Abstract: 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.

Abstract: An apparatus for setting the exposure parameters of an X-ray generator that comprises an X-ray transformer for supplying high voltage and filament current to an X-ray tube, in which data relating to the functional relationships between the unloaded voltage of the X-ray transformer, the loaded voltage thereof, the anode current of the X-ray tube and the filament current are stored in the memory of a processor, and based on a measured unloaded voltage and a preset mAs exposure value the processor calculates and displays the loaded high voltage, sets a suitable discrete filament current and determines the exposure time corresponding to the predetermined mAs value in such a way that the X-ray tube cannot be overloaded. If the predetermined exposure data cannot be set due to overload, the processor indicates this fact, whereby the operator can either adjust the voltage or change the exposure parameters.

Abstract: The invention pertains to a current-supplying device used to supply heating current to a filment of an X-ray tube. The current-supplying device comprises a current inverter delivering current to a load circuit in which there is an oscillating circuit, the impedance of which is made to vary.

Abstract: A pre-ignition type X-ray apparatus including a mode changeover switch which changes a pre-heat mode to an X-ray irradiation mode and vice versa, a tube current control circuit for feedback control of the X-ray tube's filament heating current to a target value, and pre-heat control circuit for controlling the filament heating current in the pre-heat mode to a target value lower than the target value in the X-ray irradiation mode. The pre-heat control circuit includes a differential amplifier which amplifies the difference between the detected voltage corresponding to a source voltage and the reference voltage determining the lower target value, so that the control signal is outputted from the differential amplifier.

Abstract: The invention relates to an X-ray generator including a controller for the dose rate. In order to enable universal use of this controller for different types of examination, use is made of a sampling controller in the form of a microprocessor system. There are provided memories in which the sampling frequency and the adjustment functions are stored for the various types of examination as well as the programs on the basis of which the sampling controller calculates the adjustment values for the various types of examination.

Abstract: In X-ray generators comprising a converter for generating the high-voltage for an X-ray tube, substantial dose fluctuations are liable to occur from one exposure to another of series involving a fixed exposure time due to supply voltage fluctuations or fluctuations in the object absorption. These dose fluctuations are more pronounced as the exposure time is shorter and as the converter frequency is lower. These fluctuations are reduced by terminating a series of exposures each time after the same number of converter alternations when the deviation between the actual value and the reference value of the dose or the dose rate is smaller than a predetermined value.

Abstract: In a circuit arrangement for producing high voltages by means of a voltage multiplier with rectifiers and capacitors and fed from an alternating current source in which circuit arrangement, a low amplitude voltage lying at the high voltage level is produced by the ripple voltage across one or more of the component parts of the voltage multiplier, the average potential of which component part (s) does not differ substantially from the high voltage. In the case of an X-ray tube high voltage supply the total filament circuit may be approximately on the high cathode voltage and no severe requirements for insulation need to be fulfilled. The ripple voltage may be used to produce other small amplitude voltages lying at a high voltage level.

Abstract: A circuit for controlling a medium frequency x-ray diagnostics generator, the generator having a power rectifier connected to a main power source having an unknown internal resistance. A low-voltage filter stage, and inverter, a high-voltage transformer, and a high-voltage rectifier are connected in sequence between the power rectifier and an x-ray tube. A control unit for the x-ray tube is provided which controls the x-ray tube input current dependent upon the input voltage to the inverter, so that the x-ray tube voltage is maintained constant independently of the internal network resistance of the main. The generator can thus be connected to different mains having different internal resistances without affecting operation of the x-ray tube, making the generator suitable for use as a portable generator.

Abstract: Between scans, a stand-by control (40) causes a filament current power supply (44) to supply a low level of power to a tube filament (46). When x-rays are to be generated, a non-linear digital to analog converter (50) supplies a filament current control signal which is estimated to provide a selected tube current. A space charge compensation circuit adds an offset to the selected filament signal to compensate for the selected voltage at which the tube is to be operated. A current boost circuit (70) adds an incremental current boost (26) of a magnitude in accordance with a function of the difference between the actual filament temperature and the normal operating temperature in order to bring the filament up to operating temperature more quickly. A feedback loop (90 to 98) adjusts the selected filament current signal in accordance with any difference between the selected tube current and the actual tube current.

