Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A high voltage DC/DC converter including a voltage resonance switching circuit formed by a coreless transformer, a GTO thyristor switching element connected between the primary winding of the transformer and a D.C. source, and a voltage resonance capacitor connected in parallel to the switching element. A rectifier circuit is connected to the secondary winding of the transformer to rectify an output current from the transformer circuit. The resonance frequency of the parallel resonance circuit made of the resonance capacitor and the coreless transformer is selected to be the frequency of that component of the current supplied to the circuit through the switching element, which has a greater amplitude than any other component of the current (including the fundamental frequency and other harmonic).

Abstract: Digital radiography apparatus uses a resonance-type high frequency inverter having a main switch in series with an auxiliary switch. An X-ray tube receives the pulsed power from the high frequency inverter, after voltage ampliflication and rectification, emitting pulsed X-rays to a patient. A TV camera obtains X-ray transmission images of the patient, and an image processor generates a visual diagnostic image by subtracting one X-ray transmission image from another. The high frequency inverter circuit is controlled synchronously with the processing operation of the image processor.

Abstract: An X-ray generating apparatus is adapted to obtain an X-ray tube voltage by rectifying an incoming AC voltage to obtain a DC voltage, supplying the DC voltage, after being switched through a switching section, in a predetermined cycle to a resonance circuit comprised of a primary winding of a transformer and resonance capacitors and rectifying the AC voltage which is induced in the secondary winding of the transformer. The switching section comprises a three-phase bridge inverter circuit including parallel arrays of arms each of which is made up of a pair of switching elements. The switching section is so controlled that the switching elements in each respective arm are fired without being continuously turned ON. Each resonance capacitor is connected between an intermediate connection point of the respective arm of the switching section and the primary winding of the transformer.

Abstract: An inverse rectifier for use with a high voltage transformer of an x-ray generator has an air-core coil disposed between the load output and two switching transistors in a half-bridge circuit. The junctions of the air-core coils with the switching transistors are cross-connected to a constant voltage source through respective diodes which block the constant voltage. An RC element is connected in parallel with each air-core coil.

Abstract: A DC voltage from a DC power source is supplied through a high speed switching device to a capacitor provided in the primary side of a transformer and a primary winding, thereby generating a high frequency signal at the primary winding of the transformer. A voltage between the first and the second output terminals of the transformer is applied between the anode and the filament of the X-ray tube as an X-ray tube voltage. Here, a system control device reads out a plurality of optimum switch control data for diagnostic items on the basis of various condition data from a subject information inputting device, and supplies them to the high speed switching device. The switching device varies the switching speed on the basis of the plurality of given switch control data, thereby instantaneously varying the value of the X-ray tube voltage.

Abstract: A high voltage generating device for an X-ray apparatus includes a DC output voltage control device for rectifying and smoothing a commercial AC power source voltage and a resonant circuit comprised of a series circuit of a capacitor and a primary winding of a transformer. The output DC voltage of the DC output voltage control device is supplied to the resonant circuit in a first direction or in a direction opposite to the first direction. The direction in which the voltage is applied to the resonant circuit is switched by a current switching means. Consequently, a high AC voltage is obtained through a secondary winding of the transformer. The AC voltage is converted by a rectifying/smoothing means to an X-ray tube voltage which is applied between an anode and a cathode filament of an X-ray tube. The DC output voltage control device permits its output voltage to be switched to an arbitrary level.

Abstract: A high voltage supply circuit for an x-ray tube includes a high voltage transformer having a primary side driven by voltage pulses generated by a drive circuit. The drive circuit includes sub-circuits for controlling the pulse repetition frequency, which is selected as equal to a parallel resonant frequency of a high voltage generator connected to the secondary side of the transformer, for the purpose of saving energy. The drive circuit also includes a sub-circuit for controlling the pulse duration, with the filament voltage in the x-ray tube being regulated by this pulse duration.

