Patent Publication Number: US-2023163528-A1

Title: Electrical connector for high power computing system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 63/417,973, filed on Oct. 20, 2022, entitled “ELECTRICAL CONNECTOR FOR HIGH POWER COMPUTING SYSTEM.” This application also claims priority to and the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 63/283,124, filed on Nov. 24, 2021, entitled “ELECTRICAL CONNECTOR FOR HIGH POWER COMPUTING SYSTEM.” The contents of these applications are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The technology disclosed herein relates to electrical interconnection systems, for example, electrical interconnection systems for supplying electrical power in a computing system that draws a high current. 
     BACKGROUND 
     Electrical connectors are used in many electrical systems. Electronic devices have been provided with assorted types of connectors whose primary purpose is to enable data, commands, power and/or other signals to pass between electronic assemblies. It is generally easier and more cost effective to manufacture an electrical system as separate electronic assemblies that may be joined with electrical connectors. The electrical connectors may transfer power between electronic assemblies via one or more electrical contacts, which may make up a part of the electrical connector. For example, one type of electronic assembly is a printed circuit board (“PCB”). The terms “card” and “PCB” may be used interchangeably herein. 
     In some scenarios, a two-piece connector is used to join two assemblies. One connector may be mounted to each of the assemblies. The connectors may be mated, forming connections between the two assemblies. 
     In other scenarios, a PCB may be joined directly to another electronic assembly via a one-piece connector, which may be configured as a card edge connector. The PCB may have pads along an edge that is designed to be inserted into an electrical connector attached to another assembly. Contacts within the electrical connector may contact the pads, thus connecting the PCB to the other assembly through the connector. 
     In some scenarios, busbars may be routed through an electronic device to distribute power to electronic assemblies within the device. The electronic assemblies may be connected to the busbar through connectors or screws. 
     SUMMARY 
     In one aspect the present disclosure relates to a power connector comprising a terminal. The terminal may comprise a first conductor comprising one or more tails and a second conductor comprising one or more openings. A cross sectional shape of the one or more tails and a shape of the one or more openings may be different. The one or more tails may pass through and engage the one or more openings such that the first and second conductors are electrically coupled. 
     In another aspect, a power connector may comprise a housing comprising a first slot, a second slot and a mounting face. A terminal may comprise a first mating portion in the first slot, a second mating portion in the second slot and one or more tails extending through the mounting face. The terminal may comprise a first conductor comprising the one or more tails and a mating contact portion positioned in the first slot, and a second conductor comprising a mating contact portion positioned in the second slot and one or more openings. Each of the one or more tails may pass through and electrically engage a respective opening of the one or more openings such that the first conductor and the second conductor are electrically connected. 
     In another aspect, an electrical connector may comprise a mating interface, a power tap off interface and a mounting interface. The electrical connector may comprise a plurality of terminals. Each of the plurality of terminals may comprise a first terminal subassembly comprising a plurality of first conductive members, each of the plurality of first conductive members comprising a mating interface portion disposed at the power tap off interface and tails configured for mounting to a substrate disposed at the mounting interface. Each of the plurality of terminals may further comprise a second terminal subassembly comprising a plurality of second conductive members, each of the plurality of second conductive members comprising a mating interface portion at the mating interface and a body portion comprising a plurality of holes. The tails of the plurality of first members may pass through respective holes of the plurality of second members, making an electrical connection between the plurality of first conductive members and the plurality of second conductive members. 
     It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Various aspects and embodiments of the present technology disclosed herein are described below with reference to the accompanying figures. It should be appreciated that the figures are not necessarily drawn to scale. Items appearing in multiple figures may be indicated by the same reference numeral. For the purposes of clarity, not every component may be labeled in every figure. 
         FIG.  1    is a simplified perspective view of two parallel boards connected through a straddle-mount card edge connector, according to one illustrative embodiment. 
         FIG.  2    is a schematic view illustrating distribution of power supplied through a card-edge connector in part through a conductive interconnect, such as a busbar, and in part through power planes in a PCB, according to one illustrative embodiment. 
         FIG.  3 A  is a perspective view of an exemplary embodiment of a portion of an electronic device with card-edge connector mounted to a PCB with busbars connected to distribute power to components on the PCB. 
         FIG.  3 B  is a perspective view of a portion of an alternate embodiment of an electronic device with card-edge connector mounted to a PCB with busbars connected to distribute power to components on the PCB. 
