PATENT DOCUMENT

Publication Number: US-8497753-B2
Application Number: US-63376509-A
Country: US
Kind Code: B2

Title: Electromagnetic connector for electronic device

Abstract:
An electrical plug and receptacle relying on magnetic force from an electromagnet to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one of the plug or receptacle can be a magnet or ferromagnetic material. The magnetic element on the other of the plug or receptacle is an electromagnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the electromagnet magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Claims:
What is claimed is: 
     
       1. A connector comprising:
 a first contact; 
 an electromagnet positioned on the connector; and 
 a switch element coupled to the electromagnet to control energization of the electromagnet, wherein the switch element comprises a touch switch actuatable by a user, 
 wherein the electromagnet is energizable to produce magnetic attraction with a magnetic element in a second connector and substantially maintain contact between the first contact and a second contact of the second connector in an electrically conductive relationship, 
 wherein the switch element further comprises a motion detector, and the motion detector de-energizes the electromagnet when a movement is detected. 
 
     
     
       2. The connector of  claim 1 , wherein the first contact is one of a plurality of movable first contacts to make electrically conductive paths with a plurality of second contacts in the second connector when the first connector is mated with the second connector, each of the movable first contacts biased by one of a plurality of first springs. 
     
     
       3. The connector of  claim 1  wherein the electromagnet is energizable to substantially maintain contact between a third contact in the connector and a fourth contact of the second connector,
 wherein the first and second contact form a power supply path and the second and third contact form a ground path. 
 
     
     
       4. The connector of  claim 3  wherein at least one of the first or second contacts is biased by a spring. 
     
     
       5. The connector of  claim 4  wherein the connector further comprises a raised portion around the first and third contacts, and the raised portion fits in a recess in the second connector. 
     
     
       6. A connector comprising:
 a first contact; 
 an electromagnet positioned on the connector; and 
 a switch element coupled to the electromagnet to control energization of the electromagnet, wherein the switch element comprises a touch switch actuatable by a user, 
 wherein the electromagnet is energizable to produce magnetic attraction with a magnetic element in a second connector and substantially maintain contact between the first contact and a second contact of the second connector in an electrically conductive relationship, 
 wherein if the electromagnet is energized, when the touch switch is actuated, the electromagnet is de-energized, and if the electromagnet is de-energized, when the touch switch is actuated, the electromagnet is energized. 
 
     
     
       7. The connector of  claim 6 , wherein the electromagnet comprises a ferromagnetic core wrapped with a coil, the coil connectable to a power supply. 
     
     
       8. The connector of  claim 6 , wherein the first contact and the second contact form a signal path. 
     
     
       9. The connector of  claim 6 , wherein the first contact is one of a plurality of movable first contacts to make electrically conductive paths with a plurality of second contacts in the second connector when the first connector is mated with the second connector, each of the movable first contacts biased by one of a plurality of first springs. 
     
     
       10. The connector of  claim 6 , wherein the connector is a plug. 
     
     
       11. The connector of  claim 6 , wherein the connector is a receptacle. 
     
     
       12. The connector of  claim 6 , wherein the first contact and the second contact form a path for a power supply. 
     
     
       13. The connector of  claim 6 , wherein the magnetic element in the second connector comprises a permanent magnet. 
     
     
       14. The connector of  claim 6 , wherein the magnetic element in the second connector comprises ferromagnetic material. 
     
     
       15. The connector of  claim 6  wherein the electromagnet is energizable to substantially maintain contact between a third contact in the connector and a fourth contact of the second connector,
 wherein the first and second contact form a power supply path and the second and third contact form a ground path. 
 
     
     
       16. The connector of  claim 15  wherein at least one of the first or second contacts is biased by a spring. 
     
     
       17. The connector of  claim 16  wherein the connector further comprises a raised portion around the first and third contacts, and the raised portion fits in a recess in the second connector. 
     
     
       18. A method of forming an electrical connection comprising:
 determining that a touch switch has been actuated, then energizing an electromagnet in a first connector such that the electromagnet in the first connector is attracted to a magnetic element in a second connector, and the electromagnet substantially maintains contact between the first connector and the second connector; 
 forming an electrical connection between a first contact in the first connector and a second contact in the second connector; and 
 determining that the touch switch has been actuated, then de-energizing the electromagnet in the first connector. 
 
     
     
       19. The method of  claim 18 , wherein forming an electrical connection between a first contact in the first connector and a second contact in the second connector comprises forming a signal path. 
     
     
       20. The method of  claim 18 , wherein forming an electrical connection between a first contact in the first connector and a second contact in the second connector comprises forming a path for a power supply. 
     
     
       21. The method of  claim 8  further comprising forming an electrical connection between a third contact in the first connector and a fourth contact in the second connector,
 wherein the first and second contact form a power supply path and the second and third contact form a ground path. 
 
     
     
       22. The method of  claim 21  wherein at least one of the first or second contacts is biased by a spring. 
     
     
       23. The method of  claim 22  wherein forming an electrical connection further comprises inserting a raised portion around the first and third contacts on the connector into a recess in the second connector. 
     
     
       24. A connector comprising:
 a first contact; 
 an electromagnet positioned on the connector, wherein when the electromagnet is energized, the magnetic attraction produced attracts a magnetic element in a second conductor and substantially maintains contact between the connector and the second connector, such that the first contact and a second contact in the second connector form an electrically conductive relationship; and 
 a touch switch coupled to the electromagnet to control the energization of the electromagnet, 
 wherein the switch element further comprises a motion detector, and the motion detector de-energizes the electromagnet when a sudden movement is detected. 
 
     
     
       25. The connector of  claim 24 , wherein the first contact is one of a plurality of movable first contacts to make electrically conductive paths with a plurality of second contacts in the second connector when the first connector is mated with the second connector, each of the movable first contacts biased by one of a plurality of first springs. 
     
     
       26. The connector of  claim 24  wherein the electromagnet is energizable to substantially maintain contact between a third contact in the connector and a fourth contact of the second connector,
 wherein the first and second contact form a power supply path and the second and third contact form a ground path. 
 
