Abstract: In some examples, an accelerometer system includes a first excitation ring comprising: a first housing; and a first cover removably attached to the first housing, wherein the first housing and the first cover define a first recess. The accelerometer system also includes a second excitation ring comprising: a second housing; and a second cover removably attached to the second housing, wherein the second housing and the second cover define a second recess. The accelerometer system also includes a proof mass assembly; and processing circuitry located within one or both of the first recess and the second recess, wherein the first excitation ring and the second excitation ring shield the processing circuitry from harmful levels of radiation existing outside of the accelerometer system, and wherein the processing circuitry is configured to maintain a proof mass of the proof mass assembly in a null position.

Abstract: In some examples, an accelerometer system includes a first excitation ring comprising: a first housing; and a first cover removably attached to the first housing, wherein the first housing and the first cover define a first recess. The accelerometer system also includes a second excitation ring comprising: a second housing; and a second cover removably attached to the second housing, wherein the second housing and the second cover define a second recess. The accelerometer system also includes a proof mass assembly; and processing circuitry located within one or both of the first recess and the second recess, wherein the first excitation ring and the second excitation ring shield the processing circuitry from harmful levels of radiation existing outside of the accelerometer system, and wherein the processing circuitry is configured to maintain a proof mass of the proof mass assembly in a null position.

Abstract: An example transducer includes an upper magnetic circuit assembly including an upper excitation ring, a lower magnetic circuit assembly including a lower excitation ring, and a proof mass assembly positioned between the upper and lower magnetic circuit assemblies. A coefficient of thermal expansion (CTE) of the proof mass assembly is lower than a CTE of each of the upper and lower excitation rings. The transduces also includes an outer support structure coupled to an outer surface of each of the upper and lower excitation rings, and the outer support structure includes at least one cutout configured to reduce a circumferential stiffness of the outer support structure.

Abstract: An example accelerometer includes a first excitation ring comprising a first material having a first coefficient of thermal expansion (CTE), a second excitation ring comprising the first material having the first CTE; and a proof mass assembly disposed between and in contact with the first excitation ring and the second excitation ring. The proof mass assembly comprises a second material having a second CTE, wherein a difference between the first CTE and the second CTE is equal to or less than 0.5 parts per million per degree Celsius (ppm/° C.).

Abstract: The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines an input axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet and a base layer underlying the platform layer. The outer ring overlies the base layer. An inner portion of the outer ring faces the magnet assembly and an outer portion of the outer ring is configured to couple to an outer radial portion of a proof mass assembly. The pole piece and the platform layer include a high magnetic permeability material.

Abstract: The disclosure describes a sensor that includes a transducer, a case, and a mounting flange. The transducer defines an input axis. The case is configured to house the transducer. The mounting flange is statically coupled to the case and flexibly coupled to the transducer. The mounting flange defines an opening and includes a plurality of flexure elements extending radially into the opening to contact the transducer. Each flexure element is configured to flex in a radial direction perpendicular to the input axis and remain fixed in an axial direction parallel to the input axis.

Abstract: This disclosure is related to devices, systems, and techniques for determining an acceleration. For example, an accelerometer system includes a proof mass, a pole piece connected to the proof mass, and a coil disposed around the pole piece and connected to the proof mass, where the coil is rectangular in shape. Additionally, the accelerometer system includes circuitry configured to deliver an electrical signal to the coil in order to maintain the proof mass at a null position and determine an electrical current value corresponding to the electrical signal. Additionally, the circuit is configured to identify, based on the electrical current value, an acceleration of the accelerometer system.

Abstract: This disclosure is related to devices, systems, and techniques for determining an acceleration. For example, an accelerometer system includes a proof mass, a pole piece connected to the proof mass, and a coil disposed around the pole piece and connected to the proof mass, where the coil is rectangular in shape. Additionally, the accelerometer system includes circuitry configured to deliver an electrical signal to the coil in order to maintain the proof mass at a null position and determine an electrical current value corresponding to the electrical signal. Additionally, the circuit is configured to identify, based on the electrical current value, an acceleration of the accelerometer system.

Abstract: The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines a central axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet, an upper base layer underlying the platform layer, and a lower base layer underlying the upper base layer. The outer ring overlies the upper base layer and is configured to couple to an outer radial portion of a proof mass assembly. The platform layer and lower base layer are made from high coefficient of thermal expansion (CTE) materials, while the upper base layer and outer ring are made from low CTE materials. Each relatively high CTE material has a higher CTE than each relatively low CTE material.

Abstract: The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines an input axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet and a base layer underlying the platform layer. The outer ring overlies the base layer. An inner portion of the outer ring faces the magnet assembly and an outer portion of the outer ring is configured to couple to an outer radial portion of a proof mass assembly. The pole piece and the platform layer include a high magnetic permeability material.

