Abstract:
A magnetic connector has a receptacle and a plug. The receptacle has an electromagnet comprising an inner core, an outer core, a coil disposed around the inner core and an air gap defined by the edges of the inner and outer cores. The plug has a plug core and an anchor defined by the plug core edge. The anchor is configured to insert into the air gap as a receptacle socket electrically connects with plug pins. The coil is energized and de-energized so as to assist in the insertion or removal of the anchor from within the air gap and the corresponding connection and disconnection of the socket and pins.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/159,336, filed Mar. 11, 2009, titled Magnetic Connector, hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Noninvasive physiological monitoring systems for measuring constituents of circulating blood have advanced from basic pulse oximeters to monitors capable of measuring abnormal and total hemoglobin among other parameters. A basic pulse oximeter capable of measuring blood oxygen saturation typically includes an optical sensor, a monitor for processing sensor signals and displaying results and a cable electrically interconnecting the sensor and the monitor. A pulse oximetry sensor typically has a red wavelength light emitting diode (LED), an infrared (IR) wavelength LED and a photodiode detector. The LEDs and detector are attached to a patient tissue site, such as a finger. The cable transmits drive signals from the monitor to the LEDs, and the LEDs respond to the drive signals to transmit light into the tissue site. The detector generates a signal responsive to the emitted light after attenuation by pulsatile blood flow within the tissue site. The cable transmits the detector signal to the monitor, which processes the signal to provide a numerical readout of oxygen saturation (SpO 2 ) and pulse rate. Advanced blood parameter monitors utilizing multiple LEDs that transmit a spectrum of wavelengths incorporate pulse oximetry and the capability of additional hemoglobin, perfusion and pulse measurements such as carboxyhemoglobin (HbCO), methemoglobin (HbMet), total hemoglobin (Hbt), total hematocrit (Hct), perfusion index (PI) and pulse variability index (PVI), as a few examples. 
         [0003]    High fidelity pulse oximeters capable of reading through motion induced noise are disclosed in U.S. Pat. Nos. 6,770,028, 6,658,276, 6,157,850, 6,002,952 5,769,785, and 5,758,644, which are assigned to Masimo Corporation (“Masimo”) and are incorporated by reference herein. Advanced physiological monitors and corresponding multiple wavelength optical sensors are described in at least U.S. patent application Ser. No. 11/367,013, filed Mar. 1, 2006, titled Multiple Wavelength Sensor Emitters and U.S. patent application Ser. No. 11/366,208, filed Mar. 1, 2006, titled Noninvasive Multi-Parameter Patient Monitor, assigned to Masimo Laboratories, Inc. and incorporated by reference herein. Noninvasive blood parameter monitors and corresponding multiple wavelength optical sensors, such as RainbowTM adhesive and reusable sensors and RAD-57™ and Radical-7™ monitors are also available from Masimo. 
       SUMMARY OF THE INVENTION 
       [0004]    Advanced physiological monitoring systems utilize a significant number of control and signal lines, creating a high pin density for sensor, cable and monitor connectors. This high pin density places a heavy demand on the connector mechanisms with respect to connect/disconnect ease, connection integrity, connector cost and life. A magnetic connector advantageously utilizes one or more of electromagnets, permanent magnets, magnetically permeable materials and air gaps to auto-align, attach, hold and release connectors for physiological monitoring applications. 
         [0005]    One aspect of a magnetic connector is a receptacle and a plug. The receptacle has a wiring end, a receptacle contact end, a receptacle core, a coil and a receptacle contact set. The plug has a cable end, a plug contact end, a plug core and a plug contact set. An air gap is located in the receptacle core at the receptacle contact end. The coil, the core and the air gap form a magnetic circuit so that energizing the coil creates a magnetic field in the air gap. An anchor extends from plug core at the plug contact end so as to fit within the air gap. The receptacle contact set and the plug contact set electrically connect as the anchor inserts into the air gap. 
         [0006]    In various embodiments, the receptacle core has an inner core and an outer core. The coil is wrapped around the inner core. The inner core and the outer core have concentric elongated circular receptacle edges that define the air gap. The plug core has an elongated circular plug edge that defines the anchor. The receptacle contact set has a socket block with contact apertures and contacts at least partially disposed within the contact apertures. The plug contact set has a pin block with pin apertures and pins at least partially disposed within the pin apertures. The pins insert into the contacts. 
