Abstract: Controlling air/fuel ratio perturbations in response to purging of fuel vapors from a vapor canister storing fuel vapors from the fuel tank of an internal combustion engine includes feeding forward an offsetting fuel command signal. The feedforward offsetting fuel command signal is used to change, and thereby compensate, a base fuel command signal applied to a fuel injector controller whenever fuel vapor purging is occurring.

Abstract: A spark plug for an ignition system has a ring gap between two electrodes. A first electrode has a ring shape defining a central opening. A second electrode is positioned within the central opening of the first electrode. An insulating material is positioned between the first and second electrodes so as to provide a surface for a spark path between the first and second electrodes. The insulating material is spaced from the electrode so as to provide therebetween an air gap for increased sparking.

Abstract: A silicon valve for controlling the flow of a fluid includes two generally planar silicon members. One has an orifice for passing the fluid and the other has a relatively moveable surface to selectively open and close the orifice thereby controlling the flow of fluid through the orifice. A method is disclosed which method addresses the fabrication of the aforementioned silicon valve, wherein an oxide is grown on the surface of a wafer and the wafer then is etched to define a valve seat pattern. Both a top and a bottom plate are fabricated from wafer material and the profiled wafers are bonded together in a manner which will allow fluid passage therethrough.

Abstract: A capacitive pressure sensor uses two silicon wafers hermetically sealed to each other by recrystallized silicon formed by the migration of a ring of silicon-aluminum eutectic material from the wafer interface to the surface of one wafer. Within the ring of the eutectic a cavity with opposing conductive plates forms a capacitor. Another high conductivity path through the wafer can be formed simultaneously with the ring of eutectic material by placing an aluminum dot on the interior side of one silicon wafer. Thus, a high conductivity path is available through a silicon wafer for each of the two capacitor plates.

Abstract: An automatic driver system includes an accelerator pedal actuator system with a contact sensor for sensing contact between the actuator system and the accelerator pedal. A mechanical actuation system is mounted in the vehicle to contact and move the accelerator pedal. An electronic actuator is mounted outside the vehicle for causing movement of the accelerator pedal and includes a motor coupled to a tachometer for measuring rotational speed, a lead screw assembly for transforming rotational movement to linear movement and a linear displacement transducer for measuring linear position of the lead screw assembly. The system permits a new reference point to be established each time the accelerator pedal actuator system is installed in a vehicle.

Abstract: The capacitive effect of a coaxial cable coupled to an ionization probe is reduced by an operational amplifier which applies a constant bias voltage to the coaxial cable.

Abstract: A method for controlling the idling speed of an internal combustion engine supplied with a lean air/fuel ratio includes generating a speed error signal. The speed error signal is used to generate a fuel pulse width command signal to control fuel mass charge as a function of the speed error signal. A throttle command signal is generated as a function of the fuel mass charge to maintain a desired air mass charge which in turn maintains a desired air to fuel ratio.

Abstract: A planar photoelectrochemical sensing structure includes a thin, porous layer of photoactive semiconductor powder material deposited on an electronically conducting catalyst film which has been fabricated in two regions separated by a narrow stripe. Using incident light absorbed by the semiconductor, the structure is suited to photosensitizing redox reactions of chemical species introduced to the structure in an aqueous gas-phase environment. If photocarriers generated by the incident light are prevented from reaching one of the catalyst regions, for example by use of a light shield, then an EMF develops between the two catalyst regions. The magnitude of the EMF varies with the concentration of one of the gaseous reactants and thus provides a measure of the concentration.

Abstract: A device for detecting the presence of water includes a capacitance sensor coupled to a windshield to detect capacitance changes. A multivibrator is coupled to the sensor to translate the detected capacitance change to the frequency domain. A phase-locked loop coupled to the multivibrator produces a phase pulse in response to water causing a change in capacitance and, in turn, a change in the frequency of the multivibrator.

Abstract: A planar magnetic transducer uses thin film technology to form a coil on a ceramic substrate. A relatively powerful magnet is positioned adjacent the substrate so a changing magnetic reluctance adjacent to the coil can be detected by a voltage change at the coil.

Abstract: A method of selecting a desired transmission gear by controlling the duty cycle of a solenoid applying hydraulic pressure to one side of a transmission shift valve in relation to the hydraulic pressure applied to the other side.

Abstract: A switch includes three blade contact terminals against which is biased a rotating printed circuit board. The printed circuit board is rotationally moveable with respect to the blade contacts and has conductive elements on a first side of the printed circuit board for selectively contacting the switching contacts in response to the relative rotation between the switching contacts and the printed circuit board. The conductor elements include a tab for extending around the edge of the printed circuit board to a second side of the printed circuit board so as to provide electrically connected regions on both first and second sides of the printed circuit board. An electrically conducting resilient contact abuts the second side of the printed circuit board and biases the printed circuit board against the switching contacts. The tab and resilient contact can be coupled to a ground potential.