     
     
       27. The connector of  claim 26  wherein at least one of the first or second contacts is biased by a spring. 
     
     
       28. The connector of  claim 27  wherein the connector further comprises a raised portion around the first and third contacts, and the raised portion fits in a recess in the second connector. 
     
     
       29. A connector comprising:
 a first contact; 
 an electromagnet positioned on the connector, wherein when the electromagnet is energized, the magnetic attraction produced attracts a magnetic element in a second conductor and substantially maintains contact between the connector and the second connector, such that the first contact and a second contact in the second connector form an electrically conductive relationship; and 
 a touch switch coupled to the electromagnet to control the energization of the electromagnet, 
 wherein if the electromagnet is energized, when the touch switch is actuated, the electromagnet is de-energized, and if the electromagnet is de-energized, when the touch switch is actuated, the electromagnet is energized. 
 
     
     
       30. The connector of  claim 29 , wherein the electromagnet comprises a ferromagnetic core wrapped with a coil, the coil connectable to a power supply. 
     
     
       31. The connector of  claim 29 , wherein the first contact is one of a plurality of movable first contacts to make electrically conductive paths with a plurality of second contacts in the second connector when the first connector is mated with the second connector, each of the movable first contacts biased by one of a plurality of first springs. 
     
     
       32. The connector of  claim 29 , wherein the connector is a plug. 
     
     
       33. The connector of  claim 29 , wherein the first contact and the second contact form a signal path. 
     
     
       34. The connector of  claim 29 , wherein the first contact and the second contact form a path for a power supply. 
     
     
       35. The connector of  claim 29 , wherein the magnetic element in the second connector comprises a permanent magnet. 
     
     
       36. The connector of  claim 29 , wherein the magnetic element in the second connector comprises ferromagnetic material. 
     
     
       37. The connector of  claim 29  wherein the electromagnet is energizable to substantially maintain contact between a third contact in the connector and a fourth contact of the second connector,
 wherein the first and second contact form a power supply path and the second and third contact form a ground path. 
 
     
     
       38. The connector of  claim 37  wherein at least one of the first or second contacts is biased by a spring. 
     
     
       39. The connector of  claim 38  wherein the connector further comprises a raised portion around the first and third contacts, and the raised portion fits in a recess in the second connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 12/045,704, filed Mar. 11, 2008, which is a continuation of U.S. patent application Ser. No. 11/235,873, filed Sep. 26, 2005, now U.S. Pat. No. 7,351,066, which are incorporated by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     The subject matter of the present disclosure generally relates to a magnetic connector for an electronic device and more particularly relates to an electromagnetic connector for a power adapter connecting a laptop computer to a power supply. 
     BACKGROUND OF THE DISCLOSURE 
     Electronic devices, such as laptop computers, typically use DC power supplied from a transformer connected to a conventional AC power supply. Referring to  FIG. 1 , a power adapter  20  according to the prior art is illustrated. The power adapter  20  has a transformer  22 , a power cable  26 , a male connector  30 , and a female connector  40 . The transformer  22  has a plug  24  for connecting to a conventional AC power outlet (not shown), and the male connector  30  is connected to the transformer  22  by power cable  26 . The female connector  40  is typically attached to the housing  12  of an electronic device  10 , such as a laptop computer, and is typically attached to a printed circuit board  14  of the internal electronics of the device  10 . To make the conventional power connection between the transformer  22  and the device  10 , the male connector  30  has a male end  32  that inserts into the female connector  40 . Connectors for portable computers are preferably as small as possible and low profile for today&#39;s thin notebooks. 
     Damage can occur to the conventional power connection in a number of ways. In one example, simply inserting the male connector  30  into the female connector  40  can cause damage. In another example shown in  FIG. 2 , damage can occur when any of the components (e.g., the device  10 , male connector  30 , transformer  22 , etc.) is inadvertently pulled away from other components by a non-axial force while the male and female connectors  30  and  40  are still connected together. In addition to conventional power connections, damage of other types of connections to electronic devices can also occur in the same ways described above. 
     In general, the surface area of two magnetically attracted halves determines the number of magnetic flux lines and therefore the holding force between them because the holding force is proportional to the contact area between the two magnetically attracted halves. Thus, to have a strong force holding the two magnetically attracted halves together, the two magnetically attracted halves want to be as large as possible. 
     The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above. 
     SUMMARY OF THE DISCLOSURE 
     A magnetic connector that relies on magnetic force for maintaining contact is disclosed. The magnetic connector includes a plug and a receptacle. In one embodiment, the plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a transformer connectable to a power supply. The plug includes a plurality of electrical pins, which are preferably biased towards a corresponding plurality of contacts positioned on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one or both of the plug and receptacle can be a magnet, which is preferably a permanent rare earth magnet although electromagnets may also be used. A ferromagnetic element can be used for the magnetic element on the plug or receptacle that does not include a magnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the magnet and its complement, whether another magnet or a ferromagnetic material, magnetically couples the plug and the receptacle and maintains the pins and contacts in an electrically conductive relationship. The magnetic connector allows the plug to break away from the receptacle if the plug or receptacle is inadvertently moved (with sufficient force) while still connected. 
     The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, preferred embodiments, and other aspects of subject matter of the present disclosure will be best understood with reference to a detailed description of specific embodiments, which follows, when read in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a power adapter having a power connection according to the prior art. 
         FIG. 2  illustrates a type of possible damage resulting from the prior art power connection. 
         FIG. 3  illustrates a cross-sectional view of an embodiment of a magnetic connector according to certain teachings of the present disclosure. 
         FIG. 4  illustrates a front view of a receptacle of the magnetic connector of  FIG. 3 . 
         FIG. 5  illustrates a front view of a plug of the magnetic connector of  FIG. 3 . 
         FIG. 6  illustrates an ability of the disclosed magnetic connector to prevent possible damage. 
         FIG. 7  illustrates an alternative embodiment of the magnetic connector of  FIG. 3 . 
         FIGS. 8A-8B  illustrate a plug of another embodiment of a magnetic connector according to certain teachings of the present disclosure. 
         FIGS. 9A-9B  illustrate a receptacle for the plug of the disclosed magnetic connector of  FIGS. 8A-8B . 
         FIG. 10  illustrates a perspective view of the plug and receptacle for the disclosed magnetic connector of  FIGS. 8A-8B  and  9 A- 9 B. 
         FIGS. 11A-11B  illustrate an embodiment of a magnetic connector according to certain teachings of the present disclosure having a plurality of magnets and a back plate. 
         FIGS. 12A-12B  illustrate another embodiment of a magnetic connector according to certain teachings of the present disclosure having a plurality of magnets and a back plate. 
         FIGS. 13A-13B  illustrate embodiments of magnetic connectors according to certain teachings of the present disclosure having electromagnets. 
         FIG. 14  illustrates an embodiment of a magnetic connector according to certain teachings of the present disclosure having an electromagnet and switch element. 
         FIG. 15  illustrates an embodiment of a magnetic connector according to certain teachings of the present disclosure having an electromagnet and a proximity sensor. 
         FIG. 16  illustrates an embodiment of a magnetic connector according to certain teachings of the present disclosure having an electromagnet and fault detector. 
         FIG. 17  illustrates an embodiment of a magnetic connector according to certain teachings of the present disclosure having two electromagnets and fault detector. 
         FIG. 18  illustrates an embodiment of a magnetic connector according to certain teachings of the present disclosure having an electromagnet and control circuitry. 
     