         [0007]    Additional embodiments include at least one permanent magnet disposed in either the anchor or the air gap or both. Power leads transmit current from a power source to the coil. A switch in series with one of the power leads is actuated either to block current in the power leads and de-energize the coil or to pass current in the power leads and energize the coil. An LED in series with one of the power leads illuminates according to the flow of current in the power leads so as to indicate if the coil is energized. 
         [0008]    Another aspect of a magnetic connector involves interconnecting an optical sensor and a physiological monitor with a magnetic connector having a monitor receptacle and a cable plug. A receptacle core and a plug core are each constructed of magnetically permeable material. Receptacle contacts are housed within the receptacle core, and plug contacts are housed within the plug core. The receptacle core and the plug core are interconnected so as to electrically connect the receptacle contacts and the plug contacts. The receptacle core and the plug core are also magnetically coupled so as to maintain the interconnection. In an embodiment, a coil is wrapped around either the receptacle core or the plug core so as to form an electromagnet. An air gap is formed in the electromagnet core and an anchor is formed to extend from the other core. The anchor fits within the air gap. Current to the coil is switched on or off so that the electromagnet assists in locking the anchor within the air gap or releasing the anchor from the air gap. 
         [0009]    In various embodiments, at least one permanent magnet is embedded within one of the cores. If a permanent magnet is embedded within or near the anchor or near the air gap, then the permanent magnet locks the anchor within the air gap when the coil is de-energized. When the coil is energized, it creates an opposing field to the permanent magnet within the air gap so as to release the anchor. This permanent-magnet-based magnetic coupling holds the receptacle and plug together when the coil is de-energized, but allows the receptacle and plug to be easily disconnected by briefly energizing the coil. 
         [0010]    A further aspect of a magnetic connector is first and second magnetic elements having first and second contact sets. The first contact set is housed proximate the first magnetic element, and the second contact set is housed proximate the second magnetic element. At least one of the magnetic elements is responsive to a current input so as to alter a magnetic coupling between the magnetic elements. The magnetic coupling assists in making or breaking an electrical connection between the first and second contact sets. In an embodiment, the first magnetic element comprises a core of magnetically permeable material, a conductive coil having “N” turns disposed around at least a portion of the core, coil leads in communications with a current source and an air gap defined within the core. The current source has “I” amps energizing the coil so as to generate a electromagnetic field within the air gap proportional to N times I. In an embodiment, the second magnetic element comprises an anchor of magnetically permeable material sized to closely fit within the air gap. The contact sets make an electrical connection as the anchor is manually inserted into the air gap and break an electrical connection as the anchor is manually withdrawn from the air gap. The anchor locks within the air gap in response to a magnetic field within the air gap so as to maintain an electrical connection between the contact sets. 
         [0011]    In various other embodiments, a switch in series with the coil controls whether the coil is energized, and an LED in series with the switch indicates whether the coil is energized. A permanent magnet is incorporated within the first magnetic element near the air gap and/or within the second magnetic element in or near the anchor. The permanent magnet has poles oriented so that its magnetic field opposes the air gap field. 
         [0012]    In yet another embodiment, a magnetic connector has a plug means and a corresponding receptacle means for interconnecting a sensor and a corresponding monitor. The magnetic connector also has a socket means and a corresponding pin means housed within the plug means and the receptacle means for making and breaking electrical communications between sensor conductors and monitor conductors as the plug is inserted into and removed from the receptacle, respectively. Further, the magnetic connector has a pair of mating magnetic element means housed within the plug means and the receptacle means for assisting in at least one of the making and breaking of electrical communications between the socket means and the pin means. In an embodiment, the mating magnetic element means comprises an electromagnet means for generating a magnetic field within an air gap and an anchor means for locking within and releasing from the air gap according to power provided to the electromagnet means. Various other embodiments include a permanent magnet means for opposing the air gap magnetic field disposed proximate at least one of the air gap and the anchor means, a switch means for manually controlling the air gap magnetic field so as to secure or release the anchor means within the air gap and/or an indicator means for visually identifying the state of the air gap magnetic field. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of a physiological monitoring system having a magnetic connector; 
           [0014]      FIGS. 2A-D  are illustrations of different magnetic connector configurations for connecting a sensor and a monitor; 
