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.

Examples disclosed herein relate generally to inductive angular-position sensors. An example apparatus may include a support structure, a first inductive angular-position sensor, a second inductive angular-position sensor, and a shield. The first inductive angular-position sensor may include a respective first sense coil arranged at a first portion of the support structure. The respective first sense coil may at least partially circumscribe an axis. The second inductive angular-position sensor may include a respective first sense coil arranged opposite the first sense coil of the first inductive angular-position sensor at a second portion of the support structure. The first sense coil of the first inductive angular-position sensor may at least partially circumscribe the axis. The shield may be arranged between the first sense coil of the first inductive angular-position sensor and the first sense coil of the second inductive angular-position sensor.

Provided is a resolver capable of increasing an accuracy of a detected angle of the resolver. The resolver includes: a stator; and a rotor, wherein the rotor includes a plurality of salient poles; wherein the stator includes: a stator core having a plurality of teeth, and a plurality of winding groups each of which is provided on each of the plurality of teeth, wherein the winding groups are divided into two systems, wherein the numbers of turns of the excitation windings are distributed in a form of a sine wave of N.sub.e-th spatial order, wherein each of the numbers of turns of a first output windings and the numbers of turns of a second output windings are distributed in a form of a sine wave of |N.sub.e±N.sub.x|-th spatial order, and wherein the following expressions are satisfied,

N.sub.out1=N.sub.1 cos{|N.sub.e±N.sub.x|(i−1)/N.sub.s×2Π+α},

N.sub.out2=N.sub.1 cos{|N.sub.e±N.sub.x|(i−1)/N.sub.s×2Π+β}, and

90(deg)<|α−β|<140(deg).

A variable reluctance position sensor includes a first element having magnetic sensor sections having excitation coils, first detection coils, and second detection coils, and a second element moveable with respect to the first element. An airgap surface of the second element is periodically meandering. When an alternating signal is supplied to the excitation coils, envelopes of alternating signals induced in the first and second detection coils are dependent on a position of the second element so that the envelopes have a phase shift with respect to each other. The number of the magnetic sensor sections is 1+nP.sub.2/P.sub.1, where P.sub.1 is a spatial shift between successive magnetic sensor sections, P.sub.2 is a spatial meandering period of the airgap surface, and n is an integer. The magnetic sensor section in addition to the nP.sub.2/P.sub.1 magnetic sensor sections is suitable for compensating for unwanted effects caused by ends of the first element.

In order to improve the angle detection accuracy, when an exciting order is 2, a double axial angle is 5, and the number of resolver teeth is 8, an inner diameter deformation order is one of 4, 6, 7, 8, or 9, when the exciting order is 5, the double axial angle is 4, and the number of resolver teeth is 10, the inner diameter deformation order is one of 3, 5, 7, 9 or 10, when the exciting order is 3, the double axial angle is 4, and the number of resolver teeth is 12, the inner diameter deformation order is one of the 2, 3, 5, 6, 7, 9, 10, 11 or 12, and the resolver stator is fixed to the resolver device mounting part by the number of fixing points corresponding to any one of the inner diameter deformation order.

An inductive position encoder includes a scale, a detector and a signal processor. The scale includes a periodic pattern of signal modulating elements (SME) arranged along a measuring axis (MA) with a spatial wavelength W1. The detector comprises sensing elements and a field generating coil that generates a changing magnetic flux. The sensing elements comprise conductive loops that provide detector signals responsive to a local effect on the changing magnetic flux provided by adjacent SME's. Some or all of the conductive loops are configured according to an intra-loop shift relationship wherein equal “shifted proportions” of a loop are shifted in opposite directions by W1/4K. K is an odd integer. The intra-loop shift relationship can be used to suppress Kth spatial harmonic components in the detector signals, while also overcoming longstanding detrimental layout problems. It combines easily with “loop width” spatial filtering techniques that filter other spatial harmonic signal components.

A position detection device includes a position sensor including a coil and a magnetic core, and a signal processor. The signal processor generates a rectangular wave voltage applied to the coil, converts a current which flow through the coil by the rectangular wave voltage into a voltage and outputs the voltage, and acquires a voltage measurement value obtained by sampling the output voltage after predetermined time in synchronization with a timing of rising or falling of a waveform of the rectangular wave voltage. The predetermined time is set such that the voltage measurement value is restricted within a range of 40% or more and 99.999% or less with respect to a maximum value of the rectangular wave voltage when the coil is at a position where an inductance of the coil is minimum.

A driving mechanism is provided, including a base, a movable module, and a driving assembly. The movable module has a movable member and a connecting member connected to the movable member. The driving assembly is connected to the base and the connecting member. The driving assembly has a driving element that generates a driving force to the connecting member and the movable member, so that the movable module moves relative to the base.

A sensor system for determining at least one rotation characteristic of an element rotating about at least one rotation axis includes at least one sensor wheel having a profile and being connectable to the rotating element; and at least one inductive position sensor including at least one coil arrangement that includes at least one excitation coil and at least two receiver coils, where at least in sections of the at least two receiver coils have a sinusoidal shape.

A haptic engine includes a haptic actuator having a double-wound driving coil in which the two windings are connected with each other either in series or in parallel. By using the double-wound driving coil in which the two windings are connected with each other in series, an instant back EMF voltage induced in either of the two windings can be determined without having to measure in real time a resistance of the corresponding winding, and without having to sense a driving current through the double-wound driving coil. By using the double-wound driving coil in which the two windings are connected with each other in parallel, an instant back EMF voltage induced in either of the two windings can be determined without having to measure in real time a resistance of the corresponding winding.