         FIG.  4    is a perspective, partially exploded view of a portion of the electronic device of  FIG.  3 A , including a connector mounted to a PCB and mated to a card edge of a power supply unit and a busbar, according to one illustrative embodiment. 
         FIGS.  5 A and  5 B  are a front view of the card-receiving face and right side view, respectively, of an exemplary embodiment of a card-edge connector configured for bus bar tap-off. 
         FIGS.  6 A and  6 B  are front perspective views of additional exemplary embodiments of card-edge connectors configured for cable tap off. 
         FIG.  6 C  is a front perspective view of the card-edge connector of  FIG.  6 A  mated to a cable assembly, with the cable cut away. 
         FIG.  6 D  is a bottom perspective view of the cable assembly of  FIG.  6 C . 
         FIG.  6 E  is an exploded view of the cable assembly of  FIG.  6 D . 
         FIG.  7    is an exploded view of an exemplary embodiment of a card-edge connector configured for bus bar tap-off. 
         FIG.  8 A  is an enlarged view of the portion of the card-edge connector of  FIG.  7    indicated by circle A. 
         FIG.  8 B  is cross section of the card-edge connector of  FIG.  7   , mounted to a first PCB and mated with a second PCB, from the perspective indicated by line B-B in  FIG.  8 A . 
         FIGS.  9 A,  9 B and  9 C  are a right side, back and bottom plan view of a terminal tap-off assembly of the card-edge connector of  FIG.  7   . 
         FIG.  10    is an exploded view of an exemplary embodiment of a card-edge connector configured for bus bar tap-off. 
         FIG.  11 A  is an enlarged view of the portion of the card-edge connector of  FIG.  10    indicated by circle B. 
         FIG.  11 B  is cross section of the card-edge connector of  FIG.  10   , mounted to a first PCB and mated with a second PCB, from the perspective indicated by line B-B in  FIG.  11 A . 
         FIGS.  12 A,  12 B and  12 C  are a right side, back and bottom plan view of a terminal tap-off assembly of the card-edge connector of  FIG.  10   . 
     
    
    
     DETAILED DESCRIPTION 
     The inventors have recognized and appreciated compact and reliable designs for connectors that support high speed, high performance electronic assemblies with low life-cycle costs. Such assemblies may be implemented with a substrate (e.g., a printed circuit board (PCB)) to which is mounted a first connector with power tap off. The connector with power tap off may have at least two mating interfaces. One mating interface may be configured to connect to a power supply. The other mating interface may be configured to receive a conductive interconnect, such as a busbar or a cable, that can distribute power to locations in the assembly remote from where the first connector is mounted to the substrate. Without the conductive interconnect in place, current supplied through the first mating interface of the first connector may be distributed to components of the electronic assembly through the substrate (e.g., through the power planes of a PCB). 
     With the conductive interconnect in place, a portion of the supplied current may flow through the interconnect to components of the electronic assembly remote from the first connector without flowing through the substrate in the vicinity of the connector. In this way, the current density within the substrate in the vicinity of the first connector is decreased relative to a configuration in which the interconnect is not installed. Alternatively or additionally, the total current supplied to the electronic assembly may be increased without increasing the current density within the substrate in the vicinity of the first connector. 
     An increase in current may be desired, for example, during the life of an electronic assembly when it is upgraded with additional or more powerful components, which draw more power. These components may be added in the field or may be included in newly manufactured devices using a substrate designed prior to the upgrade. The capability to add the interconnect and increase the total current without increasing current density enables the substrate to be designed with a capability to carry less than the total amount of power that every copy of such a substrate might ever have to carry over its lifetime. Because increasing the current carrying capacity of a substrate, such as a PCB, conventionally entails adding more layers to the PCB, enabling a PCB to be designed for less than the total current it might carry, a PCB may be designed to be thinner and to have a lower manufacturing cost than a conventional PCB of the same capabilities. 
     The Inventors have recognized and appreciated approaches for economically manufacturing conductive elements with mating contacts suitable for use in connectors with multiple mating interfaces. Such designs may support relatively low profile connectors, in which the height of the connector with a power tap off extends a relatively short distance from the substrate to which the connector is mounted. These designs may also support cost-effective and reliable manufacture of connectors for power tap off. 