    
    
     While the disclosed magnetic connectors are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. The figures and written description are not intended to limit the scope of the inventive concepts in any manner. Rather, the figures and written description are provided to illustrate the inventive concepts to a person skilled in the art by reference to particular embodiments, as required by 35 U.S.C. §112. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 3 , an embodiment of a magnetic connector  100  according to certain teachings of the present disclosure is illustrated in a cross-sectional view. The magnetic connector  100  includes a first connector or plug  110  and a second connector or receptacle  150 . The plug  110  is connectable to a first device or electrical relation  50 , while the receptacle  150  is connectable to a second device  60 . In one embodiment, the first device  50  is a transformer, and the second device  60  is an electronic device, such as a laptop computer, having a housing  62  and internal electronics  64 . Therefore, in one embodiment, the magnetic connector  100  can be part of a power adapter for connecting the laptop computer  60  to a conventional AC power supply (not shown) with the transformer  50 . For a standard laptop computer, the magnetic connector  100  is preferably rated for 6 A at 24V, and the plug  110  and receptacle  150  can both be approximately 4-mm tall and 6-mm wide. 
     The plug  110  includes a plug body  112  having a face  118  and connected to a cable  114 . Preferably, the body  112  is composed of a conventional non-conductive material. The body  112  houses internal wires  116  of the cable  114 , which connects to the first device  50 . A plurality of first electrical contacts  120  and a first magnetic element  130  are positioned on the plug body  112 . In a preferred embodiment and as shown in  FIG. 3 , the first electrical contacts  120  are preferably plated and spring loaded pins to maintain contact with the corresponding contacts on the receptacle  150 . The pins  120  are held in housings  124  and are connected to the wires  116  of the cable  114 . Springs  122  bias the pins  120  so that they extend from the face  118  of the plug body  112 . In the present embodiment, the first magnetic element  130  is embedded in the face  118  of the plug body  112 . 
     The receptacle  150  has a body  152  connected to the housing  62  of the second device  60 . The body  152  has a face  158 , a plurality of second electrical contacts  160 , and a second magnetic element  140 . In a preferred embodiment and as shown in  FIG. 3 , the second electrical contacts  160  are plates embedded in the face  158  of the body  152  and electrically connected to the internal electronics  64  by wires  162  or the like. In addition, the second magnetic element  170  is embedded in the face  118  of the body  152 . 
     To make the electrical connection between the first and second devices  50  and  60 , the face  118  of the plug  110  is positioned against the face  158  of the receptacle  150 . The pins  120  on the plug  110  engage the plates  160  on the receptacle  150 . Thus, the wires  116  connected to the first device  50  are electrically connected to the wires  162  connecting to the internal electronics  64  of the second device  60 . As will be appreciated by one skilled in the art, electrical connection between pointed pins  120  and substantially flat plates  160  is preferred for a number of reasons, such as issues related to Hertzian stresses around a contact point and issues related to contact asperities or aspots. 
     To maintain the electrical connection, the attractive force between the first and second magnetic elements  130  and  170  holds the plug  110  to the receptacle  150 . In one embodiment, both magnetic elements  130  and  170  are magnets, either permanent or electromagnetic, arranged to attract magnetically to one another. In an alternative embodiment, either magnetic element  130  or  170  is a magnet, either permanent or electromagnetic, while the other complementary element is a ferromagnetic material. The permanent magnet used for the magnetic elements is preferably a permanent rare earth magnet because rare earth magnets have a high flux density compared to their size. When the plug  110  and receptacle  150  are brought into proximity, the attractive force between the magnetic elements  130  and  170  maintains the contacts  120  and  160  in an electrically conductive relationship. 
     The magnetic attraction or force of the plug  110  coupled to the receptacle  150  can be configured for a particular implementation as desired. For embodiments of the magnetic connector  100  used for a power adapter, the magnetic field produced by the magnetic attraction between the elements  130  and  170  is small enough not to interfere with the supply of power through the electrical contacts  120  and  160 . Because magnetic fields of the elements  130  and  170  may interfere with the internal electronics  64  and other components of the device  60 , the receptacle  150  may be positioned on the housing  150  at a location away from various components. For example, the receptacle  150  may be positioned away from disk drives, USB ports, internal busses, etc. of a laptop computer. Alternatively, the elements  130  and  170  may be shielded from various components of the electronic device, or a flux bar may be used to direct any magnetic flux of the elements  130  and  170  away from various components. 
     In one embodiment shown in the front view of  FIG. 4 , the receptacle  150  has four electrical plates  160  positioned around the centrally located magnetic element  170 . The body  152  of the receptacle is oval or oblong and has two axes of symmetry. For the embodiment of the receptacle  150  requiring DC power, two of the electrical plates  160 (+) may be positive contacts, and two of the plates  120 (−) may be negative contacts. Various arrangements are possible and would be within the abilities on one skilled in the art. 
     In the embodiment shown in the front view of  FIG. 5 , the plug  110  is made to correspond with the arrangement of the receptacle  150  in  FIG. 4 . Therefore, the body  112  of the plug  110  is also oval, and the plug has four pins  120  positioned around the magnetic element  130 , which is centrally located on the plug  110 . For the embodiment of the plug  110  connected to an AC to DC transformer, two of the electrical contacts  120 (+) are positive contacts, and two of the contacts  120 (−) are negative contacts. 
     The arrangement of the pins  120  and plates  160  is symmetrical along the axes of symmetry defined by the oval or oblong shape of the bodies  112  and  152 . In this way, the plug  110  and receptacle  150  can be coupled in only two ways, and proper alignment of positive pins  120 (+) with positive plates  160 (+) and of negative pins  120 (−) with negative plates  160 (−) will be ensured. Although the plug  110  and receptacle  150  are shown having one magnetic element  130  and  170  each, it will be appreciated that each can include one or more magnetic elements. In addition, it will be appreciated that the plug  110  and receptacle  150  can each have one or more contacts, depending on the type of electrical connection to be made. For example, additional pins and contacts may be symmetrically arranged around the plug  110  and receptacle  150  for passing electrical signals between two devices, such as a laptop computer and power adapter. 
