Abstract: A curved prismatic, Fresnel-type lens primarily used for concentrating sunlight in a solar energy collector. The lens comprises a substantially smooth, convex outer surface and a plurality of prisms arranged side-by-side along a curve on the inner surface to direct incoming light to a common area. Each of the individual prisms has a front and back face joined by a bottom face. The front and back faces of the prisms are oriented such that the angle of incidence of the incoming light with the front face is equal to the angle of incidence of the outgoing light with the back face. Further, each of the prisms is arranged along the curve such that they do not obstruct light passing through any adjacent prism. The bottom face of each prism is over-extended beyond the path of the light passing through the prism to prevent loss of light due to blockage by the bottom face or the rounded point between the back face and bottom face.

Abstract: A digitized automatic gain controlled amplifier and gain hysteresis circuit is disclosed for preserving a low frequency, low level modulation at the output of an AGC amplifier while also providing for rapid correction of amplifier gain for large variations in the amplifier input signal level. The described amplifier is particularly adapted to satellite communications systems in which ionospheric changes produce rapid power fades and wherein satellite tracking is accomplished by dithering a high-gain antenna on the satellite to produce a low-frequency power amplitude control signal at the input to the AGC amplifier, which control signal is allowed to pass through to a control system while the larger input signal variations are gain-controlled out.

Abstract: A radio navigation, position locating and signaling arrangement employs three operative channels per vehicle for receiving three commercial radio transmissions. Each channel includes feedback circuitry for maintaining a constant phase relationship between a replica of the received broadcast carrier and a reference oscillation, both reduced in frequency. An accumulator in each channel records the number of pulses added and/or deleted from the reference pulse train to provide a measure of the radial distance travelled by a vehicle with respect to the corresponding fixed radio transmitters. Common central station equipment processes the reported vehicle accumulated coordinate pulse counts, and corrects such vehicle coordinate fixing information for frequency error in the non-cooperative commercial transmissions and in the vehicle mounted local reference oscillations.

Abstract: Small electrical resistors, such as are used in circuits of comparatively low power, are automatically fabricated on a winding machine including a chuck assembly for facilitating the start and finish of a winding operation. The chuck assembly consists of a first jaw rotatably mounted with respect to a second jaw from a wire receiving position to a wire gripping position. The chuck is closed to grip a resistance wire at the start of a winding operation and an automatic welder operates to weld the wire to a metallic terminal cap positioned at one end of a resistor core. Upon completion of the welding operation, the jaws of the chuck assembly are opened and a winding head operates to rotate the resistor core to begin a winding operation. The winding operation continues for a preset number of turns at which time the jaws of the chuck assembly are moved to a closed position to clamp the resistance wire.

Abstract: The characteristic impedance of a planar microstrip or stripline for transmitting signals along a transmission line in the TEM mode is matched by way of a tapered shunt which terminates the line in a dc short circuit to ground. The tapered shunt or termination wraps around the edge of the insulating substrate and electrically connects the microstrip to the ground plane. The geometry of the tapered shunt is incrementally adjusted by means of a series of steps to produce a termination having a selected impedance.

Abstract: A method and apparatus are disclosed for providing co-planar connections to the terminal leads of a switching device from circuit elements located on opposite sides of a planar microstrip substrate. A through hole is provided in the substrate where the switching device is to be mounted. A conductive terminal is inserted through the hole. The terminal includes a portion contacting the circuit element on one side of the substrate and a portion extending through the hole to become substantially co-planar with the circuit elements on the opposite side of the substrate. A switching device is positioned in the hole to permit its leads to be connected to the extended portion of the terminal and to the microstrip circuit elements on the opposite side of the substrate.

Abstract: The invention contemplates a heat-transfer device or heat pipe characterized by integral screen-wick structure providing relatively great contact area between the internal working fluid or condensable medium and the heat input.

Abstract: A typical alternating current two phase servomotor has two windings displaced 90.degree.; these windings are normally identified as the reference winding and the control winding. Rotational direction and speed of the motor may be controlled by applying AC voltages of the proper waveform amplitude and phase relationship to these windings. When controlling the direction of rotation and speed of such alternating current servomotors in accordance with a DC error signal, pulse width modulation is utilized. The DC error signal is compared with a periodic varying function and its inverse to generate a series of pulses that are logically combined with a square wave and its complement during an enable period to generate a first and second series of pulses each having a width related to the magnitude of the error signal and coupled to energize the control winding of the alternating current servomotor. Similarly, a second periodic signal and its inverse are used to generate pulses for the reference winding.

