Abstract: A two-junction DC SQUID is supplied a single square-wave frequency signal that both biases the SQUID and provides modulation with a square-wave train that is 90.degree. phase displaced with respect to the bias square-wave train in order to eliminate low frequency noise with cross-modulation frequency products.

Abstract: A multiple user priority network is provided by a double section priority PROM. One section of the PROM is accessed by a current priority code stored in a priority register, and new request signals that appear on lines that are coupled to the requesting components to provide an address which contains a new access code. The second section of the PROM is accessed by the new access code, which is stored in a channel access code register, and the current priority code in the priority register to provide an address which contains a new priority code. The multiple user priority network of the present invention is thus capable of providing a updated priority for all of the requesting devices which is a function of the changes in the request status of the devices.

Abstract: A multibeam acoustic apparatus utilizing a linear array of hydrophone elements in a sonar system includes a cascaded ladder capacitance-inductance network for coupling electrical signals to and from the individual hydrophone elements. The hydrophone elements are connected in series and the natural capacitance of these elements provides the capacitive characteristics of the network. Shunt inductors supply the inductance characteristics and provide a phase characteristic inversely related to frequency. Variable cumulative phase delays are provided for signals applied to successive hydrophone elements whereby a sonar beam is formed in a direction determined by the frequency of the exciting signal.

Abstract: A tubeaxial type electrical cooling fan is constructed with two or more fan struts that extend across the open back of the fan to a circular support ring that supports the shaft of the motor, which in turn supports the fan blades. In such a structure, bending or flexing can occur in the fan struts which generate and transmit structureborne noise. In addition, these types of motors have a higher than desirable external magnetic field and noise may be generated by the bearings in the motor or in the resonance of other structural numbers. A nickel-iron shield is provided that fits over the supporting hub and the radial fan struts. An intermediate sound damping adhesive layer between the struts and the shield provides both a magnetic flux shielding and vibration damping of the structureborne noise.

Abstract: A thin, nominally 150 angstroms, normal metal layer, nominally the noble normal metal palladium, sandwiched intermediate between two superconducting layers, nominally niobium, supports totally superconducting current flow therethrough such normal metal layer by the quantum mechanical tunneling effect. Such a thin normal metal layer is useful as a stop etch layer for fabrication process control, including especially the selective niobium anodization process, as an oxidation resistant or immune layer to which totally superconducting electrical contact may be reliably made such as by soldering, and as a patterned resistor in those regions of the substrate plane where such thin normal metal layer is not sandwiched by superconducting layers. Particularly concerning such stop etch function, a thin normal layer of palladium will serve as a stop etch layer to the etching of niobium while not precluding totally superconducting contact therethrough such thin palladium layer.

Abstract: This invention is directed to a modified monopulse comparator which includes two sum and difference hybrid junctions. The first hybrid junction produces a signal-free sample of any interference which is received by the datalink receiving antenna. The second hybrid junction is a standard monopulse comparator driven by amplified and filtered signals from the A and B antenna feeds after subtraction of the properly scaled and phased interference sample.

Abstract: Elements of a radar antenna are provided with one or more electromagnetic actuators capable of moving the elements (scanner or parabolic reflector), independently of the support system in response to electrical signals applied to the coils of the electromagnetic actuators.

Abstract: A system for and a method of generating a four phase clock signal is disclosed. The system includes an oscillator circuit that generates a clocking signal of frequency F. A flip-flop, under control of a Master Clear signal, establishes the first stage of a shift register in an active state while the clocking signal drives the shaft register to serial, end-around, shift the active state through the shift register. The parallel outputs of the shift register are coupled to respectively associated pulse generators which are also triggered by the clock signal to emit the four phase clock signal therefrom. The method ensures that the first phase signal is always the first signal to be emitted from the system while compatible semiconductor circuitry is used throughout and is operated at or near the frequency limit of the semiconductor circuitry used.

Abstract: Apparatus and method for control of an anode voltage power supply for reduction of fluctuation in anode power supply output during the vertical retrace period, resulting in improvements in overall CRT display performance parameters.

Abstract: A system for synchronizing information bits to any frequency signal chain with low jitter correction and adapted for gate array implementation.

Abstract: An improved multiple circuit keypad switch of the type in which a rigid key having a shorting puck on its underside is supported over exposed traces of a printed circuit card by a flexible membrane so that the puck shorts designated exposed traces to close all circuits when the key is depressed, the improvement arising from the layout of the exposed traces in which individual circuits are arranged in concentric rings and the shorting puck contains shorting elements arranged in corresponding concentric rings.

