Abstract: A battery pack comprises a stack of battery-board assemblies. Each battery-board assembly includes a circuit board, an electrical connector mounted on the circuit board, and a battery cell secured to a side of the circuit board. The battery cells are sandwiched between the circuit boards and the connectors are interconnected. The circuit boards and the connectors electrically connect the battery cells together.

Abstract: A system includes analysis circuitry. The analysis circuitry is configured to determine a first electrical resistance between a first terminal of a potentiometer and a second terminal of the potentiometer. The analysis circuitry is additionally configured to determine a second electrical resistance between the first terminal and a wiper terminal of the potentiometer. The analysis circuitry is additionally configured to determine a third electrical resistance between the second terminal and the wiper terminal. The analysis circuitry is additionally configured to determine a wiper resistance of the potentiometer based on the first electrical resistance, the second electrical resistance, and the third electrical resistance. The system additionally includes an output interface coupled to the analysis circuitry and configured to generate an output indicative of the wiper resistance.

Abstract: A quad-T transformer in some embodiments includes a first split winding, a second split winding, and two orthogonal closed-loop windings coupled between the first split winding and the second split winding. Wires can be wound around magnetic cores. A first of the two orthogonal closed-loop windings is coupled to a first portion of each of the first split winding and the second split winding. A second of the two orthogonal closed-loop windings is coupled to a second portion of each of the first split winding and the second split winding. A bi-directional single-phase/three-phase converter includes the quad-T transformer and a Scott-T transformer with an output connected to a three-phase connection. The Scott-T transformer also has a 90-degree input connected to the quad-T transformer and a zero-degree input connected to a single-phase connection.

Abstract: A method and apparatus for controlling commutation of a motor. A voltage is measured at each of a plurality of windings of a motor using an electric circuit. A controller computes an overall back electromotive force for the motor using the voltage measured at each winding in the plurality of windings. The controller generates a result having either a first value or a second value based on the overall back electromotive force. The controller adjusts the commutation phase and the commutation period of the motor using the result.

Abstract: A system includes analysis circuitry. The analysis circuitry is configured to determine a first electrical resistance between a first terminal of a potentiometer and a second terminal of the potentiometer. The analysis circuitry is additionally configured to determine a second electrical resistance between the first terminal and a wiper terminal of the potentiometer. The analysis circuitry is additionally configured to determine a third electrical resistance between the second terminal and the wiper terminal. The analysis circuitry is additionally configured to determine a wiper resistance of the potentiometer based on the first electrical resistance, the second electrical resistance, and the third electrical resistance. The system additionally includes an output interface coupled to the analysis circuitry and configured to generate an output indicative of the wiper resistance.

Abstract: Systems and methods are provided for a dual function inrush limiting circuit (ILC). The systems and methods may include a level shift circuit (LSC). The LSC may include a Zener diode, a block diode and a capacitor. The Zener diode being in anti-series with respect to the block diode. The ILC may further include a switch electrically coupled to the LSC, an input terminal and an output terminal. The LSC may be configured to activate the switch such to electrically couple the input terminal to the output terminal. The ILC may include a direct current (DC)-DC converter electrically coupled to the output terminal. The DC-DC converter being electrically coupled to the input terminal when the switch is activated.

Abstract: Systems and methods are provided for a dual function inrush limiting circuit (ILC). The systems and methods may include a level shift circuit (LSC). The LSC may include a Zener diode, a block diode and a capacitor. The Zener diode being in anti-series with respect to the block diode. The ILC may further include a switch electrically coupled to the LSC, an input terminal and an output terminal. The LSC may be configured to activate the switch such to electrically couple the input terminal to the output terminal. The ILC may include a direct current (DC)-DC converter electrically coupled to the output terminal. The DC-DC converter being electrically coupled to the input terminal when the switch is activated.

