Abstract: A system may include a first controller and a second controller communicatively coupled to the first controller via a bidirectional communication channel and configured to drive a load in accordance with a target current signal, sample a load voltage of the load at a sample rate substantially slower than a time duration of electrical transients of the load, calculate a resistance of the load based on a current signal and the load voltage and communicate information indicative of the resistance to the first controller at a time interval substantially slower than the time duration of electrical transients of the load, detect when one or more accuracy-reducing events associated with the system occur, wherein an accuracy-reducing event is one which negatively affects accuracy of calculation of the resistance, and modify the information provided to the first controller when one or more accuracy-reducing events occur.

Abstract: A downhole intelligent Circulating Sub controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent actuation of the Circulating Sub at inappropriate times. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to a Circulating Sub and/or other types of downhole tools.

Abstract: An electronic motor control system provides selectable linear and pulse-width modulated (PWM) operation without generating cross-over distortion. The system includes an output stage that has a pair of push-pull drivers each coupled to a terminal of the motor. The electronic motor control system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to an input of the output stage when the pulse-width modulated mode is selected and a linear amplifier stage that provides a linear analog signal to the input of the output stage in linear mode, so that both drivers are operated to supply the current to the motor. In pulse-width modulated mode, a driver is selected for PWM operation, while the other driver is operated to supply a fixed voltage. A feedback control loop senses motor current and provides outputs to the pulse-width modulator and the linear amplifier stage.

Abstract: Embodiments are directed to systems and methods for two or more cured composite assemblies that are bonded together to form a tubular composite structure, wherein each of the cured composite assemblies do not have a tubular shape. The tubular composite structure may form a spar for an aerodynamic component, for example. The two or more cured composite assemblies may comprise carbon or fiberglass composite materials or a combination of materials. Each of the cured composite assemblies may further comprise axial edges that are configured to be bonded to another of the cured composite assemblies, wherein the axial edges have a sloped shape. An adhesive agent may be applied on the axial edges for bonding two cured composite assemblies. Alternatively, or additionally, one or more fasteners may be used to attach the axial edges of at least two cured composite assemblies.

Abstract: Embodiments are directed to systems and methods for two or more cured composite assemblies that are bonded together to form a tubular composite structure, wherein each of the cured composite assemblies do not have a tubular shape. The tubular composite structure may form a spar for an aerodynamic component, for example. The two or more cured composite assemblies may comprise carbon or fiberglass composite materials or a combination of materials. Each of the cured composite assemblies may further comprise axial edges that are configured to be bonded to another of the cured composite assemblies, wherein the axial edges have a sloped shape. An adhesive agent may be applied on the axial edges for bonding two cured composite assemblies. Alternatively, or additionally, one or more fasteners may be used to attach the axial edges of at least two cured composite assemblies.

Abstract: A single-inductor multiple output (SIMO) switched-power DC-DC converter for a class-D amplifier provides outputs that are symmetric about a common-mode input voltage of the amplifier, while remaining asymmetric about a return terminal of the amplifier and switching converter. The DC-DC converter includes an inductive element, a switching circuit that energizes the inductive element from an input source, and a control circuit that controls the switching circuit. The control circuit may have multiple switching modes, and in one of the multiple switching modes, the switching circuit may couple the inductive element between outputs of the converter so that stored energy produces a differential change between the voltages of the outputs. The control circuit may implement a first control loop that maintains a common mode voltage of the pair of outputs at a predetermined voltage independent of the individual voltages of the pair of outputs.

Abstract: A downhole intelligent Circulating Sub controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent actuation of the Circulating Sub at inappropriate times. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to a Circulating Sub and/or other types of downhole tools.

Abstract: An electronic motor control system provides selectable linear and pulse-width modulated (PWM) operation without generating cross-over distortion. The system includes an output stage that has a pair of push-pull drivers each coupled to a terminal of the motor. The electronic motor control system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to an input of the output stage when the pulse-width modulated mode is selected and a linear amplifier stage that provides a linear analog signal to the input of the output stage in linear mode, so that both drivers are operated to supply the current to the motor. In pulse-width modulated mode, a driver is selected for PWM operation, while the other driver is operated to supply a fixed voltage. A feedback control loop motor current and provides outputs to the pulse-width modulator the linear amplifier stage.

Abstract: A single-inductor multiple output (SIMO) switched-power DC-DC converter for a class-D amplifier provides outputs that are symmetric about a common-mode input voltage of the amplifier, while remaining asymmetric about a return terminal of the amplifier and switching converter. The DC-DC converter includes an inductive element, a switching circuit that energizes the inductive element from an input source, and a control circuit that controls the switching circuit. The control circuit may have multiple switching modes, and in one of the multiple switching modes, the switching circuit may couple the inductive element between outputs of the converter so that stored energy produces a differential change between the voltages of the outputs. The control circuit may implement a first control loop that maintains a common mode voltage of the pair of outputs at a predetermined voltage independent of the individual voltages of the pair of outputs.