     Referring to  FIG. 6 , an ability of the magnetic connector  100  to prevent possible damage is illustrated. The magnetic connector  100  substantially avoids damage because male components are not required to have an interference fit with female components to maintain both electrical and mechanical connection. Instead, a user of the connector  100  needs only to position the faces  118  and  158  of the plug  110  and receptacle  150  against or away from one another when making or releasing the electrical and magnetic connection therebetween. Being biased towards plates  160 , the pins  120  can avoid damage while still maintaining contact with the plates  160 . In addition, the magnetic connector  100  can substantially avoid damage by allowing the plug  110  and receptacle  150  to break free of one another when inadvertently pulled away from each other by a non-axial force. Although shown slightly recessed in the device  60 , the face  158  of the receptacle  150  can also be flush with the housing or can protrude therefrom. However, the recess is used to prevent stray magnetic fields from interfering with other devices. 
     Referring to  FIG. 7 , another embodiment of a magnetic connector  200  according to certain teachings of the present disclosure is illustrated. This embodiment is substantially similar to the embodiment of  FIGS. 3 through 5  so that like reference numbers indicate similar components. In contrast to previous embodiments, the receptacle  250  in this embodiment is not housed in a device (not shown) to which it is connected as with previous embodiments. Rather, the receptacle  250  resembles the plug  110  in that it has a body  252  that connects to the device with a cable  254 . In addition, the bodies  112  and  252  of the plug  110  and receptacle  150  are substantially round. To ensure proper alignment of the pins  120  with the plates  160 , the plug  10  and receptacle  150  have complementary guides  119  and  159  that allow for only one way of coupling them together. Although the guides  119  and  159  are shown on the faces  118  and  158  of the plug  110  and receptacle  150 , it will be appreciated by one skilled in the art that a number of guides and techniques can be used to ensure proper alignment. 
     Referring to  FIGS. 8A-8B  and  9 A- 9 B, another embodiment of a magnetic connector according to certain teachings of the present disclosure is illustrated. A first connector or plug  310  of the magnetic connector is shown in a partial side cross-section and in a front view of  FIGS. 8A-8B . A second connector or receptacle  350  of the magnetic connector is shown in a partial side cross-section and in a front view of  FIGS. 9A-9B . Both the plug  310  and receptacle  350  can be at least partially composed of transparent, non-conductive material and can include internal lights, such as LEDs, to illuminate them. 
     As shown in  FIGS. 8A-8B , the plug  310  includes a body  312 , a plurality of pins  320 , and a first magnetic element  330 , and a shell  340 . The body  312  is made of any suitable non-conductive material and has an oblong shape with two axes of symmetry A 1  and A 2 . The body  312  houses internal wires  316  of a cable  314 , which connect the pins  320  to a first device (not shown), such as a transformer, for example. The pins  320  are biased by springs, and the pins  320  extend from a face  318 , which is slightly recessed in the plug body  312 . The first magnetic element  330  is positioned on the end of the plug body  312 . As best shown in  FIG. 8B , the first magnetic element  330  surrounds the recessed face  318  of the body  318 . 
     For the embodiment of the plug  310  connected to a transformer, the centrally located pin  320  can be designated for signals used by the electronic device to determine the type of transformer or other device attached by the plug  310 . The two outer located pins  320  can be designated for the positive DC power, and the outer shell  340  is designated for the return path of DC power. In this way, any orientation of the plug  310  will ensure proper connection of positive pins  320 (+) and signal pin  320 (S) of the plug  310  with corresponding contacts of the receptacle ( 350 ;  FIGS. 9A-9B ). Using the outer shell  340  for the return path is preferred because the plug  310  can have a smaller profile. In an alternative embodiment, however, the return path can be provided by additional pins (not shown) on the plug  310  and receptacle  350 . For example, two additional pins (not shown) for the additional return path could be provided and symmetrically arranged on the plug  310  such that the pins would only align with corresponding contacts (not shown) of the receptacle  350  regardless of the orientation in which the plug  310  is coupled to the receptacle  350 . 
     As shown in  FIGS. 9A-9B , the receptacle  350  has a body  352 , a plurality of contacts  360 , and a second magnetic element  370 , and a shell  380 . The body  352  has a casing  356  with legs  357  for mechanical connection to a printed circuit board of internal electronics of a second device (not shown), such as a laptop computer, for example. The casing  356  can be composed of a conductive or non-conductive material. The body  352  has an oblong shape with two axes of symmetry A 1  and A 2  and is made of any suitable non-conductive material. As best shown in  FIG. 9B , the body  352  also has snap connectors  359  for mechanical connection to a mounting base (not shown). In addition, the receptacle  350  has pins  364  for connecting the contacts  360  to internal electronics of the device. 
     The body  352  has an end  354  intended to extend outside the device housing the receptacle  350 . This end  354  may be illuminated by techniques known in the art. The contacts  360  are positioned in a face  358  of the body  352 . In the present embodiment, the contacts  360  are substantially flat plates electrically connected to the pins  364  by wires  362 . The second magnetic element  370  is positioned about the face  358 , and the second magnetic element  370  is preferably recessed from the face  358 . Preferably, the recess of the second magnetic element  370  is slight and is comparable to the recess of the face ( 318 ) of the plug ( 310 ) in  FIG. 8A . For the embodiment of the receptacle  350  intended to connect DC power to the device, the plates  360  are arranged to correspond with the positive pins ( 320 (+)) and signal pin ( 320 (S)) of the plug ( 310 ) of  FIGS. 8A-8B , as described previously. 
