Abstract: A torque motor for a servovalve is provided, the torque motor comprising an armature and a first pole piece. The first pole piece has a first portion and a second portion that is selectively moveable relative to the first portion such that a size of an air gap formed between the second portion and the armature is adjusted in response to the movement of the second portion relative to the first portion.

Abstract: Disclosed is a cooling circuit for cooling a heat load in an aircraft system, having: a compressor; a turbine connected to the compressor by a shaft, the turbine configured to drive the compressor via the shaft when RAM air pressure into a turbine inlet is above a first threshold; and a motor connected to the shaft configured to drive the compressor when RAM air pressure at the turbine inlet is below the first threshold to cause the compressor to draw air into the turbine inlet, through the turbine, a heat exchanger in fluid communication with the heat load, the compressor, and out of a compressor outlet.

Abstract: A generator includes a stator with a stator winding, a rotor with a field winding supported for rotation relative to the stator, and a housing enclosing the stator and the rotor. The housing has an independent system port that is connected to a shared system port by a selector. The selector fluidly couples the stator and one of the independent system port and the shared system port. The selector also fluidly separates the stator from the other of the independent system port and the shared system port. Generator arrangements and methods of making generators are also described.

Abstract: A differential assembly provided with a power distribution unit includes a first housing, an output shaft, a shaft, and a torque limiter. The first housing defines a biasing member bore and a brake bore. The output shaft extends at least partially through the first housing. The shaft is disposed about the output shaft and extends between a first shaft end that is connected to a differential unit and a second shaft end. The torque limiter is disposed within the first housing and is arranged to selectively inhibit rotation of at least one of the output shaft and the shaft.

Abstract: To join two sources in parallel, the second source output is lowered and then raised until two diodes providing an auxiliary path are passing current. This can reduce current spikes. Alternatively, the diodes can reversed, the voltage raised, and the lowered until diose are passing current.

Abstract: A vacuum assembly includes a housing and a movable assembly positioned within the housing. Movement of the movable assembly relative to the housing creates a low pressure area. A fluid flow conduit is in fluid communication with the low pressure area. A leakage valve is disposed within the fluid flow conduit and is movable between a first position and a second position to restrict a flow through the fluid flow conduit upon detection of an undesired fluid within the low pressure area.

Abstract: An apparatus for converting rotational movement into linear movement is disclosed. The apparatus comprises: a screw member having a threaded external surface and a sleeve member having a threaded interior surface for receiving the threaded external surface of the screw member, wherein the threaded surfaces are configured so that rotation of the screw member relative to the sleeve member, in use, causes the screw member to move axially relative to the sleeve member. The apparatus may also comprise a force applicator for applying pressure to the region between the screw member and sleeve member so as to urge the external surface of the screw member and the opposing interior surface of the sleeve member apart from each other.

Abstract: Provided are embodiments for a system including a zero-cross circuit. The system includes a first channel and a second channel Each channel includes a generator, a generator relay, and a bus tie relay. In addition, the system includes a zero-cross circuit, wherein the zero-cross circuit synchronizes the operation of the first and second channel, and at least one controller configured to control the operation of the first channel and the second channel based on an input from the zero-cross circuit. Also provided is a method for operating the zero-cross circuit with low phase delay. The method includes receiving an inverting input, receiving a non-inverting input, and comparing the inverting input and the non-inverting input. The method also includes receiving feedback from an output of the comparator; and outputting a waveform based on the comparison of the inverting input and the non-inverting input and the feedback.

Abstract: An electric generator including: a main generator, including a rotating portion having main field windings; a stationary portion having generator armature windings; and a woven insulator at least partially enclosing the main field windings of the rotating portion, the woven insulator being included of strips or fibers of a material woven together, wherein the woven insulator is permeable to a coolant in a liquid form.

Abstract: An environmental control system of an aircraft includes a compressing device having a compressor configured to receive a first flow of a medium and a turbine configured to receive the first flow of the medium and a distinct second flow of the medium. A dehumidification system is arranged in fluid communication with the turbine. A valve is configured to divert the second flow around the turbine and an inlet port is arranged in fluid communication with the compressor, the turbine, and the dehumidification system.

