Abstract: A linear motor magnet assembly for use in a loudspeaker unit, with a fixed base actuator component and a membrane actuating element, the membrane actuating element having a linear excursion axis. A first auxiliary magnetic element and a second auxiliary magnetic element are present, the first auxiliary magnetic element providing a first auxiliary spatial magnetic field with a major axis aligned with the linear excursion axis. The second auxiliary magnetic element is fixedly connected to the membrane actuating element of the linear motor magnet assembly and has a second auxiliary spatial magnetic field, the second auxiliary magnetic field overlapping the first auxiliary spatial magnetic field and being substantially similarly oriented as the first auxiliary spatial magnetic field over a first predetermined excursion range of the linear motor magnet assembly.

Abstract: The present disclosure relates to an electrodynamic actuator configured to operate within a wide frequency range up to the entire spectrum of audio frequencies (20 Hz to 20 KHz). The actuator comprises an open-ended hollow body, a package-type magnetic system comprising one or more pairs of magnets arranged in the hollow body, a sound-emitting membrane arranged externally to the hollow body, a support frame extending from the membrane into the hollow body and having two or more coils attached thereto, and conductive tracks connecting each of the coils with an AC power source. Each pair of magnets comprises two coaxially fixed magnets, one of which surrounds another in the form of a ring. There is a magnetic gap between the magnets in each pair of magnets. Moreover, the magnets in each pair of magnets have different magnetizations, so that their magnetic fields are directed in opposite directions.

Abstract: Techniques are provided for generating sound using a speaker mounted to an enclosure (e.g., speaker cabinet) wherein a gas pressure level (e.g., air pressure level) inside the enclosure is lower than an ambient air pressure level outside the enclosure. The reduced gas pressure level within the enclosure provides an environment with a reduced pressure level at a back side of a speaker cone of the speaker, which enhances a low frequency response for a given speaker size, while also minimizing resonant frequencies and phase cancellation issues which could otherwise occur with conventional speaker systems in which acoustic sound waves are generated at the back side of the speaker cone. A pressure compensation system is utilized counteract a force applied to the front side of the speaker cone as a result of the gas pressure level inside the enclosure being lower than the ambient air pressure level outside the enclosure.

Abstract: The present invention is a signal processing circuit 12 for an electrostatic electroacoustic transducer configured to correct signals input to a single driven electrostatic electroacoustic transducer 15 including a diaphragm 151 and a fixed electrode 152 disposed to face the diaphragm. The signal processing circuit includes a correction value determiner 122 configured to determine a correction value v1 of a level based on a level of the input signals s1 from the sound source, and a level corrector 124 configured to correct the level of the input signals based on the correction value. The level corrector is configured to correct the level of an input signal among the input signals based on the correction value. The input signal corresponds to a signal for displacing the diaphragm to a first direction side on which a fixed electrode is not disposed with respect to a predetermined position.

Abstract: A diaphragm for a micro loudspeaker includes an outer casing that is provided with a through-hole, a membrane that is disposed in the through-hole, and a suspension that connects the membrane and the outer casing. The outer casing is provided with an inner wall that wraps into the through-hole. The suspension includes an effective operation zone that is extended from the inner wall into the through-hole, and a fixed area that is extended from the inner wall to outside the through-hole. The fixed area of the suspension is provided with a cut-off area, which keeps the effective operation zone at a good intactness, and enables the membrane to vibrate up and down more uniformly, thereby improving the sound quality of micro loudspeaker.

Abstract: The present invention relates to a speaker having a frame, a magnetic circuit system and a vibrating system. The magnetic circuit system has a main magnet and an auxiliary magnet. The vibrating system has a vibrating diaphragm, a voice coil and a suspension with a first avoiding space. The auxiliary magnet is surrounding the main magnet and passed through the first avoiding space. The first avoiding space is positioned in the suspension so that the auxiliary magnet can be arranged around the main magnet, thereby enhancing the strength of the magnetic field of the magnetic circuit system, and ensuring uniform force on the vibrating diaphragm for improving BLX symmetry of the vibrating diaphragm.

