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 position sensor system for determining a position of a sensor device relative to a magnetic structure, the system comprising: said magnetic structure comprising a plurality of non-equidistant poles; said sensor device comprising at least three magnetic sensors spaced apart over predefined distances; and the sensor device being adapted for: a) measuring at least three in-plane magnetic field components, and for calculating two in-plane field gradients therefrom; b) measuring at least three out-of-plane magnetic field components, and for calculating two out-of-plane field gradients therefrom; c) calculating a coarse signal based on these gradients; d) calculating a fine signal based on these gradients; e) determining said position based on the coarse signal and the fine signal.

A rotor apparatus includes: a rotor configured to rotate around a rotational axis; a first angular position identification layer surrounding the rotational axis, configured to rotate with the rotor, and having a varying width; and a second angular position identification layer surrounding the rotational axis, configured to rotate with the rotor, and having a varying width. An angular position of the rotor corresponding to a maximum width of the first angular position identification layer is different from an angular position of the rotor corresponding to a maximum width of the second angular position identification layer. The maximum width of the first angular position identification layer is less than or equal to 1.2 times a maximum width of a corresponding first inductor. The maximum width of the second angular position identification layer is less than or equal to 1.2 times a maximum width of a corresponding second inductor.

A novel multi-phase resolver topology and apparatus is provided for measuring a displacement of movement body more precisely and economically. In variable reluctance (VR) resolvers, N coil-poles are placed at N equally spaced positions over one turn of the stator, N being an odd number greater than or equal to 5. Each coil serves both as an excitation and a sensing coil, and all N coils are wound with the same number of turns at an identical electrical polarity. Depending on the installed rotor lobe shape, N sinusoidal or quasi-square waveform displacement signals are sensed on multi-phase resolver, and from which two-phase orthogonal displacement signals are optimally and differentially synthesized. The multi-phase resolver topology and differential synthesis method is also applied to other types of resolvers, such as wound-rotor, inductance, capacitive, and magnetic resolvers.

A novel multi-phase resolver topology and apparatus is provided for measuring a displacement of movement body more precisely and economically. In variable reluctance (VR) resolvers, N coil-poles are placed at N equally spaced positions over one turn of the stator, N being an odd number greater than or equal to 5. Each coil serves both as an excitation and a sensing coil, and all N coils are wound with the same number of turns at an identical electrical polarity. Depending on the installed rotor lobe shape, N sinusoidal or quasi-square waveform displacement signals are sensed on multi-phase resolver, and from which two-phase orthogonal displacement signals are optimally and differentially synthesized. The multi-phase resolver topology and differential synthesis method is also applied to other types of resolvers, such as wound-rotor, inductance, capacitive, and magnetic resolvers.

A novel multi-phase resolver topology and apparatus is provided for measuring a displacement of movement body more precisely and economically. In variable reluctance (VR) resolvers, N coil-poles are placed at N equally spaced positions over one turn of the stator, N being an odd number greater than or equal to 5. Each coil serves both as an excitation and a sensing coil, and all N coils are wound with the same number of turns at an identical electrical polarity. Depending on the installed rotor lobe shape, N sinusoidal or quasi-square waveform displacement signals are sensed on multi-phase resolver, and from which two-phase orthogonal displacement signals are optimally and differentially synthesized. The multi-phase resolver topology and differential synthesis method is also applied to other types of resolvers, such as wound-rotor, inductance, capacitive, and magnetic resolvers.

A novel multi-phase resolver topology and apparatus is provided for measuring a displacement of movement body more precisely and economically. In variable reluctance (VR) resolvers, N coil-poles are placed at N equally spaced positions over one turn of the stator, N being an odd number greater than or equal to 5. Each coil serves both as an excitation and a sensing coil, and all N coils are wound with the same number of turns at an identical electrical polarity. Depending on the installed rotor lobe shape, N sinusoidal or quasi-square waveform displacement signals are sensed on multi-phase resolver, and from which two-phase orthogonal displacement signals are optimally and differentially synthesized. The multi-phase resolver topology and differential synthesis method is also applied to other types of resolvers, such as wound-rotor, inductance, capacitive, and magnetic resolvers.

A novel multi-phase resolver topology and apparatus is provided for measuring a displacement of movement body more precisely and economically. In variable reluctance (VR) resolvers, N coil-poles are placed at N equally spaced positions over one turn of the stator, N being an odd number greater than or equal to 5. Each coil serves both as an excitation and a sensing coil, and all N coils are wound with the same number of turns at an identical electrical polarity. Depending on the installed rotor lobe shape, N sinusoidal or quasi-square waveform displacement signals are sensed on multi-phase resolver, and from which two-phase orthogonal displacement signals are optimally and differentially synthesized. The multi-phase resolver topology and differential synthesis method is also applied to other types of resolvers, such as wound-rotor, inductance, capacitive, and magnetic resolvers.

Valve systems and related methods 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 the 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. 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.