     To make the electrical connection, the face  318  of the plug  310  of  FIG. 8A  is positioned against the face  358  of the receptacle  350  of  FIG. 9A . The pins  320  on the plug  310  engage the plates  360  on the receptacle  350 . To maintain the connection, the first and second magnetic elements  330  and  370  magnetically couple together and hold the plug  310  to the receptacle  350 . In one embodiment, the magnetic elements  330  and  370  are both permanent magnets (preferably rare earth magnets) arranged to magnetically couple together. In another embodiment, one of the magnetic elements  330  and  370  can be a permanent magnet (preferably a rare earth magnet) or an electromagnet while the other element is a ferromagnetic material. Once coupled, the magnetic connector  300  allows the plug  310  to break away from the receptacle  350  in the event of inadvertent pulling of the plug  310  or the like. 
     Referring to  FIG. 10 , additional details of the plug  310  and receptacle  350  for the disclosed magnetic connector of  FIGS. 8A-8B  and  9 A- 9 B are illustrated in a perspective view. Portions of the plug  310  and receptacle  350  are not illustrated so that various details can be better shown. On the plug  310 , the shell  340  abuts the magnetic element  310 , which can be a ferromagnetic material. The shell  340  has an extension  342  for connecting to the return path of the power supply from the adapter (not shown) to which the plug  310  is connected. Three connectors  322 (+),  322 (S), and  322 (+) extend from the back end of the body  312  for connecting the pins (not shown) with the positive power and signal from adapter to which the plug  310  is connected. 
     On the receptacle  350 , the shell  380  for the return path of the power is positioned within the casing  356 , and the magnetic element  370 , which can be a permanent magnet, is positioned within the shell  380 . An opening  372  through the magnetic element  370  allows for passage of body material (not shown) and contacts (not shown), as disclosed previously. Tabs or holders  382  of the shell  380  contact and hold the magnetic element  370 . A leg  384  of the shell  380  extends from the receptacle  350  as do legs  357  of the casing  356 . 
     When the plug  330  is coupled with the receptacle  350 , the ferromagnetic material  330  of the plug  310  positions against the permanent magnet  370  and the inside of the casing  380  of the receptacle  350 . Thus, the magnetic engagement between the ferromagnetic material  330  and the permanent magnet  370  holds the plug  310  to the receptacle. Moreover, the physical engagement between the ferromagnetic material  330  and the casing  380  creates the return path for power from the receptacle&#39;s shell pin  384  to the plug&#39;s shell pin  342 . 
     Referring to  FIGS. 11A-11B , an embodiment of a magnetic connector  360  according to certain teachings of the present disclosure is illustrated. The connector  360  is compact and preferably has a low profile. In  FIG. 11A , a plug  370  of the connector  360  is shown in a front perspective. In  FIG. 11B , some of the internal components of plug  370  and a receptacle  390  are shown in a back perspective. The receptacle  390  is housed in an electronic device (not shown), and the plug  370  attaches to a cord or the like (not shown). As best shown in  FIG. 11A , the plug  370  has magnets  380 ,  382  positioned on both sides of a plurality of contacts  376 , which are similar to other contacts disclosed herein. For example, the central contact  376  is designated for a first path of electrical communication, and the two outer contacts  376  are designated for a second path of electrical communication. Preferably, the contacts  376  are biased pins where the central pin  376  carries a signal path and the two side pins carry a positive current. The magnets  380 ,  382  are arranged with opposite polarities, as indicated by the direction of the arrows in  FIG. 11A . Preferably, the magnets  380 ,  382  are also designated for a third path of electrical communication. 
     As best shown in  FIG. 11B , the plug  370  also has a back plate  372  connected between the back ends of the magnets  380 ,  382 . The back plate  372  is made of a ferromagnetic material, such as steel. The receptacle  390  has an attraction plate  392  also made of a ferromagnetic material, such as steel. When the attraction plate  392  of receptacle  390  is attracted to the magnets  380 ,  382 , the magnetic field lines travel through the steel attraction plate  392  from one magnet to the other, completing the magnetic circuit and producing a strong attracting force. 
     The attraction plate  392  of receptacle  390  defines an opening  394  for passage of the electrical contacts (not shown in  FIG. 11B ). Likewise, the back plate  372  of the plug  370  defines openings  374  for passage of leads from the electrical contacts (not shown). As noted above, the magnets  380 ,  382  can form a path of electrical communication between the receptacle  390  and the plug  370 . Preferably, the magnets  380  and  382  and the attraction plate  392  carry negative current. Thus, the attraction plate  392  of the receptacle  390  includes a connector  396  for connecting to an electrical lead or the like (not shown). 
     Because the connector  360  is designed to be compact and have a low profile for fitting into a laptop or the like, the plates  372  and  392  must give up a certain amount of material to produce the openings  374  and  394 . When the attraction plate  392  and magnets  380 ,  382  are coupled, magnetic attractive force can be limited because the flux density can saturate the narrower portions of ferromagnetic material in both the attraction plate  392  and the back plate  374 . (Therefore, it may be desirable to use more than two magnets with the connector, as disclosed in the embodiment below). It may be desirable to have more than two magnets within the connector for two reasons. First, magnetic strength is a function of magnet thickness to cross section ratio (with thickness being defined by the dimension along the direction of magnetization). Second, for a given envelop, the leakage field associated with more than two permanent magnets is less than the leakage field associated with one or two permanent magnets. 
     Referring to  FIGS. 12A-12B , another embodiment of a magnetic connector  360  according to certain teachings of the present disclosure is illustrated. The magnetic connector  360  in  FIGS. 12A-12B  is substantially similar to that disclosed above so those like numerals indicate similar components between the embodiments. In the present embodiment, however, the plug  370  houses four magnets  380 ,  381 ,  382 , and  383 . Again, the magnets  380 ,  381 ,  382 , and  383  are arranged with opposite polarities, as indicated by the arrows in  FIG. 12A . In the present embodiment, the four magnets  380 ,  381 ,  382 , and  383  form four magnetic circuits for the travel of magnetic flux. Accordingly, most of the flux travels between magnets on the same side (e.g., between magnets  380 ,  381  on the same side and between magnets  382 ,  383  on the same side). Because the flux lines are not constrained by the narrow portions of the plates  372  and  392 , the flux density is less likely to saturate the plates  372  and  392 . Therefore, the magnetic attractive force between the receptacle  390  and the plug  370  having four magnets  380 - 384  can be significantly greater than available in the embodiment of  FIGS. 11A-11B , even though both embodiments have the same contact area. 
