Abstract: A low cost power conversion device operating at a high frequency with high efficiency is realized by using semiconductor switching devices such as FETs being inexpensive and having low withstand voltages and low forward voltage drops. A second error signal obtained by comparing the voltages across two input capacitors connected between both ends of a DC input power supply is subtracted/added from/to a first error signal obtained from a voltage corresponding to a combined DC output of rectifying circuits and the voltage corresponding to a predetermined reference power. Based on the resultant signals, the voltage of a control signal supplied to an inverter circuit in which the voltage across an input capacitor is higher is increased, while the voltage of a control signal supplied to another inverter circuit in which the voltage across another input capacitor is lower is decreased, thereby balancing the voltages across the input capacitors.

Abstract: An energy accumulating capacitor such as an excimer laser is prevented from being overcharged by stored energy in a resonance inductance device. In a resonant capacitor charging circuit, when it is forecast that an energy accumulating capacitor can be charged to a target charge voltage by the magnetic energy of a resonant inductance device after a first semiconductor switch is switched off, the first semiconductor switch is switched off, and when actually reaching the target charge voltage, a second semiconductor switch is switched on or off, in order to charge with high accuracy.

Abstract: An energy accumulating capacitor such as an excimer laser is prevented from being overcharged by stored energy in a resonance inductance device. In a resonant capacitor charging circuit, when it is forecast that an energy accumulating capacitor can be charged to a target charge voltage by the magnetic energy of a resonant inductance device after a first semiconductor switch is switched off, the first semiconductor switch is switched off, and when actually reaching the target charge voltage, a second semiconductor switch is switched on or off, in order to charge with high accuracy.

Abstract: A semiconductor integrated circuit comprises a transistor which has a first electrode, a second electrode and a third electrode, said transistor conducting a current of a first power source from the second electrode to the third electrode by a power supplied to the first electrode; a driver to supply said first electrode with power for driving said transistor; a reference voltage circuit to generate a reference voltage which is variable in response to temperature of said transistor, said reference voltage being used as the reference for comparison; a comparative voltage circuit to generate a comparative voltage which is variable in response to a current flowing from said second electrode to said third electrode, said comparative voltage being compared with said reference voltage; and a controller which receives said reference voltage and said comparative voltage and which supplies a control signal to said driver, said control signal being based on a result of the comparison between the comparative voltage and

Abstract: The charging apparatus charges a load capacitor to a predetermined voltage, and comprises an inverter which is connected to a dc power, a transformer which is connected to the ac side of the inverter, and an inductance which is connected in series to the primary and secondary windings of the transformer and comprises leakage inductance of the transformer, a rectifier which is connected to the secondary side of the transformer, and a switch element which is provided on the secondary side of the transformer. The inverter comprises a switching semiconductor element, connected to the dc power, and a feedback diode, connected in reverse parallel to the switching semiconductor element. The switching element short-circuits the output of the inductance when the charge voltage of the load capacitor has reached a predetermined value, preventing an inertial current, generated by energy which has accumulated in the inductance, from flowing to the load capacitor.

Abstract: The charging apparatus charges a load capacitor to a predetermined voltage, and comprises an inverter which is connected to a dc power, a transformer which is connected to the ac side of the inverter, and an inductance which is connected in series to the primary and secondary windings of the transformer and comprises leakage inductance of the transformer, a rectifier which is connected to the secondary side of the transformer, and a switch element which is provided on the secondary side of the transformer. The inverter comprises a switching semiconductor element, connected to the dc power, and a feedback diode, connected in reverse parallel to the switching semiconductor element. The switching element short-circuits the output of the inductance when the charge voltage of the load capacitor has reached a predetermined value, preventing an inertial current, generated by energy which has accumulated in the inductance, from flowing to the load capacitor.

Abstract: A power supply device for an X-ray tube includes first and second capacitors connected in series at one ends thereof which are connected with a secondary winding of a high-tension transformer. Connectedly arranged between a positive output terminal and the ground are first and second diodes which are connected in series to assume the same polarity, each having a cathode as a positive output side, a connecting point of the first and second diodes being connected with the other end of the first capacitor. Also connectedly arranged between a negative output terminal and the ground are third and fourth diodes which are connected in series to assume the same polarity, each having an anode as a negative output side, a connecting point of said third and fourth diodes being connected with the other end of the second capacitor. First and second high-tension cables include a covering conductor connected with the ground, respectively.

Abstract: A current detecting circuit for an X-ray tube is disclosed which includes a DC high voltage generating circuit connected across a filament and an anode of the X-ray tube and current detecting means connected in series in a filament circuit. The filament, which is at a high potential, receives a power from a secondary winding of an isolation transformer, which has sufficient dielectric strength to insulate a highest voltage generated by said DC high voltage generating circuit. A rectifier circuit is arranged to rectify a current fed from said secondary winding or another winding having same dielectric strength as that of said secondary winding, and said rectifier circuit supplies a power to a signal transmitting circuit. The signal transmitting circuit is energized, according to the current detected by said current detecting means, to transmit an output signal. The output signal is transmitted through electrically isolated transmission means to a signal receiving circuit, which is at a ground potential.