摘要:
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.
摘要:
A circuit arrangement connected to the control grid of the x-ray tube comprises a resistance bridge having its input terminals connected to a voltage exceeding the grid cut-off voltage of the tube, the output terminals of the bridge being connected to the cathode and grid of the tube, and one arm of the bridge including a thyristor serving to control turn on of the x-ray tube by placing the bridge circuit in a substantially balanced condition, and a quenching circuit including a second thyristor in parallel with the first thyristor for interrupting conduction of the first thyristor to restore the bridge circuit to an unbalanced condition with the x-ray tube biased off.
摘要:
A transportable X-ray diagnostic generator, in effect an X-ray diagnostic generator which can be transported without an interfering cable after charging of the condenser and in which the weight is maintained as low as possible. For the charging of the high-voltage condenser and for the supply of the filament transformer, a DC/AC converter or inverted converter is connected to the primary windings of the high-voltage transformer and to the filament transformer, and which has a storage cell connected ahead or at the input thereof.
摘要:
An X-ray diagnostic installation in which there is effectuated an automatic proportioning of the exposure time. In the dental X-ray exposure installation, a ray detector is applied to the pouch, which delivers an electrical signal in conformance with the ray intensity when it is impinged upon by X-radiation, and which is interconnected with the setting means to an automatic exposure timer in such a manner whereby the exposure time is determined by an output signal of the ray detector for the purpose of effectuating an optimum degree of film darkening.
摘要:
An X-ray diagnostic apparatus and an auxiliary device, such as an X-ray photographing device which requires a fixedly predetermined exposure time, and which contains a control circuit for the X-ray dosage power or output with reference to a patient; a dosage output measuring arrangement; a comparator element connected to the latter for comparing the actual value of the X-ray dosage output with a reference value, which effects optimum film darkening for each particular exposure time; and adjusting means controlled by the output signal of the comparator element for adjustment of the X-ray tube voltage for equating the actual value of the dosage output with the reference value.
摘要:
An X-ray diagnostic installation having a patient support arrangement, an X-ray tube for transilluminating a patient, a high-voltage generator for the X-ray tube, a control installation for the high-voltage generator and for a heating filament voltage generator, a plurality of exposure systems for X-ray images which are selectively employable in conjunction with the X-ray tube, and an organ selecting arrangement for the organ-programmed setting of the exposure values for each exposure system, which possesses a switch position for each organ whose exposure volume is programmed, in which switch means for the exposure values associated with the particular switch position is actuated for the setting of the programmed exposure value. The X-ray diagnostic installation has a single organ selector which is common to all exposure systems, and that there is provided a selector arrangement by means of which the switch means associated with the one switch position of the organ selector is connectable to the setting means for the exposure values corresponding to the exposure program for the currently selected exposure system and the organ which is associated with the switch position.
摘要:
An X-ray diagnostic system for angiographic X-ray examinations having an X-ray source for irradiating a patient, a television image intensification chain, and an image subtraction device for producing images which are the result of the difference between images taken at a progression of discrete times during which the concentration of an X-ray contrast medium in blood vessels changes. The subtraction device is provided with two image memories. A control device having a preprogrammable memory controls the times at which image data are stored in the image memories. The preprogrammable memory may be programmed for each time of image storage, or may be programmed only for the times of storage in the first image memory and a time delay factor for storage in the second image memory relative to the times of storage in the first image memory. The time delay factor may be constant or variable.
摘要:
In an exemplary x-ray generator with several focal spots, a supply device for energizing the heating filaments for the respective focal spots comprises a single filament supply transformer for all heating filaments with which generator circuitry for supplying different frequencies is connected, and one filter each is connected between each heating filament and the secondary winding of the filament transformer. The pass bands of the filters correspond to the different generator frequencies.
摘要:
In an illustrated embodiment a plurality of x-ray sources are arranged at equal angles about a rotating frame. Each source and detector arrangement may provide the desired number of measurements such as 240, so that the required angular movement for scanning is reduced by a factor corresponding to the number of sources. In one embodiment with three sources and 240 detectors for each source, the desired number of measured values may be obtained by rotation through 120 degrees instead of 360 degrees. In another illustrative embodiment, the narrow beam from the x-ray source covers about 30 detectors, the beam and detectors being linearly scanned so as to generate about 240 measurements, there being three source-detector arrangements separated by 60 degrees, so that scanning is carried out by rotation through 60 degrees rather than 180 degrees.
摘要:
An operating handle for an encapsulated switching apparatus which includes a housing having a door and a stationary switching shaft. The handle is fastened to the door of the housing in a switched-on position of the apparatus by means of a spring-loaded shiftable locking plate which is shifted against the force of a loading spring in a switched-off position of the apparatus into a position in engagement with a stop member for releasing the switching shaft from the locking plate. The improvement comprises the stop member being formed by a resilient detent spring disposed within the operating handle, the restraining force of which can be overcome by an operating force applied to the handle.