Abstract: An adjustable passband filter comprises at least one reentrant section in shunt with a transmission line, which section can be electronically switched between different conditions. The reentrant section, when in at least one condition acts, to reduce the band of frequencies passed by the transmission line by increasing the effective capacitance of the filter and when in another condition, operates as an open circuit, whereby the filter exhibits a broader passband.

Abstract: Multiple usage requests for a common resource, such as a memory system, are given usage priorities by a multiple request arbitration circuit. Priority is given to a predetermined one of the input signals occurring prior to any one of the remaining input signals and priority is also given to the one input signal if it occurs within a predetermined interval subsequent to any one of the remaining input signals. The circuit also provides for the suppression of voltage transients which may occur upon the essentially simultaneous occurrence of more than one input signal and the circuit also provides a faster access time for input signals other than the predetermined one of the input signals.

Abstract: The invention relates to arrangements for the production of electroradiographic x-ray photographs wherein x-ray photoconductive layers are electrically charged at their surfaces and subsequently exposed to an image-forming irradiation with x-rays, such that, due to the influence of the rays which penetrate a body, charge images are obtained which can be rendered visible through the application of pigment particles. For the simultaneous production of several images, the invention provides that several layers be arranged in a cassette. An inventive arrangement is particularly suited for use in medical radiation diagnosis.

Abstract: An ignition trigger circuit for luminous and fluorescent discharge tubes, especially for cold electrode tubes. The ignition pulses are generated by placing across the gas discharge tube a relay-activated switch. The relay windings are connected in series with a rectifying diode and a capacitor across the A.C. power source. When a charging current flows into the capacitor, the relay windings are actuated at each A.C. cycle. By suitable choice of the electrical dimensions, the charging phase of the capacitor may be extended over several A.C. cycles, thereby causing repeated actuations of the relay and closures of the switch. Once the charging current falls below the holding current of the relay, the short-circuiting switch stays open permanently. A discharge resistor is provided to return the circuit to its initial state after being removed from the A.C. current source.

Abstract: The output voltage of the inverter is supplied to a high voltage transformer to which an X-ray tube with a rotating anode is connected. The rotating anode motor is likewise fed by the inverter. To this end, the inverter can be selectively operated with a high frequency for feeding the X-ray tube and a low frequency for feeding the rotating anode motor. But it is also possible to supply the inverter output voltage in parallel to the high voltage transformer and to a frequency divider at whose output the rotating anode motor lies.

Abstract: A circuit for measuring the relative phase of two periodic signals. Two analog waveforms are applied to limiting amplifiers which provide digital output signals. The output signals therefrom are applied to digital circuitry which provides an analog voltage representative of the phase difference between the two input signals over a 360 degree range. The digital circuitry compensates for any offset errors which may be introduced by the limiting amplifiers.

Abstract: A compact and light weight radiographic collimator including two pairs of radiation absorbent shutters connected together by a parallelogram linkage which provides a nested arrangement when the shutters are in their full open position yet provides an aligned relationship when fully closed. An off-focal vane construction in which the vanes are moved reciprocally is also disclosed.The shutters and vanes may be either manually or automatically adjusted. Manual adjustment is automatically limited to the maximum safe open position.A collimator adjusting drive train using constantly meshing gearing and a slip clutch is employed. A series of filter plates of varying thicknesses are provided. The operator can select the filtration desired by positioning each filter plate in either its filtering or nonfiltering position and then insert the stack of plates into a slot. A sensor provides an indication of when the filter assembly is positioned in the collimator.

Abstract: In the exemplary embodiments, the x-ray tube current is controlled in such manner that the desired x-ray tube voltage is established on the basis of the voltage drop in the supply circuit of the x-ray tube. For the adjustment of the x-ray tube voltage, in addition to the control means for the x-ray tube current in the primary circuit of the high voltage transformer, a circuit is present for altering the primary voltage of the high voltage transformer.

Abstract: A focus alignment system for X-ray photography devices is provided for use with such devices where the film holder is independent of the X-ray source. The X-ray source has associated therewith two light beam projectors. The beam of one light projector is aligned with the X-ray beam while the beam of the other projector is at an angle thereto. The X-ray beam focus to film distance is correctly set when the light beams intersect on the surface of the film holder. Markings on the film holder indicate central positioning of the X-ray beam when the one light beam is aligned with the markings.

Abstract: A digital tuning element and method of making same for an electronic tuning means for an automobile radio which has a drive means for positioning said element, detecting means providing an electrical output signal related to the position of said tuning element, and means receiving the output signal for controlling a tuning circuit. The tuning element is a body which is angularly positionable and includes a coding means on its surface, with the detecting means sensing the coding means for providing binary coded output signals over a plurality of output channels to a receiving means for controlling a tuning circuit.

