Hitachi Medical Corporation

Other

Hirofumi Hino

Kazuo Kaneko

Takanobu Hatakeyama

Hideki Uemura

Kazuo Yamamoto

Norikazu Tokunaga

Masaji Ootakeguchi

Masaji Ohtakeguchi

In an inverter type X-ray apparatus comprising an inverter including a plurality of switching elements operated alternately to generate an AC voltage having a rectangular waveform, a high voltage transformer transforming the AC voltage of rectangular waveform into a high AC voltage, a high voltage rectifier circuit rectifying the high AC voltage into a DC voltage, and an X-ray tube to which the DC voltage is applied as a tube voltage, the switching elements are driven to make chopping operation at a frequency high than the inverter drive frequency, and a pattern signal is generated for gradually increasing the duty cycle of the chopping operation in synchronism with the timing of switching over the switching elements.

Inverter type X-ray apparatus

A power supply system including a DC-to-AC inverter stage and a voltage step-up transformer is intended to have the output voltage settlement with a minimal delay and suppressed bounce at the start-up of power supply to the load, and also intended to reduce the load voltage bounce caused by the leakage inductance and stray capacitance of a high tension step-up transformer.

A method of operating a power supply system including inverter stage

Disclosed is a resonant DC-DC converter which comprises an inverter for converting DC power into AC power, a rectifier connected to the AC output of the inverter through a resonant transformer for rectifying AC output power of the transformer to obtain DC power to be applied to a load, means for determining respective operation phases of a first, a second, a third and a fourth switching elements constituting the inverter in accordance with set signals indicating a voltage and a current to be supplied to the load, and a phase control circuit for controlling the respective operation phases of the first, second, third and fourth switching elements on the basis of an output signal of the phase determining means in a manner so that the first and second switching elements are alternately turned on with a phase difference of 180 degrees with respect to an operation frequency of the inverter, the third and fourth switching elements are alternately turned on with a phase difference of 180 degrees with respect to the operation frequency of the inverter, while varying a phase difference from turn-on of the first switching element to turn-on of the fourth switching element and a phase difference from turn-on of the second switching element to turn-on of the third switching element to thereby control or feed-back control the DC power to be supplied to the load.

Resonant DC-DC converter

Disclosed is an inverter type X-ray apparatus comprising a DC-DC converter for converting a DC voltage into a different DC voltage, an inverter for inverting an output voltage of the DC-DC converter into an AC voltage, a high voltage transformer for transforming an output voltage of the inverter into a higher voltage, a rectifier for converting an AC output voltage of the transformer into a DC voltage, and an X-ray tube to which an output voltage of the rectifier is applied. In the apparatus, the DC-DC converter includes a reactor, a switching element and a capacitor which are interconnected so that the DC-DC converter can generate an output voltage higher or lower than an input voltage.

A high voltage generating apparatus for an X-ray tube comprises an inverter for converting a DC voltage into an AC voltage, a high voltage transformer for boosting an output voltage of the inverter, a rectifier for converting an output voltage of the transformer into a DC voltage, and a detector for detecting an X-ray tube voltage to produce an output signal corresponding to the X-ray tube voltage. The output signal of the detector is sampled and held by a sample/hold circuit in synchronism with an operating period of the inverter so that the X-ray tube voltage is controlled in accordance with an error between an output signal of the sample/hold circuit and an X-ray tube voltage set level.

High voltage generating apparatus for x-ray tube

An inverter-type switching power supply circuit which comprises an inverter for converting the DC output of a DC power source to an AC output, a transformer for receiving the AC output of the inverter, a rectifier for rectifying the output of the transformer, a smoothing capacitor for smoothing the output of the rectifier and supplying it to a load, and a transformer short-circuiting circuit for short-circuiting either the primary side or the secondary side of the transformer. The transformer is frequency controlled such that the product of the applied voltage and time of the transformer becomes constant. Thus, the transformer can be designed to have a small size and a light weight.

Growing community of inventors

Noda, Japan

Hirofumi Hino