Abstract: The quality of x-ray shadowgraphic images is improved by beam equalization controlled to ensure that just the right amount of radiation is used to accomplish the desired result, be it a desired image density and contrast or a desired signal-to-noise ratio or some other desired characteristic. The new techniques include: (1) maintaining a substantially constant signal-to-noise ratio throughout the image by measuring both scattered and primary radiation and using the results in a feedback loop to control the x-ray tube output, (2) raster scanning an x-ray beam along straight lines at constant velocity within a line by using a curved slit rotating aperture, (3) simultaneously controlling each of the intensity and hardness of a scanned x-ray beam as determined by post-patient x-ray measurements, and (4) using a segmented fan to scan the patient in a direction transverse to the plane of the fan and individually modulating each beam segment to achieve desired image characteristics.

Abstract: An X-ray generator with current measuring device has an X-ray tube, a power supply unit for feeding high voltage to the X-ray tube, a high voltage cable for connecting the X-ray tube and power supply unit. The high voltage cable is comprised of a core conductor, an insulating layer surrounding the core conductor and a covered shield surrounding the insulating layer and the covered shield is disconnected near one end of the cable connected to the X-ray tube so as to be divided into a major shield portion adjacent to the power supply unit and a minor shield portion adjacent to the X-ray tube. An insulating member is provided for electrically insulating the major and minor shield portions, and a magnetic sensor sensitive to a magnetic field generated by a current flowing through the high voltage cable is positioned around the minor shield portion. The X-ray generator can measure the X-ray tube current accurately and readily under electrical insulation.

Abstract: A dynamic calibration and self-check circuit for a mobile X-ray machine. A high voltage regulator circuit provides dynamic regulation of peak anode voltage and a tube current regulator circuit provides dynamic regulation of the X-ray filament current which controls the X-ray tube current. In the regulation of the anode voltage, a voltage sensor provides continuous feedback of the actual anode voltage of the tube to the regulation circuit. A processor selects a predetermined value for the pulse width duration of the high voltage regulator. When an exposure cycle commences, the preselective value is compared with the actual sensed value in an error amplifier. The error amplifier generates an error signal which varies the pulse width of the drive signal to control the peak high voltage to the anode. In the control of the tube current, a sensor which measures the actual tube current is compared with a predetermined value selected by the processor in a second error amplifier.

Abstract: A structure and method for providing optimum recording of X-ray images without need for experimenting to learn optimum X-ray tube voltage, current, anode focal spot size and exposure time. The method and structure of this invention sample the radiation passed through an object to be radiographed during a short portion of the total exposure time and adjust voltage, current and focal spot size so that the radiation delivered by the X-ray tube during the remainder of the exposure time will produce optimum contrast between structures within the object being radiographed, also optimum sharpness of the image and optimum darkening of a film, xerographic picture, fluoroscopic image, or other recording medium. The method and structure of this invention account for variations in absorption coefficient between one object to be radiographed and the next. This invention is particularly useful for medical applications, and in the medical field, particularly important in mammography.

Abstract: An X-ray examination system comprising an X-ray generator, an image intensifier tube connected to an output optical path and an X-ray exposure control arrangement which measures the light image intensity LI at the output of the image intensifier during fluoroscopy, and from the relationshipI.sub.EXP1 =(LA.times.I.sub.FL)/LI.times.T.sub.EXP),derives the exposure value I.sub.EXP1 of the switch-on tube current required to provide a desired exposure density during subsequent fluorography with a tube voltage V.sub.FL and exposure time T.sub.EXP, and wherein LA is a predetermined constant.

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 bridge inverter arrangement for use with high-voltage generators for X-ray apparatus includes a single phase transformer having primary and secondary windings, a capacitor series-connected via a current-limiting resistor to the primary winding so as to constitute a series resonant circuit, a bridge inverter having series-connected thyristors for inverting DC low voltage into pulsating low voltage, and a switching controller for controlling turn-on times of the thyristors. A switching circuit is connected in parallel to the resistor. The switching circuit is controlled under the switching controller in response to switching signals for the thyristors so as to vary the value of the pulsating low voltage, thereby changing the value of high AC voltage induced at the secondary winding and reducing the ripple components contained therein.

