Abstract: A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

Abstract: A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

Abstract: A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

Abstract: A multi-axis, single mass acceleration sensor includes a three-dimensional frame, a test mass, a plurality of transducers, and a plurality of struts. The test mass may have three principal axes disposed within and spaced apart from the frame. The transducers are mechanically coupled to the frame. The struts are configured to couple to the central mass at each of the three principal axes, respectively, and to couple with respective sets of the transducers, thereby suspending the test mass within the frame. The sensor is thus responsive to translational motion in multiple independent directions and to rotational motion about multiple independent axes.

Abstract: A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

Abstract: A multi-axis, single mass acceleration sensor includes a three-dimensional frame, a test mass, a plurality of transducers, and a plurality of struts. The test mass may have three principal axes disposed within and spaced apart from the frame. The transducers are mechanically coupled to the frame. The struts are configured to couple to the central mass at each of the three principal axes, respectively, and to couple with respective sets of the transducers, thereby suspending the test mass within the frame. The sensor is thus responsive to translational motion in multiple independent directions and to rotational motion about multiple independent axes.

Abstract: A seismic sensor comprises a central mass having three principal axes and disposed within a frame. A plurality of transducers is mechanically coupled between the frame and the central mass. The transducers are arranged in pairs, with the transducers in each pair being coupled to opposing sides of the central mass, as defined along each of the three principal axes. Electronics can be provided to combine signals of the transducers in each pair to generate output characterizing acceleration and rotation of the frame.

Abstract: Embodiments of an apparatus for direct coupling of a capacitive sensor to a delta-sigma converter are described. One apparatus includes a sensor, a charge coupling circuit configured to transfer at least a portion of charge generated by the sensor to an integrating circuit, a first charge feedback circuit configured to feed back charge to the sensor, a second charge feedback circuit configured to feed back charge to the integrating circuit, a comparing circuit configured to detect accumulated charge at the integrating circuit for a current cycle to determine a polarity of charge feedback for a subsequent cycle, and a logic circuit configured to provide a digital output corresponding to the sensed quantity and also configured to provide the polarity of charge feedback determined by the comparing circuit to the first charge feedback circuit and also to the second charge feedback circuit.

Abstract: A seismic node assembly includes a power source and a seismic sensor, e.g., with the power source disposed in a power source module and the seismic sensor disposed in a sensor module. A coupling can be defined by selective engagement between the power source (or power source module) and the sensor (or sensor module), with the power source electrically coupled to the seismic sensor, or a singular housing can be used. The seismic sensor is configured for acquiring seismic data when deployed to a seismic medium, and an acoustic transponder or wireless transceiver can be adapted for communicating command and clock signals during deployment and retrieval, or when the node is operationally deployed to the seismic medium.

Abstract: Embodiments of an apparatus for direct coupling of a capacitive sensor to a delta-sigma converter are described. One apparatus includes a sensor, a charge coupling circuit configured to transfer at least a portion of charge generated by the sensor to an integrating circuit, a first charge feedback circuit configured to feed back charge to the sensor, a second charge feedback circuit configured to feed back charge to the integrating circuit, a comparing circuit configured to detect accumulated charge at the integrating circuit for a current cycle to determine a polarity of charge feedback for a subsequent cycle, and a logic circuit configured to provide a digital output corresponding to the sensed quantity and also configured to provide the polarity of charge feedback determined by the comparing circuit to the first charge feedback circuit and also to the second charge feedback circuit.