A rotary transformer is provided. The transformer has a stator and a rotor. The stator has a stator core and the rotor has a rotor core sleeved in the stator core. An air gap is defined between an inner side wall of the stator core and an outer side wall of the rotor core. During rotation of the rotor, a length S of the air gap along a circumferential direction of the transformer and a mechanical rotation angle θ of the rotor satisfy a sinusoidal function relationship containing third-harmonic components, and the length changes periodically according to the functional relationship to define a shape of the rotor core. As a result, the output signal amplitude and measurement accuracy of the position of the rotary transformer can be improved under the same maximum and minimum air gaps.

An apparatus for inductive linear-position sensing is disclosed. An apparatus may include a support structure and an electrically conductive material defining a continuous path for electrical current to flow between a first location and a second location. The continuous path may include: a first path portion defining a first spiraling path for the electrical current to flow in a clockwise direction around a first axis; a second path portion laterally spaced from the first path portion and defining a second spiraling path for the electrical current to flow in a counter-clockwise direction around a second axis; a first coupling portion coupling an inner portion of the first path portion to an inner portion of the second path portion; and a second coupling portion coupling an outer portion of the second path portion to an outer portion of the first path portion. Related systems, devices, and methods are also disclosed.

A rotational position sensor arrangement having first and second sensors positioned adjacent to first and second axial faces or a first axial face and a radial face of a target disc. The target disc has first and second wave profiles on the first axial face and the second axial or radial face, having respectively, first and second pluralities of segments, with each segment being formed with axially offset peaks and valleys which extend along radial lines/planes. The valleys separate the segments, and the number of the first plurality of segments is different than that of the second plurality of segments. The first and second sensors signal a controller with data on a field variance due to a difference in at least one of a size or location of the first and second wave profiles as they pass the first and second sensors to determine a rotational speed and/or position.

In accordance with one embodiment of the present disclosure, an inductive position sensor assembly is provided. The inductive sensor assembly includes a sensor and a coupler element. The sensor includes a transmitter coil having an inner diameter and an outer diameter and a receiver coil positioned within the outer diameter of the transmitter coil. The coupler element has a geometric continuous curve shape. The coupler element is positioned within the outer diameter of the transmitter coil such that a maximum diameter of the geometric continuous curve shape is the outer diameter of the transmitter coil. When the coupler element is moved, the geometric continuous curve shape of the coupler element modify an inductive coupling between the transmitter coil and the receiver coil.

Systems and methods for determining angular position in rotating machines. A repeating sequence of segments are arranged in a track disposed at a diameter around a shaft of a rotor that rotates about an axis. A sensor is positioned to face the track and is fixed relative to the stator. The track and the sensor face to each other, which may be in directions that are parallel to the axis. The sensor generates an output that is decoupled from the diameter of the track and is related to the repeating sequence of segments.

A rotational angle detection apparatus is provided with a magnet disposed so as to be rotatable integrally with an axis of rotation, having a substantially circular shape when viewed along the axis of rotation, and including a magnetization vector component in a direction orthogonal to the axis of rotation; a magnetic sensor that outputs a sensor signal on the basis of change in a magnetic field accompanying rotation of the magnet; and a rotational angle detector that detects a rotational angle of the rotating body on the basis of the sensor signal output by the magnetic sensor; wherein the magnet has a curved inclined surface with a concave shape along the axis of rotation from a prescribed position on the outer side in a radial direction toward the axis of rotation, and when a circular virtual plane orthogonal to the axis of rotation and centered at the axis of rotation is established at a position opposed to the curved inclined surface, the magnetic sensor is disposed at a position at which the amplitudes of a magnetic field intensity H.sub.r in a radial direction and a magnetic field intensity H.sub.θ in a circumferential direction on the virtual plane are substantially the same, and the magnetic field intensities H.sub.r and H.sub.θ in the radial direction and/or the circumferential direction is output as the sensor signal.

A variable reluctance resolver with a stator assembly including a printed circuit board having a first surface and a second surface. A plurality of inductors coupled with the annular printed circuit board first surface, wherein the plurality of inductors are in electrical connection with a power source. The variable reluctance resolver also having a rotor including a body with a first surface and a second surface, an annular recess located in the rotor first surface. The annular recess including a radially inner surface and a radially outer surface, wherein the annular recess defines a width variable with angular position. The plurality of inductors are located at least partially within the annular recess and the rotor is operable to rotate relative to the stator assembly.

A rotational angle sensor includes a rotary plate and a printed circuit board in which a primary coil and a secondary coil group are arranged. Loops of the primary coil and the secondary coil group are along a surface of the printed circuit board. The rotary plate includes a target portion whose outer circumferential edge portion has a sine-wave shape. The primary coil overlaps with the target portion, and has a circular-arc shape along a rotational direction of the rotary plate. The secondary coil group includes 4n (n is a natural number) secondary coils arranged in a line along the rotational direction, on an inner circumferential side of the primary coil. The number of turns of a secondary coil on an end side in a line is smaller than that of a secondary coil on an inner side in the line.

Valve systems include at least one component comprising a conductive material and at least one inductance-to-digital converter (LDC) sensor configured to wirelessly sense at least one property of the conductive material and relay a value associated with the at least one property to a control system of the valve system. Methods of sensing a position of a component of a valve system include wirelessly sensing at least one property of a conductive material of the component of the valve system with at least one inductance-to-digital converter (LDC) sensor.

Valve systems include at least one component comprising a conductive material and at least one inductance-to-digital converter (LDC) configured to wirelessly sense a position of at least a portion of the conductive material. The valve system is configured to determine at least one force applied to a portion of the valve system based at least partially on the position of the at least a portion of the conductive material. Methods of determining a force associated with a valve system include wirelessly sensing a position of at least a portion of the conductive material with the at least one inductance-to-digital converter (LDC) sensor and determining a force applied to a portion of the valve system based at least partially on the position of the at least a portion of the conductive material.