Abstract: A phase-detector (16, 18, 20) is provided for use in a power factor controller for a three-phase induction motor. The power factor controller includes switching thyristors (10, 12 14) for each motor phase winding and the phase detector for each phase includes an operational amplifier (36) which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier.

Abstract: A power factor type motor controller in which the conventional power factor constant voltage command signal is replaced during a starting interval with a graduated control voltage. The present invention adds to the three-phase system of pending application Ser. No. 199,765, filed Oct. 23, 1980, means for modifying the operation of the system for a motor start-up interval of 5 to 30 seconds. The modification is that of providing via ramp generator 174 an initial ramp-like signal which replaces a constant power factor signal supplied by potentiometer 70. The ramp-like signal is applied to terminal 40 where it is summed with an operating power factor signal from phase detectors 32, 34, and 36 to thereby obtain a control signal for ultimately controlling SCR devices 12, 14, and 16 to effect a gradual turn-on of motor 10.

Abstract: A failure detector is provided for detecting unidirectional failures in triacs, particularly as used in power factor controllers for induction motors. In a first embodiment, the triac voltage waveform is sensed and upon detection of an unbalanced signal, corresponding to failure of the triac in either the positive or negative direction, the triac is turned full on in both directions. In a second embodiment, a pair of pulsed signals are derived, the pulse durations of which are proportional to the phase difference between the load current and voltage for each half cycle, and the triac is turned full on responsive to a difference in pulse duration between the half cycle signals. An unidirectional open circuit detector is adapted to use a signal from either of the first and second embodiments to turn the triac off in response to an open circuit failure in either direction.

Abstract: A hand held device (12) having a forward open window portion (14) adapted to be pushed downwardly into the frost on a surface, and a rear container portion (22) adapted to receive the frost removed from the window area. A graph (FIG. 4) on a side of the container enables an observer to determine the density of the frost from certain measurements noted. The depth of the frost is noted from calibrated lines (28) on the sides of the open window portion (14).

Abstract: A control system for a permanent-magnet motor (10) driven by a multiphase line-commutated inverter (12) is provided with integrators (24) for integrating the back EMF of each phase of the motor for use in generating system control signals for an inverter gate logic (30) using a sync and firing angle (.alpha.) control generator (26) connected to the outputs of the integrators. A precision full-wave rectifier (16) provides a speed control feedback signal to a phase-delay rectifier (14) via a gain and loop compensation circuit (20) and to the integrators for adaptive control of the attenuation of low frequencies by the integrators as a function of motor speed, whereby as the motor speed increases, the attenuation of low frequency components by the integrators is increased to offset the gain of the integrators to spurious low frequencies. The .alpha.-control signals are produced by the firing angle control generator by means (48, 50) for combining 120.degree.

Abstract: A satellite retrieval system (10) wherein first and second pairs of coacting parallel bars (40), and (94) are separately mounted in spaced parallel planes on the front of a spacecraft (14). The bars of one pair are at right angles to bars of the other pair, and together the two pairs of bars effect a variable aperture adapted to close around a rod (26) extending from a second spacecraft (22) to thereby effect the capture of the latter.

Abstract: A dual laser optical system and method is disclosed for visualization of phenomena in transparent substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. According to the invention two images 68 and 70 representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen 66. Two lasers 10 and 12 having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams 14 and 20 which are collimated into a beam 32 containing components of the different wave lengths. The collimated beam 32 is passed through a test volume 33 of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused on to a pair of knife edges arranged mutually perpendicular to produce and project images 68 and 70 onto screen 66.

Abstract: A method and apparatus for preparing and studying samples of materials supercooled and solidified in a containerless, low-gravity environment in bulk form is disclosed which includes an enclosure 10 in which a containerless environment is provided in which a sample specimen 52 is positioned. Method contemplates heating the specimen 52 in the containerless environment, dropping the specimen melt through the tube 12 wherein it cools by radiation, and alternately backfilling the tube 12 with an inert gas whereby the specimen melt cools by both radiation and convection during its free fall. During the free fall, the sample is in a containerless, low-gravity environment which will enhance supercooling in the sample and prevent sedimentation and thermal convection influences. The sample will continue to supercool until nucleation occurs which is detected by silicon photovoltaic detectors. The sample will solidify after nucleation and be completely solid before entering the detachable catcher.

Abstract: A power generating system for adjustably coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn "on" at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

Abstract: Connector apparatus and assembly is disclosed for connecting beams and the like structural members which is particularly advantageous for connecting two members together when moved laterally into place since the connector apparatus requires no relative longitudinal movement between the ends of the beams or members being connected to make a connection joint. The connector apparatus includes a receptacle member A and a connector housing B carried by opposed ends of the structural member being connected wherein a spring-loaded connector member C is carried by the connector housing B which may be released for extension and engagement into the receptacle member A.