     In some embodiments, a terminal for a connector with power tap off may be assembled from a first conductor and a second conductor. The first conductor may have tails, such as may be used for mounting to a printed circuit board. The second conductor may have openings. The openings and cross sectional shape of a tail in a plane of the openings may be different such that, where the tails pass through the openings, they engage to form an electrical connection. The tails and openings may form an interference fit. The openings may be circular, for example, and the tails may have a rectangular cross section, such as a square. Each of the first and second conductors may have mating contact portions, which may form, respectively, a part of a power tap off interface or a mating interface for the connector. 
     In some embodiments, each of the first and second conductors forming a terminal may be part of a terminal subassembly. Each subassembly may have a plurality of conductors, with the conductors of a first and a second subassembly engaging to form a terminal with a power tap off interface, a mating interface and a mounting interface. In some embodiments, each terminal subassembly may include multiple conductors. The terminal subassemblies may include an insulative portion holding the conductors of that terminal subassembly. For a terminal subassembly with conductors having openings therethrough, the conductors may include alignment features such that the holes can be readily aligned, which controls the force required to insert tails of other conductors through the openings. 
     Turning to the figures, specific non-limiting embodiments are described in further detail. The various systems, components, features, and methods described relative to these embodiments may be used either individually and/or in any desired combination as the disclosure is not limited to only the specific embodiments described herein. 
       FIG.  1    shows a Printed Circuit Board (“PCB”)  200  connected to PCB  240  via a connector, which in this example is a card-edge connector  220 . PCBs mechanically support and electrically connect one or more electronic components using conductive traces, pads, and other features etched from one or more conductive layers laminated onto layers of a non-conductive material. Traditionally, conductive layers are made from copper and non-conductive layers are made from woven fiberglass and flame-resistant epoxy resin binders. PCBs are generally made with interspersed conductive layers of conductive traces that carry signals and layers that are largely continuous sheets. The largely continuous layers serve as grounds for the signal traces and can also carry power, and are sometimes called power planes. 
     In the embodiment of  FIG.  1   , PCB  200  is illustrative of a portion of a power supply unit (PSU) configured for insertion into a card-edge connector via a parallel board (straddle-mount) arrangement. Other arrangements, such as vertically oriented or right-angle oriented connections are also possible. PCB  200  contains two conductive pads  202  configured to supply power and six conductive pads  204  configured to supply signals, although it should be understood that any number of each could be used in alternate embodiments. 
     The power pads  202  of PCB  200  may be on an edge suitable for a contact surface, which may be inserted into a slot  224  of a card-edge connector  220  containing power terminals  222 . In some embodiments, the conductive pads  202  may comprise a high-conductivity material able to conduct electric current sufficient for applications requiring at least 3000 W of power and having sufficient robustness to withstand repeated mating and unmating with a connector. For example, conductive pads  202  may be surface portions with cladding, such as a layer of Cu that has a thickness of at least 0.14 mm, or at least 0.5 mm, or at least 1 mm, or at least 1.5 mm, in some embodiments. The power supply may deliver relatively large currents, such as up to 60 A, 80 A, 100 A, 120 A, 180 A, 200 A or greater. 
     As illustrated in the example of  FIG.  1   , the power pads  202  may be wider than the signal pads  204 . Such a design enables the power pads  202  to carry more current than the signal pads  204 , without excessive heating. The larger cross-sectional area of the power pads  202  provide a lower contact resistance, a lower bulk resistance, and a lower current density, all of which contribute to less heating within the connector when a relatively large amount of current passes through the power pads  202 . 
     Power terminals  222  in the card-edge connector may similarly be designed to pass larger amounts of current with an acceptable amount of heating. Current flow is often used as an indication of delivered power, because power and current are related, and heating is proportional to current flow. Acceptable heating may be expressed as temperature rise at a rated current. As a specific example, a connector, or a power terminal within the connector, may have a rated current capacity that reflects the amount of current that will increase the temperature from ambient conditions by a set amount, such as 30° C. For example, the heating in the connector may be below this threshold amount when a high current, such as 60 A, 80 A, 100 A, 120 A, 180 A, 200 A or greater in some embodiments is transmitted. 
