A rotary anode driving device includes a DC power supply, an inverter circuit which is connected to the DC power supply and includes a plurality of switching elements and, the inverter circuit generates an AC voltage from a DC voltage of the DC power supply, and outputs the AC voltage to a stator coil which generates a rotating magnetic field of an X-ray tube; a pulse width modulation (PWM) waveform generator configured to generate an AC voltage of two phases or three phases as the AC voltage from the DC voltage by performing PWM control of the switching elements of the inverter circuit; and a capacitor connected in series to an input side of a stator coil of at least one phase of the stator coil, the capacitor having an electrostatic capacitance constituting a series resonant circuit with the stator coil to which the capacitor is connected.

A rotary anode driving device includes a DC power supply, an inverter circuit which is connected to the DC power supply and includes a plurality of switching elements and, the inverter circuit generates an AC voltage from a DC voltage of the DC power supply, and outputs the AC voltage to a stator coil which generates a rotating magnetic field of an X-ray tube; a pulse width modulation (PWM) waveform generator configured to generate an AC voltage of two phases or three phases as the AC voltage from the DC voltage by performing PWM control of the switching elements of the inverter circuit; and a capacitor connected in series to an input side of a stator coil of at least one phase of the stator coil, the capacitor having an electrostatic capacitance constituting a series resonant circuit with the stator coil to which the capacitor is connected.

A power conversion system includes a first capacitor, an isolated type converter circuit, and a control circuit. The first capacitor is connected to the direct-current power supply via an inrush current prevention circuit. The inrush current prevention circuit is switchable at least between a high-impedance state and a low-impedance state. The converter circuit includes a transformer, and the first capacitor is connected to a primary winding wire of the transformer. The control circuit controls the inrush current prevention circuit and the converter circuit to cause the converter circuit to start operating, and then, the control circuit switches the inrush current prevention circuit from the high-impedance state to the low-impedance state.

A power conversion system includes a first capacitor, an isolated type converter circuit, and a control circuit. The first capacitor is connected to the direct-current power supply via an inrush current prevention circuit. The inrush current prevention circuit is switchable at least between a high-impedance state and a low-impedance state. The converter circuit includes a transformer, and the first capacitor is connected to a primary winding wire of the transformer. The control circuit controls the inrush current prevention circuit and the converter circuit to cause the converter circuit to start operating, and then, the control circuit switches the inrush current prevention circuit from the high-impedance state to the low-impedance state.

A method and device is disclosed for charging and/or maintenance of lead-acid and alkaline accumulator batteries, allowing a charge, discharge, or recovery in control-conditioning cycles of these batteries. To increase efficiency of the battery recovery process, its charge is created by a reversible current in consecutive stages. Correction of the charging mode is provided based on voltage and temperature of the accumulator battery.

A method and device is disclosed for charging and/or maintenance of lead-acid and alkaline accumulator batteries, allowing a charge, discharge, or recovery in control-conditioning cycles of these batteries. To increase efficiency of the battery recovery process, its charge is created by a reversible current in consecutive stages. Correction of the charging mode is provided based on voltage and temperature of the accumulator battery.

In an inverter module (10) including a plurality of switching elements (11), a positive-polarity bus bar (14), a negative-polarity bus bar (15), and a plurality of output bus bars (16, 17, and 18), the plurality of output bus bars (16, 17, and 18) are disposed in a first direction (D1) in which upper-stage-side switching elements (11U) and lower-stage-side switching elements (11L) are placed side by side, and the positive-polarity bus bar (14) and the negative-polarity bus bar (15) are disposed in a second direction (D2) intersecting the first direction (D1).

In an inverter module (10) including a plurality of switching elements (11), a positive-polarity bus bar (14), a negative-polarity bus bar (15), and a plurality of output bus bars (16, 17, and 18), the plurality of output bus bars (16, 17, and 18) are disposed in a first direction (D1) in which upper-stage-side switching elements (11U) and lower-stage-side switching elements (11L) are placed side by side, and the positive-polarity bus bar (14) and the negative-polarity bus bar (15) are disposed in a second direction (D2) intersecting the first direction (D1).

A gate-drive system according to the present invention which transmits a drive signal to a semiconductor switching device, includes: an inverter circuit to supply high-frequency power including a fundamental wave component and plural harmonic components each having different frequencies; a power transmission circuit which is connected to the inverter circuit and transmits the high-frequency power outputted from the inverter circuit; power receiving circuits to individually receive the fundamental wave component and plural harmonic components of the high-frequency power transmitted from the power transmission circuit; and a control circuit to generate the drive signal for the semiconductor switching device on the basis of the plural harmonic components of the high-frequency power received by the power receiving circuits.

A gate-drive system according to the present invention which transmits a drive signal to a semiconductor switching device, includes: an inverter circuit to supply high-frequency power including a fundamental wave component and plural harmonic components each having different frequencies; a power transmission circuit which is connected to the inverter circuit and transmits the high-frequency power outputted from the inverter circuit; power receiving circuits to individually receive the fundamental wave component and plural harmonic components of the high-frequency power transmitted from the power transmission circuit; and a control circuit to generate the drive signal for the semiconductor switching device on the basis of the plural harmonic components of the high-frequency power received by the power receiving circuits.