           [0015]      FIG. 3  is a general block diagram of a magnetic connector; 
           [0016]      FIGS. 4A-C  are illustrations of various magnetic coupling mechanisms incorporated within a magnetic connector; 
           [0017]      FIGS. 5A-F  are front and back, perspective and exploded, connected and disconnected views of a magnetic connector receptacle and plug; 
           [0018]      FIGS. 6A-E  are cross sectional exploded, disconnected, connected and detailed views of receptacle and plug core assemblies; 
           [0019]      FIGS. 7A-D  are top, perspective, front and side views, respectively, of a receptacle inner core; 
           [0020]      FIGS. 8A-D  are top, perspective, front and side views, respectively, of a receptacle outer core; 
           [0021]      FIGS. 9A-D  are top, perspective, front and side views, respectively, of a receptacle contact set; 
           [0022]      FIGS. 10A-D  are top, perspective, front and side views, respectively, of a plug core; and 
           [0023]      FIGS. 11A-D  are top, perspective, front and side views, respectively, of plug contact set. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]      FIG. 1  illustrates a physiological monitoring system  100  having a sensor  110 , a monitor  120 , a cable  130  interconnecting the sensor  110  and the monitor  120 , and a magnetic connector  140 . The magnetic connector  140  has a receptacle  142  mounted in the monitor  120  and a plug  144  terminating the cable  130 . Advantageously, the magnetic connector  140  utilizes magnetic fields generated by combinations of electromagnets, permanent magnets, magnetically permeable materials and air gaps to auto-align, attach, hold and release the receptacle  142  and plug  144 . In this manner, a relatively small connector having the high contact density needed for advanced physiological monitoring applications can be made to have ease of use, durability and low cost characteristics. These characteristics are particularly important for handheld monitoring applications. Various combinations of sensor  110 , monitor  120 , cable  130  and magnetic connector  140  are described with respect to  FIGS. 2A-D , below. 
         [0025]      FIGS. 2A-D  illustrate different configurations of one or more magnetic connectors  240 ,  250  utilized to connect a sensor  210  and a monitor  220 .  FIGS. 2A-B  illustrate dual magnetic connector configurations and  FIGS. 2C-D  illustrate single magnetic connector configurations. As shown in  FIG. 2A , in a first configuration, a sensor  210  is connected to a monitor  220  via a patient cable  230  and a sensor cable  212 . The patient cable  230  is a standalone component and the sensor cable  212  is integral to the sensor  210 . A first magnetic connector  240  is disposed proximate the monitor  220  for connecting the patient cable  230  to the monitor  220 . A second magnetic connector  250  is disposed between the patient cable  230  and the sensor cable  212  for connecting the patient cable  230  to the sensor  210 . 
         [0026]    In particular, the first magnetic connector  240  has a receptacle  242  mounted to the monitor  220  and a plug  244  mounted to one end of the patient cable  230 . A magnetic field provides at least some force for assisting a person to join and/or disjoin the receptacle  242  and plug  244  so as to electrically connect and/or disconnect patient cable  230  conductors and monitor  220  conductors. The monitor  220  has a button  260  that is actuated so as to energize/de-energize the magnetic field in the receptacle  242 . The monitor  220  also has an indicator light  262  that signals the magnetic field status as on or off. 
         [0027]    Similarly, the second magnetic connector  250  has a receptacle  252  mounted to one end of the patient cable  230  and a plug  254  mounted to the end of the sensor cable  212 . Likewise, a magnetic field provides at least some force for assisting a person to join and/or disjoin the receptacle  252  and plug  254  so as to electrically connect and/or disconnect patient cable  230  conductors and sensor cable  212  conductors. Also, the patient cable receptacle  252  has a button  270  so as to energize/de-energize the magnetic field in the receptacle  252  and an indicator light  272  that signals the magnetic field status as on or off. A magnetic connector embodiment including a receptacle and a plug are described with respect to  FIGS. 5-11 , below. 
         [0028]    As shown in  FIG. 2B , in a second configuration, a sensor  210  is connected to a monitor  220  via a patient cable  230 . A first magnetic connector  240  is disposed proximate the monitor  220  and a second magnetic connector  250  is disposed proximate the sensor  210  for interconnecting the sensor  210  and the monitor  220  via the sensor cable  230 . The first magnetic connector  240  is as described with respect to  FIG. 2A , above. The second magnetic connector  250  is as described with respect to  FIG. 2A , above, except that the plug portion  254  is disposed proximate the sensor  210 . 
         [0029]    As shown in  FIG. 2C , in a third configuration, a sensor  210  is connected to a monitor  220  via a sensor cable  212 . A single magnetic connector  240  is disposed proximate the monitor  220  for connecting the monitor  220  to the sensor  210  via the sensor cable  212 . The magnetic connector  240  has a receptacle  242  mounted to the monitor  220  and a plug  244  mounted to the end of the sensor cable  212  for interconnecting the sensor  210  and the monitor  220 . Otherwise, the magnetic connector  240  is as described with respect to  FIG. 2A , above. 