     Card-edge connector  220  passes electrical signals and/or power between PCB  200  and PCB  240 . To do so, card-edge connector  220  contains a slot  224  which receives PSU PCB  200 . This slot can be uniform, if the card to be inserted has a consistent thickness along its insertion edge, or non-uniform if this thickness varies. Once inserted, power terminals  202  and signal terminals  204  come into contact with one or more conductive elements  222  that pass electrical signals and/or power to PCB  240 . These elements may be formed of conductive materials and may be sufficiently robust to allow for the repeated mating and unmating with a mating component, such as a card edge like that on PCB  200  or conductive elements of a mating connector. PCB  204  may contain components (not shown) that use, condition, or otherwise interact with the electronic signals and/or power transmitted across card-edge connector  220 . Power may be distributed to these components through power pads  242 ,  244 ,  246 , to which the conductive elements of connector  220  are electrically and mechanically connected. The components may be connected directly to the pads. Alternatively, the pads and the components may be connected through conductive layers within the PCB, which are sometimes referred to as power planes. 
     In some embodiments, the various functions of these components may require different and incompatible electronic signals and/or power. For example, some components may require 5V whereas other components may require 12V. As such, the designs of PCB  200 , card-edge connector  220 , and PCB  240  are constructed to provide discrete electric pathways as required for different voltage levels. 
     The Inventors have recognized that in the card-edge connector embodiment shown in  FIG.  1   , the full amount of current that is transmitted to PCB  240  across card-edge connector  220  is distributed to the power planes of PCB  240 , creating a high current density in the PCB  240  adjacent connector  220 . As such, the amount of current that can be transmitted is limited by both the thickness of each power plane and the number of power planes in the region of PCB  240  adjacent connector  220 . Making thicker power planes may undesirably increase the size, cost and/or manufacturing complexity of the PCB. Adding additional power planes may increase the amount of power that can be transmitted via PCB  240 . More power planes add cost, weight, and thickness to the PCB and to an electronic assembly incorporating it. The number of power planes required to supply large currents (e.g., 60-100 Amps, 180-260 Amps, etc.) may therefore be undesirable. In scenarios in which a PCB is designed for possible upgrades that will draw high currents, initial construction with enough power planes to support future high currents may similarly be undesirable. 
     In some embodiments described herein, a PCB may be designed with fewer power planes than are necessary to carry a desired maximum current. One or more connectors with power tap off interfaces may be mounted to the PCB. When more power than can be carried by the power planes is desired, a conductive interconnect, such as a busbar or cable assembly, that may distribute power to locations on the PCB remote from the one or more connectors, may be connected to a power tap off interface. To facilitate a separable connection to a conductive interconnect, the power tap off interface may also be configured as a mating interface. The conductive interconnect may extend in a direction parallel to the PCB. 
     The one or more connectors may have multiple interfaces, including a first mating interface, which may be configured as a mating interface of a conventional card edge connector. Current may be supplied to the connector through the first mating interface and then distributed through other interfaces of the connector to the PCB directly or to the conductive interconnect, which may pass over the PCB. Splitting the current within the connector reduces the current density in the PCB adjacent the connector. In some embodiments, a terminal used in such a connector may have two mating contact portions and a tail portion, supporting a mating interface, a power tap off interface and a mounting interface. 
       FIG.  2    is a schematic illustration of a PCB  300  with such a card-edge connector  310 . In this example, connector  310  may be configured to mate with a PSU (not illustrated in  FIG.  2   ). Card-edge connector  310  contains a power tap off interface  312  which is configured to receive a conductive interconnect, which in this example is a busbar  330 . Mating interface  312  enables power to be tapped off from within connector  310  and delivered through the conductive interconnect to a remote location on the PCB  300 . 
     Busbar  330  may be implemented as a metallic strip, such as a metal bar. The busbar may be insulated or uninsulated and may have sufficient thickness to be unsupported or, in some embodiments the busbar may be supported in air by insulated pillars. These features enable the busbar to be air cooled. In some embodiments, the bus bar is bent at a right angle, forming two legs, with each of its two legs between 2″ and 24″ long, and in some embodiments between 3″ to 10″, such as 3.5″ in some embodiments. A busbar may be configured to carry power at a single voltage or may be configured to carry power of multiple voltage levels. In embodiments in which the busbar is configured to carry power at multiple voltage levels, the busbar may contain multiple, electrically insulated metal strips. 
