Abstract: A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from the engine to the alternator. Vinternal is the sum of the voltage induced on the alternator winding and the voltage across the equivalent circuit lumped resistance of the alternator winding and a switching mode rectifier connects the alternator winding to an energy storage capacitor or battery.

Abstract: An electro-optic modulator modulates light in response to a life-form bio-potential to provide a bio-potential modulated light output. Modulation can be carried out as a result of capacitive coupling with the bio-potential. Phase, polarization, and intensity light modulation can be used. The light output can then be converted to electronic form for further processing. An optical power splitter is used to split light into multiple portions that are converted to electrical form. A pilot tone is used to achieve high sensitivity and synchronize multiple electro-optic modulators while phase modulation can be used to reduce noise in the bio-potential signal. Low-coherent light may be used as the light source. A housing is provided that can be hermetically-sealed and provided with electro-magnetic shielding.

Abstract: A waste heat source (100) is used to heat a high temperature heat transfer fluid which is used to heat an absorption heat transfer machine (10) having a generator (20), an absorber (30), a condenser (40), and an evaporator (50) operatively connected together. The high temperature heat transfer fluid can also be used to heat a load (190) such as a room space or a process. The waste heat source (100) can also be used to heat an intermediate heat transfer fluid, which can be used to heat a second load (175) such as a space, a process, or an absorption heat transfer machine. Novel flow control devices (70, 60) for controlling the flow of weak solution from generator (20) to absorber (30) or of refrigerant from condenser (40) to evaporator (50), respectively, are also described.

Abstract: The cool down time for a multi-stage, pulse tube cryocooler is reduced by configuring at least a portion of the acoustic impedance of a selected stage, higher than the first stage, so that it surrounds the cold head of the selected stage. The surrounding acoustic impedance of the selected stage is mounted in thermally conductive connection to the warm region of the selected stage for cooling the acoustic impedance and is fabricated of a high thermal diffusivity, low thermal radiation emissivity material, preferably aluminum.

Abstract: An improved pulse tube cooler having a resonator tube connected in place of a compliance volume or reservoir. The resonator tube has a length substantially equal to an integer multiple of ¼ wavelength of an acoustic wave in the working gas within the resonator tube at its operating frequency, temperature and pressure. Preferably, the resonator tube is formed integrally with the inertance tube as a single, integral tube with a length approximately ½ of that wavelength. Also preferably, the integral tube is spaced outwardly from and coiled around the connection of the regenerator to the pulse tube at a cold region of the cooler and the turns of the coil are thermally bonded together to improve heat conduction through the coil.

Abstract: A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. At least one type of fibers includes an extractable agent on the outer surfaces thereof. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.

Abstract: A pipe coupling for joining two electrolyte-conveying pipes of electrochemically dissimilar metals and inhibiting galvanic corrosion resulting from the dissimilarity. A tubular pipe coupling has a pair of axially spaced protection electrodes mounted to its interior wall in electrical contact with the electrolyte. A control electrode is also mounted to the interior wall of the tubular pipe coupling between one of the pipes and the pair of protection electrodes. A current sensing circuit is connected to sense the galvanic current through the control electrode. A controllably variable source of electrical current is connected to vary the current through the protection electrodes. A negative feedback control circuit receives the sensed current as a feedback signal and controls the variable source to increase the electrical current through the protection electrodes and the electrolyte so that the sensed current is reduced thereby reducing the galvanic current in the electrolyte between the pipes.

Abstract: A dock light for mounting in a void in the side of a floating dock. The light has a housing with a floor, sidewalls, lens and lid defining a chamber. The chamber houses a power source, such as a battery and photovoltaic cell, and a light source, such as a light emitting diode (LED). The lid is removably mounted to the sidewalls, and is flush with, or set beneath, the top surface of the dock when in an operable position. The lens extends from the void at a side opening when the dock light is in an operable position, and is flush with, or set beneath, the side surface of the dock. The light shines from the side of the dock, and is powered by collecting energy from the sun, thereby requiring little to no maintenance. The dock light is protected by the surrounding surfaces of the dock.

Abstract: A non-contact device for measuring current in a conductor. The device includes an interferometer with an optical fiber that extends around the conductor and through which light beams pass. The magnetic field around the conductor, caused by the current conducted through the conductor, causes a phase shift in the light beams, which is measured. The measured current is corrected as a function of the temperature of at least the fiber, and possibly also the temperature of the quarter wave plate and/or the compensation coil in the interferometer. Multiple sensors are evenly spaced and mounted to the fiber in the preferred embodiment, and the signals from the sensors are averaged. The average signal is used to correct the measured current.

Abstract: An apparatus and method for compressing gas refrigerant using two different compressors operated alternatively in a series or parallel mode for obtaining two different compression ratios and thereby provide efficient operation for both a relatively lower suction pressure and a relatively higher suction pressure. This system avoids an unbalanced mass flow rate when the compressors are operated in series by unloading a downstream one of the compressors. When operated in the series mode, refrigerant is bypassed back to a suction inlet of the downstream compressor during a portion of a compression stroke of the downstream compressor for equalizing the mass flow rate through the two compressors.