         [0030]    As shown in  FIG. 2D , in a fourth configuration, a sensor  210  is connected directly to a monitor  220 . A single magnetic connector  240  is disposed between the monitor  220  and sensor  210 . In particular, the magnetic connector  240  has a receptacle  242  disposed proximate the monitor  220  and a plug  244  disposed proximate the sensor  210 . Otherwise, the magnetic connector  240  is as described with respect to  FIG. 2A , above. 
         [0031]    As described with respect to  FIGS. 2A-D , a monitor  220  may be, as examples, any of a multi-parameter patient monitoring system (MPMS), a plug-in to a MPMS, a standalone monitor, a handheld monitor, a handheld monitor docked to a docking station, a personal monitoring device or any physiological parameter calculating device that processes one or more sensor signals to derive a physiological measurement. As described above, a sensor  210  may be a reusable, resposable or disposable sensor; an optical transmission or reflection sensor; a blood pressure sensor; a piezo-electric or other acoustic sensor; an assembly of EKG or EEG electrodes; or any non-invasive or invasive device for providing physiological signals to a monitoring or calculating device. 
         [0032]      FIG. 3  generally illustrates a magnetic connector  300  having a receptacle  301  and a plug  302 . The receptacle  301  has a contact set  310  and magnetic element(s)  320 . The plug  302  has a contact set  360  and magnetic element(s)  370 . The magnetic element pair  320 ,  370  provides a magnetic coupling  305  between receptacle  301  and plug  302 . This magnetic coupling assists a user in making or breaking the electrical/mechanical connection between the contact sets  310 ,  360 , making or breaking continuity between receptacle wiring  312  and plug wiring  362 . In a particularly advantageous embodiment, the receptacle magnetic element(s)  320  incorporate an electromagnet. When energized by a current source  322 , the electromagnet generates a magnetic field within an air gap  330  so as to attract or repel a corresponding anchor  380  that closely fits within the air gap  330 . In various embodiments, the magnetic elements  320 ,  370  may include one or more of electromagnets, permanent magnets, materials with high magnetic permeability, air gaps and anchors. In various embodiments, the receptacle or plug may be integrated with a monitor, such as mounted to a monitor chassis, or attached to a sensor cable or patient cable, for example. 
         [0033]      FIGS. 4A-C  generally illustrate various magnetic coupling  305  ( FIG. 3 ) embodiments between the receptacle and plug of a magnetic connector, such as generally described above with respect to  FIG. 3 . These embodiments include a receptacle core  410  defining an air gap  412  and a corresponding plug core  480  defining an anchor  482 . An electromagnet is formed from the receptacle core  410 , a coil  420 , a DC current source  430 , a switch  440  and an indicator  450 . When the switch  440  is closed, the coil  420  is energized, the indicator  450  is on and the electromagnet generates a magnetic field within the air gap  412 . When the switch  440  is opened, the coil  420  is de-energized, the indicator  450  is off and the air gap magnetic field is extinguished. The receptacle core  410  and plug core  480  are constructed of materials having a high magnetic permeability. A substantial magnetic field is created in the air gap  412  having north “N” and south “S” polarities as shown. The receptacle core  410  and plug core  480  can be any of a variety of shapes and sizes. For example, the embodiment described below with respect to  FIGS. 5-11  utilizes a receptacle core that defines an elongated, circular air gap and a plug core that defines a corresponding elongated, circular anchor. 
         [0034]    As shown in  FIG. 4A , in a first embodiment, the plug core  480  or at least the anchor  482  is a soft iron material and the switch  440  is normally closed (N.C.). Accordingly, D.C. current normally flows in the coil  420  and a magnetic field is maintained in the air gap  412 . As such, the anchor  482  is attracted to and held within the air gap  412 , locking the corresponding plug (not shown) to the corresponding receptacle (not shown). The switch  440  is actuated to interrupt the D.C. current, which releases the anchor  482  from the air gap  412  and allows the plug to be pulled from the receptacle. 
         [0035]    As shown in  FIG. 4B , in a second embodiment, the plug core  480  is a permanent magnet or is a material with a high magnetic permeability embedded with one or more permanent magnets  490 . The permanent magnet field attracts the anchor  482  to the air gap  412 , so as to lock a corresponding plug to a corresponding receptacle. The switch  440  is normally open (N. 0 .). Accordingly, actuating the switch  440  pulses the D.C. current to the coil  420 , temporarily creating an opposing field (N), (S) within the air gap  412 . This releases the anchor  482  from the air gap  412  and allows the plug to be pulled from the receptacle. 