     A first end of busbar  330  may be inserted into mating interface  312 , which here serves as a power tap off interface. Mating interface  312  may be configured as a card-edge connector with a slot of sufficient width to receive the busbar  330 . A second end of busbar  330  may be coupled to the power planes of PCB  300  at a location remote from connector  310 . In the illustrated example, busbar  330  is inserted into a second connector  320  to provide coupling to PCB  300 . Connector  320  may similarly have a mating interface configured to receive the busbar  330 . As power is supplied via card-edge connector  310 , a first portion of the power may pass through the mounting interface of connector  310  to PCB  300  in the vicinity of connector  310 . A second portion of the power may be tapped off and transmitted to PCB  300  via busbar  330  and connector  320 . Once coupled to the PCB, the power may be distributed to components attached to the PCB through power planes in the PCB. 
     In the example of  FIG.  2   , the first portion of the power is delivered to section  300   a  of PCB  300  and the second portion of the power is delivered to section  300   b  of PCB  300 . In the schematic shown in  FIG.  2   , section  300   a  and section  300   b  are on the same PCB but are not electronically connected. However, it is not necessary that the sections  300   a  and  300   b  be electrically decoupled. In some embodiments, PCB  300  may be implemented as a conventional PCB with power planes that extend substantially continuously throughout the PCB. Even in such a configuration, current flow may split based on the power draw of components and electrical properties of PCB  300 . Thus, even if the sections are not physically separate, the power flow throughout each of the sections  300   a  and  300   b  is less than the total supplied power, resulting in lower maximum power density in the PCB than without busbar  330 . 
     While this embodiment shows a single busbar  330  and traces from each connector  310  and  320  to respective sections of the PCB, it should be appreciated that  FIG.  2    is a schematic illustration of current splitting.  FIG.  2    is provided to schematically illustrate lower maximum current density, with lower maximum heat generation per unit area of the PCB, that enables the assembly formed with busbar  330  to operate at a higher power level than without busbar  330 . 
       FIGS.  3 A-B  show two possible configurations of the connector with power tap off schematically shown in  FIG.  2   . In both figures, the PCB and card-edge connection arrangement remains the same, although in alternate embodiments they may be different. In both figures, a source of power, here illustrated as PSU  470 , is inserted into slot  412 , forming a first horizontal mating interface  410  of L-shaped card-edge connector  400 . Electrical signals and a first portion of the supplied current is coupled to PCB  480  through L-shaped card-edge connector  400 , which may have a board mounting interface as in a conventional connector. 
     In addition, a portion of the supplied current may pass through a second vertical mating interface  420  of connector  400 , serving as a power tap off interface. In this example, vertical mating interface  420  includes a second slot  422  into which a busbar  430 , in the case of  FIG.  3 A , or busbar  440 , in the case of  FIG.  3 B , is inserted. A second portion of the supplied current may be carried to connector  450 , which includes a third mating interface  452  and second mounting interface  454 , via busbar  430  in  FIG.  3 A . In the example of  FIG.  3 B , current is delivered to connector  460 , which includes a third mating interface  462  and second mounting interface  464 , via busbar  440 . From the remote connector  464 , the second portion of the current may pass into PCB  480  adjacent connector  450  or  460 , enabling that second portion to be distributed to components mounted to PCB  480 , without increasing the current density adjacent connector  400 . 
     In the illustrated embodiment, busbars  430  and  440  are configured with two electrically separate paths. To support this function, busbar  430  contains a first portion  431  and a second portion  432  in the example of  FIG.  3 A , and busbar  440  contains a first portion  441  and a second portion  442  in the example of  FIG.  3 B . In both figures, these portions may be separated by sheets of insulation,  433  in  FIGS.  3 A and  443    in  FIG.  3 B . These first and second portions may be configured to transmit electric power of different characteristics, such as different polarities to provide a supply and a return, different voltages, or different frequencies. In other embodiments, the portions of the busbar may be electrically coupled and may transmit electric power of identical characteristics with higher current carrying capacity than one portion alone. 
     In some embodiments, an insulative support, an example of which is post  434  in  FIG.  3 A and  444    in  FIG.  3 B , may provide additional structural support to busbars  430  and  440 . In this example, the posts hold busbars  430  and  440  parallel to PCB  480 . In this example, busbars  430  and  440  bend at an approximately 90-degree angle, and the posts provide support at the bends. 
