Abstract: A system, method, and sensor tool for enhancing sensor effectiveness. A wave is received utilizing multiple sensors in a downhole tool. Hodogram analysis of the wave is performed in response to measurements from the multiple sensors. A direction associated with the wave is determined. The multiple sensors are rotated to best sense the wave in response to the direction associated with the wave.

Abstract: A self-damping geophone, in some embodiments, comprises a housing containing a conductive coil and one or more springs; a first magnet suspended within said housing by the one or more springs, said conductive coil located within a magnetic field of the first magnet; and damping magnets disposed outside of said housing, each of the damping magnets oriented to repel a pole of the first magnet closest to that damping magnet.

Abstract: A communication system can include a first subsystem of a well tool that can include a first cylindrically shaped band positioned around the first subsystem. The first cylindrically shaped band can be operable to electromagnetically couple with a second cylindrically shaped band. The communication system can also include a second subsystem of the well tool. The second subsystem can include the second cylindrically shaped band positioned around the second subsystem. The communication system can further include an intermediate subsystem positioned between the first subsystem and the second subsystem. The intermediate subsystem can include an insulator positioned coaxially around the intermediate subsystem.

Abstract: A system includes a downhole tool configured to transmit uplink data. The system also includes a surface controller configured to receive the uplink data and to transmit downlink data to the downhole tool. The system also includes a plurality of acoustic telemetry modules deployed downhole, wherein each of the modules selectively operates in a first communication mode in which its transducers simultaneously convey uplink data and downlink data, and in a second communication mode in which its transducers simultaneously convey only uplink data or only downlink data.

Abstract: Methods and tools for modifying magnetic tilt angle using a magnetically anisotropic material are disclosed. An electromagnetic logging tool includes an antenna coil oriented at a physical tilt angle relative to a longitudinal axis of the tool and a magnetically anisotropic material that modifies a magnetic tilt angle of the coil relative to the physical tilt angle a coil tilted at a physical tilt angle relative to an axis of the tool.

Abstract: A communication system for use with a well tool can include an of outer toroid antenna. The outer toroid antenna can be positionable around an outer housing of the well tool. The communication system can also include an inner toroid antenna positionable within the outer housing of the well tool. The communication system can further include a switch coupled to the outer toroid antenna and the inner toroid antenna. The switch can be operable to enable or disable a wireless communication via the outer toroid antenna or the inner toroid antenna.

Abstract: A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.

Abstract: A synchronous rectifier driver pre-positions a gate of a synchronous rectifier to allow for fast turn-off. The synchronous rectifier driver turns ON the synchronous rectifier by driving the gate at a high level for a period of time that is based on a previous conduction time of the synchronous rectifier. The synchronous rectifier driver thereafter drives the gate at a lower level that is sufficient to keep the synchronous rectifier ON. The synchronous rectifier can be quickly turned OFF by further reducing the level of the drive signal at the gate of the synchronous rectifier.

Abstract: An illustrative geophone with tunable resonance frequency includes a first inductive assembly including an inductive coil having a first magnet arranged therein, wherein the first magnet and the first inductive coil move relative to each other, and a second inductive assembly including a second inductive coil having a second magnet arranged therein, wherein the second magnet and the second inductive coil move relative to each other. A coupling element couples a movable element of the first inductive assembly with a moveable element of the second inductive assembly. The first inductive assembly employs tunable damping to modify a resonant frequency of the second inductive assembly.

Abstract: A start-up circuit to discharge EMI filter is developed for power saving. It includes a detection circuit detecting a power source for generating a sample signal. A sample circuit is coupled to the detection circuit for generating a reset signal in response to the sample signal. The reset signal is utilized for discharging a stored voltage of the EMI filter.

Abstract: In some embodiments, an apparatus, method, and a system may operate to include an AEM sensor configured to generate an electromagnetic wave into a geologic formation. The AEM sensor is further configured to receive a reflected electromagnetic wave from the formation. The reflected electromagnetic wave is representative of a velocity of an acoustic wave traveling through the geologic formation.

Abstract: A dual core geophone includes a dual magnetic core packaged in a housing providing higher sensitivity and a reduction of electric wires in the device. The geophone includes a locking mechanism for the dual magnetic core to protect the device from strong vibrations when the device is not in use. A method for measuring acoustic vibrations in a downhole with a dual core geophone as above includes locking the dual magnetic core when the geophone is not detecting acoustic vibrations.

