Abstract: A system for transmitting an alternating current in an aircraft. The system includes a source of electricity in the aircraft having a source connector housing, an electric load in the aircraft having a load connector housing, a cable electrically coupling the source of electricity to the electric load, a shield surrounding the cable and having a first end electrically connected to the source connector housing, and a capacitor disposed inside the load connector housing and electrically coupling a second end of the shield to the load connector housing.

Abstract: A method of operation is provided during which a pre-charge switch is closed to electrically couple a power supply to a motor controller through a pre-charge supply circuit, where a main switch is open. An electrical parameter of electricity directed through the pre-charge supply circuit is measured when the pre-charge switch is closed and the main switch is open. The main switch is closed to electrically couple the power supply to the motor controller through the main supply circuit when the electrical parameter is equal to or passes a threshold.

Abstract: An assembly for an aircraft propulsion system includes a propulsor, an electric motor, and an electrical distribution system. The electric motor is operably connected to the propulsor and operable to drive rotation of the propulsor. The electrical distribution system includes an electrical power source, an electrical cable, and a temperature protection assembly. The electrical cable electrically connects the electrical power source and the electric motor. The electrical cable extends through at least one thermal zone between the electrical power source and the electric motor. The temperature protection assembly includes a temperature sensor operable to sense a temperature in each thermal zone of the at least one thermal zone. The temperature protection assembly further includes a controller. The controller is configured to determine a zone temperature in the at least one thermal zone.

Abstract: An arc detection assembly is provided and includes a first conductor comprising a first terminal end, a second conductor comprising a second terminal end, an enclosure to partially enclose a space in which the first and second terminal ends are engageable to form an electrical connection and an optical detection system. The optical detection system includes an optical element within the enclosure with a line-of-sight to an engagement of the first and second terminal ends and a sensor. The sensor is displaced from the enclosure and coupled to the optical element. The sensor is configured to determine when the optical element senses an arcing condition between the first and second terminal ends.

Abstract: An electric apparatus is provided that includes a fiber optic system and an electric conductor. The fiber optic system includes an inner cladding, an outer cladding and a fiber optic core between the inner cladding and the outer cladding. The electric conductor extends longitudinally along a centerline within the fiber optic system. The centerline may be a centerline of any one or more or all of the fiber optic system, the inner cladding, the outer cladding, the fiber optic core and/or the electric conductor.

Abstract: Systems and methods for measuring an axial position of a phonic wheel or other rotating component are provided. The system includes a phonic wheel rotatable about a rotation axis and translatable along the rotation axis, a first sensor, a second sensor and a computer. The phonic wheel includes an inclined tooth having an axially non-uniform radial height and a reference tooth having an axially uniform radial height. The first sensor generates a positioning signal indicative of a gap between the inclined tooth and the first sensor. The second sensor generates a reference signal indicative of a gap between the reference tooth and the reference sensor. The first and second sensors have different orientations. The computer generates an output indicative of the axial position of the phonic wheel based on the positioning signal and the reference signal.

Abstract: An arc detection assembly is provided and includes first and second conductors including first and second terminal ends, respectively, which are engageable to form an electrical connection and an arc detection system. The arc detection system includes a fusible link disposed proximate to one of the first and second terminal ends and configured to break in response to an arcing condition between the first and second terminal ends and a monitoring circuit coupled to the fusible link and configured to determine when breakage of the fusible link occurs and to thereby determine that the arcing condition has occurred.

Abstract: An assembly for an aircraft includes an aircraft electrical distribution bus, a battery, and a battery monitoring system. The battery includes a plurality of battery strings and a main battery contactor. The plurality of battery strings are electrically connected in parallel. Each battery string includes a string contactor. The string contactor is positionable in a closed string position or an open string position. The main battery contactor is electrically connected in series with the string contactor of each battery string. The main battery contactor is positionable in a closed battery position or an open battery position. The battery monitoring system is configured to control a position of the string contactor of each battery string. Control of a position of the main battery contactor in the closed battery position and the open battery position is independent of the battery monitoring system.

Abstract: An assembly for an aircraft includes an aircraft electrical distribution bus, a battery, and a battery monitoring system. The battery includes a plurality of battery strings. The plurality of battery strings is configured as a main subset and a reserve subset.