Abstract: Magnetic mirror enabling a beam F of charged particles to be reflected along its incident path whatever the value W of the momentum of said particles. This magnetic mirror includes a first magnetic deflector having polepieces of circular shape, a second and a third magnetic deflector provided respectively with pairs of polepieces arranged symmetrically with regard to an axis XX coinciding with the mean incident path of the beam F, the entry and exit face of these polepieces being determined in such a way that the beam F emerging from the second magnetic deflector is perpendicular to the symmetry axis of the mirror and that the vertical divergence of the beam is compensated.

Abstract: A digital phase lock circuit wherein both the phase and frequency of an output signal are synchronized to an input signal. The present phase lock circuit is comprised of a clock signal source, first, second, and third counters, and a holding register. The first counter is utilized to count a predetermined number of cycles of the input signal to establish a first time period. The second counter receives as another input the clock signal and counts the clocks during the established first time period. The value of counted clocks contained in the second counter at the end of the first time period is divided by the predetermined number of cycles the first counter is set to count, and the result is stored in the holding register. The count in the holding register is used to preset the third counter which is then allowed to count down to zero, at the clock rate. The third counter is preset to the value contained in the holding register at each establishment of the first time period.

Abstract: A circuit for controlling the brightness of a vacuum fluorescent display having filament terminals and connected to anode or segment biasing means includes a transformer having a filament winding connected to the filament terminals. The transformer is driven by a 60-cycle power source. An electronic switch, including a transistor, is connected between a center tap of the filament and the anode biasing means (at a common ground) and circuit means open and close the switch at a 60-cycle rate. The ratio of time during which the switch is closed to the time during which the switch is open is variable to control the brightness of the display.

Abstract: Apparatus for counting platelets and red blood cells in a whole blood sample includes an aperture type transducer. Alarm techniques are provided for indicating defects in the counting procedure due to excessive noise or red cell fragments, small (microcytic) red cells, and giant (macro) platelets.

Abstract: For the formation of an electric signal corresponding to the x-ray tube voltage, the high voltage transformer is provided with a low voltage winding. The low voltage at the terminals of the low voltage winding is conducted to the exterior of the tank. Here, a low voltage rectifier circuit is connected which corresponds in its circuit configuration to the high voltage rectifier circuit so that the electric signal supplied by the low voltage rectifier circuit accurately corresponds to the x-ray tube voltage and can be used for control purposes. The high voltage rectifier circuit and the low voltage rectifier circuit can operate as voltage multipliers.

Abstract: A frequency band dividing filter comprises a delay-line filter which is supplied with an input signal and produces a divided frequency band signal as an output, a circuit for deriving a delayed signal in which the input signal has been delayed by a predetermined amount of time, and a circuit for substantially performing subtraction of the delayed signal output signal of the delay-line filter, and producing another divided frequency band output signal. The delay-line filter comprises a plurality of delay circuits cascade connected, coefficient multipliers respectively supplied with the input signal and the output signal of the delay circuits and for multiplying specific coefficients to the signals thus supplied, and an adder for adding output signals of each of the coefficient multipliers.

Abstract: A high repetition rate high power spark gap switch of the type useful in pulsed lasers, radar systems and pulse-forming networks is enabled to operate with higher switching speed at high power levels by rapid chemical composition change cyclically made in the spark gap at high frequency with differing standoff voltage capabilities of different compositions produced in the gap in each cycle. The different standoff voltage capabilities are produced by injecting different gases under fluidic switching control.

Abstract: A mechanism is provided for varying the distance between a detector and a measuring crystal in an X-ray spectrometer. The crystal is arranged on a rotatable shaft and the detector is arranged on an arm which can perform a circular movement about the crystal shaft. The crystal shaft and the detector arm are coupled so that a rotation of the crystal shaft through an angle .theta. is accompanied by a rotation of the detector arm through an angle 2.theta.. A first pulley having a radius r is mounted on the crystal shaft and a second disc having a radius 2r is rotatably mounted on the crystal shaft. A belt or cord is guided over each one of two guide rollers. One end of each of these belts is permanently connected to the first pulley, while its other end is permanently connected to the second pulley.

Abstract: Radiographic apparatus reconstituting an image by processing by means of a computer the signals delivered by a detector measuring the coefficient of absorption of a body through which an X-ray beam passes.A plurality of detectors disposed in a fan arrangement are used, whereby it is possible to decrease the number of scanning stations. According to the invention, this number of stations is an odd number for a complete revolution. Further, a number of detectors in excess is used for a given included angle of the fan arrangement so that the response of defective detectors can be eliminated.

Abstract: Apparatus for removing exposed sheets of X-ray film from and for thereupon introducing unexposed sheets into cassettes of the type having two pivotally connected sections and a locking mechanism for the sections has a housing with a cylindrical chamber which communicates with an opening for insertion or withdrawal of locked cassettes. A drum-shaped carrier is sealingly received in the chamber and is rotatable between a first position in which the open end of a diametrically extending compartment therein registers with the opening of the housing to allow for insertion or removal of a cassette. A cassette which is introduced into the compartment is automatically unlocked and opened during movement of the carrier to a second angular position in which the exposed sheet leaves the cassette by gravity and the cassette remains open during movement of the carrier to a third position in which the cassette receives an unexposed sheet.