Abstract: A desiccant type air dryer for an air supply system for a motor vehicle brake system. The air dryer incorporates features for convenient mounting and dismounting of a desiccant cartridge to the air dryer body assembly. This connection is achieved through the use of an externally accessible through bolt which passes through the body assembly and engages a central threaded boss on the load plate of the desiccant cartridge. Interlocking engagement between the desiccant cartridge and body assembly prevent these parts from rotating relative to one another during mounting and dismounting of the cartridge. The desiccant cartridge is readily removed through engaging the through bolt driving head using conventional tools.

Abstract: An electronically controlled compressed air system (10) includes an air dryer (16) which dries compressed air before the compressed air is communicated to a reservoir (26). The air dryer (16) includes a desiccant (18) which is purged by using air stored in the reservoir (26). A pressure transducer (13) is installed on the reservoir (26) and transits an electrical signal, indicative of the pressure in the reservoir (26) to an electric controller (11). Electric controller (11) transmits signals at various selected pressure levels to solenoid value (28) to control loading and unloading of the compressor (12), to solenoid valve (36) to control purging of the air dryer (16), and to the warning light (40) to alert an operator of a low air pressure condition.

Abstract: An air supply system for a motor vehicle air brake system incorporating a desiccant type air dryer. The purge capacity of the air dryer is enhanced providing greater water and contaminant removable characteristics for the air dryer. The system incorporates a pressure reducing element and a control system for the system compressor causing air passing through the air dryer to be at a higher pressure than that necessary for charging the system reservoir. The higher pressure air supplied to the air dryer provides greater volumetric capacity for the purge volume of the air dryer. In this way an air dryer purge volume of a given size provides a greater purge capacity.

Abstract: A two degree of freedom gyroscope having a drive motor (20), with a permanent magnet rotor (22), which includes an optical sensor (11) for providing an X-axis signal and a Y-axis signal which are indicative of the displacement of the actual rotor (22) spin axis from the null spin axis (28), a torquer coil (26) looped around the permanent magnet rotor (22) and disposed in a plane orthogonal to the null spin axis, and torquer drive elements (52, 54, 56) responsive to the X-axis and Y-axis signals induced in the sensor when the actual rotor (22) spin axis is displaced form the null spin axis (28) for providing current to said torquer coil (26) to urge the axes to coincide. A voltage induced in an open phase of a two phase motor stator is used to provide the instantaneous position of the rotor poles to obtain correct phasing information for commutation of the single polar torquer.

Abstract: A sensor (10) is disclosed for measuring the specific force and angular rotation rate of a moving body and is micromachined from a silicon substrate (16). First and second accelerometers (32a and b) are micromachined from the silicon substrate (16), each having a force sensing axis (38) and producing an output signal of the acceleration of the moving body along its force sensing axis (38). The first and second accelerometers (32a and b) are mounted within the substrate (16) to be moved along a vibration axis (41). The first and second accelerometers (32a and b) are vibrated or dithered to increase the Coriolis component of the output signals from the first and second accelerometers (32a and b). A sinusoidal drive signal of a predetermined frequency is applied to a conductive path (92) disposed on each of the accelerometers.

Abstract: An aircraft engine start system eliminates the need of a separate exciter field inverter by rearranging the exciter field windings and by utilizing external AC power. The aircraft engine is started by external AC power and once the engine has started, the engine can supply power back to a variable frequency AC bus as well as back to a constant frequency AC bus through the start/generator converter mode.

Abstract: A tunnel current position sensor has a first sensing electrode coupled to a compliant beam for providing force relief to the sensor. The beam is connected in fixed relationship with a first object. A second sensing electrode is coupled to a second object. The compliant beam elastically deforms to prevent damage resulting from crashing of the electrodes.

Abstract: A radar utilizes an antenna stabilization error correction system to automatically estimate and correct attitude sensor errors in pitch, roll and elevation. The radar system includes an antenna, an antenna positioner, a transmitter receiver, a signal processor, an antenna controller and stabilization processor and the antenna stabilization error correction system. As part of the normal signal processor sub function, ground clutter signals are extracted from the received signals. These signals are the primary input to the antenna stabilization error correction system. Other inputs are received from the signal processor, antenna controller and stabilization processor and an external aircraft radio altimeter. The antenna stabilization error correction system processes the signals and estimates pitch, roll and elevation errors which are passed back to the antenna controller and stabilization processor.

Abstract: An active matrix electroluminescent display having an array of pixel electrodes disposed on a transparent substrate. Each pixel electrode having an associated electronic circuit formed intermediate the pixel electrode and the transparent substrate to which it is electrically connected. The array of pixel electrodes are overlayed with an electroluminescent stack and a transparent ITO conductive layer. The surface of each pixel electrode is uniformly texturized to enhance the brightness of the pixel element when it is activated to its luminous state by its associated electronic circuit.

Abstract: Azimuth and elevation information relating to ground based weapons equipment is inputted to a north finding system. The system determines angular azimuth and elevation errors and transmits signals to a display arrangement for indicating the direction to rotate the system so as to eliminate the errors. As the system is aimed, a gyro included in the north finding system measures angular rotation about its input axis and accelerometers measure the change in tilt. The computer projects the rotations to the horizontal plane and determines the change in azimuth. This is a continuous procedure until all errors are eliminated.