Abstract: In accordance with one or more aspects of the disclosed embodiments, a drive circuit having a source of modulation for producing a modulated signal, a level shifter configured to receive the modulated signal and produce a level-shifted driver signal, an inverter circuit configured to receive the level-shifted driver signal and produce a MOSFET control signal, and at least one p-channel metal oxide semiconductor field effect transistor (MOSFET) configured to receive the MOSFET control signal and modulate an application of high current to a load, where the MOSFET control signal is supplied directly to the p-channel MOSFET through the inverter circuit.

Abstract: A method and apparatus for controlling commutation of a motor. A voltage is measured at each of a plurality of windings of a motor using an electric circuit. A controller computes an overall back electromotive force for the motor using the voltage measured at each winding in the plurality of windings. The controller generates a result having either a first value or a second value based on the overall back electromotive force. The controller adjusts the commutation phase and the commutation period of the motor using the result.

Abstract: A quad-T transformer in some embodiments includes a first split winding, a second split winding, and two orthogonal closed-loop windings coupled between the first split winding and the second split winding. Wires can be wound around magnetic cores. A first of the two orthogonal closed-loop windings is coupled to a first portion of each of the first split winding and the second split winding. A second of the two orthogonal closed-loop windings is coupled to a second portion of each of the first split winding and the second split winding. A bi-directional single-phase/three-phase converter includes the quad-T transformer and a Scott-T transformer with an output connected to a three-phase connection. The Scott-T transformer also has a 90-degree input connected to the quad-T transformer and a zero-degree input connected to a single-phase connection.

Abstract: Systems and methods for powering an airborne transport vehicle from a ground power supply are provided. One system is a hovercraft power system having a ground power supply coupled with at least one on-board DC-DC power converter, wherein the on-board DC-DC power converter is positioned on-board a hovercraft. The hovercraft power system further includes a power cord tethered to the hovercraft, wherein the power cord is capable of delivering at least 100 kilowatts (kW) of power from the ground power supply to the hovercraft. The hovercraft power system also includes a tether dispenser configured to dispense or retract the power cord tethered to the hovercraft.

Abstract: Embodiments described herein provide for detecting an angle of a cable attached to a rotorcraft for transporting a hanging payload using a pair of linear displacement sensors that are coupled to both the rotorcraft and the cable. One embodiment is a cable angle detector mounted to an underside of a rotorcraft. A cable has one end coupled to the rotorcraft and another end coupled to a payload. A pair of linear displacement sensors has one end coupled to the underside of the rotorcraft and another end coupled to the cable. The detector measures the displacement of the sensors and calculates an angle of the cable relative to the rotorcraft based on the measurements.

Abstract: In accordance with one or more aspects of the disclosed embodiments, a drive circuit having a source of modulation for producing a modulated signal, a level shifter configured to receive the modulated signal and produce a level-shifted driver signal, an inverter circuit configured to receive the level-shifted driver signal and produce a MOSFET control signal, and at least one p-channel metal oxide semiconductor field effect transistor (MOSFET) configured to receive the MOSFET control signal and modulate an application of high current to a load, where the MOSFET control signal is supplied directly to the p-channel MOSFET through the inverter circuit.

Abstract: A battery pack comprises a stack of battery-board assemblies. Each battery-board assembly includes a circuit board, an electrical connector mounted on the circuit board, and a battery cell secured to a side of the circuit board. The battery cells are sandwiched between the circuit boards and the connectors are interconnected. The circuit boards and the connectors electrically connect the battery cells together.

Abstract: Embodiments described herein provide for detecting an angle of a cable attached to a rotorcraft for transporting a hanging payload using a pair of linear displacement sensors that are coupled to both the rotorcraft and the cable. One embodiment is a cable angle detector mounted to an underside of a rotorcraft. A cable has one end coupled to the rotorcraft and another end coupled to a payload. A pair of linear displacement sensors has one end coupled to the underside of the rotorcraft and another end coupled to the cable. The detector measures the displacement of the sensors and calculates an angle of the cable relative to the rotorcraft based on the measurements.