Patent Document

TRADEMARKS 
       [0001]    IBM® is a registered trademark of International Business Machines Corporation, Armonk, New York, U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to interconnecting bulk power assemblies, and particularly to electrical engagement of the interconnection. 
         [0004]    2. Description of Background 
         [0005]    Utilizing multiple bulk power assemblies requires interconnecting them for operability. All IBM high-end servers require a power supply it is also desirable to provide a backup power supply. The output of IBM&#39;s commercially available bulk power supplies was sufficient for IB3M&#39;s commercially available servers, therefore a single bulk power assembly as a primary source and a second as a backup source has been a convenient and efficient expectant for some time. 
         [0006]    IBM&#39;s newer node-based clustered servers, however, exceeds the rating of a single bulk power assembly when more than about 12 nodes are installed. Therefore, for such large systems the combined power output of both the primary and the “backup” bulk power assemblies is required for normal operation, with an attendant loss of line-cord redumdancy. The loss of redundancy has been considered an acceptable trade-off in the high-performance computing marketplace to get the performance that a fall 16-node server provides. 
         [0007]    For these large servers the outputs of the two bulk power assemblies must be electrically connected to supply twice the power rating of a single bulk power assembly. Since, however, each bulk power assembly consists of three independent bulk power regulators, some measure of redundancy can be retained by rating the total system power for 2N-1 times the rating of each bulk power regulator, where N represents the power rating of the bulk power regulator. In one previous approach the two bulk power assemblies were electrically connected by substituting a bulk power jumper card for a bulk power distribution card in each bulk power assembly and a single high-current cable was plugged into each bulk power jumper to complete the connection. There are several drawbacks associated with such an arrangement: a card slot is required for the jumper card, each jumper card requires two connectors (backplane and cable connections) at a significant cost, the required cable also adds cost to the design, room inside the system cage is required to rout the cable with its associated bend radius, and the connectors limit the maximum current to 60 amps, which will be insufficient to power the new higher performance servers. 
         [0008]    Accordingly, there is a need for a simple and cost effective way to electrically connect bulk power supplies together with high current handling capabilities. 
       SUMMARY OF THE INVENTION 
       [0009]    The shortcomings of the prior art are overcome and additional advantages are provided through the provision of an engagement system for bulk power assemblies. The system comprising, a first bulk power assembly having a plurality of electrical terminals and at least one guide boss on a surface thereof, a second bulk power assembly having an equal number of electrical terminals as there are electrical terminals of the first bulk power assembly and an equal number of guide bosses to the number of guide bosses of the first bulk power assembly on a surface thereof. And a rigid interface member having a first end and a second end, both ends having an equal number of terminal blades as there are electrical terminals on the first bulk power assembly and an equal number of guide blades as there are guide bosses on the first bulk power assembly. The terminal blades being receptive to make an electrical connection with the electrical terminals and the guide blades being receptive to engage with the guide bosses, in response to the interface member being functionally engaged with both bulk power assemblies simultaneously. 
         [0010]    Further advantages are provided through the provision of a method of engaging bulk power assemblies together. The method comprising, engaging a plurality of electric terminals of a first bulk power assembly with a plurality of male terminals of a first end of an interface member, and engaging a plurality of electric terminals of a second bulk power assembly with a plurality of male terminals of a second end of the interface member. The engagement resulting from compressing the rigid interface member between the two bulk power assemblies. 
         [0011]    Systems and methods corresponding to the above-summarized systems and methods are also described and claimed herein. 
         [0012]    Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0014]      FIG. 1  illustrates one example of a server system disclosed herein; 
           [0015]      FIG. 2  illustrates one example of a top view of bulk power assemblies disclosed herein; 
           [0016]      FIG. 3  illustrates one example of a perspective view of a bulk power assembly disclosed herein; 
           [0017]      FIG. 4  illustrates one example of a section view of two bulk power assemblies in functional engagement disclosed herein; 
           [0018]      FIG. 5  illustrated one example of a perspective view of an interface member disclosed herein; and 
           [0019]      FIG. 6  illustrates one example of a cover disclosed herein. 
