In one example implementation, a rotary position sensor can include a first member and a second member, one of the first and second members having a transmit aerial and a receive aerial and the other of the first and second members having an intermediate coupling element. The receive aerial has at least one receive conductive winding arranged to form a first set of current loops and a second set of current loops. The intermediate coupling element comprises a conductive material arranged in a pattern. The pattern of the intermediate coupling element and the layout of the first and second set of current loops are mutually arranged such that any electromotive force induced in the first set of current loops by a background magnetic field is substantially balanced by an electromotive force induced in the second set of current loops by the background magnetic field.

A rotation sensing apparatus includes a detected part, a sensor unit, and a rotation information calculation circuit. The sensor unit includes a first sensor disposed opposite to a first pattern portion, a second sensor disposed opposite to a second pattern portion, a third sensor disposed to be spaced apart from the first sensor in the rotation direction and opposite to the first pattern portion, and a fourth sensor disposed to be spaced apart from the second sensor in the rotation direction and opposite to the second pattern portion. The rotation information calculation circuit is configured to sense the rotation direction, in response to a differential signal, generated based on the first oscillation signal and the second oscillation signal, and an oscillation signal corresponding to maximum and minimum frequencies, from among the first oscillation signal, the second oscillation signal, the third oscillation signal, and the fourth oscillation signal.

A position detection device of active magnetic bearings (AMB's) maintaining the position of a rotating shaft and comprising two sensing inductance coils, the position detection device comprising a programmable digital component for generating a 25 KHz square waveform signal, a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and, depending on the displacement of the rotating shaft, an analog to digital (A/D) converter for delivering a position value from the voltage difference.

An assembly includes at least a first motor (10) and a second motor (20) on which first targets (13) and second targets (23) being respectively mounted, the first targets (13) and the second targets (23) are respectively distributed angularly over the first motor (10) and over the second motor (20), each first target (13) having a first angular aperture, each second target (23) having a second angular aperture, the assembly furthermore having an angular position sensor (5) positioned between the motors (10, 20) and adapted to measure the angular position of the targets (13, 23).

An apparatus for sensing a rotating body includes a rotating body including a detection target portion; a pattern portion disposed in the detection target portion in a direction in which the rotating body rotates; a frame that rotatably supports the rotating body; a first sensor disposed to oppose a first region of the detection target portion; a second sensor spaced apart from the first sensor and disposed to oppose a second region of the detection target portion; and a holder portion coupled to the frame to hold the first sensor and the second sensor.

Rotary position sensors are provided. In one example implementation, a rotary position sensor can include a first member and a second member, one of the first and second members having a transmit aerial and a receive aerial and the other of the first and second members having an intermediate coupling element. The receive aerial has at least one receive conductive winding arranged to form a first set of current loops and a second set of current loops. The intermediate coupling element comprises a conductive material arranged in a pattern. The pattern of the intermediate coupling element and the layout of the first and second set of current loops are mutually arranged such that any electromotive force induced in the first set of current loops by a background magnetic field is substantially balanced by an electromotive force induced in the second set of current loops by the background magnetic field.

An interface circuit for a position sensor system including an oscillator generating an oscillation signal having a carrier frequency and a primary phase, a primary coil responsive to the oscillation signal, and a secondary coil electromagnetically coupled to the primary coil by a target and configured to generate a secondary signal having the carrier frequency and a secondary phase provides phase compensation. The interface circuit includes a sampling and conversion circuit configured to sample the secondary signal during sample periods and convert the secondary signal into a digital signal, a demodulator coupled to receive the digital signal and configured to demodulate the digital signal in order to generate a position signal indicative of a position of the target, a phase detector coupled to receive the position signal and configured to detect an alignment of the secondary phase with respect to the sample periods and generate a phase detector output signal indicative of whether the secondary phase is aligned with the sample periods, and a delay circuit responsive to the phase detector output signal and configured to apply a delay to the sampling and conversion circuit if the phase detector output signal indicates that the secondary phase is not aligned with the sample periods.

A method for defining a measurement range, called the useful span, of the inductive position sensor with emission of a cosine and sine signal by at least one first receiver winding and at least one second receiver winding, respectively. The cosine signal emitted by the one or more second receiver windings is taken as reference signal between the two sine and cosine signals for an adjustment of at least one parameter of the sine signal depending on a corresponding parameter of the cosine signal, at least one of the dimension and positioning parameters of the one or more first receiver windings being configured to generate a sine signal having the at least one parameter of the sine signal adjusted with respect to the cosine signal.

An inductive position sensor for determining the position of a moving body along a linear or rotary path (F), including: a moving target (3) adapted to modify an electromagnetic field; a fixed circuit board (5) extending along a limited portion and including a primary coil (7) surrounding two secondary coils (8, 9) having substantially identical lengths (L) and having shapes of sine and cosine functions; a current generator (11) to create an inductive coupling modulated by the position of the target; a detector (13) of the linear or angular position of the target; and a system for balancing the coupling between the primary coil (7) and the secondary coils (8, 9) to compensate for the measurement offset induced by the proximity between the secondary coils (8, 9) and the end segments (7b) of the primary coil (7).

An interface circuit for a position sensor system including an oscillator generating an oscillation signal having a carrier frequency and a primary phase, a primary coil responsive to the oscillation signal, and a secondary coil electromagnetically coupled to the primary coil by a target and configured to generate a secondary signal having the carrier frequency and a secondary phase provides phase compensation. The interface circuit includes a sampling and conversion circuit configured to sample the secondary signal during sample periods and convert the secondary signal into a digital signal, a demodulator coupled to receive the digital signal and configured to demodulate the digital signal in order to generate a position signal indicative of a position of the target, a phase detector coupled to receive the position signal and configured to detect an alignment of the secondary phase with respect to the sample periods and generate a phase detector output signal indicative of whether the secondary phase is aligned with the sample periods, and a delay circuit responsive to the phase detector output signal and configured to apply a delay to the sampling and conversion circuit if the phase detector output signal indicates that the secondary phase is not aligned with the sample periods.