A reluctance transducer includes a soft ferromagnetic yoke and a soft ferromagnetic core element, which is movable relative to the yoke. Two permanent magnets bear the core element. The permanent magnets are arranged relative to each other and to the yoke so that the reluctance transducer has a good linear relationship between displacement and force. The reluctance transducer can be applied as stiffness compensating element. The reluctance transducer can include an electrical winding to allow its application as a magnetic bearing, an actuator or as a displacement, velocity or acceleration sensor with improved intrinsic linearity.

A reluctance transducer includes a soft ferromagnetic yoke and a soft ferromagnetic core element, which is movable relative to the yoke. Two permanent magnets bear the core element. The permanent magnets are arranged relative to each other and to the yoke so that the reluctance transducer has a good linear relationship between displacement and force. The reluctance transducer can be applied as stiffness compensating element. The reluctance transducer can include an electrical winding to allow its application as a magnetic bearing, an actuator or as a displacement, velocity or acceleration sensor with improved intrinsic linearity.

A sensing system includes a wire coil. The wire coil is located opposite a target and the inductance of the wire coil is configured to change in response to movement of the target relative to the wire coil.

A sensing system includes a wire coil. The wire coil is located opposite a target and the inductance of the wire coil is configured to change in response to movement of the target relative to the wire coil.

A single sensing unit having two electrodes with a common thermal reference is positioned near the centroid of the inertial mass of a differential inductive accelerometer. As the mass is displaced a first sensor detects an increase in inductance while a second sensor detects a decrease in inductance. Significantly, the first and second sensors share a common thermal reference eliminating any thermal differential. As the sensor system is closely aligned with the centroid of the inertial mass the sensor system of the present invention reduces or eliminates any systemic error.

A single sensing unit having two electrodes with a common thermal reference is positioned near the centroid of the inertial mass of a differential inductive accelerometer. As the mass is displaced a first sensor detects an increase in inductance while a second sensor detects a decrease in inductance. Significantly, the first and second sensors share a common thermal reference eliminating any thermal differential. As the sensor system is closely aligned with the centroid of the inertial mass the sensor system of the present invention reduces or eliminates any systemic error.

An apparatus and use of the apparatus for monitoring a current-carrying device wherein at least one acceleration sensor produces acceleration measurement values and a communication device transmits produced acceleration measurement values. A power supply unit is for the acceleration sensor and the communication device. The power supply unit includes an induction plate of a metallic material and a conductor loop extending around the induction plate and produces a power supply for the acceleration sensor and the communication device exclusively through induction from an electromagnetic alternating field of the current-carrying device. The apparatus can be positioned in a closed housing having a housing wall and the induction plate can be at least a subregion of the housing wall.

An apparatus and use of the apparatus for monitoring a current-carrying device wherein at least one acceleration sensor produces acceleration measurement values and a communication device transmits produced acceleration measurement values. A power supply unit is for the acceleration sensor and the communication device. The power supply unit includes an induction plate of a metallic material and a conductor loop extending around the induction plate and produces a power supply for the acceleration sensor and the communication device exclusively through induction from an electromagnetic alternating field of the current-carrying device. The apparatus can be positioned in a closed housing having a housing wall and the induction plate can be at least a subregion of the housing wall.

An accelerometer as disclosed herein includes a support wafer, a bottom wafer, a top wafer, and an inductive pick-off. The support wafer may define a plane and may comprise a first side, a second side, and a proof mass. The proof mass may be configured to move in the plane defined by the support wafer. The bottom wafer may comprise a first side and a second side, and the first side may be positioned over the first side of the support wafer. The top wafer may comprise a first side and a second side, and the first side may be positioned over the second side of the support wafer. The inductive pick-off may comprise a near field resonant conductive coupling mechanism and may be configured to output a signal indicative of an amount of displacement of the proof mass to electronics.

An accelerometer as disclosed herein includes a support wafer, a bottom wafer, a top wafer, and an inductive pick-off. The support wafer may define a plane and may comprise a first side, a second side, and a proof mass. The proof mass may be configured to move in the plane defined by the support wafer. The bottom wafer may comprise a first side and a second side, and the first side may be positioned over the first side of the support wafer. The top wafer may comprise a first side and a second side, and the first side may be positioned over the second side of the support wafer. The inductive pick-off may comprise a near field resonant conductive coupling mechanism and may be configured to output a signal indicative of an amount of displacement of the proof mass to electronics.