Abstract: An inverter receives a d.c. voltage and delivers to an X-ray tube, by way of a high-voltage transformer, filter, and rectifier, a high-voltage d.c. output. The inverter is driven in response to control signals which are responsive to the difference between a voltage demand signal and a voltage feedback signal. The control signals are also responsive to various status conditions of the system which are monitored by a microprocessor. Inputs to the microprocessor include various signals which are indicative of voltage or current conditions. In this way, such conditions as an over-voltage at the output, an unbalance between the anode and cathode with respect to ground, or an excessive current flow are detected and precautionary measures are quickly taken to prevent further damage to the system.

Abstract: An X-ray generator system is provided with a high-voltage feedback loop for controlling the output of an inverter to thereby maintain a desired output voltage level. The voltage-feedback loop is provided with a phase-advance network to selectively vary the gain of the system in such a way as to provide for high gain during the initial stage so as to obtain a short rise time, while subsequently reducing the gain so as to clamp the kV overshoot at the end of the rise time. A phase-lag network is also included to effectively eliminate noise that is introduced by the phase-advance network.

Abstract: The dissipation of the filament power of an X-ray tube is controlled by a heating circuit including a voltage resonance type DC-to-DC converter and a filament current detector/controller. The DC-to-DC converter is comprised of a switch, a capacitor, a damper diode and a transformer. These circuit elements constitute a voltage resonance type switch. A DC voltage is interrupted and applied to the primary winding of the transformer. The AC voltage is induced to the secondary winding of the transformer, thereby heating the filament of the X-ray tube. In accordance with the load curve of the X-ray tube, the filament heating voltage can be controlled within a control range defined by the resonant conditions of the switch.

Abstract: The invention relates to a high-voltage generator for supplying two different output voltages or output currents, particularly for X-ray tubes whose anode current deviates from the cathode current. Symmetrical output voltages can be obtained during operation of this device, despite asymmetrical loads to the anode and cathode, by using a resonant direct current/alternating current converter with a capacitor circuit which is discharged through two different primary windings. The discharge through one primary winding takes place with a preferably adjustable delay with respect to discharge through the other primary winding.

Abstract: An X-ray apparatus, after an AC output from an AC power source is rectified by a first rectifier circuit, supplies it to a primary winding side of a high-tension transformer through a bridge inverter. The bridge inverter includes first and second switching elements arranged at its first and second arms and operating as high-frequency choppers, a third switching element and first parallel circuit arranged at its third arm and forming a closed circuit together with the primary winding of the high-tension transformer, and a fourth switching element Q.sub.4 and second parallel circuit arranged at its fourth arm and forming a closed circuit together with the primary winding of the high-frequency transformer, the first parallel circuit being connected in series with the third switching element and comprised of a diode and resistor and the second parallel circuit being connected in series with the fourth switching element and comprised of a diode and resistor.

Abstract: A safety device for an X-ray tube is disclosed which makes it possible to continue the examination which was taking place while a brief blocking of the E.H.V. application occurred which was necessary to bring about rapid stoppage. By this safety device, the rapid automatic rearming takes place so that the interruption was almost negligible in order to provide for stoppage of the examination which was taking place when the tube had repeated starting operations at rapid intervals.

Abstract: In an exemplary embodiment, a medium frequency generator is mounted on the rotating frame together with at least one x-ray tube, preferably, however, a plurality of x-ray tubes. The x-ray tubes are grid-controlled and, together with their filament transformer are provided in one separate housing each. A grid control circuit is connected with the component parts on the rotating frame.

Abstract: In an exemplary embodiment a rotary anode motor is likewise supplied by the inverter circuit which is in the form of a full bridge with two pairs of alternately closable electronic switches. In one bridge diagonal the load (e.g. the x-ray tube) is disposed, while a d.c. voltage source is connected to the other bridge diagonal. The rotary anode motor is capable of connection, via a switch, to a connection point at one side of the load diagonal, and the bridge-half at the opposite side of the load diagonal is capable of being maintained in an open circuit condition during motor operation.