Abstract: Control signals for phase-delay rectifiers, which require a variable firing angle that ranges from 0.degree. to 180.degree., are derived from line-to-line 3-phase signals (.phi.A, .phi.B, .phi.C) and both positive and negative firing angle control signals (+.alpha. and -.alpha.) which are generated by comparing (at 20) current command and actual current (sensed at 16). Line-to-line phases are transformed (32) into line-to-neutral phases and integrated (at 34) to produce 90.degree. phase delayed signals (A.phi., B.phi., and C.phi.) that are inverted (at 26a, b, c) to produce three cosine signals (C, A and B RAMP) such that for each its maximum occurs at the intersection of positive half cycles of the other two phases which are inputs to other inverters. At the same time, both positive and negative (inverted) phase sync signals are generated for each phase by comparing (at 27a, b, c) each with the next and producing a squarewave when it is greater.

Abstract: Apparatus is disclosed for immersing minute integrated circuit chips in an etching solution in manufacturing integrated circuits during research and development. The apparatus includes holder member C having a handle 24 and basket support 26 for carrying a removable unitary basket A and lid structure B wherein fluid flow-through passages 20 are formed and wherein graduated openings 28 in the handle provide for adjustably supporting the basket in a beaker at a desired level.

Abstract: The invention relates to an end effector device for a robot or teleoperated type space vehicle which includes an inflatable balloon member carried on the end of a tubular member which has a hollow center or conduit through which a suitable pressurized fluid is supplied. The device may be inserted into a variety of shaped openings or truss-type structures for handling in space.

Abstract: A pump/valve unit for controlling the inflation and deflation of a urethral collar in a prosthetic urinary sphincter device is disclosed including a compressible bulb pump defining a reservoir made integral with a valve unit for implant wherein the valve unit includes a movable valve member operable by depression of a flexible portion of the valve unit housing for controlling fluid flow between the reservoir and collar and a pressure sensing means which operates the valve member to relieve an excess pressure in the collar should too much pressure be applied by the patient.

Abstract: A method and apparatus for enhancing and shaping acoustical levitation forces in a single-axis acoustic resonance system wherein specially shaped drivers and reflectors are utilized to enhance the levitation force and better contain fluid substances by means of field shaping.

Abstract: A drive system characterized by a base supporting a pair of pillars arranged in spaced parallelism, a shaft extended between and supported by the pillars for rotation about the longitudinal axis thereof, a worm gear affixed to the shaft and supported thereby in coaxial relation therewith. A bearing housing of a sleeve-like configuration is concentrically related to the shaft and is supported thereby for free rotation with respect thereto. A first and a second normally quiescent drive train, alternatively activatable, is provided for imparting rotation into said bearing housing.

Abstract: Cork-resin ablative insulation material is prepared in a form suitable for application to complex curved surfaces by mixing finely divided cork with a B-stage curable thermosetting resin, forming the resulting mixture into a block, B-stage curing the resin-containing block and slicing the block into sheets. The B-stage cured sheet is shaped to conform to the surface being insulated, and further curing is then performed. Curing of the resin only to B-stage before shaping enables application of sheet material to complex curved surfaces and avoids limitations and disadvantages presented in handling of fully cured sheet material.

Abstract: Monotectic alloys having aligned spherical particles or rods of the minor component dispersed in a matrix of the major component are prepared by forming a melt containing predetermined amounts of the major and minor components of a chosen monotectic system, providing in the melt a dopant capable of breaking down the liquid-solid interface for the chosen alloy, and directionally solidifying the melt at a selected temperature gradient and a selected rate of movement of the liquid-solid interface (growth rate). Shaping of the minor component into spheres or rods and the spacing therebetween are controlled by the amount of dopant and the temperature gradient and growth rate values. Specific alloy systems include Al-Bi,Al-Pb and Zn-Bi, using a transition element such as iron.

Abstract: A retractable environmental seal for use in sealing the opening of the exit cone for a rocket nozzle comprising a diaphragm-like cover having a central region adapted to be seated in sealing relation with the periphery of the opening and characterized by radially extended failure zones for facilitating a pressure-induced rupture of the cover, and a plurality of angularly spaced tension springs connected with the peripheral portion of the cover for retracting fractured segments of the cover from the opening subsequent to a pressure-induced rupture thereof.

Abstract: An apparatus for producing a structure in outer space from rolls of prepunched ribbon or sheet material that are transported from the earth to the apparatus located in outer space. The apparatus spins the space structure similar to a spider spinning a web utilizing the prepunched ribbon material. The prepunched ribbon material is fed through the apparatus and is shaped into a predetermined channel-shaped configuration. Trusses are punched out of the ribbon and are bent downwardly and attached to a track which normally is a previously laid sheet of material. The size of the overall space structure may be increased by merely attaching an additional roll of sheet material to the apparatus.