Abstract: A voltage signal proportional to the brightness of an x-ray image is derived. In a mA loop the ratio of a reference voltage to brightness is determined. If the brightness ratio does not equal 1 it causes the x-ray tube current controller to adjust current (mA) to eliminate the error. A command proportionate to the ratio is stored until the next image frame. In a kV loop a ratio of the last mA command and a set limit for mA is taken. This error ratio is multiplied by the brightness ratio to provide a kV control ratio indicative of how much of the brightness error the kV loop is obliged to correct. The kV control ratio is corrected for nonlinearity between kV change and brightness change and the resulting command is used to adjust the kV applied to the x-ray tube anode.

Abstract: A hand held x-ray source includes an x-ray tube and integral generator for exciting the tube at precisely controllable high voltage and direct current levels. The integral generator includes an elongated housing grippable by the hand and an elongated unitary molded block mounted in the housing and thermally sumped thereto. The block defines a first heat conduction fluid fillable cavity for receiving the tube and for providing a high voltage connection to the anode adjacent to the interior end thereof, the block being formed to contain and insulate interconnected elements providing a single voltage multipliers tack, and primary and secondary windings of a single high voltage switching transformer having a ferrite magnetic core external to the block. A heat conduction fluid is disposed between the tube and the block for conducting heat generated during tube operation to the block.

Abstract: A circuit for measuring anode current in an X-ray tube having an anode and a heater electrode both operable at high voltage, includes a heater transformer generating current pulses with a timewise constant first pulse repetition frequency and an adjustable duty cycle, a first frequency separator connected in series with the heater transformer for receiving the output thereof, a high voltage-proof transformer having a primary winding connected in series with the first frequency separator, and separate first and second secondary windings, the first secondary winding being connected to the heater for supplying heater current for the X-ray tube, an anode circuit connected to the anode of the X-ray tube including a current/duty cycle converter generating a current with a constant second pulse repetition frequency different from the first pulse repetition frequency, the first secondary winding being connected to the current/duty cycle converter for supplying voltage from the high voltage-proof transformer, a second

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: Current limit protection is provided to ensure that the current flow within the transistor inverter does not exceed a predetermined safe level to thereby cause damage to the various components such as the transistor inverters. The current in the primary of the transformer is sensed and a representative signal is compared with a reference signal to provide a digital output indicating whether a safe limit has been exceeded. A logic network then operates on the output signal to shut down or reduce the system operation accordingly. In the event of a shut-down, current decay is accommodated by shutting off only the top transistors in the inverter diagonals so as to thereby allow the remaining current to flow in the bottom transistors and diodes.

Abstract: A modular portable X-ray source with integral generator system for generating continuous X-rays of regulated intensity and energy level over a range from zero to maximum and includes a unitary housing containing an X-ray tube, a direct current high voltage power supply for generating a directly controllable, regulated high voltage, a regulated filament supply for generating a directly controllable, regulated beam current, both supplies being directly connected to the X-ray tube without cabling, both supplies being controlled by feedback control signals directly from the X-ray tube, and both being operated directly from a low voltage high current supply, such as a storage battery.

Abstract: An automatic exposure device for obtaining X-ray pictures with superior quality and constant contrast by feedback of both tube voltage and tube current according to the residual X-ray dose which penetrates the body of a patient. This device is further characterized in that the feedback control is compensatingly done according to the changes in the tube voltage and tube current caused by fluctuations of the power supply.

Abstract: Anode life in an x-ray tube is extended by applying a reduced power density to the anode to afford controlled heating of the anode to a predetermined ductile temperature prior to operating the tube at full power. Controlled heating of the anode is accomplished by defocusing the electron beam for a period of time sufficient to enable the anode to reach the desired temperature. The electron beam source of the tube may also be controlled during heating of the anode so as to supply a reduced beam current.