           [0020]    The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Turning now to the drawings in greater detail, it will be seen that in  FIG. 1  there is a server system shown generally at  10 . The server system  10  comprises a rack  14  that structurally holds the components of the system  10  in relation to one another. For example, multiple processor units  18  mount in a one above the other stacking fashion inside the rack  14  while a first bulk power assembly  22  and a second bulk power assembly  26  are positioned near an inside lower surface of the rack  14 . 
         [0022]    Referring to  FIG. 2  the bulk power assemblies  22 ,  26  are shown from above with a centerline  30  drawn through the centers of both bulk power assemblies  22 ,  26 . Guide bosses  34  and terminal bosses  38  on both bulk power assemblies  22 ,  26  are aligned along the centerline  30  and will be described in more detail below. 
         [0023]    Referring to  FIG. 3  a perspective view of the first bulk power assembly  22  shows the guide bosses  34  and the terminal bosses  38  in more detail. The bosses  34 ,  38  all protrude from a back plane  42 , which forms one surface of the bulk power assembly  22 . The bosses  34 ,  38  are aligned along the centerline  30  of the bulk power assembly  22  in a vertical direction. It should be noted that in other embodiments the bosses  34 ,  38  could be aligned in other orientations, directions and relationships to one another while still remaining within the scope and spirit of the present invention. An upper guide boss  44  and a lower guide boss  45  comprise the guide bosses  34  of the first bulk power assembly  22 . Similarly, an upper terminal boss  48  and a lower terminal boss  49  comprise the terminal bosses  38  of the first bulk power assembly  22 . All four bosses  44 ,  45 ,  48 ,  49  include an opening that will be described in more detail in reference to  FIG. 4 . It should be noted that the second bulk power assembly  26  is substantially identical to the first bulk power assembly  22  for purposes of embodiments disclosed herein and therefore to avoid repeating detailed descriptions will not be described in detail. 
         [0024]    Referring to  FIG. 4  a cross sectional view of the first bulk power assembly  22  is shown in electrical engagement with the second bulk power assembly  26  through a rigid interface member  54 , sandwiched therebetween. The interface member  54  includes an injection molded, plastic nonconductive housing  58 , an upper guide blade  64 , a lower guide blade  65 , upper terminal blade  68 , and a lower terminal blade  69 . The blades  64 ,  65 ,  68 ,  69  may be pressed into holes formed in the housing  58  and held in place by friction or by a detent, not shown, or insert molded into the housing  58  during the molding of the housing  58 . Alternatively, the guide blades  64 ,  65  could be plastic and molded as part of the housing  58 , thereby eliminating two separate components. The terminal blades  68 ,  69 , on the other hand, cannot be molded as part of the housing  58  since they need to be conductive to complete the circuit with the bulk power assemblies  22 ,  26 . 
         [0025]    The positioning and orientation of the blades  64 ,  65   68 ,  69  of the interface member  54  must match the positioning and orientation of the bosses  44 ,  45 ,  48 ,  49  on the bulk power assemblies  22 ,  26  in order to assure they engage properly. The guide blades  64 ,  69  slidably engage with holes  74 ,  75  in the alignment bosses  44 ,  45  to align and pilot the interface member  54  with the bulk power assemblies  22 ,  26  prior to the terminal blades  68 ,  69  engaging with holes  78 ,  79  in the terminal bosses  48 ,  49 . Such alignment assures that the upper terminal blade  68  engages with the an upper female terminal  88  located within the hole  78 , and the lower terminal blade  69  engages with a lower female terminal  89  located within the hole  79 . To assure the guide blades  64 ,  65  engage with the alignment bosses  44 ,  45  before the terminal blades  68 ,  69  engage with the terminal bosses  48 ,  49  the lengths of the guide blades  64 ,  65  are longer than the lengths of the terminal blades  68 ,  69 . The ends of the guide blades  64 ,  65  are radiused, or alternatively chamfered, to allow for some misalignment of the guide blades  64 ,  65  with the holes  74 ,  75  at initial contact. 
