Abstract: A synchro-to-step data converter for coupling one of a plurality of different synchro transmitters to one of a plurality of different step motors. The three wire output data of a synchro transmitter is demodulated into a three bit binary step data code and is applied to digital decoding means. The digital decoding means converts the step data code into a format suitable for application to a particular step motor and/or compensates for the speed of the synchro input shaft relative to the step motor output shaft.

Abstract: A gravity gradiometer disposed upon a gyroscopically stabilized platform in a vehicle can be modified, without impairment of its normal operation, to perform compassing functions.

Abstract: A combined high voltage power supply regulator and modulator which may be used with, for example, voltage tuned microwave devices. The circuit is characterized by a capacitively coupled variable impedance comprising fast acting semiconductor devices which are disposed in the low voltage return leg of the power supply to facilitate biasing. The variable impedance is controlled by a feedback signal to remove unwanted power supply ripple and may also be controlled by a wide variety of modulation signals to produce a modulated voltage for application to the voltage tuned microwave device.

Abstract: The peaks of synchro or step data representative of compass heading are detected and the resulting logic levels are latched into a register by an enable pulse generated in response to the data itself. Three outputs from the register are fed directly to the computer input port and provide 1/6.degree. resolution and 1.degree. range. Two of the register outputs are decoded and used to operate an up/down counter. The output of the counter is applied to the computer input port and provide 1.degree. resolution and 16.degree. range.

Abstract: An improved surface acoustic wave device having an acoustic substrate is mounted on multidirectional deflection structures that provide isolation from shocks and vibration and permit thermal expansion without stress to the acoustic substrate.

Abstract: An adaptive clutter canceller for adaptively cancelling clutter with non-zero mean Doppler frequencies. Received clutter signals averaged over a predetermined number of range cells and over an azimuth extent. The resulting averaged signal is used to shift the clutter spectrum to a zero mean Doppler and subsequently cancelled.

Abstract: Electromagnetic pulses of substantially nanosecond duration are transmitted from a merge location along transmission lines paralleling merging guideways to be incident to reflecting or repeating apparatus on vehicles approaching the merge. Coupling of the reflecting or repeating apparatus to the transmission line is such that sufficient electromagnetic energy is returned from the n.sup.th vehicle to the merge location for detection and processing thereafter. The returned signals are used to calculate, for each vehicle, the distance from the merge location and the approach speed.

Abstract: In a geothermal energy conversion system of the type having a down-hole turbine pump unit driven by a heated working fluid, a heat exchanger is disposed at the surface of the earth for heating the working fluid. The turbine pump unit pumps the geothermal brine to surface heat exchanger where it is used to heat the working fluid. The same heated working fluid is used to drive the down-hole turbine pump and to drive the power generating equipment at the earth's surface.

Abstract: The invention pertains to improved electrooptical devices for switching pluralities of unpolarized or polarized optical signals between input and output multimode single strand fiber optical guides and more particularly relates to novel electrooptical switch elements employing electric field-effect liquid crystal compositions adaptable for the construction of large scale, integrated multiple switch arrays.

Abstract: A color cathode ray tube display apparatus particularly for use under a wide range of ambient light conditions, such as in an aircraft cockpit, wherein each of the primary color phosphors has a unique brightness versus cathode drive characteristic, which characteristic also is dependent upon whether the displayed information is raster written or stroke written and wherein such characteristics also may vary from tube to tube. The output of at least one cockpit ambient light sensor in addition to a pilot selected brightness is used on a continuous basis to calculate a reference brightness level for the sensed ambient brightness conditions and display writing mode, this reference brightness level being used to calculate the corresponding brightness level for each of the primary color components of the commanded symbology color and concomitant drive voltages to the CRT's cathode or cathodes.

Abstract: An apparatus for providing precise convergence compensation in a shadow mask type color CRT display. Coarse compensation is provided by the coefficients of primary terms x.sup.2, y.sup.2 of the beam's longitudinal and vertical position polynomial in an analog format, and fine compensation is provided by digital programmable read-only-memories. The fine compensation is representative of the precise values of the coefficients of the remaining terms in these polynomials, and a digital-to-analog converter converts the fine compensation to an analog format. The coarse and fine data are summed together and applied to the convergence correction coils of the CRT.