Abstract: The invention concerns a dental X-ray diagnostic unit for panoramic planigraphy, with a radiation source, an X-ray film cassette that is moved during the exposure in relation to the radiation source, with an adjusting mechanism to move the radiation source and the cassette around the object, and with a slit stop located in the radiation path between the radiation source and the cassette. For a given exposure process, the time sequence of the dosage from the radiation source can be predetermined by a control apparatus.

Abstract: An apparatus for supplying high voltage pulsed direct current to an X-ray tube includes a transformer, a high frequency inverter circuit and a nonlinear feedback loop. The invention uses the high frequency inverter connected in series with a DC power supply source and the primary winding of the transformer in order to generate high voltage, high frequency AC in the secondary winding. A rectifier connected to the secondary winding supplies high voltage pulsed DC to the X-ray tube. A detector, such as a voltage divider, detects the voltage supplied to the X-ray tube and supplies a representation of it to a nonlinear feedback circuit connected between the detector and the high frequency inverter. The inverter circuit includes at least one switch generated by electrical pulses.

Abstract: An X-ray control device is held in a constant position relative to an X-ray tube and an X-ray detector, while the X-ray tube is moved toward or away from the rotational scanning axis at which an object to be examined is located. The X-ray control device allows selection of a spot size and a tube voltage of the X-ray tube. The X-ray control device is controlled in synchronism with a shift mechanism. When the X-ray tube is close to the object, a smaller spot and a higher tube voltage than those when the X-ray tube is separated from the object are selected.

Abstract: Improved diagnostic imaging methods and systems for automatically controlling variable parameters used when translating detected radiation intensities caused by radiation that has passed through an object and impinged on a detector to fixed values for display images by determining the maximum and minimum intensities at the impinged on detector locations and adjusting the parameters as functions of the said maximum and minimum intensities.

Abstract: An X-ray tube is movable between a minimum distance from an image receptor and a maximum distance. Signals are generated representative of the X-ray tube focal spot-to-image distance (SID), the peak kilovoltage (kVp) that is to be applied to the X-ray tube anode during a fluorographic exposure and the desired brightness of the X-ray image. The signals are processed in a manner that results in a control signal being developed that adjusts the X-ray tube filament current in a way that produces an X-ray tube current (mA) during the exposure which results in a constant limited X-ray dose rate at the X-ray beam entrance plane of a patient at any permissible kVp and SID setting and assures that the dose rate limit will not be exceeded at minimum permissible SID regardless of the selected kVp.

Abstract: An X-ray system tester for measuring a set of electrical signals comprising anode voltage, cathode voltage, anode current, filament current and line voltage produced by an X-ray system during the operation of such system. A selector is provided, which couples one of the electrical signals of the sets thereof produced or one of a plurality of processing control signals entered by an operator from a control panel, to a digitizing section, selectively in accordance with control signals provided to the selector by a computing section. The digitizing section converts the selected signal whether produced by the X-ray system or entered from the control panel, into a train of pulses having a frequency proportional to the value of the selected signal. The pulses in the pulse train are counted by a counter. The number of counts being used by the computing section to determine the frequency, and hence, the value of the selected signal.

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: A method and apparatus for regulating and stabilizing the radiation intensity level of an X-ray source. The apparatus includes high voltage circuitry for supplying anode and cathode voltages to an X-ray tube and filament voltage circuitry for supplying voltage to the filament of the tube. Both the high voltage and filament voltage circuitry are regulated by multiple feedback voltage level control circuits. The method of the present invention involves the forming of the high voltage and filament voltage circuitry and the supplying of appropriate feedback signals to such circuitry to maintain the high voltages and filament voltage at desired levels.

