Abstract: Provided is a screw shaft in a ball screw device. At least a part of the screw shaft includes a cylindrical body which is manufactured by a filament winding method or a sheet winding method, and a spiral member or a partitioned spiral member which is fixed to an outer circumferential surface of the cylindrical body and forms a thread groove.

Abstract: A microwave processing apparatus is provided with an oscillator, a power amplifier, a heating chamber that accommodates an object to be heated, a power feeder which is disposed on a wall surface of the heating chamber, which receives an output transmitted from a microwave generator and which radiatively feeds the microwave into the heating chamber, and a power detector that detects the power reflected from the power feeder to the power amplifier. The microwave processing apparatus determines a plurality of points of heating frequencies by using top several points of minimum point frequencies of the reflected power, and performs frequency hopping heating within a predetermined unit time.

Abstract: Provided is a screw shaft in a ball screw device. At least a part of the screw shaft includes a cylindrical body which is manufactured by a filament winding method or a sheet winding method, and a spiral member or a partitioned spiral member which is fixed to an outer circumferential surface of the cylindrical body and forms a thread groove.

Abstract: Electric power conversion device has first and second operation modes. First operation mode is of converting DC power from a first terminal into DC power having a desired voltage to be output to second terminal. Second operation mode is of converting DC power from the second terminal into DC power having a desired voltage to be output to first terminal. Switching section is configured to, in first operation mode, be turned on to cause short-circuiting between both ends of capacitor of rectifying circuit, and, in second operation mode, be turned off. First conversion part is configured to, in first operation mode, supply DC power-from first terminal, from first winding to second conversion part through a conversion circuit, and, in second operation mode, output to first terminal a voltage obtained by adding an output voltage of rectifying circuit to an output voltage of conversion circuit.

Abstract: A switching circuit is configured to switch on/off a current that flows through a resonance circuit constituted by a primary winding of a transformer, a capacitance element, and an inductor that are connected in series. Electric power that is induced in a secondary winding of the transformer is rectified by a rectifier circuit. A switch is connected in parallel with the capacitance element. A control unit is configured to control the switching circuit and the switch. The control unit is configured to select a first operation in which an operation frequency of the switching circuit is controlled by switching off the switch, and select a second operation in which a period during which a current flows from the switching circuit to the primary winding of the transformer is controlled by switching on the switch.

Abstract: A switching circuit is configured to switch on/off a current that flows through a resonance circuit constituted by a primary winding of a transformer, a capacitance element, and an inductor that are connected in series. Electric power that is induced in a secondary winding of the transformer is rectified by a rectifier circuit. A switch is connected in parallel with the capacitance element. A control unit is configured to control the switching circuit and the switch. The control unit is configured to select a first operation in which an operation frequency of the switching circuit is controlled by switching off the switch, and select a second operation in which a period during which a current flows from the switching circuit to the primary winding of the transformer is controlled by switching on the switch.

Abstract: A microwave processing apparatus is provided with an oscillator, a power amplifier, a heating chamber that accommodates an object to be heated, a power feeder which is disposed on a wall surface of the heating chamber, which receives an output transmitted from a microwave generator and which radiatively feeds the microwave into the heating chamber, and a power detector that detects the power reflected from the power feeder to the power amplifier. The microwave processing apparatus determines a plurality of points of heating frequencies by using top several points of minimum point frequencies of the reflected power, and performs frequency hopping heating within a predetermined unit time.