Abstract: Within a High Performance Storage Unit (HPSU) digital memory resource, plural ones (up to 4) of a multiplicity (nominally 8) of independently operative storage memory banks, each consisting of four storage modules, are each simultaneously communicating voluminous read data (nominally 144 data bits plus 16 parity bits) read from each to a respective one of plural (nominally 4) output ports of the memory resource, said communicating being upon and via a selected one of a like plural number (4) of wired-OR communication buses.

Abstract: An apparatus for detecting jet engine failures during aircraft flight. Low and high speed rotor rotation velocities of one engine are compared with low and high rotor rotation velocities of other engines and the difference between them utilized to determine engine failure. Equivalent low speed rotor velocity of an engine is computed from the high speed rotor velocity of that signal. This computed value is compared with measured low speed rotor velocity of the same and of different engines. Differences between the computed values and the actual values are compared to a computed threshold, which allows for normal differences between engines, to determine the operational state of the engine. Additional engine testing is performed by comparing low speed rotor rotational velocity to a computer windmilling value for each engine.

Abstract: A video display terminal is provided with controls which permit independent adjustment of the background information and the foreground information. Each control comprises an adjustable constant current source connected to one of two branches of a differential amplifier. One branch of the differential amplifier is employed to control the background intensity and the other branch of the differential amplifier is employed to control the foreground intensity.

Abstract: An apparatus for reducing terminal-to-terminal circuit resistance and enhancing heat transfer in a rotary power transfer apparatus of the roll ring type comprising a connecting thimble for attaching an external power cable to a cone shaped terminal which is attached to a tab integral to an outer ring. An inner ring having a spherical recess mates with the spherical end of a tie connector. A cone shaped terminal is fitted to a second connecting thimble for attaching a second external power cable.

Abstract: An improved multiple port memory system has a priority network for selecting between multiple units seeking access thereto. The priority network responds to requests for access and provides encoded port identifying signals indicative of the port to have access. Decode circuitry decodes the encoded port identifying signals and provides unique port enabling signals for the selected port. Decode error detection circuitry responds to the decoded port enabling signals and provides a decode error indication any time multiple port enabling signals are detected as occurring simultaneously. Port Code error detecting circuitry respond to the encoded port identifying signals and the decoded port enabling signals to provide a code error indicating signal when a port code error condition is detected.

Abstract: An apparatus for flicker reduction and increased writing speed into image memory in a CRT display having an interlaced scan with masking of low priority symbols. The apparatus expands or duplicates adjacent picture elements to provide redundant illumination for alternate fields, thereby providing at least two adjacent illuminated picture elements proximate to a masking image to reduce flickering during the writing of alternate fields. Writing into a single memory location commands illumination of a plurality of adjacent pixels, thereby reducing image memory writing time. The apparatus utilizes an image memory wherein video bit signals are written into only storage locations whose binary x coordinate has a predetermined first digit, and whose binary y coordinate has a predetermined first digit. Signals in storage locations whose addresses correspond to picture elements P.sub.I,J, P.sub.I-1,J, P.sub.I-1, .sub.J+1, and P.sub.

Abstract: A compliant lead clip comprises a single strip of metal bent to form a C-shaped member and an S-shaped member, the two members having a common portion. An integrated circuit chip is inserted into the C-shaped member and soldered thereto after which the lower part of the S-shaped member is soldered to the top surface of a printed circuit board whereby the chip is supported above the printed circuit board. The S-shaped member bends or twists to absorb forces which would otherwise be exerted on the solder joints as a result of warpage of the printed circuit board or temperature changes where the chip carrier and printed circuit board have different thermal coefficients of expansion.

Abstract: In an n-wide (n nominally equals 4) snapshot priority network apparatus the access of n+1 requestors to a memory unit is prioritized. Two requestors--the lowest priority one of normal system requestors called instruction processors plus a maintenance exerciser type requestor--share a single memory port which is nominally the lowest priority one of n such prioritized ports. Requests from both requestors are both honored upon a single priority snap, the instruction processor request nominally proceeding before the maintenance processor request. Although the n-wide priority network remains generally faster than any (n+1)-wide priority network, the maintenance exerciser type requestor is expediently serviced and cannot be locked out of access to memory by the competing higher priority requests of the instruction processor.

Abstract: An inclinometer includes two coplanar electrodes positioned within a chamber of a metallic housing containing a high relative dielectric constant fluid and a gas. With the inclinometer positioned on a level surface equal areas of the two electrodes are immersed in the dielectric fluid creating two equal capacitors formed by the electrodes and the metallic housing. When the inclinometer is rotated through an inclination angle, unequal areas of the electrodes are immersed in the fluid causing a capacitance differential that is a measure of the inclination angle.