         [0036]    As shown in  FIG. 4C , in a third embodiment, the plug core  480  is a soft iron material. One or more permanent magnets  460  are embedded within the receptacle core  410 . The permanent magnet field attracts the anchor  482  to the air gap  412 , so as to lock a corresponding plug to a corresponding receptacle. The switch  440  is normally open (N.O.). Accordingly, actuating the switch  440  pulses the D.C. current to the coil  420 , temporarily creating an opposing field (N), (S) within the air gap  412 . This releases the anchor  482  from the air gap  412  and allows the plug to be pulled from the receptacle. 
         [0037]      FIGS. 5A-F  illustrate a magnetic connector embodiment  500  having a receptacle  501  and a plug  502 . The receptacle  501  is mountable to a device, such as a physiological monitor. The plug  502  is attachable to a sensor cable or a patient cable. The receptacle  501  has a core  700 ,  800  ( FIGS. 5E-F ) that defines an elongated circular air gap  510 . The plug  502  has a core  1000  ( FIGS. 5E-F ) that defines an elongated circular anchor  550 , which inserts within the air gap  510 . The receptacle core  700 ,  800  and corresponding coil  600  ( FIGS. 5E-F ) form an electromagnet that, when energized, generates a magnetic field within the air gap  510 . Depending on the configuration, the electromagnetic field holds or releases the anchor  550  from the air gap  510  so as to lock or unlock the connection between the receptacle  501  and plug  502 . 
         [0038]    Also shown in  FIGS. 5A-F , the receptacle  501  has a receptacle contact set  900  and the plug  502  has a plug contact set  1100 . When the receptacle  501  and plug  502  are connected, the plug contact set  1100  inserts into the receptacle contact set  900 , electrically coupling the receptacle  501  and socket  502 . This electrical coupling provides an electrical path between cable conductors attached to the plug  502  at a cable end  560  ( FIG. 5A ) and wires attached to the receptacle  501  at a device end  530  ( FIG. 58 ). 
         [0039]    As shown in  FIGS. 5E-F , the receptacle  501  has a coil  600 , an inner core  700 , an outer core  800  and a contact set  900 . The receptacle core  700 ,  800  forms a receptacle housing. In particular, the coil  600  is wound around the inner core  700  and enclosed by the outer core  800 . The contact set  900  is mounted inside the inner core  700 . The plug  502  has a core  1000  and a contact set  1100 . The plug core  1000  forms a plug housing, and the contact set  1100  is mounted inside the plug core  1000 . 
         [0040]      FIGS. 6A-E  are cross-sections of the receptacle core  700 ,  800  and plug core  1000 . As shown in  FIGS. 6A-C , the coil  600  is wound around the receptacle inner core  700  and enclosed by the outer core  800 . Thus configured, the front edges of the receptacle core  700 ,  800  form an air gap  510 . Likewise, the front edge of the plug core  1000  forms an anchor  550  that inserts ( FIG. 6C ) into the air gap  510 . As shown in  FIG. 6D , if DC current flows in the top-half of the coil in a direction into the page and in the bottom-half of the coil in a direction out of the page, then the magnetic field  603  produced by the coil has a north pole, N, at the left and a south pole, S, at the right (right-hand rule). As shown in  FIG. 6E , the magnetic flux  604  in the receptacle core resulting from the magnetic field  603  is mostly confined within the walls of the receptacle core  700 ,  800 , and results in a magnetic field in the air gap  510  as shown. As a result, the magnetic field in the air gap  510  has a north pole at the outer core portion and a south pole at the inner core portion. Thus, a “slice” of the receptacle core  700 ,  800  and corresponding air gap  510  are analogous to the core and air gap described with respect to  FIGS. 4A-C , above. Likewise, a “slice” of the plug core  1000  and plug anchor  550  are analogous to the plug core and anchor described with respect to  FIGS. 4A-C , above. 
