Abstract: A solar dish concentrator is provided having a rotationally symmetrical elliptical shape for focusing an uniform flux density of solar radiation on a receiver. The solar flux pattern reflected to the receiver is evenly distributed over the four quadrants of the receiver without containing any hot spots.

Abstract: There is provided an analog-to-digital conversion technique that utilizes a sample and hold circuit for each bit try stage whereby after the most significant bit try, the remainder is sampled and held by the succeeding stage as an unknown input voltage for comparison with its respective reference voltage representing its corresponding bit weight. Thus, remainders for each bit weight comparison are successively passed from the most significant bit to the least significant bit as input voltages to the next bit try stage. The previous bit stage takes a new sample input voltage and starts another conversion at the next clock pulse. After the first full digital output of the initial conversion, a new digital output word of the successive sampled signal voltage is available after each clock pulse.

Abstract: There is provided by this invention an automated machine tool having a rotary indexing table that allows the machine tool to precisely rotate a workpiece 360.degree. to perform a machining function. The rotary indexing table has an aperture therein designed to accommodate an indexing tool supported in a rotatable spindle such that with appropriate movements of the moveable worktable the indexing tool causes rotation of the rotary indexing table to a precise position.

Abstract: There is provided by this invention an automated machine tool having a workpiece transfer apparatus that allows the machine tool to automatically load and unload a workpiece during machining. The automated machine tool has the capacity to select a workpiece from a stack of raw material, transfer the workpiece to a machining station, and select a new workpiece from the stack of raw material without human intervention.

Abstract: There is provided by this invention an adjustable torque driving tool for use with an automated machine tool wherein the adjustable torque driving tool is comprised of a releasable clutch that releases the tool from the rotating spindle of the automated machine tool when a pre-selected torque is applied. The adjustable torque driving tool gives the automated machine tool the capability to bolt workpieces to the worktable prior to machining and unbolting the workpiece from the worktable after machining.

Abstract: A method of automatically aligning heliostats by comparing the actual sunbeam centroid position on a target to a command reference position to determine the error in the sunbeam centroid location.The sunbeam centroid position error is then analyzed to correlate the error to errors in the heliostats' track alignment system. New coefficients are established for the heliostats' track alignment system to automatically correct for errors in the system, this eliminates the need for resurveying and field work normally associated with aligning heliostats.

Abstract: There is provided a static VAR generator employing a bank of series-connected inductors, each inductor being supplied by different secondary taps of a step-down transformer. The voltage rating of each inductor is appropriately decreased so as to make their sum correspond to the supply voltage. All but one of the inductors are controlled by thyristors in an on-off fashion to supply reactive power to the network in incremental steps. One of the thyristors is continuously phase-angle fired in combination with the incremental insertion of the other inductors to vary the VAR output over the full range, but generating harmonics that are proportional only to the continuously controlled inductor.

Abstract: There is provided by this invention a part turnover attachment for use with an automated machine tool comprised of a chuck for supporting the tool in the rotatable spindle of the machine tool and a rotatable pickup mechanism that attaches to a workpiece. The rotatable pickup mechanism is rotated by the controlled rotation of rotatable spindle whereby the workpiece can be inverted.

Abstract: A static VAR generator utilizing a multitude of reactor banks each having different computation circuits and firing angle control circuits is provided. The different computation and firing angle control circuits allows the VAR generator the flexibility of being able to change the reactor power in an A.C. network repetitively in any cycle in response to rapid changes in load demand. This is accomplished by each reactor bank having progressively longer computation times and later insertion of additional banks into the network after the first bank has responded to load demand.

Abstract: There is provided by this invention a vacuum monitoring device for use in vacuum circuit interrupters comprising a stacked resistor assembly as a voltage divider coupled to an internal shield of the vacuum bottle and a low voltage detection circuit for monitoring leakage currents under abnormal pressure conditions.

Abstract: There is provided a novel vacuum detection means utilizing a high frequency, high voltage device to excite an electrical discharge in a vacuum whose characteristics are dependent on the level of the vacuum contained therein. This discharge current allows the degree of vacuum to be continuously monitored.

Abstract: An auxiliary thyristor control circuit inserts a zinc oxide varistor in series with the capacitor bank of a static VAR generator for discharging the capacitor bank when the static VAR generator is subjected to high transient voltages.

Abstract: There is provided a static VAR generator having voltage regulation in combination with the capability to damp subsynchronous resonance should it occur. A novel method for controlling subsynchronous resonance is provided by monitoring the frequency of the electrical generating system and controlling the insertion of compensating inductance in response to disturbances that may result in voltage and frequency pulsations.

Abstract: There is provided by this invention an eddy current bus means in combination with a plurality of electrical contact fingers disposed to make contact with an electrical bus means whereby said eddy current bus means generates electromagnetic forces that cause increased electrical contact pressure between said plurality of electrical contact fingers and said electrical bus means.

Abstract: A current control device which may act as a current limiter and/or a VAR generator through the use of a superconducting inductor is taught. In one of the embodiments of the present invention, a full wave bridge rectifier network is serially inserted in one leg of a high voltage transmission system. The output of the full wave bridge network has connected between it a superconducting coil in series with a bias supply. The biasing supply circulates current in the inductor. Should the line current exceed the value of the current circulating in the inductor, the inductor impedes the increase of current giving sufficient time for current interruption devices, should they be utilized, to operate. Additionally, the biasing supply may act as a VAR generator by controlling the current in the superconductor or in the power supply feeding it.

Abstract: There is provided a static VAR generator having a novel method for controlling subsynchronous resonance by monitoring the frequency of the electrical generating system and controlling subsynchronous resonance by phase-firing thyristor controlled inductance.

Abstract: There is provided a static VAR generator generally comprised of a fixed capacitor bank and a first and second switched conductor bank whereby said second switched inductor bank is operated at voltages leading the first inductor bank by 30 electrical degrees to allow the VAR generator to adjust its output current twice in each half cycle of operation.

Abstract: A circuit comprising a load sensor connected to a multiple rated motor for monitoring the motor load demand and a switching apparatus connected to the source of electrical power for changing the connection of electrical power to the windings of the motor under load in response to the motor load demand.

Abstract: This invention provides a new circuit interrupter construction utilizing a means of mounting the interrupter units on the roof of the control housing that supports the drive mechanism and other control apparatus.

Abstract: A circuit breaker switchgear housing device having a stab positioning system whereby a draw-out circuit breaker having separable contacts is contained in the switchgear housing. A stab positioning system is utilized so as to precisely locate stabs so that a circuit breaker having contact clusters which are electrically attached to the circuit breaker contacts make accurate and uniform contact with the stabs. The stabs are generally a rectangular-shaped bar with one of the ends being rounded off. Cut into two sides of the stab and opposing each other are notches. The stab is inserted into a retainer or positioning washer which has a bayonet-type lock opening into which the stab is inserted and rotated 90.degree., thereby prohibiting axial movement of the stab with respect to the washer. A retainer or positioning washer having an opening slightly larger than the stab cross-section is used to rigidly position an inserted stab, prohibiting rotational movement with respect to the opening in the stab.