Abstract: An apparatus for converting digital signals into analog pulse width modulated signals without a D/A Converter includes an up-down counter, programmed by the digital signal, which provides a signal to logic circuitry at the conclusion of each count. The logic circuitry responds to the counter signal and clock signals coupled thereto to provide an analog pulse width modulated signal corresponding to the digital signal.

Abstract: In an automatic flight control system of the type having automatic stabilizer trim control, the long term, constant altitude cruise trim threshold limits which alter the maximum and minimum pull-in/drop-out deflection of the elevator relative to the stabilizer minimize the steady-state downward deflection of the elevator, thereby reducing unnecessary aerodynamic drag and realizing significant savings in fuel costs.

Abstract: A geothermal deep well energy extraction system is provided of the general type in which solute-bearing hot water is pumped to the earth's surface from a relatively low temperature geothermal source by transferring thermal energy from the hot water to a working fluid for driving a primary turbine-motor and a primary electrical generator at the earth's surface. The superheated expanded exhaust from the primary turbine motor is conducted to a bubble tank where it bubbles through a layer of sub-cooled working fluid that has been condensed. The superheat and latent heat from the expanded exhaust of the turbine transfers thermal energy to the sub-cooled condensate. The desuperheated exhaust is then conducted to the condenser where it is condensed and sub-cooled, whereupon it is conducted back to the bubble tank via a barometric storage tank. The novel condensing process of this invention makes it possible to exploit geothermal sources which might otherwise be non-exploitable.

Abstract: An automatic pilot apparatus, for controlling an aircraft during the execution of a maneuver to capture a predetermined altitude, utilizes an altitude control law formula and signal which define a circular flight path intercepting the predetermined altitude and which result in a normal acceleration force on the aircraft. A signal representative of the normal acceleration force is utilized to generate a predictive pitch command signal which is combined with the control law signal to generate a pitch attitude command signal, thereby allowing the aircraft to smoothly capture the predetermined altitude.

Abstract: The crop discharge spout of an agricultural machine is continuously adjusted so that the crop material discharge therefrom is always directed into an associated, but not necessarily connected, collector vehicle. An electro optical device affixed to the crop discharge spout illuminates a scanning area with an optical signal. A passive retroreflective target affixed to the collector vehicle and disposed within the scanning area reflects the optical signal back to the electro optical device. The electro optical device receives the reflected optical signal and causes logic means to generate control signals, such that appropriate utilization means aligns the crop discharge spout with the associated but not necessarily attached collector vehicle.

Abstract: Stripline interlevel couplers capable of power splitting signals incident thereto at a given level of a multilevel stripline circuit between a plurality of levels and of coupling such incident signals between levels substantially unattenuated.

Abstract: A multilevel stripline transformer which transforms the center strips of a one level stripline system to a common ground plane between levels of a multilevel stripline system. The upper and lower ground planes of the one level system are each ribboned to form extensions of inner strips of the one level system, which are converted alternately to upper and lower level microstrips having the common ground plane as its ground plane. These upper and lower level microstrips are then transformed to be the center conductors of the upper and lower levels of the multilevel stripline system.

Abstract: A full rotational, substantially zero friction electrical conductor assembly conducts relatively high electrical currents between a pair of relatively rotatable members. Electrical conductor modules are axially stacked to provide multiple circuit capabilities wherein each module has a pair of electrical conductive rings affixed to the rotatable members defining an annular radial gap therebetween. A plurality of resilient filamentary conductor loops are disposed between these conductive rings, and the loops contact, roll on, and are captured by the conductive rings thereby providing electrical continuity between the relatively rotatable members. Loop separating spools are interspaced between and in rolling contact with the conductor loops to prevent the loops from touching one another and generating frictional losses. A circular raceway, carried by one of the rotatable members, keeps the spools in rolling alignment with the loops.

Abstract: A unidirectional current with i-f variations superimposed thereon is applied to the interconnected emitters of a pair of transistors, the collectors of which are coupled to a succeeding stage by a narrow-band filter and by a wide-band filter respectively. The unidirectional current with i-f variations is amplified by a selected one of the transistors and filtered accordingly, depending upon which of two polarities of potential is applied between the bases of the transistors.