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: A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate. The coating comprises:(a) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte,(b) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group, and(c) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters.sup.2 /gram, at least one second filler material having a surface area of 10 to 25 meters.sup.2 /gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 meters.sup.2 /gram, and the amount of plasticizer is sufficient to coat each filler particle.A method of forming the battery separator.

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: This invention is concerned with improving adhesion, friction and wear properties of sputtered refractory coatings on substrates of materials that form stable nitrides.Each substrate (10) is placed directly below a titanium carbide target (16) of a commercial radiofrequency diode apparatus (14) in a vacuum chamber (26). Nitrogen is bled into the system through a nozzle (3) resulting in a small partial pressure of about 0.5% to 2.5% during the first two minutes of deposition. The flow of nitrogen is then stopped, and the sputtering ambient is reduced to pure argon through a nozzle (28) without interrupting the sputtering process.When nitrogen is deliberately introduced during the crucial interface formation, some of the titanium at the interface reacts to form titanium nitride while the metal of the substrate also forms the nitride. These two nitrides atomically mixed together in the interfacial region (38) act to more strongly bond the growing titanium carbide coating (12) as it forms on the substrate (10).

Abstract: The object of the invention is to improve the film stiffness of a face seal without increasing the sealing and dam area.The improved sealing apparatus (16) has a primary seal ring (20) in the form of a nose piece. A spring (24) forces a sealing surface (28) on the seal ring into sealing contact with a seat (18) to form a face seal. A circumferential clearance seal is formed in series with this face seal by a lip (34) on the nose piece. The width of the surface (36) of the lip is substantially the same as the width of the sealing surface (28) on the face seal. Also the clearance between the surface (36) on the lip and the shaft (10) is substantially the same as the spacing between the face sealing surfaces (28 and 30) on the face seal when the shaft is rotating.The circumferential clearance seal restricts the flow of fluid from a main cavity (14) to an intermediate cavity (32) with a resulting pressure drop.

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 film-forming polyvinyl alcohol polymer is mixed with a polyaldehyde-polysaccharide cross-linking agent having at least two monosaccharide units and a plurality of aldehyde groups per molecule, preferably an average of at least one aldehyde group per monosaccharide units. The cross-linking agent, such as a polydialdehyde starch, is used in an amount of about 2.5 to 20% of the theoretical amount required to cross-link all of the available hydroxyl groups of the polyvinyl alcohol polymer. Reaction between the polymer and cross-linking agent is effected in aqueous acidic solution to produce the cross-linked polymer. The polymer product has low electrical resistivity and other properties rendering it suitable for making separators for alkaline batteries. In that event, the mixture of polymer and cross-linking agent is formed into a sheet or film or the like and the film is cut to size and otherwise fabricated into a configuration suitable for a particular end use.

Abstract: There is disclosed an electricity producing cell of the reduction-oxidation (REDOX) type divided into two compartments by a membrane, each compartment containing a solid inert electrode. A ferrous/ferric couple in a chloride solution serves as a cathode fluid which is circulated through one of the compartments to produce a positive electric potential disposed therein. A chromic/chromous couple in a chloride solution serves as an anode fluid which is circulated through the second compartment to produce a negative potential on an electrode disposed therein. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which has been added to the anode fluid.

Abstract: A method is provided for alleviating the stress damage in metallic matrix composites, such as laminated sheet or foil composites, wherein non-intersecting discrete discontinuities are positively introduced into the interface between the layers so as to reduce the thermal stress produced by unequal expansion of the materials making up the composite. The discontinuities are preferably produced by drilling holes in the metallic matrix layer. However, a plurality of discrete elements may be used between the layers to carry out this purpose.

Abstract: A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.