Abstract: A fuel tank inerting system is disclosed. In addition to a fuel tank, the system includes a catalytic reactor with an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from the fuel tank and air from an air source, and to react the fuel and air along the reactive flow path to generate an inert gas. The system also includes an inert gas flow path from the catalytic reactor to the fuel tank. The system also includes a non-uniform catalyst composition along the reactive flow path.

Abstract: An outlet header of a heat exchanger is provided. The outlet header defines a flow-tap-off duct and includes an L-tube. The L-tube defines first and second legs. The first leg is fasteningly installed in the flow-tap-off duct such that the second leg is directed toward a cold-cold corner of the heat exchanger. The second leg is configured to capture cool air from the cold-cold corner for providing the cool air to and through the flow-tap-off duct and exterior the heat exchanger.

Abstract: A counterflow heat exchanger configured to exchange thermal energy between a first fluid flow at a first pressure and a second fluid flow at a second pressure less than the first pressure includes a first fluid inlet, a first fluid outlet fluidly coupled to the first fluid inlet via a core section, a second fluid inlet, and a second fluid outlet fluidly coupled to the second fluid inlet via the core section. A heating arrangement is configured to heat the second fluid inlet to prevent ice ingestion via the second fluid inlet.

Abstract: Provided are techniques that include operating a spiral contactor. The techniques include receiving, by a spiral contactor, a first fluid, and receiving a second fluid, wherein the first fluid is different than the second fluid. The techniques also include exchanging the first fluid and the second fluid using the spiral contactor, and outputting a deoxygenated fluid from the spiral contactor, wherein the deoxygenated fluid has a lower oxygen concentration than the first fluid.

Abstract: A valve is provided and includes a valve body defining a pathway, a diaphragm and a wire. The diaphragm is configured to assume first or second conditions in which the diaphragm blocks or permits fluid flow through the pathway, respectively. The diaphragm is biased toward assumption of the first condition. The wire is coupled to the diaphragm. The wire has an uncontracted length in an unheated state whereby the wire permits assumption of the first condition by the diaphragm due to the bias and a contracted length in a heated state whereby the wire pulls the diaphragm toward assumption of the second condition in opposition to the bias.

Abstract: A plug for retaining a filter screen in a fluid port of a servovalve, comprises an annular body, the annular body comprising: opposed first and second axial end surfaces, a radially inner surface extending between the first and second axial end surfaces, a radially outer surface extending between the first and second axial end surfaces and at least one recess formed in the radially inner surface for receiving a tool for removing the plug from the port. A tool for removing the plug comprises a pair of handles pivotally mounted to one another about a pivot, each handle having a plug gripping portion extending therefrom beyond the pivot, each plug gripping portion comprising an outwardly projecting tooth for engaging in the recess of the plug when the plug gripping portions are moved apart by operation of the handles.

Abstract: A system is provided. The system includes a semi-conductor device and a gate drive board. The gate drive board provides a voltage to the semi-conductor device. The system also includes a controller and a monitoring circuit. The controller drives the voltage provided by the gate drive board. The monitoring circuit is coupled to the gate drive board to monitor operations of the controller and the semi-conductor device.

Abstract: A method of preserving power quality on a power grid is provided. The method is implemented by a voltage overflow device that is electrically coupled to the power grid through electrical contacts. A voltage monitoring circuit of the voltage overflow device monitors a voltage via the electrical contacts on the power grid with respect to a predetermined voltage. The voltage monitoring circuit determines whether the voltage exceeds the predetermined voltage. A switch of the voltage overflow device shunt an excess voltage over the predetermined voltage to a resistive load when the voltage exceeds the predetermined voltage to preserve the power quality on the power grid.

Abstract: A fuel metering unit includes a metering valve and a sensor. The metering valve includes a valve body movably disposed within a valve housing. The valve body defines a first bore that extends from a first valve body end towards a second valve body end along a first axis and a first window that extends through the valve body along a second axis. The sensor extends at least partially through the valve housing and faces towards the first window. The sensor being arranged to provide a signal indicative of a position of the first window relative to the sensor.

Abstract: A pin fin heat sink includes a plurality of pin fins extending from a base plate, at least one of the plurality of pin fins defining a hollow portion therein. The pin fin heat sink also includes an annular ring of metal foam material disposed within the hollow portion, the annular ring of metal foam material having a radially outer surface in direct contact with an inner diameter of the pin fin, the annular ring of metal foam material defining a central cavity. The pin fin heat sink further includes a phase change material disposed within the central cavity.