Abstract: Embodiments are directed to systems and methods for creating a tubular composite structure. In one embodiment, a device comprises multiple layers of cured composite fabric bonded together to form a tubular composite structure, wherein alternating groups of the multiple layers comprise on-axis fabric and off-axis fabric. The tubular composite structure may form a spar for an aerodynamic component. The composite fabric may comprise one or more of carbon, fiberglass, or other composite materials, or a combination of materials. One or more stacks of the fabric wrap completely around the tubular composite structure, and other stacks of fabric may not wrap completely around the tubular composite structure.

Abstract: A downhole intelligent reamer controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent deployment of reamer members at inappropriate times such as when drilling out cement, testing, and running in and out of the wellbore. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to an expandable reamer and/or other types of downhole tools.

Abstract: A system may include an output stage for driving a load at an output of the output stage, a pulse-width modulation mode path configured to pre-drive the output stage in a first mode of operation, a linear mode path configured to pre-drive the output stage in a second mode of operation and a loop filter coupled at its input to the output of the output stage and coupled at its output to both of the pulse-width modulation mode path and the linear mode path. The pulse-width modulation mode path and the linear mode path may be configured such that a first transfer function between the output of the loop filter and the output of the output stage is substantially equivalent to a second transfer function between the output of the loop filter and the output of the output stage.

Abstract: Embodiments are directed to systems and methods for manufacturing composite assemblies comprising laying up composite plies on molds for two or more uncured components, joining the molds for the two or more uncured components to form a tubular body, and curing the joined components simultaneously to create a single composite assembly. The single composite assembly may form a spar for an aerodynamic component. The method may further comprise forming at least one axial edge having a sloped shape on the uncured components and mating the sloped axial edges together when joining the uncured components. The molds for the two or more uncured components may comprise female tools or both female tools and male tools. The two or more cured composite assemblies may comprise one or more of carbon and fiberglass composite materials.

Abstract: A downhole intelligent reamer controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent deployment of reamer members at inappropriate times such as when drilling out cement, testing, and running in and out of the wellbore. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to an expandable reamer and/or other types of downhole tools.

Abstract: A system may include a first capacitor, a first switched-mode power supply configured to deliver energy from a power source to the first capacitor at an output load of the first switched-mode power supply, a second capacitor having a capacitance larger than the first capacitor, a second switched-mode power supply configured to deliver energy from the power source or a second power source to the second capacitor and one or more switching elements coupled between the first capacitor and the second capacitor. The system may operate in a plurality of modes, including a first mode in which the first switched-mode power supply transfers energy to the first capacitor and the second capacitor, a second mode in which the second capacitor transfers energy to the first capacitor, and a third mode in which first switched-mode power supply transfers energy to the first capacitor and the second capacitor and the second switched-mode power supply transfers energy to the first capacitor and the second capacitor.

Abstract: A downhole intelligent reamer controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent deployment of reamer members at inappropriate times such as when drilling out cement, testing, and running in and out of the wellbore. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to an expandable reamer and/or other types of downhole tools.

Abstract: Embodiments are directed to systems and methods for creating a tubular composite structure. In one embodiment, a device comprises multiple layers of cured composite fabric bonded together to form a tubular composite structure, wherein alternating groups of the multiple layers comprise on-axis fabric and off-axis fabric. The tubular composite structure may form a spar for an aerodynamic component. The composite fabric may comprise one or more of carbon, fiberglass, or other composite materials, or a combination of materials. One or more stacks of the fabric wrap completely around the tubular composite structure, and other stacks of fabric may not wrap completely around the tubular composite structure.

Abstract: Embodiments are directed to systems and methods for two or more cured composite assemblies that are bonded together to form a tubular composite structure, wherein each of the cured composite assemblies do not have a tubular shape. The tubular composite structure may form a spar for an aerodynamic component, for example. The two or more cured composite assemblies may comprise carbon or fiberglass composite materials or a combination of materials. Each of the cured composite assemblies may further comprise axial edges that are configured to be bonded to another of the cured composite assemblies, wherein the axial edges have a sloped shape. An adhesive agent may be applied on the axial edges for bonding two cured composite assemblies. Alternatively, or additionally, one or more fasteners may be used to attach the axial edges of at least two cured composite assemblies.

Abstract: A system may include an output stage for driving a load at an output of the output stage, a pulse-width modulation mode path configured to pre-drive the output stage in a first mode of operation, a linear mode path configured to pre-drive the output stage in a second mode of operation and a loop filter coupled at its input to the output of the output stage and coupled at its output to both of the pulse-width modulation mode path and the linear mode path.

Abstract: A system may include a first capacitor, a first switched-mode power supply configured to deliver energy from a power source to the first capacitor at an output load of the first switched-mode power supply, a second capacitor having a capacitance larger than the first capacitor, a second switched-mode power supply configured to deliver energy from the power source or a second power source to the second capacitor and one or more switching elements coupled between the first capacitor and the second capacitor. The system may operate in a plurality of modes, including a first mode in which the first switched-mode power supply transfers energy to the first capacitor and the second capacitor, a second mode in which the second capacitor transfers energy to the first capacitor, and a third mode in which first switched-mode power supply transfers energy to the first capacitor and the second capacitor and the second switched-mode power supply transfers energy to the first capacitor and the second capacitor.