Abstract: A shading ring is disposed in a magnetic circuit system. The magnetic circuit system includes a main magnet, a washer, a voice coil and a secondary magnet. The shading ring is located inside the voice coil. The shading ring includes a first ring body and a second ring body. The second ring body is formed by bending a lower end of the first ring body outward. The first ring body includes a first perpendicular portion and a first horizontal portion. A first cavity is formed inside the first perpendicular portion. The secondary magnet is located in the first cavity. The first horizontal portion is fixedly connected to an upward side of the secondary magnet. The shading ring is arranged into a structure having the first ring body and the second ring body.

Abstract: The present disclosure discloses a speaker assembly including a frame with an accommodation space, a magnetic circuit system and a vibration system accommodated in the frame. The vibration system includes a first vibration system and a second vibration system which are arranged with an interval. The first vibration system includes a first diaphragm and a first voice coil driving the first diaphragm, the second vibration system includes a second diaphragm and a second voice coil driving the second diaphragm to vibrate. The first diaphragm and the second diaphragm have the same vibration direction. The present disclosure has two vibration systems which break through the restriction of the height of the voice coils in the traditional structure and therefore further improve the product performance.

Abstract: The present invention relates generally to audio speakers, and systems and methods for making audio speakers. More specifically, the present invention relates to reliable precision audio speaker coil assemblies, and systems and methods for manufacturing reliable precision audio speaker coil assemblies.

Abstract: A magnetic field transmitter, especially a transmitter used in conjunction with wireless communications earplugs. In one embodiment, a plate of magnetic material is used behind a coil of electrical conductor to improve the efficiency of the transmitter and to provide electrical and magnetic shielding. The specific dimensions and characteristics of the preferred embodiment of the transmitter described herein provide for efficient wireless communications.

Abstract: The present invention relates generally to audio speakers, and systems and methods for making audio speakers. More specifically, the present invention relates to reliable precision audio speaker coil assemblies, and systems and methods for manufacturing reliable precision audio speaker coil assemblies.

Abstract: A loudspeaker device is presented which includes a zeolite material comprising zeolite particles having a silicon to aluminum mass ratio of at least 200. For an increased pore fraction of pores with a diameter in a range between 0.7 micrometer and 30 micrometer shows an increased shift of the resonance frequency down to lower frequencies has been observed.

Abstract: A loudspeaker device is presented which includes a zeolite material comprising zeolite particles having a silicon to aluminum mass ratio of at least 200. For an increased pore fraction of pores with a diameter in a range between 0.7 micrometer and 30 micrometer shows an increased shift of the resonance frequency down to lower frequencies has been observed.

Abstract: The invention provides a planar-magnetic transducer with a frame and a primary magnet row structure of elongated magnets adjacent and air gapped from a first surface side of a mobile portion of a thin film or thin structure diaphragm with conductive traces incorporated with the diaphragm. An additional pair of magnetic sources attached to the frame outside of the vibratable region of the diaphragm and mounted above the plane of the opposite, second surface side of the diaphragm to enhance magnetic energy near the second surface side of the film diaphragm, without any magnet rows attached directly in front of the second surface side of the vibratable region of the diaphragm between the additional pair of magnetic sources.

Abstract: An electro-acoustic micro-converter can be applied in an audio device, and in particular in a hearing aid. The micro-converter is at least substantially block-shaped and includes an at least substantially rectangular acoustic membrane tensioned therein transversely of a longitudinal direction. A coil element is carried by the membrane and extends in a magnetic field maintained by magnet elements, including a permanently magnetic magnet body, in a coil gap around the magnet body.

Abstract: A magnetostrictive phased array transducer for transducing shear horizontal bulkwaves including a plurality of magnetostrictive members each having a bottom surface of a plate-shaped structure made of a ferromagnetic material, which is mounted to be adhered closely to the surface of a mounting place; an insulator disposed on a side surface of each magnetostrictive member; a meander coil having a plurality of coil lines extended in the direction parallel with the bottom surface on each insulator, wherein adjacent coil lines are connected so that current flows in the opposite directions to each other, thereby generating a dynamic magnetic field with respect to each magneto strictive member; and a magnet mounted to generate a static magnetic field perpendicular to the dynamic magnetic field. When the current is supplied to the meander coil, a plurality of magnetostrictive members generate a plurality of shear horizontal bulkwaves while being deformed by the magnetostriction effect.

Abstract: Coaxial transducers, some of which include a first assembly and assembly, each of which includes a magnet and a coil.