Abstract: An assembly for an aircraft includes a battery, a charger, and a battery monitoring system. The battery includes a plurality of battery strings. The charger is configured to charge the plurality of battery strings. The battery monitoring system further includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to determine the battery string voltage for each battery string of the plurality of battery strings, identify a highest-voltage battery string of the plurality of battery strings and a lower-voltage subset of the plurality of battery strings, and sequentially charge each battery string of the lower-voltage subset of the plurality of battery strings with the charger to a first target string voltage.

Abstract: An assembly for an aircraft includes a battery, a charger, and a battery monitoring system. The battery includes a plurality of battery strings. The charger is configured to charge the plurality of battery strings. The battery monitoring system further includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to determine the battery string voltage for each battery string of the plurality of battery strings and identify a battery string voltage hierarchy for the plurality of battery strings, the battery string voltage hierarchy identifying at least a lowest-voltage battery string of the plurality of battery strings, at least one intermediate-voltage battery string of the plurality of battery strings, and a highest-voltage battery string of the plurality of battery strings, and sequentially charge the plurality of battery strings with the charger based on the battery string voltage hierarchy.

Abstract: An assembly for an aircraft includes an aircraft electrical distribution bus, a battery, and a control system. The battery includes a plurality of battery strings. Each battery string includes a string contactor. The control system is in signal communication with the string contactor of each battery string. The control system is configured to control a position of the string contactor of each battery string in a closed string position or an open string position. The control system is configured to: detect a fault in a faulted first battery string of the plurality of battery strings and position the string contactor of the faulted first battery string in the open string position, in response to the detected fault in the faulted first battery string and maintain the string contactor of at least one unfaulted second battery string of the plurality of battery strings in the closed string position.

Abstract: An arc detection assembly is provided and includes first and second conductors including first and second terminal ends, respectively, which are engageable to form an electrical connection and a temperature sensing system. The temperature sensing system includes a temperature sensor disposed in contact with one of the first and second terminal ends and configured to sense a temperature of the one of the first and second terminal ends and a temperature monitoring circuit. The temperature monitoring circuit is coupled to the temperature sensor and configured to determine when the temperature sensor senses an increase in temperature of the one of the first and second terminal ends and to determine whether the increase in temperature is indicative of an arcing condition of the electrical connection.

Abstract: An arc detection assembly is provided and includes first and second conductors including first and second terminal ends, respectively, which are engageable to form an electrical connection and an arc detection system. The arc detection system includes a fusible link disposed proximate to one of the first and second terminal ends and configured to break in response to an arcing condition between the first and second terminal ends and a monitoring circuit coupled to the fusible link and configured to determine when breakage of the fusible link occurs and to thereby determine that the arcing condition has occurred.

Abstract: An arc detection assembly is provided and includes a first conductor comprising a first terminal end, a second conductor comprising a second terminal end, an enclosure to partially enclose a space in which the first and second terminal ends are engageable to form an electrical connection and an optical detection system. The optical detection system includes an optical element within the enclosure with a line-of-sight to an engagement of the first and second terminal ends and a sensor. The sensor is displaced from the enclosure and coupled to the optical element. The sensor is configured to determine when the optical element senses an arcing condition between the first and second terminal ends.

Abstract: A flowmeter for gaseous fluid includes a conduit composed of non-electrically conductive material for passage of an ionized flow of the gaseous fluid therethrough. The flowmeter further includes an electromagnetic sensor arranged to measure a magnetic field generated about the conduit by the passage of the ionized flow and generate a signal proportional to the magnetic field.

Abstract: A method for operating a glow plug includes controlling a temperature of the glow plug by switching between applying a voltage VH and applying a voltage VN<VH to the glow plug. Applying the voltage VH and applying the voltage VN causes a glow plug current to oscillate about a glow plug current threshold. The glow plug current threshold is associated with one of the voltage VH and the voltage VN. The method includes monitoring the glow plug current at the one of the voltage VH and the voltage VN.

Abstract: In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes.

Abstract: In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes.

Abstract: A multi-rotor electric machine having a stator, a first rotor magnetically coupled to the stator and a second rotor magnetically coupled to the stator is disclosed. A method of operating the electric machine comprises driving a gear via a first face of the gear using the first rotor and driving the gear via a second face of the gear using the second rotor.