Abstract: A circuit for controlling at least two power switches that are series connected between a source of electrical power and an electrical load, for energizing the load in response to a signal at a control input. The circuit includes a programmed controller having an input as the control input and a voltage sensor circuit connected to sense the voltage between the power switches and apply a voltage signal to a controller input. It may also have a sensor for sensing the current through the switches and applying a current signal to the controller. The controller inputs the voltage between the switches or the current through the switches to provide a sensed first value. It compares the sensed first value to an expected first value that exists if both switches are turned off. One of the two switches is turned on if the sensed first value is equal to the expected first value.

Abstract: An overload protection device (1) with a primary section (4) for the coupling of the overload protection device (1) with a drive device (2) and with a secondary section (6) for coupling of the overload protection device (1) with an operating section (7). The primary section (4) and the secondary section (6) can be turned around a rotation axis (8), with respect to one another, around a rotation angle phi. A spring element (5), which is interposed between the primary section (4) and the secondary section (6) is formed in such a way that the spring element (5) counteracts a rotation of the primary and secondary sections (4, 6). The invention is characterized by a spring element (5) that extends concentrically around the rotation axis (8) in an angular range of at least 180°.

Abstract: The invention relates to the determination of the gas pressure in an evacuated thermal insulating board (9) having an insulating core (1) covered by a film (2). The inventive device comprises an assembly, which is integrated between the insulating core and the covering film of the thermal insulating board and which has a body that acts as a heat sink (3) (Al, Co, Fe, ceramic), and the body's thermal conductivity and thermal capacity relative to volume are greater than those of the insulating core. Said assembly also comprises a test layer (4) (0.3 mm nonwoven fabric made of plastic and glass fibers), which is arranged between the heat sink and the covering film and has a defined thermal conductivity that changes according to the gas pressure inside the evacuated thermal insulating board. From the exterior, a sensor device is applied to or pressed against the test device, which is placed inside the evacuated thermal insulating board and which is covered by the covering film.

Abstract: A compression molding apparatus and method for the manufacture of abrasive layers for abrasive tooling which provides a compression mold space defined between an inflexible wall surface and a flexible wall surface. The apparatus and method of the present invention is particularly well suited to making annular or hollow cylindrical shaped abrasive layers of novel configurations during a single mold cycle useful for grinding wheel and the like, as well as other shapes such as laps, wherein the flexible wall expanded with fluid pressure provides a highly uniform distribution of pressure against the surface of the mold composition being formed. In an annular configuration, the flexible wall is used to radially direct pressure against a molding composition disposed in an annular configuration wherein the axial length of the annular mold shape formed may be many times greater than priorly obtained by the prior art means.

Abstract: An apparatus for producing portions severed from a poultry breast of controlled size and weight having a rotary mounted product holder including a generally cylindrical outer surface provided with at least one product cavity for receiving a first portion of a poultry breast for travel along an arcuate path defined by the outer surface of the product holder. A pressing means including an arcuate surface selected to generally mate with a portion of the arcuate path of travel of said cavity is mounted a selected distance from the path of travel of said cavity for engaging the portion of poultry breast to urge and hold the first portion into the cavity. A cutting member is disposed generally tangentially relative to the path of travel of the cavity between the surface of the pressing means and the outer surface of the product holder to engage the poultry breast and separate the first portion of said poultry breast contained in the cavity from the remaining portion thereof.

Abstract: A piston position sensing circuit for sensing the instantaneous position of a piston of a free piston Stirling machine or a compressor mechanically connected to a reciprocating member of a linear electric motor or alternator. A source of a high frequency, alternating, electrical signal applies a high frequency signal to the winding circuit of the linear alternator or motor. A filter circuit is connected to the winding circuit and passes electrical signals at the frequency of the high frequency source and blocks signals at the operating frequency of reciprocation. A peak detector circuit is connected to the filter circuit and detects the peak of the filter circuit output signal to provide an instantaneous peak magnitude that is proportional to the instantaneous piston position.

Abstract: An apparatus for producing multiple portions of meat. A plurality of product mandrels having an open-top recess are mounted on a conveyor for travel along a selected path. The mandrels are selectively rotatable about a vertical axis. Two sets of parallel slots are provided in the mandrel and extend to a depth at least equal to the depth of the recess. Each set of parallel slots is disposed to intersect the other at a selected angle. Each product mandrel is moved through a pair of cutting stations which carry laterally spaced knives extending downwardly. The product mandrel is rotated through an angle which aligns one set of intersecting slots parallel to the knife blades in a cutting station after passing through the other cuffing station. A plurality of laterally spaced cuts are made through the larger piece of meat to produce smaller portions.

Abstract: An alkali metal thermoelectric conversion device formed from a porous tube or plate coated with a thin film of beta-alumina, the porous tube or plate is sintered metal or metal alloy having a coefficient of thermal expansion which approaches that of the beta-alumina to form a mechanically stable device with high electrical output.