Abstract: A magnetic motor system for driving a loudspeaker voice coil. The system has first and second parts that define a volume for receiving a voice coil. The first and second parts each have a respective permanent magnet with first and second sidewalls that extend in a direction away from the volume. The first sidewall slopes in a direction towards the second sidewall as the sidewalls extend away from the volume. The first and second parts further have respective guide members for channelling lines of magnetic flux in a return path between the permanent magnets.

Abstract: A planar speaker system may include a bottom frame having a cavity. Within this cavity a plurality of magnets may be arranged to form a substantially circular pattern. A diaphragm that includes a plurality of electrically conductive traces may be connected to the bottom frame and extend across the cavity of the bottom frame. When alternating current flows through the electrically conductive traces, the diaphragm may vibrate in response to the interaction between the current flowing in the electrically conductive traces and the magnetic field, thereby producing sound. The planar speaker system may include a top frame having a cavity, and a second set of magnets may be disposed in the cavity of the top frame.

Abstract: A single-ended planar transducer device for generating a sound signal based on an electrical signal comprising at least two primary rows of primary magnets, at least one return row of at least one return structure, a diaphragm, a conductive trace formed on the diaphragm, and a frame. The frame supports two primary rows to define at least one core set comprising no more than two primary rows. A primary magnetic field is established between the primary rows in the at least one core set. The frame supports at least one return row adjacent to the at least one core set. A return magnetic field is established between each return row and any primary row adjacent thereto. A first portion of the trace is arranged at least partly within each primary magnetic field and a second portion of the trace is arranged at least partly within each return magnetic field.

Abstract: A loudspeaker magnet assembly for a loudspeaker transducer having a voice coil is provided that has a low profile construction. The loudspeaker magnet assembly may include: a first magnet assembly; top plate position below the first magnet assembly; second magnet assembly positioned below the top plate; and bottom plate positioned below the second magnet assembly. The first magnet assembly may include an annular outer magnet and a circular inner magnet. The top plate may include an annular outer top plate and a circular inner top plate and the second magnet assembly may include an annular outer magnet and a circular inner magnet.

Abstract: An apparatus related to a magnetic circuit design is disclosed. The apparatus includes a magnetic assembly and an electrically-conductive mobile member. The magnetic assembly includes an inner magnet, an outer magnet, an inner cap, an outer cap and a washer. The magnetic assembly is configured to produce a magnetic field having a zone of operation between the inner cap and the outer cap. The zone of operation has substantially uniform magnetic field strength. The zone of operation has magnetic field directions substantially perpendicular to an ideal motion direction. The electrically-conductive mobile member is disposed in the zone of operation of the magnetic field and electrically coupled to a diaphragm of a driver. The electrically-conductive mobile member is configured to move within the zone of operation of the magnetic field in response to the magnetic field when an alternating current is passed through the electrically-conductive mobile member.

Abstract: A low frequency transducer arrangement includes a substantially cylindrical structure surrounding a pole piece. The pole piece and the substantially cylindrical structure define a substantially cylindrical air gap therebetween. Two opposite ends of the air gap are both open and separated from each other in an axial direction. A first magnet is disposed in either the pole piece or the substantially cylindrical structure. A second magnet is separated in the axial direction from the first magnet by a middle magnetic gap. The second magnet is disposed in either the pole piece or the substantially cylindrical structure. The first and second magnets provide flux in a same direction in the middle magnetic gap. A top magnetic gap is disposed axially adjacent the first magnet and opposite the middle magnetic gap. A bottom magnetic gap is disposed axially adjacent the second magnet and opposite the middle magnetic gap. A voice coil is at least partially disposed in the air gap and operates in the middle magnetic gap.

Abstract: A linear interleaved magnetic motor in which the B-field flows between a plurality of motor cell elements, creating a long, serpentine gap. The motor is used with at least one flex circuit as a drive coil. The motor can be used as a drive motor for a loudspeaker transducer. Multiple loudspeaker transducers can be connected together to make a loudspeaker frame or system.

Abstract: A coaxial loudspeaker for reproducing an electrical sound signal is provided. The loudspeaker has a magnetic driver assembly with a first annular slot and an opposed, coaxial second annular slot, each establishing a permanent magnetic field therein from a single magnet. Independently driven first and second voice coils are positioned within the respective one of the first and second annular slots, each being connected to a transducer element.

