Abstract: Tomography apparatus is used to irradiate a body cross section and acquire a relatively small amount of data which is mapped into a two dimensional array or sinogram and image enhancement techniques are applied to the sinogram to reveal visible lines representing flaws. An array processor operates on the sinogram to perform edge enhancement and averaging convolutions, a fast Fourier transform, low pass filtering in frequency domain, and an inverse fast Fourier transform to generate the enhanced sinogram.

Abstract: The invention introduces the concept of very low cost, fully integrated, large scale planar polymer light guide networks. These networks are intended primarily for automotive applications, including data communication, multiplex, sensor, switch and display networks. However, the concept is also applicable in other areas where the length of the network does not exceed a few meters. The basic idea is to `cut` a thin sheet of clear plastic (polymethylmetacrylate polycarbonate, or polystyrene) into a whole network consisting of optical links, couplers, sensors, etc. . . . In addition to being low cost, planar polymer light guide networks extend the one dimensional geometry of fiber optics into two dimensions, adding tremendous design capability and versatility.

Abstract: An airflow sensor in a flat chip configuration having sensing elements on only one side is subject to causing turbulence in the airflow which has a deleterious effect on the flow signal. The turbulence is diminished or prevented and sensitivity is enhanced by tilting the plane of the sensor a few degrees to the flow direction. Flow in both directions through a passage is measured by bending the passage at the sensor location so that the flow in either direction is inclined to the surface carrying the sensing elements. Flow in both directions through a straight passage is measured by providing the sensor with sensing elements on both sides and mounting the sensor at a tilt so that flow in both directions is inclined to a surface of the sensor.

Abstract: In conjunction with a vehicle borne infrared receiver, sign indicia are defined by infrared reflective surfaces oriented so as to reflect infrared radiation to the receiver from a contrast enhancing source of radiation such as the sky and/or the ground thereby improving the contrast of the sign indicia within the displayed image.

Abstract: A mass air flow meter has a time lag which varies according to the air flow rate. A digital filtering method enhances the raw meter output signal by calculating a correction term based on varying time constants which are dependent on the instantaneous raw signal. The correction term is added to the raw signal. Alternatively first and second order time constants are used to calculate first and second order correction terms.

Abstract: A fluid flowmeter includes a sensor mounted on or in the inner surface of a conduit for measuring fluid flow through the conduit where the sensitivity of the sensor is dependent upon the thickness of the fluid boundary layer extending over the sensor. According to the invention, fluid is drawn out of the conduit through an aperture located a predetermined distance upstream of the sensor to remove the boundary layer developed upstream of the sensor thereby rendering the sensor immune to fluctuations in the thickness of the removed boundary layer. At the same time, a fresh boundary layer of reduced thickness and greater stability is initiated over the sensor so as to improve the sensitivity and repeatability of the sensor.

Abstract: A bridge-type "hot wire" flowmeter is temperature compensated by selecting the values of a power resistor, a ballast resistor and a calibration resistor in accordance with an iterative numerical solution of a pair of equations of the form.0.=C5*Ti.sup.5 +C4*Ti.sup.4 +C3*Ti.sup.3 +C2*Ti.sup.2 +C1*Ti+C.0..0.=K2*Tr.sup.2 +K1*Tr+K.0.wherein the ideal temperature Ti to which the self-heated resistor should be heated for ideal temperature compensation and the real temperature Tr to which the self-heated resistor is actually heated are specified to be equal at three predetermined values of ambient temperature within the range over which it is desired to temperature compensate the flowmeter.

Abstract: In an ion-drag flowmeter, an improvement is provided for alleviating the problem that the deflection of the ion stream may be altered dependent upon the concentration of polar molecules due to changes in the mobility of the ions caused by the clustering of polar molecules to the ions as result of collisions therebetween in which the polar molecules adhere to the ions. The improvement involves keeping the ambient electric field sufficiently weak that the clustering of polar molecules to the ions approaches a dynamic equilibrium in which thermal effects dominate electric field effects in promoting collisions between polar molecules and ions such that the mobility of the ions is substantially stabilized independent of the concentration of polar molecules.

Abstract: A high DC voltage power supply includes a three-phase autotransformer and a three-phase full-wave rectifier applied to the usual motor vehicle electrical system of the low DC voltage type. The low three-phase AC voltage of the usual system is transformed by the autotransformer to obtain a high three-phase AC voltage which is then rectified by the rectifier to provide a high DC voltage. The load energized by the high DC voltage is ungrounded to reduce the voltage available for inadvertent discharge from either load terminal to ground. Switching apparatus is provided for selectively applying the low three-phase AC voltage to the autotransformer only when it is desired to energize the load thereby avoiding at all other times the energy losses that would otherwise be associated with energization of the autotransformer. In one embodiment, the load is windshield heater element and the autotransformer has multiple sets of input taps to provide deice and defog modes of operation, respectively.

