Abstract: A driver unit for an interior permanent magnet motor (IPM) is presented. The driver unit includes sensor electronics configured to sense a phase voltage corresponding to one or more phase terminals of the IPM motor to generate a corresponding phase voltage signal. The driver unit further includes a controller electrically coupled to the sensor electronics and configured to extract one or more triplen harmonics of an order of a ninth harmonic and higher than the ninth harmonic of a fundamental frequency of the phase voltage signal corresponding to the one or more phase terminals. The controller is further configured to determine an angular position of a rotor of the IPM motor based on the extracted one or more triplen harmonics. Related motor assembly and method for controlling the IPM motor are also presented.

Abstract: A stator-less electric motor for an MRI system is provided. The stator-less electric motor includes a body, a rotor rotatable connected to the body, and at least one coil winding disposed on the rotor. The at least one coil winding is arranged so as to rotate the rotor when energized via an electrical current in the presence of a magnetic field generated by a magnet assembly of the MRI system.

Abstract: A stator-less electric motor for an MRI system is provided. The stator-less electric motor includes a body, a rotor rotatable connected to the body, and at least one coil winding disposed on the rotor. The at least one coil winding is arranged so as to rotate the rotor when energized via an electrical current in the presence of a magnetic field generated by a magnet assembly of the MRI system.

Abstract: An electronic filter assembly includes a magnetically conductive annular body extending around a center axis, a set of magnetically conductive prongs radially extending from the center axis toward the annular body, and conductive windings extending around the prongs. The conductive windings can be disposed around the prongs instead of the annular body to assist in conduction of common mode magnetic flux, to reduce impedance of the filter assembly, and/or to more evenly distribute temperature in the filter assembly. A method for forming an electronic filter assembly includes forming an electronic filter assembly having a magnetically conductive annular body extending around a center axis and a set of magnetically conductive prongs radially extending from the center axis toward the annular body. The annular body and the prongs can be formed by coupling plural layers of magnetically conductive bodies together.

Abstract: A driver unit for an interior permanent magnet motor (IPM) is presented. The driver unit includes sensor electronics configured to sense a phase voltage corresponding to one or more phase terminals of the IPM motor to generate a corresponding phase voltage signal. The driver unit further includes a controller electrically coupled to the sensor electronics and configured to extract one or more triplen harmonics of an order of a ninth harmonic and higher than the ninth harmonic of a fundamental frequency of the phase voltage signal corresponding to the one or more phase terminals. The controller is further configured to determine an angular position of a rotor of the IPM motor based on the extracted one or more triplen harmonics. Related motor assembly and method for controlling the IPM motor are also presented.

Abstract: An electromagnetic actuator includes a plunger, an armature, and a coil. The plunger is moveable between a first position and a second position. The armature includes a first armature portion proximally disposed about the first position, and a second armature portion proximally disposed about the second position. The coil is proximally disposed with the first armature portion and, when energized, is configured to generate a magnetic field. The magnetic field causes the plunger to move toward the first position by a magnetic flux through a magnetic circuit. The magnetic circuit includes the first armature portion, the plunger, a main air gap, and a variable air gap. The main air gap and variable air gap are between the first armature portion and the plunger. The main air gap diminishes as the plunger moves toward the first position. The variable air gap enlarges as the plunger moves toward the first position.

Abstract: An electromagnetic actuator includes a plunger, an armature, and a coil. The plunger is moveable between a first position and a second position. The armature includes a first armature portion proximally disposed about the first position, and a second armature portion proximally disposed about the second position. The coil is proximally disposed with the first armature portion and, when energized, is configured to generate a magnetic field. The magnetic field causes the plunger to move toward the first position by a magnetic flux through a magnetic circuit. The magnetic circuit includes the first armature portion, the plunger, a main air gap, and a variable air gap. The main air gap and variable air gap are between the first armature portion and the plunger. The main air gap diminishes as the plunger moves toward the first position. The variable air gap enlarges as the plunger moves toward the first position.

Abstract: An electronic filter assembly includes a magnetically conductive annular body extending around a center axis, a set of magnetically conductive prongs radially extending from the center axis toward the annular body, and conductive windings extending around the prongs. The conductive windings can be disposed around the prongs instead of the annular body to assist in conduction of common mode magnetic flux, to reduce impedance of the filter assembly, and/or to more evenly distribute temperature in the filter assembly. A method for forming an electronic filter assembly includes forming an electronic filter assembly having a magnetically conductive annular body extending around a center axis and a set of magnetically conductive prongs radially extending from the center axis toward the annular body. The annular body and the prongs can be formed by coupling plural layers of magnetically conductive bodies together.