Abstract: In a guided projectile such as a missile, it is often necessary to negate the lift force imparted by the wings (5) during early low velocity stages of flight. Thus, wings (5) can be flattened against the airframe (2) of the missile (1) by a passive constraint, e.g., a shrink tubing (35) which disintegrates due to aerodynamic heating at a higher velocity stage of the flight, allowing each wing (5) to deploy into a position generally orthogonal to the airframe (2). The deployment force can be provided by torsionally and compressionally preloaded springs (19).

Abstract: A digital system for controlling the attitude of a spacecraft (14), e.g., a satellite, with respect to three orthogonal axes. The system can control satellites (14) in parking orbit, transfer orbit, or final operational orbit, whether or not the satellite (14) employs one or more momentum wheels. A processor (2) converts weighted data from spacecraft sensors (12), representing angular orientation and angular velocities about each of the three axes, into thruster pulsetrain signatures to command the firing of each of six thrusters positioned about spacecraft (14), a positive and a negative thruster being positioned to impart both directions of angular momentum about each of the three axes. Each thruster pulsetrain signature is created once every processed error cycle period T1, and contains a varying number of pulses of varying widths. A negative feedback PWPF loop (2, 16, 20, 22, 24) is actuated for each of the three axes, preferably several times each T1 in order to achieve better thruster on/off resolution.

Abstract: A metal and an insulator are alternately deposited on a substrate. The alternate deposition is continued until the desired film thickness of the cermet is obtained, at least one of the metal or insulator materials being deposited in sufficiently small quantities so that only a discontinuous film of that material is formed during a deposition. The metal insulator composition of the cermet is controlled by the relative deposition rates of the insulator metal. The metal particle size is controlled by the duration of each metal deposition.

Abstract: A current balanced linear amplifier which does not contain a transformer. A differential transistor pair (22, 32) forms the amplifying element, with at least one transistor (22 or 32) having an input signal (71, 72) applied to its base. A current sink (52) sinking a fixed value of current (I) is coupled to the commonly-coupled emitters of the transistor pair (22, 32). Coupled to the collector of each amplifying transistor (22, 32) is a self-biasing constant current source (2, 12) which produces a fixed amount of current (I/2) equal to one half the current (I) sunk by the current sink (52). Each self-biasing constant current source (2, 12) comprises a field effect transistor (2, 12) having a capacitor (6, 16) connected between the gate G and source S of the FET (2, 12) in a positive feedback arrangement. The balanced current output (61, 62) is taken from the collectors of each of the two amplifying transistors (22, 32).

Abstract: A method and apparatus for demodulating quadrature phase shift keyed (QPSK) signals in a manner which reduces crosstalk between channels. The in phase (I) data is recovered first by recovering the carrier frequency and then multiplying the carrier frequency by the QPSK signal. The I channel is contemplated to require higher power and thus the crosstalk error in the recovered I channel data is relatively small. The QPSK signal is then modulated with the recovered I channel data. The resulting signal is multiplied by a carrier in quadrature to the recovered carrier to produce a second signal in which the crosstalk component has been eliminated and which contains the quadrature (Q) channel data with the I channel modulation. The I channel modulation is removed by modulating the signal again by the I channel data to produce a signal containing only the Q channel data.

Abstract: A controlled system (10) has a control means (12) supplying a manipulated input, Y, to a plant (14). The control means (12) has external inputs V, input control model parameters C, and a predetermined mathematical model to compute a desired controlled system output X.sub.D into Y as a function of V and C. The method for operating the controlled system (10) includes establishing an initial value for C, measuring V, and generating an initial model for generating Y from X.sub.D as a function of V and C. The method also includes correcting C as a function of the difference between X.sub.D and the actual controlled system output, X, and as a function of measured external inputs V.

Abstract: An active cooling system (40, 41) for cooling electrochemical cells (11) that are arranged in a stack (9) in a fuel cell or battery (3). The cooling system (40, 41) comprises cooling panels (15, 16) carrying a cooling fluid that flows adjacent to, and parallel to the plane of, each cell (11). The rate of cooling fluid flow past each cell (11) is made to be substantially equal, so that each cell (11) experiences substantially the same cooling environment, adding to the longevity of the fuel cell or battery (3). This can be accomplished by equalizing the resistance to cooling fluid flow for each cooling path (12), e.g., by using pressure equalizing, monotonically increasingly sized orifices (28) in an input manifold (25). Dual cooling panels (15, 16) are preferably employed, in a counterflow mode. The panels (15, 16) may be divided into parallel channels (33). Heat pipe panels (35) containing a two-phase fluid may be used in lieu of panels (15, 16) that contain cooling fluid in a single state.

Abstract: The invention relates to a connector for enabling wires to be connected to a battery terminal, comprising a conducting component having a portion for attachment to the battery terminal and a further portion formed with bores for enabling additional connections to be made.The conducting component comprises a base plate 10 formed with bores 12 capable of directly engaging with male screwthreaded members for establishing the desired additional connections. The portion 9 for connection to the terminal 3 projects from the plane of the base plate 10, and the base plate 10 is provided with support flanges 11 to space the bores 12 from the surface of the battery.