtained by the flow volume measurement means 1, pressure measurement means 2, instantaneous flow volume time differential operation means 3 and pressure time differential operation means 4.

Abstract: According to the present invention, the type of gas appliance in use can be identified and a gas leak can be detected, efficiently and accurately. The flow volume data noise removal means 21 removes noise from the instantaneous flow volume data measured by the flow volume measurement means 11, and from the data after noise removal, the flow volume data object extraction means 22 extracts data on the variable portion and the flat portion of the flow volume. The gas flow characteristics extraction means 31 extracts the “length”, “initial flow volume” and “sequence of transited regions” of the variable portion of the flow volume and the “length”, “average value” and “gradient” of the flat portion of the flow volume.