Abstract: A falling load type X-ray diagnostic apparatus comprises a low voltage power source, AC-DC converting means connected to the low voltage power source so as to apply a rectified low DC voltage, chopping means connected to the AC-DC converting means and chopping said DC voltage into a low AC voltage, high voltage applying means for transforming said low AC voltage into a high AC voltage, said high AC voltage being applied as a tube voltage to an X-ray tube from which X-rays are irradiated toward an object to be examined, means for controlling a filament heating power of the X-ray tube, programming means for supplying a control signal to said filament heating control means so as to reduce the emission current of said X-ray tube during the irradiation, and chopper control means for controlling the chopping ratio of said chopping means by evaluating said rectified DC voltage with a preset tube voltage generated in said programming means, said programming means compensating said tube voltage by receiving said contr

Abstract: An X-ray apparatus comprising a step-down transformer for stepping down a line voltage, a first timer for generating a pulse signal of the pulse width corresponding to a preheating period in response to a start signal, and a second timer for generating a pulse signal of the pulse width corresponding to an X-ray radiation period in response to the stoppage of the output of the pulse signal of the first timer. The stepped down line voltage is impressed on an X-ray generator during the period of time, i.e., the preheating period for generating the pulse signal of the first timer to preheat an X-ray tube. The line voltage is impressed on the X-ray generator during the period of time for generating a pulse signal from the second timer to supply a rated tube voltage and filament voltage to the X-ray tube. At this time the X-ray tube radiates an X-ray.

Abstract: The density of an X-ray exposure depends not only on the exposure parameters, but also on the film development parameters. In order to eliminate the effect of fluctuations in the latter parameters, the X-ray generator in accordance with the invention comprises a measuring device which measures the density of a test exposure and which acts on an adjusting member for the exposure parameters. By subjecting the test exposure to the same conditions as the X-ray exposure, the effects of parameter fluctuations during film processing process can be eliminated to a high degree.

Abstract: A power supply is switchable to apply a low kilovoltage and a relatively higher kilovoltage alternately to the anode of an X-ray tube that includes a filament and a control grid. A grid bias voltage generator uses an inverter driven in the kilohertz frequency range to feed the primary winding of a first transformer whose parasitic capacitance and inductance are used to produce a peak ac output voltage from the secondary of the first transformer at resonant frequency. The secondary output voltage is rectified and the resulting negative bias voltage is applied to the control grid synchronously with the high kilovoltage being applied to the anode so the X-ray tube current is then relatively low. A less negative or zero bias voltage is applied to the grid synchronously with the lower kilovoltage being applied to the anode so the X-ray tube current is then relatively high and substantially limited by the temperature and emissivity of the filament.

Abstract: A dental x-ray diagnostic installation has an exposure unit consisting of an x-ray tube and a cassette holder for generating a dental x-ray exposure. The exposure unit is rotatable about a patient's head by a motor. A radiation detector is attached to the cassette holder which supplies an electrical signal corresponding to the radiation dose rate to a dose rate regulator which in turn operates a voltage control unit which sets the level of high voltage supplied to the x-ray tube such that the dose rate of the radiation emitted by the x-ray tube is maintained at a value for producing an optimum film exposure. A range adjustment for the x-ray tube voltage is externally selected and limits operation of the voltage control unit such that if the dose rate regulator supplies a signal to the voltage control unit requiring a voltage which exceeds the set limit, the voltage control unit is inhibited and instead the motor speed is adjusted to maintain the optimum exposure.

Abstract: An X-ray apparatus is disclosed which comprises an X-ray tube, a high voltage generating circuit for applying a high voltage between the anode and the cathode of the X-ray tube, a filament heating circuit for heating a filament of the X-ray tube, first switching element connected between one terminal of said filament and the negative bus of said high voltage generating circuit, second switching element connected between the other terminal of said filament and the negative bus of said high voltage generating circuit and an inverter circuit for alternately switching said first and second switching elements at a given period to switch the tube current paths.

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 control loop for the x-ray tube current is present which adjusts the x-ray tube current to a value which is a function of the exposure time and the selected mAs-product. In order that deviations of the x-ray tube voltage from a desired value can be controlled via the x-ray tube current, but that the mean value of the x-ray tube current can nevertheless be kept constant, a phase angle control device, arranged in the primary circuit of the high voltage transformer, can be present as the regulating unit for the mean value of the x-ray tube current. As controller for the x-ray tube voltage, a circuit for the adjustment of the filament current of the x-ray tube can be provided.