Abstract: In an optical device containing material which is dielectric wherein the device is switchable between an inactive relatively opaque state and an activated relatively transparent state in response to the application of a driving electric field of sufficiently low frequency, a problem may arise in that the switching time between the inactive-opaque state and the activated-transparent state is increased and/or the light transmissivity in the activated-transparent state is decreased when the device is at a relatively low temperature. This problem is alleviated by applying a heating electric field of sufficiently high frequency as to heat the dielectric material while not switching the device to the activated-transparent state thereby raising the temperature of the device to decrease the switching time between the inactive-opaque state and the activated-transparent state and/or to increase the light transmissivity in the activated-transparent state.

Abstract: A conventional PNP transistor current mirror provides identical first and second reference currents each containing the same noise component (which may be due to high frequency supply voltage variations). An input current is subtracted from the first reference current to provide a difference current containing the noise component in the first reference current. An NPN current mirror subtracts the difference current from the second reference current such that the noise component in the difference current cancels the noise component in the second reference current to provide an output current which is an identical "mirror image" of the input current and which is free of the cancelled noise component.

Abstract: In an automotive vehicle having a visual glass pane subject to collecting vision obscuring moisture in the form of ice, frost, mist, fog, etc., apparatus is provided for removing the collected moisture. Specifically, the apparatus comprises a transparent layer of dielectric material underlying the glass pane in heat conducting relationship thereto, and means for producing dielectric heating of the dielectric material to thereby heat the glass and remove the collected moisture. Preferably, the layer of dielectric material is a polymer film and the means for producing dielectric heating includes a pair of transparent electrodes extending over the layer of dielectric material. For ease of fabrication, the pair of electrodes may be interdigitated on the same side of the layer of dielectric material.

Abstract: An improvement is provided for an electrically heated glass panel of the type where a resistive film is disposed on the panel and is connected between and along the length of a pair of spaced bus bars each of which is terminated in a respective voltage input terminal and where one of the bus bars includes a connector section to which the resistive film is not connected extending from the input terminal of the bus bar to a junction point on the bus bar beyond which the resistive film is connected to the bus bar. A sensor conductor is disposed on the glass panel and connected from at or beyond the junction point on the one bus bar to a sensor terminal and extends generally adjacent to the connector section of the bus bar.

Abstract: A transistor is protected from excessive power dissipation in the event of a shorted load condition by alternately turning the transistor off for a relatively long period of time during which a capacitor is discharged through a resistor network and turning the transistor on for a relatively short period of time during which the capacitor is charged through a diode by the voltage developed across a resistor connected in circuit with the transistor.

Abstract: A high DC voltage power supply includes a three-phase autotransformer and a three-phase full-wave rectifier applied to the usual motor vehicle electrical system of the low DC voltage type. The low three-phase AC voltage of the usual system is transformed by the autotransformer to obtain a high three-phase AC voltage which is then rectified by the rectifier to provide a high DC voltage. The load energized by the high DC voltage is ungrounded to reduce the voltage available for inadvertent discharge from either load terminal to ground. Switching apparatus is provided for selectively applying the low three-phase AC voltage to the autotransformer only when it is desired to energize the load thereby avoiding at all other times the energy losses that would otherwise be associated with energization of the autotransformer. In one embodiment, the load is a windshield heater element and the autotransformer has multiple sets of input taps to provide deice and defog modes of operation, respectively.

Abstract: A windshield heater element for an automotive vehicle is controlled to provide a maximum power deice mode of operation and a reduced power defog mode of operation. The deice mode of operation is initiated in response to an operator actuated deice command and is terminated in response to the first to occur of expiration of a predetermined time period after initiation, or an operator actuated off command. The defog mode of operation is initiated in response to termination of a preceding deice mode of operation provided that such termination was not in response to an operator actuated off command, or an operator actuated defog command. The defog mode of operation is terminated in response to the first to occur of expiration of a predetermined time period after initiation provided that such initiation was not in response to an operator actuated defog command, or an operator actuated off command.

Abstract: An automotive electrical system with a generator has outputs for loads requiring a high and low voltage, e.g., a heater and a battery. A field-controlled a.c. generator with three-phase output windings has a low voltage main terminal and an auxiliary terminal for high voltage loads. A step-down transformer and a first rectifier connect the windings and the main terminal while a second rectifieer directly connects the windings and the auxiliary terminal. A selector switch having a open and closed positions is connected between the main terminal and the auxiliary terminal. A voltage regulator for controlling current through the generator field is connected to the main terminal. When the selector switch is open the generator provides a dual voltage output i.e.

Abstract: An electrical system for a motor vehicle includes a three-phase AC generator having wye-connected output windings and a three-phase full-wave rectifier. The neutral node of the wye-connected generator is grounded while the rectifier is ungrounded. As a result, three distinct DC voltages are produced: two three-phase half-wave rectified DC voltages of opposite polarity in respect to ground and a three-phase full-wave rectified voltage which is the sum of the other two DC voltages. One of the former lower-magnitude DC voltages may be employed to supply the usual low DC voltage loads of the vehicle while latter higher-magnitude DC voltage may be employed to energize a higher DC voltage load such as a window glass heater element.