Abstract: A multifunctional vibrator includes a frame, a vibrating unit receiving in the frame and including a magnetic circuit part with a magnetic gap, a plurality of elastic members connecting the vibrating unit and the frame, and a voice coil partially inserted into the magnetic gap. Each elastic member includes a retaining portion assembling to an inner face of the frame, a connecting portion attached to the vibrating unit, and an elastic portion extending from the retaining portion to the connecting portion along a devious way. The elastic portion of elastic members includes a first arm capable of generating elastic deformation along a short axis direction of the vibrating unit and a second arm capable of generating elastic deformation along a long axis direction of the vibrating unit.

Abstract: Disclosed is a multi-magnet system for speaker. The multi-magnet system includes a yoke having a bottom, a pair of main magnets separated from each other and mounted on the bottom of the yoke, respectively, a mid-magnet mounted on the bottom of the yoke and located between the pair of main magnets, and a pair of auxiliary magnets attached to two ends of the yoke. Wherein, the first main magnet together with the first auxiliary magnet and the mid-magnet defines a first magnetic gap and the second main magnet together with the second auxiliary magnet and the mid-magnet defines a second magnetic gap. By virtue of place the magnets at appropriate locations, the sensitivity of the speaker is effectively enhanced.

Abstract: To provide a speaker unit and a portable information terminal that are reduced in size and thickness and still produce a high sound pressure. A speaker unit includes: a yoke having a rectangular outline as seen in a plan view; a magnet member placed on the yoke and magnetized so that an upper surface of the magnet member has an N pole and an S pole aligned in one direction; a coil placed above and spaced from the upper surface of the magnet member; a diaphragm attached to the coil; and a frame supporting the diaphragm. An engagement protrusion which allows the frame and the yoke to engage with each other is provided on a side which is one of the sides defining the rectangular outline of the yoke and extends along the one direction.

Abstract: A speaker includes a yoke defining a receiving cavity therein, a first magnet received in the receiving cavity of the yoke, a second magnet received in the receiving cavity of the yoke and opposite to the first magnet, a first coil surrounding the first magnet, a second coil surrounding the second magnet, and a diaphragm drove to vibrate by both of the first coil and the second coil. A shape of the first coil is approximately a horse's hoof and defines a first linear side, a flexuous side and a pair of first arc sides coupled with two ends of the first linear side and two ends of the flexuous side.

Abstract: A transducer magnet for a low profile loudspeaker transducer is provided having a voice coil, surround suspension, diaphragm, and top plate. The transducer magnet may include a first magnet assembly, including an annular outer magnet having an outer perimeter, an outer diameter and an inner diameter. The inner diameter defines a vacant circular center within the annular outer magnet, and the difference in length between the diameter of the circular inner magnet and the inner diameter of annular outer magnet define an annular first magnet assembly air gap. The annular outer magnet includes one or more channels extending inwardly from the outer perimeter of the annular outer magnet to the first magnet assembly air gap, which is configured to receive the voice coil. The channels are configured to pass hookup wires from the voice coil to an external device from the transducer magnet.

Abstract: An electromechanical transducer 180, motor structure 200 and voice coil winding support structure or bobbin 210 are configured to protect and transport heat away from a voice coil 220 which is would solely within the interior of bobbin 210 and configured for reciprocating movement in close proximity to an extended cooling pole piece 204. A compact, economical and efficient adaptation of a pancake style motor includes generous volume for a powerful magnet 208, while providing an extended, linear range of excursion and continuous cooling for the generously overhung voice coil 220.

Abstract: Contemplated planar magnetic transducers include a magnet and diaphragm arrangement such that substantially homogenous vertical and high horizontal magnetic flux density is realized in the inter-magnet space. Most preferably, the diaphragm is a tensioned polymer membrane in which the voice coil covers a significant portion of the active portion of the membrane, and the magnets are rare-earth metal-type magnets of ultra-high strength. Particularly preferred planar magnetic transducers allow for exceptionally large excursion of the diaphragm in a substantially homogenous magnetic field at virtually no distortion, thereby providing heretofore unachieved sound pressure levels. Arrays of such and other transducers are disclosed that provide a full-range speaker with acoustic plane source characteristics.

