Reactance sensors of radial position for magnetic bearings and bearingless drives

A radial position sensor comprising:

• a plurality of emitters, the emitters being electrically isolated from each other, each of the plurality of emitters being configured to receive a respective one of a corresponding plurality of time-varying input electrical signals;
• a receiving element disposed in juxtaposition to each of the plurality of emitters, the receiving element being coupled to each of the plurality of emitters by a respective electrical reactance;
• a rotatable element disposed between the emitters and the receiving element, the rotatable element being configured to rotate about an axis of rotation;
• and
• an output terminal coupled to the receiving element for providing a time-varying output signal, a phase of the time-varying output signal being proportional only to an angular component of a radial displacement, an amplitude of the time-varying output signal being proportional only to a magnitude of the radial displacement of the rotatable element.

A radial position sensor comprising:

• a emitting element comprising a plurality of electrically isolated emitters, each emitter configured to produce a magnetic field when it is energized, thereby producing a plurality of magnetic fields when two or more of the emitters are energized;
• a receiving element;
• and
• a rotatable disposed in juxtaposition to the emitting element and to the receiving element, the rotatable element configured to rotate about an axis of rotation, wherein a radial displacement of the rotatable element causes a change in electromagnetic coupling between the plurality of magnetic fields and the receiving element when the plurality of emitters are energized,
• the receiving element producing an output signal when the plurality of magnetic fields are electromagnetically coupled thereto by the rotatable element,
• wherein an amplitude of the output signal is proportional only to a magnitude of a radial displacement of the rotatable element, wherein a phase of the output signal is proportional only to an angle of the displacement of the rotatable element.

A radial position sensor comprising:

• a emitting element comprising a plurality of electrically isolated emitters, each emitter configured to produce an electric field when it is energized, thereby producing a plurality of electric fields when two or more of the emitters are energized;
• a receiving element;
• and
• a rotatable element disposed in juxtaposition to the emitting element and to the receiving element, the rotatable element configured to rotate about an axis of rotation, wherein when the rotatable element is radially displaced a change occurs in the electromagnetic coupling between the plurality of electric fields and the receiving element when the plurality of emitters are energized,
• the receiving element producing an output signal when the plurality of electric fields are electromagnetically coupled thereto by the rotatable element,
• wherein an amplitude of the output signal is proportional only to a magnitude of a radial displacement of the rotatable element, wherein a phase of the output signal is proportional only to an angle of the displacement of the rotatable element.