     Busbar  440  in  FIG.  3 B  is configured with different dimensions than busbar  430  in  FIG.  3 A . Busbar  440  has a reduced cross-sectional area relative to busbar  430 . Busbar  440  may be used, for example, in applications with lower power requirements than those of busbar  430 . For example, busbar  430  could be configured to carry a maximum current between 180-260 Amps, such as 220 Amps, whereas busbar  440  could be configured to carry a maximum current between 60-100 Amps, such as 80 Amps. The reduced cross section of busbar  440  also means that it contacts fewer of the terminals within the second mating interface  420  of connector  400 . 
     System configurations as shown in  FIGS.  3 A and  3 B  may result from using a PCB  480  to which a connector  400  is attached. Connector  400  has a mating interface that may mate with a PSU or other component through which current may be supplied. Connector  400  also includes a mounting interface in which terminals inside the connector are connected to PCB  480 , coupling current received through the mating interface into the power planes within PCB  480 . In some embodiments, there may be a sufficient number of power planes in PCB  480  for current to pass through the mounting interface of connector  400  without exceeding the current rating at any portion of PCB  480 . 
     In such a configuration, no conductive interconnect may be inserted into the second mating interface  420  of connector  400 . In such a configuration, a second connector, such as connectors  450  and  460  may be present, but not connected to connector  400  through a conductive interconnect separate from PCB  480 . Alternatively, the second connector may be omitted. 
     Nonetheless, PCB  480  may be manufactured with a footprint for a second connector, which may be used to mount a second connector when the power draw of all the components mounted on PCB  480  will cause the current density in the vicinity of connector  400  to exceed the current carrying capacity of the power planes within PCB  480 . In that scenario, a second connector, such as connector  450  or  460 , may be mounted in the footprint and connected to connector  400  through a conductive interconnect capable of carrying a portion of the supplied current from connector  400  to the second connector without passing through PCB  480 . 
     The configuration of the second connector, and of the conductive interconnect joining the first and second connectors, may depend on the amount by which the current required for operation of the components on PCB  480  exceeds the current carrying capacity of the power planes in the vicinity of connector  400 . The second connector may be sized to receive a wider busbar, for example, when the required current exceeds the current capacity by a larger amount. As specific examples, PCB  480  may be designed with  18  or fewer layers but may nonetheless carry up to 60 Amps. If the required current is between 60 and 100 Amps, a busbar as shown in  FIG.  3 B  may be added to carry an additional 40 Amps. If a current between 100 and 200 Amps is required, a busbar as shown in  FIG.  3 A  may be added to carry up to an additional 140 Amps, for example. 
     In this example, a connector mounted to PCB  480  may be configured based on the amount of current to be diverted from the first connector to the second connector. Alternatively or additionally, the conductive interconnect between connectors may be configured based on the amount of current to be diverted. As illustrated in  FIG.  3 B  in connection with the second mating interface on connector  400 , a bus bar may be inserted into only a portion of a slot that forms the mating interface. Using this technique, a larger connector suitable for diverting a relatively large amount of current, such as connector  450 , may be mounted to PCB  480 . If a system is configured such that less than the full amount of this large current needs to be diverted, a smaller busbar may be used and a portion of the mating interface of the larger connector  450  may be unoccupied. 
       FIG.  4    shows the connector from  FIG.  3 A  with busbar and PSU disconnected. A plurality of conductive elements within L-shaped card edge connector  400  are configured to electrically connect portions of at least three surfaces. In the embodiment shown in  FIG.  4   , those surfaces are non-coplanar and are on the following components: the power terminals  436  of busbars  431  and  432 ; and the power terminals  471  and signal terminals  472  of PSU  470 ; and PCB  480 . 
     In the embodiment of  FIG.  4   , busbar  430  includes two electrically separate portions,  431  and  432 , stacked one above the other. Each of the portions may have terminal portions forming power terminals  436 . A tap-off interface  82   b  is shown. 
       FIGS.  5 A and  5 B  show front and side views, respectively, of L-shaped card-edge connector  400 . Connector  400  has an L-shaped housing  402 . Housing  402  could be formed of a rigid, insulative material capable of withstanding the high heat generated by the transfer of high voltage electricity. Housing  402 , for example, may be molded from high temperature plastic with fiberglass fillers. Housing  402  may be molded as one or more components. When housing  402  is formed of multiple components, the components may interlock, snap together or otherwise be joined. 
