Abstract: A non membrane-based overpressure proof gas pressure microsensor. It is not a membrane-based microsensor but is based on an open microbridge sensor structure. A method and apparatus is described to determine gas pressure from thermal conductivity, k, and volumetric specific heat, c.sub.pu, as well as pressure, P, using a microbridge sensor.

Abstract: A low cost piezoresistive pressure transducer utilizing premolded elastomeric seals in which at least one seal is electrically conductive. A piezoresistive stress sensitive element in the form of a diaphragm of semiconductor material having a thickened rim is held at its rim between a pair of premolded elastomeric seals in a two piece housing. Electrical connections with external circuitry are made by conductive paths through one of the elastomeric seals which makes contact with electrical leads which pass through the housing wall.

Abstract: Apparatus and an associated method are described for testing liquid crystal matrix displays that can be performed prior to the assembly of the display. This display procedure involves applying of square wave signal to the control elements and a sine wave signal to the input terminal of an active element associated with the pixel under test. By selection of the sine wave signal frequency, the modulation products resulting from the combination of the square wave signals and the sine wave signal fall between the components resulting from the application of the square wave signal alone. As a result of the symmetry of the modulation components, a comb filter can be used to select the modulation components. The power of the transmitted modulation products provides a figure of merit for the active element associated with the pixel.

Abstract: A hand controller which includes a hand grip having therein a mechanism for allowing truly linear motion along at least two axes by modifying a four-bar linkage with a second four-bar linkage to counteract any rotational motion that would otherwise occur.

Abstract: A rotary actuator uses a two degree of freedom gear train with three torque members to provide torque to the output element from a first torque member. The torque is supplied to a second torque member from a drive motor. A torsion spring on the third torque member is normally wound tight and held wound by a brake which locks the third torque member during normal operation when electrical power is available for the drive motor. When power is lost, the brake releases the third torque member, allowing the spring to apply torque to the third torque member to drive the output element through the first torque member to a return position. This allows loads such as valves to be returned to a safety condition upon loss of electrical power to the system of which the load and the actuator are a part.

Abstract: A digital synthetic serrodyne phase difference controller for a rotation sensor capable of sensing rotation about an axis of an optical fiber coil based on having a pair of electromagnetic waves propagating through the optical fiber in opposite directions to both impinge on a photodetector with a phase difference relationship therebetween, the digital synthetic serrodyne phase difference controller including a positive serrodyne generator and a negative serrodyne generator having outputs which input to a common adder. The bit output of the adder is converted to analog in a digital-to-analog converter and applied to operate a frequency translating device in the optical path with the coil.

Abstract: A retrofit apparatus for providing a signal indicative of the position of an aircraft control surface comprises a rotary coupling flexibly coupled to the control surface, an extensible coupling driven by the rotary coupling, a quadric-chain linkage coupled to the extensible coupling for converting a linear output into a substantially translatory displacement, a linkage for converting the translatory displacement into a substantially angular motion, and a transducer coupled to the linkage for converting the angular motion into an electrical output indicative of the position of the aircraft control surface. The invention is a simple modification to an existing quadric-chain linkage driving a mechanical indicator, enabling an electrical transducer to be retrofitted in the crowded control stand of an aircraft.

Abstract: A out-of-lock detector is described which provides a first series of pulses that are compared to a data stream of pulses. Second and third series of pulses are also created by the present invention. These lead and lag pulses are provided to represent particular logical relationships between the data stream and a clock signal. The sequential relationship between the lead pulses and the lag pulses are compared to determine whether or not the clock pulses and the data pulses are in a phase lock condition or, alternatively, are in an out-of-lock condition. A sequence comparator provides a logically low output pulse if an out-of-lock event is detected. A counter compares the number of out-of-lock events which occur in a predetermined period of time to a preset and programmable value. If an out-of-lock condition is detected, some external means for providing corrective action can then be implemented to bring the phase locked loop into a condition where it can again achieve a locked state.

Abstract: A proximity sensor is provided with a means for directly measuring parameters of a proximity sensor coil which permit the determination of both the AC and DC resistances of the coil. These parameters are then used to determine a discriminator value magnitude according to a mathematical relationship that has been predetermined through previous analysis of empirical data for the particular coil and application intended for the proximity sensor. In one particular application of the present invention, the rear AC resistance is utilized and is added to the DC resistance after the DC resistance has been mathematically altered by a preselected factor. Alternative embodiments of the present invention can also utilize the imaginary AC component of the impedance either by itself or in conjunction with the rear AC component of the impedance.

