Abstract: A system for minimizing periodically induced vibration in a mechanical structure, particularly rotary shaft apparatus that is not limited to the use of any particular number or type of forcers or sensors and requires no knowledge of the mechanical structure's transfer function. In accordance with a preferred embodiment the system senses periodically induced vibration utilizing a plurality of sensors and produces a complex output representative of the algebraic sum of the vibrations sensed for each harmonic and counteracting the vibration with a plurality of actuators operatively coupled to the structure by producing a counteracting vibration therein in response to a complex input signal for each actuator in the form of a matrix of system responses to vibrational inputs at selected harmonics of interest.

Abstract: The present invention is a radar system that detects turbulence by breaking a range cell return down into spectral segments using an FFT processor. The standard deviation of the spectrum is determined and the system compares that standard deviation to a reference threshold of a non-turbulent return if the signal is above noise. If the threshold is exceeded, the range cell is marked for turbulence display. Once the turbulence display is completed it is overlayed on the weather display. To improve matching of the feature size to the variance calculation the invention performs both range and azimuth post detection integration subsequent to the FFT but before variance calculation.

Abstract: Apparatus and method for a twelve-pole inverter for eliminating all of the relevant low-order harmonic component frequencies, except the fundamental for an AC output from a source of DC input voltage. The inverter circuit provides four separate three-phase sets of constantly phase displaced pole voltages from controlled six-pulse bridge inverter circuits. Additional phase displacements for straddled paired-sets of the pole voltages are introduced with a first and second predetermined phase displacement proportion of 2:1 or 15 degrees. One paired-set of pole voltages is input to a transformer configuration of a wye with a delta, and the other paired-set of pole voltages is input to a neutralizing transformer with a truncated delta paired configuration for low-order cancellation of harmonics.

Abstract: The present invention is a system and method that uses a digital spectrum analyzer to digitize a spectrum and loads the digitized spectrum into a computer. The computer scans the spectrum to determine a zero dB reference by cyclic averaging and determines the upper and lower cutoff frequencies using inward and outward scan techniques which are averaged. During zero dB level determination holes in the spectrum are ignored and during upper and lower cutoff frequency determination the holes or drop outs in the spectrum are located, counted and characterized.

Abstract: A license plate reader and method for reading the characters of a license plate and for identifying the state which issued the plate utilizes image intensity transition information gathered while scanning the plate. With the gathered intensity transition information, the plate image is identified and the license plate characters are extracted from the plate background with a relatively high degree of accuracy. A chopper isolates the region of the plate containing the character set for character-reading purposes and compensates for rivets in the plate and character appendages. A contour tracer is adapted to trace the exterior edges of each license plate character, and a tilt compensator compensates for the tilted condition of the characters when the plate is tilted relative to the horizontal.

Abstract: An IF Clutter Canceller using delay lines and acoustic charge transport (ACT) devices to subtract one interpulse period from another interpulse period. The first interpulse period is time demultiplexed with a tapped delay line and stored in ACT devices. The second interpulse period is time demultiplexed through the same delay line as was the first interpulse period. The stored time segments of the first interpulse period are released from the ACT devices and subtracted from the time demultiplexed time segments of the second interpulse period. The resulting clutter cancelled time segments are then assembled into a clutter cancelled interpulse period with a second tapped delay line.

Abstract: An integrated semiconductor chip includes, integral to its substrate, a thermal sensing circuit formed from an array of transistors connected together in a stacked array so as to multiply the inherent effects of temperature on output voltage. A series of gates is connected to the output of the transistor array. A reference voltage is applied to the transistor array, and the inherent temperature-variable output of the array is then applied to the gates. The gates change states at known temperatures and voltages, so that the digital state output of each gate indicates whether the substrate temperature is greater than or less than the switching temperature associated with that gate. By sensing gate output, the chip itself or an external device can determine the temperature of the substrate within a certain range. When the temperature is outside the safe operating range for the chip, the chip or an external device takes steps to prevent unsafe operation.

Abstract: An extraction tool is inserted between an electrical connector and an electrical device by which it is held for extracting the connector without rocking or substantially bending electrical contacts extending between them. The tool has a lever arm and an object-contacting arm. A pivot is adjacent the lever arm and the object-contacting arm for pivoting the tool about the electrical device. The distal end of the object-contacting arm is convexly contoured for slidably contacting the connector while the pivot is in contact with the electrical device. Preferably the tool has multiple spaced apart object-contacting arms and pivots for linearly extracting the connector from the device without bending their connections.

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The amplitude is monitored through an analog to digital converter by a supervisor computer. The supervisor computer produces patient response curves from which it diagnoses visual system malfunction and/or prescribes correction. A control processor controls a stimulus generator to produce the image and an optical system, that includes polarizers, an astigmatism test slit or a cylindrical lens, a zoom lens system and a variable focal length test lens, transmits the image to the patient. The steady state visual potential stimulus generator is a device by which a rapidly complementing or flashing pattern can be presented to the patient.

Abstract: A thin film electroluminescent edge emitter assembly includes an edge emitter structure disposed on a layer of substrate material. The structure has a configuration to define a linear array of spaced-apart, light-emitting pixels. A packaging assembly surrounds at least a portion of the edge emitter structure to enclose the linear array of light-emitting pixels in a contaminant-free environment. At least the wall of the packaging assembly adjacent to the array of pixels is made from a translucent material to permit light energy emitted by selected pixels of the array interior to the packaging assembly to pass through the wall of the packaging assembly.

Abstract: A method and apparatus for cancelling vibrations caused by periodic pulsating forces acting on a rotating shaft which are synchronous with the shaft rotation. An adaptive algorithm is implemented which utilizes the sensed velocity or acceleration of the difference between the pulsting forces acting on the shaft and an applied control force to generate an estimate of the phase shift existing therebetween to adjust a pair of adaptive weighting coefficients for sine and cosine force components which are adjusted by a least mean square (LMS) algorithm. Actuating signals for the reaction mass actuator are generated from the weighted force components which applies a controlled force to the shaft to oppose the shaft pulsation force and thus cancel the vibration.

Abstract: A conduit has a core and an axial length susceptible to being pinched and chafed by other structure adjacent the conduit. An inner semiconductive layer extends the length of the conduit susceptible to being pinched and has a reference point adapted to be electrically connected with a detecting circuit for detecting a pinch and/or a computing unit for determining the location of a pinch. A resiliently compressible electrical switching layer, which is nonconducting when not pinched and conducting when pinched, is superposed against the inner semiconductive layer.

Abstract: An electrophotographic-type imaging station or printer includes a focusing lens positioned between the printer light source and a photosensitive medium. As the light source projects beams of light energy forming a row in a direction towards the photosensitive medium, the lens focuses each projected beam into a rectangular beam. The speed of the photosensitive medium and the operation of the light source are coordinated so that adjacent rows of generally rectangular beams are positioned in abutting relation with each other. The plurality of focused rows projected in row-at-a-time fashion onto the surface of the photosensitive medium form an informational array pattern having a resolution in a direction parallel with the direction of medium movement which is greater than the resolution of the pattern in a direction perpendicular to the direction of medium movement.

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The amplitude is monitored through an analog to digital converter by a supervisor computer. The supervisor computer produces patient response curves from which it diagnoses visual system malfunction and/or prescribes correction. A control processor controls a stimulus generator to produce the image and an optical system, that includes polarizers, an astigmatism test slit or a cylindrical lense, a zoom lense system and a variable focal length test lense, transmits the image to the patient. The steady state visual potential stimulus generator is a device by which a rapidly complementing or flashing pattern can be presented to the patient.