A method and apparatus is disclosed for allowing a magnetic tracking system to detect, and operate in close proximity in the same physical environment with, additional magnetic tracking systems. The first user's magnetic tracking system that becomes active in the physical space becomes the master system, and assigns time slots for its own transmitting antennas to generate the magnetic field which is used to determine the position and orientation of the user's limbs relative to the user's head. The master system also determines when other magnetic tracking systems become active in the physical space and assigns to those systems identification codes and time slots for their transmitting antennas to generate a magnetic field so that the position and orientation of the user's hands relative to the user's head for each of those systems may be determined. By requiring each magnetic tracking system to operate in different time slots, there is no interference between the systems.

A resonant rotor, for use in an inductive position sensor, includes a rotor core, a first rotor coil, and a rotor capacitor. The first rotor coil includes a first twisted rotor loop drawn about the rotor core and the rotor capacitor is connected in series with the first rotor coil. For a second embodiment, the first rotor coil includes a second twisted rotor loop. The first rotor coil has a first symmetry and the inductive position sensor includes a stator. An excitation coil is drawn on the stator and has a second symmetry. The first symmetry substantially corresponds to the second symmetry. A method for determining a position of an object using an inductive position sensor includes generating three electromagnetic fields using respective excitation coils, inducing voltages, respectively, in three receive coils, and determining based on voltages a position of an object coupled to a resonant rotor. The voltages being based on mutual inductances arising between the rotor with each of the excitation and receive coils, and the elimination, by the resonant rotor, of mutual inductances arising between the excitation and receive coils.

Systems, devices, and methods for determining a torque on a target using an inductive torque sensor are described. The inductive torque sensor may include an excitation coil, two rotors, and two or more receive coils. Each of the receive coils and the rotors may be inductively coupled. The two or more receive coils may be configured to generate a received voltage which can be approximated by a sine waveform function based on the angular changes of the coils on each rotor, the distance of the receive coils from the rotors and the distance between the receive coils. An integrated circuit may be configured to determine the torque generated on the target based on calculated differences between the angular rotation of the first rotor versus the second rotor over a given period.

A motor driving circuit includes a plurality of pins, a Hall sensor, a Hall signal processing portion and a driving processing circuit. The test-starting pin for receiving the test-starting signal and the test signal output pin for outputting the test signal are shared with at least one pin of the plurality of pins. The Hall sensor senses the change in the magnetic field of the motor to generate a Hall signal. The Hall signal processing unit amplifies the generated Hall signal, and the driving processing circuit drives the motor based on an output signal of the Hall signal processing unit and a control signal input from one of the plurality of pins. In a test mode, the output signal is output from the test signal output pin as a test signal. In a normal mode, at least one pin is used for normal operation.

Devices, systems, and method for detecting, determining and compensating for offset error arising in inductive position and torque sensors are described. In accordance with at least one embodiment, an offset coil can be configured for use within an inductive sensor and include a first trace and at least one second trace. The first trace and the at least one second trace may be drawn within a stator of an inductive sensor. The first trace and the at least one second trace may be drawn within the stator proximate to a pair of excitation coil connecting leads, drawn on a first plane within the stator, and on at least one plane substantially parallel to the first plane such that wherein an excitation coil flowing through the pair of excitation coil connecting leads induces an offset coil signal in the first trace and at least second trace.

A rotational angle sensor includes a stator element and a rotor element. The stator element has a stator transmitting coil, a stator circuit board with first and second planes, and at least two identically configured stator receiving coils arranged within the stator transmitting coil on the stator circuit board angularly offset from each other. The rotor element is mounted rotatably about a rotational axis relative to the stator element. The stator transmitting coil is inductively coupled to the stator receiving coils via the rotor element such that the inductive coupling is configured with reference to a rotational angle between the stator element and the rotor element so that the stator transmitting coil induces at least two angle-dependent alternating voltages in the stator receiving coils. The stator transmitting coil has coil conducting tracks positioned on the first and second planes of the stator circuit board. The coil conducting tracks on the first plane are interrupted in a passage region, and are connected to diverting tracks on the second plane by vias. The stator receiving coils have connection conductors on the first plane lead from stator receiving coil connections within the stator transmitting coil, through the passage region, and to circuit board connections for the stator receiving coils. Each connection conductor is curved so as to form a conductor loop in order to compensate differently sized coil areas of the stator receiving coils formed by connection conductors of different lengths within the stator transmitting coil.

Devices, systems, and method for detecting, determining and compensating for offset error arising in inductive position and torque sensors are described. In accordance with at least one embodiment, an offset coil can be configured for use within an inductive sensor and include a first trace and at least one second trace. The first trace and the at least one second trace may be drawn within a stator of an inductive sensor. The first trace and the at least one second trace may be drawn within the stator proximate to a pair of excitation coil connecting leads, drawn on a first plane within the stator, and on at least one plane substantially parallel to the first plane such that wherein an excitation coil flowing through the pair of excitation coil connecting leads induces an offset coil signal in the first trace and at least second trace.

A resonant rotor, for use in an inductive position sensor, includes a rotor core, a first rotor coil, and a rotor capacitor. The first rotor coil includes a first twisted rotor loop drawn about the rotor core and the rotor capacitor is connected in series with the first rotor coil. For a second embodiment, the first rotor coil includes a second twisted rotor loop. The first rotor coil has a first symmetry and the inductive position sensor includes a stator. An excitation coil is drawn on the stator and has a second symmetry. The first symmetry substantially corresponds to the second symmetry. A method for determining a position of an object using an inductive position sensor includes generating three electromagnetic fields using respective excitation coils, inducing voltages, respectively, in three receive coils, and determining based on voltages a position of an object coupled to a resonant rotor. The voltages being based on mutual inductances arising between the rotor with each of the excitation and receive coils, and the elimination, by the resonant rotor, of mutual inductances arising between the excitation and receive coils.

A motor driving circuit includes a plurality of pins, a Hall sensor, a Hall signal processing portion and a driving processing circuit. The test-starting pin for receiving the test-starting signal and the test signal output pin for outputting the test signal are shared with at least one pin of the plurality of pins. The Hall sensor senses the change in the magnetic field of the motor to generate a Hall signal. The Hall signal processing unit amplifies the generated Hall signal, and the driving processing circuit drives the motor based on an output signal of the Hall signal processing unit and a control signal input from one of the plurality of pins. In a test mode, the output signal is output from the test signal output pin as a test signal. In a normal mode, at least one pin is used for normal operation.

Systems, devices, and methods for determining a torque on a target using an inductive torque sensor are described. The inductive torque sensor may include an excitation coil, two rotors, and two or more receive coils. Each of the receive coils and the rotors may be inductively coupled. The two or more receive coils may be configured to generate a received voltage which can be approximated by a sine waveform function based on the angular changes of the coils on each rotor, the distance of the receive coils from the rotors and the distance between the receive coils. An integrated circuit may be configured to determine the torque generated on the target based on calculated differences between the angular rotation of the first rotor versus the second rotor over a given period.