Abstract: A position measurement device using a variable differential transducer. The primary of the transducer is supplied with a triangular pulse causing a similar pulse to be produced at the transducer secondary. The induced pulse is then compared with a constant reference voltage. Due to the triangular shape of the induced pulse, the time that the induced pulse is greater than the reference voltage is indicative of the magnitude of that pulse. The time period is then counted and communicated to subsequent devices.

Abstract: An electronic microvalve design and fabrication process for a miniature gas valve. In this microvalve design an objective is to minimize the operating voltage of the valve and minimize the force necessary to close the valve and hold it tightly closed against high gas pressures. The microvalve is an integral structure made on one piece of silicon and is a flow through valve with inlet and outlet on opposite sides of the silicon wafer.

Abstract: A current sensor is provided with a flux concentrator which is made of two or more annular laminae. The laminae, or lamina plate, each are provided with a gap formed in its circumferential length. Each lamina has a gap which is defined by two opposing faces. The laminae are stacked with their planar surfaces in contact and in such a way so as to define a central opening. The gaps of the laminae are arranged proximate each other. One lamina is rotated relative to another to change the width of the effective gap by misalign the faces of the one gap relative to another. The lamina is rotated during the manufacture of the current sensor while an output voltage signal is measured as a function of a current passing through an opening of the flux concentrator. The degree of rotation of the lamina is determined as a function of the output signal to achieve a preselected current/voltage relationship.

Abstract: A method and apparatus for providing a texture mapped perspective view for digital map systems. The system includes apparatus for storing elevation data, apparatus for storing texture data, apparatus for scanning a projected view volume from the elevation data storing apparatus, apparatus for processing, apparatus for generating a plurality of planar polygons and apparatus for rendering images. The processing apparatus further includes apparatus for receiving the scanned projected view volume from the scanning apparatus, transforming the scanned projected view volume from object space to screen space, and computing surface normals at each vertex of each polygon so as to modulate texture space pixel intensity. The generating apparatus generates the plurality of planar polygons from the transformed vertices and supplies them to the rendering apparatus which then shades each of the planar polygons.

Abstract: A TCAS view image format with horizontal trend for a traffic situation awareness display in a craft, having the craft represented by a center symbol, having traffic represented by position symbols that indicate by shape the horizontal heading of a craft, having the shape of the represented vehicle and varying size to represent level of traffic threat or closeness in altitude differential, having symbols that indicate altitude and trend of altitude, and having symbols that in shape and color redundantly indicate the level of traffic threat.

Abstract: A method of determination of gas properties at reference conditions of temperature and pressure. This determination is needed in systems including mass flow meters, combustion control systems, gas meters and the like. The system disclosed enables the determination of properties including specific heat and thermal conductivity at reference conditions.

Abstract: A flow control device includes a housing with separate main flow and flow control (servo) passages between an inlet port and an exit port. A control chamber in the housing is in fluid communication with the servo passage. A flexible membrane forms a partition between the main flow passage and the control chamber. The servo passage includes a variable servo orifice upstream of the control chamber and a fixed orifice downstream of the chamber. When the servo valve is open to permit passage of fluid into the control chamber, the resultant pressure on the membrane maintains the main valve closed. The main valve opens in response to closing the servo valve. The fixed orifice has a profile sufficiently small to provide for an acceptable leak or continuous fluid flow through the device when the servo valve is open, and further provides for a soft start when the servo valve is closed to open the main valve.

Abstract: A transfer sheet for use in printing of patterns such as alphanumeric characters onto a keyboard or other workpiece from the transfer sheet where the patterns are originally formed has a realignment area in which a plurality of slits are formed. The slits allow at least one portion of the transfer sheet to be repositioned with respect to at least one other portion to improve alignment of the patterns with respect to the workpiece. The patterns may become misaligned because of inherent dimensional instability of the transfer sheet arising from temperature or humidity variations.

Abstract: An actuator suitable for use with a valve has a design allowing for easy control or adjustment of the force applied to the valve. The actuator motor has a cam which operates a follower surface of a spring-loaded arm mounted for rotation on a carriage. The carriage is mounted for linear motion and connected to the control element of the valve. The actuation force can be controlled or adjusted by changing the relative positions of the arm's center of rotation, the point on the arm at which the spring applies force, and the position of the cam. In a preferred embodiment, the position of the arm's center of rotation is changed by moving a pin from one set of holes in the carriage and the arm to a second set of holes in the carriage and the arm.

Abstract: A structure and method of making a piezoresistive transducer with reduced offset current. The transducer is comprised of a piezoresistive die having a support rim and a diaphragm, and a support housing having a wall and an aperture. The shape of the diaphragm is matched with the shape of the aperture while the shape of the support rim is matched with the shape of the wall. By matching these shapes, temperature induced stresses are reduced, thus reducing temperature induced offset currents.