     As noted previously, the magnetic attraction or force coupling the plug  370  and the receptacle  390  can be configured as desired for a given implementation. In one embodiment, a straight pullout force to uncouple the plug  370  from the receptacle  390  is preferably between 3-lbf and 7-lbf. It should be noted that pulling the plug  370  out sideways, up, or down can produce torque. Preferably, the magnetic attraction produces less torque in the up direction but produces more torque in the other directions. Target torque values can be 0.5 kgf-cm for the up direction and 0.7 to 1.5 kgf-cm in the other directions. 
     In one aspect, the asymmetrical torque values can be achieved by extending the upper magnets  380  and  382  upwards. In this way, the upper magnets  380  and  382  are stronger and provide more attraction upwards than the lower magnets  381  and  383 . One resulting effect is that there can be more holding force and displacement of the application point of the force upward, subsequently leading to more torque. This also helps compensate for any downward torque that may be produced by a cable (not shown) coupled to the plug  370 . In another aspect, the asymmetrical torque values can be achieved by changing the angle of the magnetic flux lines in the upper magnets  380  and  382 . For example, the separate, upper magnets  380  and  382  can have flux direction that point downward at an approximately 20-degree angle in comparison to the direction of coupling. 
     Referring to  FIG. 13A , an embodiment of a magnetic connector  400  having an electromagnet is illustrated. The connector  400  includes a plug  410  and a receptacle  450 . The plug  410  is not substantially different from that disclosed in the embodiment of  FIG. 8A-8B . The plug  410  has contacts  420  for conveying power from a transformer (not shown) and has a magnetic element  430 , which can be a ferromagnetic material. The receptacle  450  has contacts  460  for conveying power to internal electronics  76  of the device  70 , which is a laptop computer in the present embodiment. 
     In contrast to previous embodiments, the receptacle  450  has an electromagnet formed by a metal core  470  wrapped by a wire coil  472 . Using an electromagnet in the plug  410  or receptacle  450  can overcome some of the disadvantages of having a permanent magnet on either the plug  410  or receptacle  450 . For example, the electromagnet may reduce potential interference with internal components of the electronic device  70  or storage media. 
     The coil  472  is connected to a power supply or battery  72  of the laptop  70 , and an internal switch  74  among other electronics can be used to operate the electromagnet of the core  470  and coil  472 . The internal switch  74  causes power from the battery  72  to energized the electromagnet of core  470  and coil  472 . Consequently, the energized electromagnet produces a magnetic field that attracts the ferromagnetic material  430  of the plug  410  and that can hold the plug  410  to the receptacle  450 . The battery  72  can be an independent battery of the device or can be the same battery used to power the internal electronics  76  of the device  70 . In either case, operation of the internal switch  74  and other electronics for connecting the battery  72  to the electromagnetic is preferably controlled to conserve power consumption of the battery  72 . 
     Referring to  FIG. 13B , another embodiment of a magnetic connector  500  having an electromagnet is illustrated. The connector  500  includes a plug  510  and a receptacle  550 . The receptacle  550  is not substantially different from that disclosed in the embodiment of  FIG. 9A-9B . The receptacle  550  has contacts  560  for conveying power and signals to internal electronics  76  of the device  70 . The receptacle  550  also has a magnetic element  570 , which can be a ferromagnetic material. The plug  510  has contacts  520  for conveying power and signals from a power supply, such as power adapter  80 , via wires  522  of a cable  86 . In contrast to previous embodiments, the plug  510  has an electromagnet formed by a metal core  530  wrapped by a wire coil  532 . The coil  532  is connected to a power supply by wires  534 . For example, the coil  532  can draw power output from the transformer  82  of the adapter  80 , form a conventional power supply to which the outlet plug  88  connects, or from a battery  84  housed internally in the adapter  80 . Use of the battery  84  can overcome the need for a user to first connect the adapter  80  to the power supply before the electromagnet in the plug  510  is operated and can magnetically connect to the receptacle  550 . The drawn power energizes the electromagnet of core  530  and coil  532  to produce a magnetic attraction to the ferromagnetic material  570  that can hold the plug  510  to the receptacle  550 . 
     Referring to  FIG. 14 , an embodiment of a magnetic connector  600  according to certain teachings of the present disclosure is illustrated. The connector  600  has a plug  602  having contacts  604  and an electromagnet  606 . The connector  600  also has a receptacle  620  positioned on a portable computer or electronic device  630 . The receptacle  620  has an attraction plate or magnet  622  and contacts  624 . The contacts  624  act as paths for electrical communication so that they are electrically coupled to internal electronics  632  of electronic device  630 . In addition, the attraction plate or magnet  622  acts as a path of electrical communication so that it is also electrically coupled to the internal electronics  632 . In the schematic view of  FIG. 14 , various components, such as leads, contacts, and coils, are not shown for simplicity. 
     In the present embodiment, the electromagnet  606  is in the plug  602 ; however, it can be positioned in the receptacle  620 . The electromagnet  606  derives its power from circuitry  612  of the power adapter  608  so the electromagnet  606  does not drain a battery (not shown) of the electronic device  630 . In the present embodiment, the plug  602  includes a switch element  610  interrupting the electrical connection between the electromagnet  606  and the circuitry  612  of the adapter  608 . 
     In one embodiment, the switch element  610  includes a mechanical switch that a user presses to turn the electromagnet  602  on and off. Any mechanical switch, such as a conventional micro-switch, for controlling the power load of the electromagnet  602  is suitable for the connector  600 . In general, the switch element  610  allows the electromagnet  606  to run directly from power of the adapter  608 . 