Abstract: The invention comprises a velocity sensor (10, 30, 50, 60, 70, 110) that measures velocity in only one degree of freedom and is insensitive to the other five degrees of freedom. The velocity sensor uses differential flux splitting, and by sensing changes in flux, common mode effects are removed. In practicing the invention, a permanent magnet (17, 33, 55, 65, 71, 131) is used to create a flux field, and multiple return paths are used to split the flux. A plurality of pole pieces (20-21, 39-40, 58-59, 66-67, 72-73, 111-112) simultaneously move an equal amount in relation to the return paths for differentially varying the amount of flux carried by each return path (13-14, 34-36, 52-53, 63-64, 73A-C and 75A-C, 115-117), to thereby induce a differential voltage in secondary coils (15-16, 37-38, 56-57, 68-69, 80-83 and 90-93, 140-143 and 150-153). Detection means (not shown) is used to sense the change in voltage and provide an indication of the sensed velocity.

Abstract: A radar system includes a stabilization calibration arrangement wherein a module stores particular parameters for relating the radar system to a gyro which provides stabilizing data for the radar system. The storage module, the radar system and the gyro are mounted on the same mounting platform so that the particular calibration features remain with the mounting platform. With the arrangement described, the radar system is independent of the gyro and can be of a generic configuration as is advantageous for stabilization calibration purposes.

Abstract: A monolithic micromachined temperature switch obviates the necessity of assembling discrete components and also allows the temperature switch to be disposed in a relatively small package. In one embodiment of the invention, the temperature switch includes a bimetallic element operatively coupled to a pair of electrical contacts. In order to minimize contact wear due to contact arcing, a biasing force such as an electrostatic force is applied to the switch which provides snap action of the electrical contacts in both the opening and closing directions which enables the temperature set point to be adjusted by varying electrostatic force biasing voltage. In an alternate embodiment of the invention, the biasing force for providing the snap action effect can be eliminated by substituting the movable contacts with a field effect transistor with a movably mounted gate terminal.

Abstract: A micromachined vibrating beam accelerometer provides an acceptable mechanical Q at pressures above vacuum. Electrodes are formed on the beams for connection to a source of excitation voltage. In addition, electrodes are formed on a pick-off capacitance plate disposed adjacent the vibrating beams. The electrodes formed on the pick-off capacitance plate form capacitors with the electrodes formed on the beam. The output signals from these capacitors are connected in a feedback loop to the source of excitation voltage to form a relatively simple oscillator. In order to reduce the squeeze film damping, the pick-off capacitance plate is formed with grooves along one edge adjacent the vibrating beams. The grooves, which may be formed by either isotropic or reactive ion etching, reduce the squeeze film damping resulting from the vibratory motion to obviate the need to operate the vibrating beam accelerometer in a vacuum.

Abstract: A high accuracy laser accelerometer has a differential pathlength element having an outer annulus and a combined acceleration sensing proof mass with a laser mirror, a closed cavity including a cathode, anode and a movable pathlength control mirror, a lens prismatic readout, a photodetector and associated electronics. When the laser accelerometer is subjected to linear acceleration, the acceleration sensing proof mass moves relative to the outer annulus of the differential pathlength element causing a differential pathlength change in the cavity which is readily detected by the photodetector.

Abstract: A micromachined push-pull accelerometer formed with dual vibrating beam transducers in one plane of a silicon substrate includes a pair of proof masses or pendulums supported by flexures formed in a plane adjacent a surface of the silicon substrate opposite the vibrating beam transducers on opposing sides of the pendulums to define opposing pendulous axes. The accelerometer is configured such that the dual vibrating beam transducers are in a push-pull relationship (e.g., one transducer is subjected to a tension force while the other transducer is subjected to a compression force in response to accelerations along a sensitive axis SA). In order to form the push-pull configuration, one vibrating beam transducer is connected to one pendulum on a side opposite the hinge axis for that pendulum while the other vibrating beam transducer is connected to the other pendulum on the same side as the hinge axis for that pendulum.

Abstract: Flux information in a magnetic circuit such as may be used for rate damping and vibration suppression in a magnetic forcer system is sensed and is used in conjunction with a differentiated forcer position signal to provide a rate damping signal. The sensed magnetic flux is used to synthesize an inertial velocity signal which is applied as a position rate damping input to a closed position control loop.

Abstract: A reactionless single beam vibrating force transducer utilizes counterbalances at opposite ends of the beam that rotate in directions opposite to the ends of the vibrating beam to reduce rotational and normal forces transmitted to the end supports for the beam. The proportions of the counterbalances relative to the size of the beam may be chosen to reduce forces in a direction normal to the beam to zero at the expense of some rotational moments at the end of the beam support, or to reduce moments at the expense of some normal force. The relative amounts of residual rotational moments and normal force can be adjusted to suit particular applications. Flexures may also be utilized to reduce the rotational moments transferred to the beam support even further.

Abstract: An optical component consists of two or more plane-parallel windows with, respectively, two or more partially reflective surfaces. Each partially reflective surface splits off part of an original beam and produces another redirected beam. The redirected beam undergoes further redirection and attenuation by multiple reflections. Each even-numbered reflection produces a beam deviated from the original's beam direction by an even multiple of the angle between the windows. Thus, for a pair of windows a series of beams are produced that are in a straight line and are equally spaced.

Abstract: An apparatus for isolating electronic devices from mechanical shock and thermal environments utilizes a metal outer protective shell surrounding the electronic device to be protected. Interposed between the protective shell and the electronic device are a thermal insulating layer, a layer of phase change material and a layer of mechanical shock absorbent material.