Abstract: A magnetic circuit includes an inner permanent magnet assembly and an outer permanent magnet assembly, a magnetically permeable yoke, and first and second air gap portions conducting first and second magnetic flux densities, respectively, the first and second air gap portions being adapted to receive first and second voice coil segments, respectively. The magnetic flux density in the first air gap portion is generated by superposition of magnetic flux generated by the inner permanent magnet assembly and magnetic flux generated by the outer permanent magnet assembly, and wherein the magnetic flux density in the second air gap portion is generated substantially exclusively by the inner permanent magnet assembly.

Abstract: A speaker device, wherein vibration of a magnetic circuit section is suppressed with a magnetic influence on the magnetic circuit section suppressed. A speaker device having a vibration section and generating an audio sound by vibration of the vibration section is provided with a magnetic circuit section for forming a magnetic field for vibrating the vibration section and also with a weight section fixed to the magnetic circuit section and suppressing vibration of the magnetic circuit section subjected to reaction force caused by vibration of the vibration section. The weight section is fixed to the magnetic circuit section through a joint section for joining the magnetic circuit section and the weight section to each other, and this forms between the magnetic circuit section and the weight section a predetermined space for magnetically separating the magnetic circuit section and the weight section from each other.

Abstract: An electroacoustical apparatus and method is described that alters the output properties of an audio device to improve the sound properties for both hearing impaired and normal hearing listeners. The device includes a coil element of specific design and may incorporate digital signal processing techniques to modify audio signal output. The electrical device and method of processing provides for the beneficial alteration of sound waves to an audio signal, and further modification of the audio signal to provide for improved loudness and clarity characteristics. The improved characteristics provide for greater intelligibility of the audio signal to persons with hearing impairments and to persons with normal hearing.

Abstract: The present invention is to provide a loudspeaker, which includes a frame having a through hole centrally provided at a bottom side thereof, a coil tube with a coil unit fixedly mounted around the outer periphery thereof and having a first end fixed to the through hole and a second end received in a receiving space of the frame, a diaphragm attached to periphery of an opening of the frame, and a plurality of oppositely oriented magnetic elements fixed on the diaphragm, wherein every two adjacent magnetic elements are spaced apart by an appropriate distance, and the magnetic elements are located in the coil tube at positions that magnetic lines generated by the coil unit are highly concentrated. Since vibration of the magnetic elements caused by the magnetic forces generated from the coil unit is enhanced, output power of the loudspeaker will increase accordingly.

Abstract: A novel ribbon microphone incorporates rounded-edge magnet motor assembly, a backwave chamber, and a phantom-powered JFET circuit. In one embodiment of the invention, one or more novel rounded-edge magnets may be placed close to a ribbon of the ribbon microphone, wherein the one or more novel rounded-edge magnets reduce or minimize reflected sound wave interferences with the vibration of the ribbon during an operation of the ribbon microphone. Furthermore, in one embodiment of the invention, a novel backwave chamber operatively connected to a backside of the ribbon can minimize acoustic pressure, anomalies in frequency responses, and undesirable phase cancellation and doubling effects. Moreover, in one embodiment of the invention, a novel phantom-powered JFET preamplifier gain circuit can minimize undesirable sound distortions and reduce the cost of producing a conventional preamplifier gain circuit.

Abstract: An acoustic transducer includes a sound-producing member at least partially disposed within the first magnetic flux gap region between the magnetic poles, the sound-producing assemblage is magnetically excited through a magnetic circuit that passes from a location outside the magnetic flux gap region to inside the magnetic flux region through an air gap.

Abstract: The present disclosure relates to a coil transducer motor structure (20) including at least one coil (22), at least one magnetic element (23) arranged in use to provide a path for magnetic flux between the ends of said coil (22), wherein the magnetic element (23) has a structure providing a curvilinear path therethrough for said magnetic flux.

Abstract: An acoustic transducer including a sound producing cone that is activated by a voice coil cylinder having a pair of spaced electrical windings that are retained in spaced relationship from a surround ferromagnetic ring that is carried by a heat sink and wherein a magnetic subassembly is mounted within the voice coil cylinder. The voice coil cylinder is supported by a pair of spaced suspension members or spiders and by the sound producing cone.

Abstract: A speaker includes a case, a dome, a diaphragm, a first voice coil, a second voice coil, a first pole plate, a second pole plate, a first magnet, a second magnet and a yoke. The case is supported on the frame to form a receiving room therebetween. The yoke includes a bottom portion and a side portion perpendicularly extending upward from the center of the bottom portion. A first magnetic gap is formed between the inner wall of the side portion and the outer wall of the magnet for receiving the first voice coil, and a second magnetic gap is formed between the outer wall of the side portion and the inner wall of the second magnet for receiving the second voice coil.