     In another embodiment, the switch element  610  includes a touch sensor that energizes (e.g., turns on) the electromagnet  606  when a user touches the sensor  610  by picking up the plug  602 . Touch sensors are known in the art. For example, the touch sensor  610  can include logic circuitry and contacts (not shown) and can use principals of capacitance of the human body for operation. Once activated by the touch sensor  610 , the electromagnet  606  can remain energized for a time interval to allow the user to couple the plug  602  to the receptacle  620  and to turn on the electronic device  630 . Once the energized electromagnet  606  is magnetically coupled to the attraction plate  622  of the receptacle  650 , the contacts  604  and  624  that form a signal path between the adapter  608  and the device  630 , and a signal along the signal path can be used to keep the touch sensor  610  activated and the electromagnet  606  energized. 
     While the plug  602  is connected and the electromagnet  606  energized, the touch sensor  610  can turn off the electromagnet  606  when touched to allow the user to disconnect the plug  602 . Alternatively, the touch sensor  610  can reduce the energization of the electromagnet  606  to enable easy removal by the user but to keep a small remaining attraction. In addition, when the device  630  is turned off, the device  630  may no longer send a signal along the signal path of the contacts  604  and  624  or may send a quit signal to the touch sensor  610  to stop energization of the electromagnet  606 . Then, the de-energized electromagnet  606  can allow the plug  602  to be released from the electronic device  630 . 
     In yet another embodiment, the switch element  610  includes a motion sensor, which detects when the plug  602  is moved. The motion sensor  610  can maintain the electromagnet  606  energized for a time interval to allow the user to couple the plug  602  with the receptacle  620  and to turn on the electronic device  630 . Once coupled, the signal path formed by contacts  604  and  624  can allow a signal to control the circuitry of the motions sensor  610  to maintain it activated while coupled to the device  630 . The motion sensor  610  can automatically shut off the electromagnet  606  so as to release the plug  602  from the device  630  if a sudden movement occurs (e.g., the device  630  is dropped or pulled away with the plug  602  connected). 
     Referring to  FIG. 15 , an embodiment of a magnetic connector  600  according to certain teachings of the present disclosure is illustrated having an electromagnet  606  and a proximity sensor  640 . Reference numerals in  FIG. 15  that are the same as those in other Figures represent like components between embodiments. The proximity sensor  640  is positioned in the plug  602  and is coupled to a switch element  642 . The electromagnet  606  is also coupled to the switch element  642 , which in turn is coupled to circuitry  644  for providing power located in the adapter  608 . The proximity sensor  640  and switch element  642  turn on the electromagnet  606  when the sensor  640  is positioned near plate  622  of the receptacle  620 . 
     In one embodiment, the proximity sensor  640  includes a Hall Effect sensor, which detects magnetic field levels. In use, the electromagnet  606  is initially energized before being coupled to the receptacle  620 . The initial energization can be achieved, for example, when the adapter  608  is coupled to a power source (not shown) or when a touch sensor (not shown) or the like is activated by the user. The initial energization can be less than that necessary to magnetically couple the electromagnet  606  to the plate  622 . Once the plug  602  is moved in proximity to the receptacle  622 , the magnetic field associated with the initial energization of the electromagnet  606  is changed, which is subsequently detected by the Hall Effect sensor  640 . The sensor  640 , in turn, causes the energization of the electromagnet  606  to be increased to allow it to magnetically couple to the attraction plate  622 . 
     Referring to  FIG. 16 , an embodiment of a magnetic connector  600  according to certain teachings of the present disclosure is illustrated having an electromagnet  606  and fault detection circuitry  650 . Reference numerals in  FIG. 16  that are the same as those in other Figures represent like components between embodiments. As before, the electromagnet  606  is energized to magnetically couple with the attraction plate  626  of receptacle  620 , which can be ferromagnetic material or a permanent magnet. The fault detection circuitry  650  detects a fault event caused, for example, by a surge or spike in the power supply. 
     The fault detection circuitry  650  can be similar to that commonly used in the art for power adapters. In one embodiment, for example, the fault detection circuitry  650  can include circuitry for detecting an over-current. In another embodiment, for example, the fault detection circuitry  650  can include circuitry for detecting an over-temperature. 
     When the fault detection circuitry  650  detects a fault event, the circuitry  650  can stop energizing the electromagnet  606  and allow the plug  602  to be released from the embodiment of the receptacle  620  having a ferromagnetic attraction plate  626 . Alternatively, the circuitry  650  can reverse the direction of current supplied through the electromagnet  606  so the electromagnet  606  is repelled by the polarity of the embodiment of the receptacle  620  having a permanent magnet on the attraction plate  626 . It will be appreciated that the electromagnet  606  and fault circuitry  650  can be positioned on the device  630  while the attraction plate can be positioned on the plug  602  of the connector  600  to achieve the same protection. 
     Referring to  FIG. 17 , an embodiment of a magnetic connector  600  according to certain teachings of the present disclosure is illustrated having two electromagnets  606  and  660 . The plug  602  has the first electromagnet  606 , which is energized by the power adapter  608 . The receptacle  620  positioned in the device  630  has the second electromagnet  660 , which is power by an internal power supply  662 , such as a battery. The two electromagnets  606  and  660  have opposite polarities allowing them to be magnetically coupled. 
     In one embodiment, the adapter  608  includes fault detection circuitry  650 . When a fault is detected by fault detection circuitry  662 , the polarity of the first electromagnet  606  can be reversed by the circuitry  650  so that the first and second electromagnets  606  and  660  repel one another and actively prevent connection. 
     In another embodiment, the adapter  608  includes circuitry  650  for identifying the adapter  608 . For example, the identification circuitry  650  can identify a type of electronic device to which it is intended to be connected or can even identify a specific device to which is can only be used. When a user intends to connect the plug  602  to the receptacle  620 , the first electromagnet  606  can be energized according to the techniques disclosed herein. However, the second electromagnet  660  can remain de-energized. When the user positions the plug  602  against the receptacle  620 , the signal path formed by contacts  604  and  624  allow the identification circuitry  650  to send a signal to the internal electronics  632  of the device, which can identify the adapter  608  being connected to the device  630 . 