Abstract: A segmented voltage function is generated at the output of a primary differential amplifier having an input voltage connected to the noninverting terminal. As the input voltage increases at the noninverting amplifier input, the output increases with the same slope until a voltage as sensed at the inverting input of the amplifier equals a first breakpoint. The inverting input to the primary differential amplifier connects to a feedback circuit that also includes a plurality of secondary differential comparator amplifiers coupled to a voltage ladder network. Each of the secondary differential amplifiers has a noninverting input connected to a separate voltage on the ladder network. The inverting input of each of the secondary differential amplifiers is connected to a feedback loop.

Abstract: A timing circuit receives substantially square wave clock signals and generates sine and cos driving signals therefrom at a predetermined frequency for application to first and second mutually perpendicular Hall effect generators. The output signals from the Hall effect generators are algebraically summed to provide a heading signal, the phase displacement of which with respect to the driving signals, is representaive of the orientation angle between one of the Hall effect generators and magnetic north. A counter is synchronized to begin to count clock pulses at the beginning of each period of the driving signals. A logic circuit is effective to disable the counter when the Count signal therein is representative of the orientation angle. The sine and cos of the Count signal are derived and each is multiplied by a distance signal related to the number of revolutions of a wheel of the vehicle being monitored.

Abstract: A timing circuit receives substantially square wave clock signals and generates Sine and Cosine driving signals therefrom at a predetermined frequency for application to first and second mutually perpendicular Hall effect generators. The output signals from the Hall effect generators are algebraically summed to provide a heading signal, the phase displacement of which with respect to the driving signals, is representative of the orientation angle between one of the Hall effect generators and magnetic north. A counter is synchronized to begin to count clock pulses at the beginning of each period of the driving signals. A logic circuit is effective to disable the counter when the count therein is representative of the orientation angle. The count is stored in a memory and displayed on a readout device which is, in turn, updated at the end of each period of the driving signals' frequency.

Abstract: A flexible line distributed antenna, defining a perimeter of interest, radiates energy supplied from a transceiver. Motion around the flexible line causes the reflected energy which is intercepted by the flexible distributed antenna to be coupled back to the transceiver as a doppler frequency for processing in an alarm system. Reflected energy from the antenna to the transceiver is amplified and rectified into a DC voltage. This DC voltage is integrated to produce a time varying signal to a level detector that responds to a predetermined value of the integrated DC voltage. A response by the level detector provides an actuating signal to an alarm indicator through alarm logic. Ambient conditions around the extended flexible line distributed antenna are monitored by external sensors having outputs for controlling amplifier gain and triggering the alarm logic. For improved motion detection reliability, reflected energy from the antenna is coupled to a transceiver providing two output signals.

Abstract: A valve device includes primary and secondary fluid systems. The secondary fluid system includes source pressure and controlled pressure channels containing secondary fluid at source and controlled pressures, respectively. A master cylinder primary fluid source is connected through first and second parallel paths to a primary fluid portion of a changeover cavity which is also connected to the brake cylinders of a vehicle. The changeover cavity includes primary and secondary movable piston member therein, separating primary and secondary fluid portions thereof. Each parallel primary path includes a valve member for controlling the flow of primary fluid to the primary portion of the changeover cavity.

Abstract: Tactical radio navigation systems provide bearing information to an interrogating aircraft in response to pairs of interrogation pulses received at a beacon transponder, the system also provides distance measuring and identification information. To provide the required bearing information, pulses radiated from the central antenna array are modulated at a 15 Hz frequency and by 135 Hz frequency, by parasitic elements rotating around a stationary central array. Broadband operation of the system is provided by a distribution pattern of the 135 Hz parasitic elements mounted radially from the central antenna array on a dielectric disc. Nine groups of radially displaced 135 Hz elements are circumferentially arranged around the dielectric disc and each element of a group is tailored to a particular frequency band in the frequency spectrum allotted to radio navigation systems.