Abstract: A magnetic circuit includes a cylindrical yoke member having an inner circumferential surface and a collar formed at one end thereof and turned back substantially at right angles, and a plurality of permanent magnet segments of a partially circular arc in cross section. Each of the permanent magnets has an outer surface attracted magnetically to the inner circumferential surface of the cylindrical yoke member, and one end face attracted magnetically to the collar of the cylindrical yoke member. The magnetic circuit is applied to an actuator or a speaker.

Abstract: A dual-coil, dual magnetic gap electromagnetic transducer is provided where each voice coil is wired to include separate leads so that each individual voice coil may be driven by a separate amplifier or by a separate bridged amplifier. Signal processing may further be utilized to increase the output of the loudspeaker, to achieve extreme excursion without extreme distortion and to provide for alternative voice coil designs to address common problems with dual-coil, dual magnetic gap transducers, including, but not limited to, heat generation.

Abstract: A variety of loudspeaker arrangements may have any of multiple adjacent magnetic circuits, single magnetic circuits, an improved loudspeaker voice coil assembly, multiple voice coil windings (124-127, 315-317), and commutated current. The radial direction of flux may alternate at adjacent poles and may have a controller that commands the current through each of the windings. The position of the moving components may be measured or inferred by the controller (213). An encoding track (318a) applied to the surface of the assembly may allow the assembly to function as part of a position transducer to permit appropriate action based on position. Calculated or sensed actual position may be used to determine the relative current in each of the windings and the controller may have compensation such as a motion control algorithm, thermal monitoring, and management of the driver.

Abstract: The present invention relates to a miniature electro-acoustic transducer including a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm. The magnetic circuit includes first and second air gap portions adapted to receive first and second voice coil segments, respectively. The magnetic flux acting on the first voice coil segment is provided by inner magnetic means and first outer magnetic means in combination and the magnetic flux acting on the second voice coil segment is essentially provided by the inner magnetic means only.

Abstract: An electromagnetic transducer includes an electromagnetic dual-coil or multi-coil driver having at least one spacer member placed between at least two permanent magnets. The inclusion of at least one spacer member increases the axial dimension of the magnetic assembly of the driver so that the magnetic gaps in a dual-coil or multi-coil driver are moved farther apart than would occur with a corresponding electromagnetic driver using a permanent magnet instead of two permanent magnets separated by a spacer member.

Abstract: A speaker diaphragm is configured by a compound mixed with resin and bamboo fiber. The diaphragm satisfying the advantage of the bamboo fiber of high sound quality and a large degree of freedom in the setting of the characteristic value of the diaphragm and the advantage of the diaphragm made of a resin with improved humidity resistance reliability and strength, excellent external appearance, and enhanced productivity and dimension stability is obtained.

Abstract: A speaker diaphragm is configured by a compound mixed with resin and bamboo fiber. The diaphragm satisfying the advantage of the bamboo fiber of high sound quality and a large degree of freedom in the setting of the characteristic value of the diaphragm and the advantage of the diaphragm made of a resin with improved humidity resistance reliability and strength, excellent external appearance, and enhanced productivity and dimension stability is obtained.

Abstract: A speaker diaphragm is configured by a compound mixed with resin and bamboo fiber. The diaphragm satisfying the advantage of the bamboo fiber of high sound quality and a large degree of freedom in the setting of the characteristic value of the diaphragm and the advantage of the diaphragm made of a resin with improved humidity resistance reliability and strength, excellent external appearance, and enhanced productivity and dimension stability is obtained.

Abstract: A moving coil loudspeaker has an interchangeable magnet assembly with a plurality of interchangeable magnet segments configured to be circumferentially disposed about a voice coil within the loudspeaker. Heat sink members can be arranged in between the magnet segments to absorb excess heat generated during operation of the loud speaker. In one embodiment, the magnet assembly has at least one annular magnetic member made up of the plurality of magnet segments, a plurality of heat sink members disposed in between the magnet segments, an annular first plate adjacent a first side of the annular magnetic member, and a yoke member having a second plate adjacent a second side of the annular magnetic member and a central cylindrical portion configured to pass through a central opening in the annular magnetic member.