Abstract: The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines a central axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet, an upper base layer underlying the platform layer, and a lower base layer underlying the upper base layer. The outer ring overlies the upper base layer and is configured to couple to an outer radial portion of a proof mass assembly. The platform layer and lower base layer are made from high coefficient of thermal expansion (CTE) materials, while the upper base layer and outer ring are made from low CTE materials. Each relatively high CTE material has a higher CTE than each relatively low CTE material.

Abstract: The disclosure describes a sensor that includes a transducer, a case, and a mounting flange. The transducer defines an input axis. The case is configured to house the transducer. The mounting flange is statically coupled to the case and flexibly coupled to the transducer. The mounting flange defines an opening and includes a plurality of flexure elements extending radially into the opening to contact the transducer. Each flexure element is configured to flex in a radial direction perpendicular to the input axis and remain fixed in an axial direction parallel to the input axis.

Abstract: A magnetic circuit assembly for an accelerometer includes an excitation ring that includes a base portion defining oppositely facing first and second sides, a ring portion extending from the second side of the base portion to define a ring recess, a first metallic inlay recessed into the first side of the base portion in which the first metallic inlay includes a material different than that of the base portion, a second metallic inlay recessed into the second side of the base portion in which the second metallic inlay includes a material different than that of the base portion, and a magnet received within the ring recess and attached to the second metallic inlay.

Abstract: In some examples, a device comprises a proof mass and a support base configured to support the proof mass, wherein the proof mass is configured to displace in response to an acceleration of the device. The device also comprises a flexure configured to flexibly connect the proof mass to the support base. The device also comprises a strain-monitoring device configured to measure an amount of strain on the support base.

Abstract: A magnetic circuit assembly for an accelerometer includes an excitation ring that includes a base portion defining oppositely facing first and second sides, a ring portion extending from the second side of the base portion to define a ring recess, a first metallic inlay recessed into the first side of the base portion in which the first metallic inlay includes a material different than that of the base portion, a second metallic inlay recessed into the second side of the base portion in which the second metallic inlay includes a material different than that of the base portion, and a magnet received within the ring recess and attached to the second metallic inlay.

Abstract: Accelerometers as disclosed herein include a proof mass assembly and an accelerometer support. In some examples, a combined height and a combined coefficient of thermal expansion (CTE) of the materials of the accelerometer support is configured to substantially match a CTE of material of the non-moving member with a height substantially similar to the combined height of the accelerometer support. In some examples, the accelerometer support is configured to connect to a center raised pad of the proof mass assembly and maintain a capacitance gap between a capacitance plate on a proof mass of the proof mass assembly and a portion of the non-moving member.

Abstract: An accelerometer includes a first stator, a second stator, a proof mass assembly disposed between the first stator and second stator, and a controller. The first stator includes a first magnet and the second stator includes a second magnet. The proof mass assembly includes a first coil configured to receive a first amount of current and a second coil configured to receive a second amount of current. The controller is configured to distribute the first amount of current to the first coil and the second amount of current to the second coil. The first amount of current is different than the second amount of current.

Abstract: An accelerometer includes an upper stator, a lower stator, and a proof mass assembly disposed between the upper and the lower stator. At least one of the upper stator or the lower stator includes an excitation ring, a magnet coupled to the excitation ring, and an asymmetric pole piece coupled to a top surface of the magnet. The asymmetric pole piece covers at least a portion of the top surface of the magnet such that a center of magnetic flux associated with the at least one of the upper stator or the lower stator is aligned with a center of mass of the proof mass assembly.

Abstract: In some examples, the disclosure describes an accelerometer having improved hysteresis effects, the accelerometer including a proof mass assembly including a proof mass, a support structure, and a flexure flexibly connecting the proof mass to the support structure to allow the proof mass to move about the plane defined by the support structure. Some examples may include at least one thin film lead including an electrically conductive material on the flexure, where the at least one thin film lead provides an electrical connection between an electrical component on the support structure and an electrical component on the proof mass, and where the at least one thin film lead comprises at least one of a yield strength greater than pure gold or a thermal expansion coefficient less than pure gold.

Abstract: An accelerometer includes a first stator, a second stator, a proof mass assembly disposed between the first stator and second stator, and a controller. The first stator includes a first magnet and the second stator includes a second magnet. The proof mass assembly includes a first coil configured to receive a first amount of current and a second coil configured to receive a second amount of current. The controller is configured to distribute the first amount of current to the first coil and the second amount of current to the second coil. The first amount of current is different than the second amount of current.