Abstract: A system, method, and sensor tool for enhancing sensor effectiveness. A wave is received utilizing multiple sensors in a downhole tool. Hodogram analysis of the wave is performed in response to measurements from the multiple sensors. A direction associated with the wave is determined. The multiple sensors are rotated to best sense the wave in response to the direction associated with the wave.

Abstract: A discharge circuit for an electromagnetic interference (EMI) filter is provided. The discharge circuit includes a switch circuit, a control circuit, and a detection circuit. The switch circuit is coupled to an X-capacitor of the EMI filter. The control circuit is coupled to the switch circuit and configured to turn on the switch circuit in a predetermined period to provide a discharge path. The detection circuit is coupled to the discharge path. In the predetermined period, the detection circuit detects whether a cross point occurs between a discharge voltage signal on the discharge path and a reference voltage signal to generate a detection signal which is provided to the control circuit. When the detection circuit detects that the cross point does not occur, the control circuit continuously turns on the switch circuit according to the detection signal after the predetermined period has elapsed.

Abstract: A control circuit with deep burst mode for power converter according to the present invention comprises a load detection circuit and a PWM circuit. The load detection circuit generates a switching control signal in response to a feedback signal. The feedback signal is correlated to a load condition of the power converter. The PWM circuit generates a switching signal to regulate an output of the power converter in response to the switching control signal and the feedback signal. The control circuit performs a deep burst mode to switch the switching signal only one time during each deep burst period when the load condition of the power converter is a very light-load. Therefore, switching loss is reduced so that the power consumption of the power converter is also reduced.

Abstract: An illustrative geophone with tunable resonance frequency includes a first inductive assembly including an inductive coil having a first magnet arranged therein, wherein the first magnet and the first inductive coil move relative to each other, and a second inductive assembly including a second inductive coil having a second magnet arranged therein, wherein the second magnet and the second inductive coil move relative to each other. A coupling element couples a movable element of the first inductive assembly with a moveable element of the second inductive assembly. The first inductive assembly employs tunable damping to modify a resonant frequency of the second inductive assembly.

Abstract: A controller with power saving for a power converter includes a delay circuit, a detection circuit, an output circuit, a counter circuit, a wake-up circuit and a PWM circuit. The delay circuit determines a delay time. The detection circuit activates the delay circuit whenever an output load of the power converter is lower than a light-load threshold. The output circuit generates a power-saving signal to cease a regulation of the power converter after the delay time ends. The regulation of the power converter is resumed once the output load increases during the regulation of the power converter is being ceased. The counter circuit coupled to the delay circuit is counted by the delay circuit to determine a sleep period. The output circuit generates the power-saving signal to cease the regulation of the power converter after the sleep period ends.

Abstract: This invention provides a control circuit for burst switching of a power converter comprising: an adaptive circuit generating an adaptive threshold in response to a feedback signal correlated to an output load of the power converter; and a switching circuit generating a switching signal to switch a transformer of the power converter in accordance with the adaptive threshold and the feedback signal for regulating an output of the power converter.

Abstract: The present invention provides a power saving circuit for PWM circuit. The power saving circuit is utilized to control at least one internal circuit. The power saving circuit comprises a switching circuit which generates a switching signal. The power saving circuit controls the internal circuit in response to the switching. The power saving circuit disables the internal circuit for power saving when the switching signal is disabled.

Abstract: A discharge circuit for an electromagnetic interference (EMI) filter is provided. The discharge circuit includes a switch circuit, a control circuit, and a detection circuit. The switch circuit is coupled to an X-capacitor of the EMI filter. The control circuit is coupled to the switch circuit and configured to turn on the switch circuit in a predetermined period to provide a discharge path. The detection circuit is coupled to the discharge path. In the predetermined period, the detection circuit detects whether a cross point occurs between a discharge voltage signal on the discharge path and a reference voltage signal to generate a detection signal which is provided to the control circuit. When the detection circuit detects that the cross point does not occur, the control circuit continuously turns on the switch circuit according to the detection signal after the predetermined period has elapsed.