         [0026]    The upper terminal boss  48  of the first bulk power assembly  22  has an upper female terminal  88  connected to a wire  98 , a lead frame, or other electrical circuit component within the bulk power supply  22  which has a positive electrical potential. The terminal  88  is positioned substantially in the center of the hole  78  and is slightly recessed from the surface  42 . The terminal  88  is held in position relative to the housing  58 , by common methods, so as to allow the terminal blade  68  to frictionally engage into the terminal  88  resulting in a reliable electrical connection between the blade  68  and the terminal  88 . The lower terminal boss  49  as well as the terminal bosses of the second bulk power assembly  26  each has female terminals housed therein for similar electrical connections to their respective terminal blades. In order to properly connect the bulk power assemblies  22 ,  26  together in parallel the polarity of the upper terminals in both bulk power assemblies  22 ,  26  should be positive and the lower terminals in both bulk power assemblies  22 ,  26  should be negative. 
         [0027]    In order to prevent the interface member  54  from disconnecting from both bulk power assemblies  22 ,  26  in the event that the second bulk power assembly  26  is removed from the rack  14  while the first bulk power assembly  22  is left in the rack  14 , for example, the interface member  54  is attached to one of the bulk power assemblies  22 ,  26 . To attach the interface member  54  to the first bulk power assembly  22 , as shown, a fastener  92 , disclosed herein as a screw, is threadably engaged with a hole  96  in the bulk power assembly  22  through a clearance hole  100  in the housing  58 . Since the back plane connection details on the first bulk power assembly  22  are substantially identical to those on the second bulk power assembly  26 , the interface member  54  can just as easily be fastened to the second bulk power assembly  26 . To do so, rotate the interface member  54  by rotating the by 180 degrees to align the hole  100  with a hole  104  in the second bulk power assembly  26 , and threadably engage the fastener  92  to the hole  104 . 
         [0028]    In the case described above, wherein the second bulk power assembly  26  has been removed from the rack  14  and the first bulk power assembly  22  remains in the rack  14  with the interface member  54  thereattached, it is possible for the server system to be powered up. In such an instance the terminal blades  68 ,  69  will have electrical potential applied thereon. Such electrical potential may be as high as 350 volts direct current, for example. With bulk power assemblies  22 ,  26  capable of supplying as much as 150 amps of current a dangerous situation exists with the possibility that a conductor could come in contact, simultaneously, with both exposed terminal blades  68 ,  69 . 
         [0029]    Referring now to  FIGS. 5 and 6  an embodiment of the invention includes a cover  108  for frictionally engaging with either a first end  112  or a second end  116  of the interface member  54 . For example, if the first end  112  is functionally engaged with the first bulk power assembly  22 , which may be electrically powered up, the cover  108  can be applied to the second end  116  of the interface member  54  thereby providing an electrically insulative shield over the exposed terminal blades  68 ,  69 . The cover  108  itself may be injection molded from a nonconductive plastic with features for attachment to the bulk power assemblies  22 ,  26  integrally formed thereon. Such features could include, for example, holes, not shown, molded within projections  120  that are sized to frictionally engage with the guide blades  64 ,  65  or the terminal blades  68 ,  69 . Alternately, a rectangular shaped surface  124  of the cover  108  could frictionally engage with inner surfaces  128  of the housing  58  to removably attach the cover  108  to the interface member  54 . Additionally, fasteners, not shown, could be employed to attach the cover  108  to the interface member  54  if more positive attachment is desired. 
         [0030]    While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may male various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.

Technology Category: h