     If the adapter  608  is intended for the device  630 , then the second electromagnet  660  can be energized with opposite polarity to couple with the first electromagnet  606 , or the second electromagnet  660  can remain de-energized while the first electromagnet  606  is simply allowed to magnetically couple with the ferromagnetic components of the de-energized electromagnet  660 . If, on the other hand, the adapter  608  is not intended for the device  630 , then the second electromagnet  660  can be energized with the same polarity to repel the first electromagnet  606  and actively prevent connection. 
     Referring to  FIG. 18 , an embodiment of a magnetic connector  600  according to certain teachings of the present disclosure is illustrated having an electromagnet  606  and control circuitry  670 . In one embodiment, the control circuitry  670  includes a switch element, which receives a control signal from the internal electronics  632  of the device  630 . When the battery of the electronic device  630  is fully charged, the internal electronics  632  sends a control signal to the control circuitry  670  via the signal path formed by contacts  604  and  624 . Moreover, when the internal electronics  632  detects a fault, it can send a control signal to the control circuitry  670 . 
     As described above, one of the contacts  604  on the plug  602  and one of the contracts  624  on the receptacle  620  (preferably, the centrally located contacts  604  and  624 ) can form a signal path between the device  630  and the adapter  608 . It is along such a signal path that the control signal indicating the fully charged battery is sent. When the signal for “full charge” is received, the control circuitry  670  causes its internal switch element to stop energization of the electromagnet  606 , and the plug  602  becomes decoupled from the receptacle  626 . If it is desirable to keep the plug  602  magnetically coupled, albeit slightly, to the receptacle  620  even after full charging of the battery, the plate  627  on the receptacle  620  can include a magnet (not shown) for maintaining at least some magnetic coupling with ferromagnetic material of the electromagnet  606 . 
     In another embodiment, the control circuitry  670  receives a control signal, which governs whether the adapter  608  associated with the control circuitry  670  can operate with the electronic device  630 . In this embodiment, the internal electronics  632  on the device  630  produces a control signal that identifies the device  630 , such as by its make or model. The control signal can be a digital signal, for example, identifying the device  630 . The control circuitry  670  in the adapter  608  is pre-configured to energize the electromagnet  606  only when the identifying control signal is received. To respond to the control signal, the control circuitry includes a switch element for controlling the electrical connection of the electromagnet  606  with its energizing source, and the circuitry includes a logic element for interpreting the control signal and activating the switch element. 
     Thus, when a user positions the plug  602  against the receptacle  620  to connect them, the signal contacts  604  and  624  on the plug and receptacle  602  and  620  will make contact, allowing the internal electronics  632  of the device  630  to communicate its identifying control signal to the control circuitry  670  of the adapter  608 . If the circuitry  670  receives the correct signal, an internal switch within the circuitry causes the electromagnet  606  to be energized for coupling with the receptacle. Otherwise, the electromagnet will not be energized, and the plug  602  will not stay coupled to the receptacle  620 . 
     Accordingly, the electromagnet  606  on the adapter  608  will only be energized for a particular model or type of device, which may prevent the possibility of a user inadvertently coupling an adapter with a specific power rating to a device requiring a different power rating. For example, harm to a computer can be prevented because the computer will not allowing itself to be connected to the wrong type of power adapter (e.g., one that supplies a higher voltage than the computer&#39;s specification). Furthermore, the control circuitry  670  and identification of the device  630  can be configured so that the device  630  will only draw power only from a particular power adapter or a group of power adapters. Such a configuration can be useful in various settings, such as a school or other public organization, to discourage theft. 
     In yet another embodiment, the control circuitry  670  includes a security system, which requires the user to enter a particular code or other identification. Without the entered code, the control circuitry  670  will not energize the electromagnet, and the plug  602  will not engage with the receptacle  620 . 
     In the present disclosure, embodiments of magnetic connectors have been disclosed in the context of providing power from a transformer to a laptop computer. However, it will be appreciated with the benefit of the present disclosure that the subject matter of the present disclosure is applicable to various types of connectors, which provide electrical connection in the form of power and/or signals between an electronic device and any of a number of electronic devices or electrical relations. For example, other applicable electronic devices or electrical relations include portable DVD players, CD players, radios, printers, portable memory devices, portable disk drives, input/output devices, power sources, batteries, etc. Other applicable types of electrical connections that can be provided by the connectors of the present disclosure include Universal Serial Bus, D-subminiature, FireWire, network connectors, docking connectors, etc. 
     In the present disclosure, a number of embodiments of magnetically coupleable connectors are disclosed. With the benefit of the present disclosure, it will be appreciated that aspects or features of one embodiment disclosed herein can be used in or combined with aspects and features of other embodiments disclosed herein to produce additional embodiments consistent with the teachings of the present disclosure. 
     The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.

Metadata:
Filing Date: 20091208
Publication Date: 20130730
Grant Date: 20130730
Priority Date: 20050926
Inventors: DIFONZO JOHN
ANDRE BARTLEY K.
LIM KANYE
ROHRBACH MATTHEW DEAN
DOUTT MARK EDWARD
GERY JEAN-MARC
Assignee: APPLE INC
CPC Classifications: [{"code": "H01R13/6205", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R13/641", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/6205", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R13/641", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/641", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/6205", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R11/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R13/62", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 37450880