     L-shaped housing  402  provides a first mating interface  410  and a second mating interface  420  and a mounting interface  582 . In the example of  FIGS.  5 A and  5 B , housing  402  has a horizontal section  404 , which will be parallel to a surface of a printed circuit board to which connector  400  is attached. The first mating interface  410  is formed in the horizontal section. Housing  402  also has a vertical section  406 . The second mating interface  420  is formed in the vertical section. A mating interface  82   a  is shown. 
     In the embodiment illustrated, mounting interface  582  is formed at the intersection of the horizontal and vertical sections. The illustrated configuration supports parallel board connections between a PCB to which connector  400  is attached and a board inserted into the first mating interface  410 , such as is illustrated in  FIGS.  3 A and  3 B . However, other relative positions of the mating and mounting interfaces are possible to support other system configurations. 
     In some embodiments, the horizontal and vertical sections could be of the same length. In other embodiments, such as the embodiment shown in  FIGS.  5 A and  5 B , these sections could be of different length. In the illustrated embodiment, the first mating interface  410  has a power portion  490  and a signal portion  492 . In this example, the second mating interface supports only power connections and is approximately the same length as the power portion  490  of the mating interface. In some configurations, however, only a portion of the power supplied through the first mating interface is delivered to components of the PCB to which connector  400  is attached and the second mating interface may be shorter than even the power portion  490  of the first mating interface  410 . 
     Both mating interfaces  410  and  420  are configured, in this embodiment, as card edge connectors. The housing  402  comprises a first slot  412 , forming a portion of the first mating interface  410  and a second slot  422  ( FIG.  3 A ) forming a portion of the second mating interface  420 . In this embodiment shown, slots  412  and  422  are offset by an angle of 90 degrees, resulting in an L-shape, but it should be understood that other angular offsets are possible to support different system configurations. In this embodiment, the housing  402  is configured to receive a PCB configured for edge connection (e.g., a PSU) in the first slot  412  and a conductive interconnect, such as a busbar, in the second slot  422 . 
     Located within housing  402  are two types of terminals. The first types of terminals  416  transmit electric power and the second type of terminals  418  transmit electric signals. In the embodiment illustrated, the power terminals are configured to make power connections between the first mating interface  410 , second mating interface  420  and mounting interface  582 . The signal terminals  418  may be shaped as in a conventional connector or otherwise to provide connections. Tails  415  and  417  of terminals  416  and  418  are exposed at mounting interface  582  where they can be attached to a printed circuit board. In the example of  FIG.  5 B , the tails protrude from the underside of card-edge connector  400 . The tails are configured to electrically connect a card-edge connector  400  to a PCB for the purposes of transmitting electrical power and signals. The tails may be shaped for attachment to a PCB via soldering, press fitting, or any other attachment technique. In some embodiments, different tail configurations may be used for signal and power terminals. Power connections, for example, may be made through post in hole soldering and signal connections may be made through surface mount soldering or may be press fit. 
       FIGS.  6 A- 6 B  illustrate alternative embodiments of a connector configured for use in a system in which a first portion of the power supplied through a connector may be delivered to an electrical assembly (e.g., a PCB, another connector, etc.) through a mounting interface of the connector and a second portion may be delivered to a remote location on the electrical assembly through a conductive interconnect. 
     As shown in  FIGS.  6 A- 6 B , a connector housing, such as housing  600  or housing  620 , may hold terminals that provide a plurality of mating interfaces. For example, in some embodiments, housing  600  or housing  620  may include a plurality of first type terminals  624  and a plurality of second type terminals  626 . First type terminals  624  may be power terminals configured for making power tap off connections in addition to connections at a mating interface and a mounting interface and second type terminals  626  may be conventional power terminals, making connections between a mating interface and a mounting interface. 
     In these examples, the first type terminals  624  have two mating contact portions and a tail for mounting to a PCB. One of the mating contact portions is positioned within mating interface  660  or  662  in a main body of housing  600  or  620  and the second in positioned within a chimney like projection  608  extending from the main body. The second type terminals  626  have one mating contact portion and a tail for mounting to a PCB. The mating contact portion is positioned within mating interface  660  or  662  in a main body of housing  600  or  620 , as in a conventional power connector. In this example, both the first and second type terminals have similarly shaped mounting tails and similarly shaped mating contact portions within the main body of housing. In this example, the mating contact portions of the first type terminals within projection  608  are the same as the mating contact portions within the main body of the connector housing. However, it is not a requirement that all terminal types have identical mating contact portions. 