Abstract: The invention relates to a drive system for a rotary-anode X-ray tube which comprises an asynchronous motor. The current through the stator windings is generated by two pulse-width modulators to which sinusoidal signals which are phase-shifted 90.degree. with respect to one another are supplied by a sine and a cosine memory. The amplitude thereof is controlled in dependence on the amplitude of the current through the relevant stator winding.

Abstract: This device feeds back an output proportional to the electric current flowing through an X-ray tube to a filament current controlling means, reads out a difference between the increase and decrease in the current of the X-ray tube made by the effect of charge on the wall of the X-ray tube, and constantly stabilizes the current in the tube at the optimum value by increasing and decreasing a filament current in response to the difference read out.

Abstract: Method and apparatus for rapidly achieving stabilized x-ray emissions from an x-ray tube are disclosed. The essentially constant current characteristics of an x-ray tube are utilized so as to initially establish relatively low voltage but approximately full current, operating conditions in the x-ray tube during an initial tube preparation time period. Any relatively low energy x-rays emitted during this initial period are of little concern since they are readily absorbed in the usual beam hardening materials placed in the x-ray path. Once the x-ray tube has been stabilized at such relatively low energy output, the operating voltage may thereafter be very rapidly raised to normal operating levels while permitting concurrent rapid stabilization of the relatively small corresponding further required increase in x-ray tube current which, in turn, provides for rapid stabilization of the useful high energy x-ray tube emissions.

Abstract: The temperature of the anode disc of a rotary-anode X-ray tube is continuously determined by means of the method apparatus in accordance with the invention. When the temperature exceeds a first limit value, the power of the X-ray tube is reduced to a fraction (for example, 80%) of the otherwise permissible power. When a second limit value of the anode disc temperature is exceeded, exposures are completely inhibited. In the case of exposures which are performed in rapid succession with a comparatively low power, it may occur that the anode disc temperature does not reach the second limit value, but that the mean value of the applied electric power is so high that the bearing of the rotary anode, and possibly also the joint between the anode shaft and the rotor, is overloaded. Overloading is prevented by generating a bearing-temperature signal indicative of the rotary anode bearing temperature and comparing it with a third limit value.

Abstract: X-ray pulses at two different photon energy levels are produced with an x-ray tube that has an adjustable resistor element in a circuit that connects the anode and filament of the tube to a high voltage supply. Two bias voltage supplies are connected in additive fashion between a control grid element of the tube and its filament to enable control of voltage drop and current through the tube. Switch means are provided to selectively shunt either or both bias voltage supplies in a repeatable order to thereby alter the bias voltage on the control grid and enable producing x-ray pulses having energies corresponding with the voltage drop and current through the tube at a selected bias voltage in accordance with the load line on the anode characteristic curve plot of the tube as determined by the value of the adjustable resistor element.

Abstract: A low ripple high voltage power supply is disclosed for use in a dental X-ray system, utilizing a rectifier and regulator circuit to provide a low voltage regulated DC signal, a DC-AC converter for providing a high frequency chopped power signal suitable for efficient transformation to a high voltage, followed by a multiplier for generating the final high voltage signal to be applied to the X-ray tube. A high frequency clock circuit is used for driving the converter and also for controlling logic circuitry used to develop the regulator control signals. Both a voltage and a current control loop are utilized in the regulator control, and the tube anode current and filament current are controlled as a function of sensed anode current.

Abstract: The disclosure relates to an X-ray photographic apparatus which can prevent the overshoot of the tube current, which is apt to generate at the start of X-ray radiation. The apparatus comprises an integration capacitor which is charged by the preset preheating level setting voltage during the preheating period, an integration circuit which integrates the difference between the reference voltage and the detection voltage corresponding to the X-ray tube current during the X-ray radiation and a filament heating current control circuit driven by said integration circuit.

Abstract: The energy interlock system contains a measuring device, a discriminator and a switch. The measuring device determines the level of the particle beam pulses which are emitted by the accelerator. For this purpose it contains a target which is exposed to the particle beam pulses. The discriminator determines whether the level of the particle pulses has crossed a predetermined value. The switch is operated by the discriminator. It is connected for supervision of the accelerator.