         [0041]      FIGS. 7-11  illustrate further details of the receptacle inner core  700 , outer core  800 , receptacle contact set  900 , plug core  1000  and plug contact set  1100 . As shown in  FIGS. 7A-D , the receptacle inner core  700  mounts the receptacle contact set  900  ( FIGS. 9A-D ), supports the coil  600  ( FIGS. 5E-F ), and defines a portion of the receptacle core air gap  510  ( FIG. 5A ). The inner core  700  has a planar base  710  defining a back side  702  and a tubular coil support  720  extending from the base  710  and defining a front side  701 . Both the base  710  and the coil support  720  have an elongated, circular cross-section. Inside the coil support  720  is a bracket  730  and corresponding bracket holes  732  for mounting the receptacle contact set  900  ( FIGS. 9A-D ). A wiring aperture  740  provides wiring access to the contact set  900  from the back side  702 . An elongated circular edge  722  defines a portion of the air gap  510  ( FIG. 5A ) at the front side  701 . In an embodiment (not shown), the base  710  provides chassis mounts for attaching the receptacle  501  ( FIGS. 5A-B ) to a monitor. 
         [0042]    As shown in  FIGS. 8A-D , the receptacle outer core  800  houses the coil, inner core and contact set and defines a portion of the receptacle core air gap  510  ( FIG. 5A ). The outer core  800  has a tubular housing  810  defining a back side  802  and a tubular edge  820  extending from the housing  810  and defining a front side  801 . Both the housing  810  and the edge  820  have elongated circular cross-sections, with the edge  820  cross-section having a smaller circumference than the housing  810  cross-section. The edge  820  also defines a portion of the air gap  510  ( FIG. 5A ). 
         [0043]    As shown in  FIGS. 9A-D , the receptacle contact set  900  has a front side  901 , a back side  902 , a socket block  910  and corresponding contacts (not visible). The socket block  910  has a generally rectangular cross-sectioned body  910  and generally circular mounting ears  920  extending from the block sides. The ears have ear holes  922  that accept fasteners. The socket block  910  also has several rows of apertures  912  that extend from the front side  901  to the back side  902 . Conductive contacts (not visible) are disposed within the apertures  912  and are configured to mate with corresponding plug pins  1130  ( FIGS. 11A-D ), described below. The receptacle contact set  900  mounts within the inner core  700  ( FIGS. 7A-D ) so that the mounting ears  920  rest on the core bracket  730  ( FIGS. 7A-D ). The contact set  900  is attached to the inner core  700  ( FIGS. 7A-D ) with fasteners disposed through the ear holes  922  and mounting holes  732  ( FIGS. 7A-D ). 
         [0044]    As shown in  FIGS. 10A-D , the plug core  1000  mounts the plug contact set  1100  ( FIGS. 11A-D ) and defines an anchor  550  ( FIG. 5B ) that releasably locks within the receptacle air gap  510  ( FIG. 5A ). The plug core  1000  has a tubular housing  1010  defining a back side  1002  and a tubular edge  1020  extending from the housing  1010  and defining a front side  1001 . The edge  1020  has an elongated, circular cross-section. The housing  1010  has an elongated, circular cross-section near the front side  1001  and a circular cross-section near the back side that accommodates a cable (not shown). Inside the housing  1010  is a bracket  1030  and corresponding bracket holes  1032  for mounting the plug contact set  1100  ( FIGS. 11A-D ). A cable aperture  1040  provides cable entry for wiring access to the plug contact set  1100  ( FIGS. 11A-D ) via the back side  1002 . The elongated circular edge  1020  defines the anchor  550  ( FIG. 5B ) at the front side  1001 . 
         [0045]    As shown in  FIGS. 11A-D , the plug contact set  1100  has a front side  1101 , a back side  1102 , a pin block  1110  and corresponding pins  1130 . The pin block  1110  has a generally rectangular cross-sectioned body having generally circular mounting ears  1120  extending from the block sides. The ears  1120  have ear holes  1122  that accept fasteners. The pin block  1110  also has several rows of apertures  1112  that extend from the front side  1101  to the back side  1102 . Conductive pins  1130  are disposed within the apertures  1112  and are configured to mate with corresponding receptacle contacts, described above. The contact set  1100  mounts within the plug core  1000  ( FIGS. 10A-D ) so that the mounting ears  1120  rest on the core bracket  1030  ( FIGS. 10A-D ). The contact set  1100  is attached to the receptacle core  1000  ( FIGS. 10A-D ) with fasteners disposed through the ear holes  1122  and mounting holes  1032  ( FIGS. 10A-D ). 
         [0046]    A magnetic connector has been disclosed in detail in connection with various embodiments. These embodiments are disclosed by way of examples only and are not to limit the scope of the claims that follow. One of ordinary skill in art will appreciate many variations and modifications.