     In the example of  FIG.  6 A , multiple ones of the first type terminals  624  are grouped together while multiple ones of the second type terminals  626  are grouped together. In this example, from left to right, in the embodiment of first housing  600  (shown in  FIG.  6 A ), first housing  600  includes a first grouping of the second type terminals  626 , followed by a second grouping of the first type terminals  624 , followed by a third grouping of second type terminals  626 . Alternatively, in the embodiment of second housing  620  (shown in  FIG.  6 B ), second housing  620  includes a first grouping of the second type terminals  626 , followed by a second grouping of the first type terminals  624 , followed by a third grouping of second type terminals  626 , followed by a fourth grouping of the first type terminals  624 , followed by a fifth grouping of second type terminals  626 . 
     Regardless of the number of groups and the shape of the terminals within each group, each group of first type terminals with mating interfaces within a projection  608  may form a mating interface for power tap off via the connector. In the embodiment of  FIG.  6 A , one such tap off interface is shown. In the embodiment of  FIG.  6 B , two such tap off interfaces are shown. In some embodiments, a power connector may be configurable to have none, 1, 2, 3 or, in some embodiments, more tap off interfaces. The housing components may have multiple locations, each of which may receive a terminal subassembly. Terminal subassemblies with either the first type terminals or the second type terminals may fit within each location. In this way, a connector may be assembled by inserting terminal subassemblies with the first type terminals in locations at which a tap off interface is to be formed and conductive element subassemblies with the second type terminals in other locations. 
     The connector housing may also be configurable. As shown in  FIGS.  6 A and  6 B , housings  600  and  620 , respectively, are shaped to receive covers  602  and  622 , respectively. Each of the covers may have an opening such that portions of conductive elements forming the tap off interface may pass through the cover. In this way, the housing may be configured for a desired number of tap off interfaces by attaching a cover with openings aligned with the desired number of tap off interfaces. 
     A cover may alternatively or additionally enable the insertion of terminal subassemblies into the connector housing. For example, a connector housing may be constructed with an open rear portion such that, with the cover removed, terminal subassemblies of both the first and second type may be inserted from the rear. The cover may then be installed in a downward direction with openings in the cover aligned with the first type conductive elements that extend out of the housing at a power tap off interface. 
     Further, a cover may provide a mechanism to incorporate into a connector one or more projections  608 , which provide mechanical support for a desired number of tap off interfaces. Projection  608  may be formed as an integral portion of or may be attached to cover  602  in locations where there is an opening in the cover for mating portions of the first type conductive elements to pass through. 
     Regardless of the number of power tap off interfaces, each tap off interface may mate with a conductive interconnect, such as a bus bar or a cable assembly. In the embodiment of  FIG.  6 C , a connector is illustrated with a single power tap off interface and a cable assembly mated to that interface. The connector of  FIG.  6 C  may be constructed using techniques as described above, and in this example is shown with a housing  640  that has been configured to provide a power tap off interface to which a cable connector  650  has been mated. 
     Cable connector  650 , for example, may have an opening configured to receive a projection  608  that bounds the power tap off interface, as described above in connection with  FIGS.  6 A and  6 B . Mating contact portions within that opening may extend into the mating interface  664  and make contact with the mating contact portions of the first type terminals at the mating interface  664 . 
     One or more mechanisms for mechanical support of cable connector  650  and/or to secure cable connector  650  to connector housing  640  may be provided on the cable connector  650  and/or the housing  640 . In this example, cable connector  650  includes a latch  652  with a hooked end that engages a complementary latching element on the connector housing  640 . For example, a projection  608  may include a complementary latching element. 
       FIG.  6 D  is a bottom view of a cable assembly including connector  650  in an unmated position. In this perspective, opening  654 , sized to receive a projection  608  is visible. Mating contacts  656  of conductive elements are visible within opening  654 . In the embodiment illustrated in  FIGS.  6 A and  6 B , each of the mating interfaces  664  is formed from two conductive element subassemblies. A corresponding number of mating contacts  656  are shown in  FIG.  6 C , each aligned with one of the conductive element subassemblies. 
       FIG.  6 E  is an exploded view of the cable assembly with connector  650 . In this example, connector  650  includes a housing  670  and a cover  672 . These components may be made of an insulative material, such as a polymer with reinforcing filler, such as glass fibers. Housing  670  and a cover  672  may be made with interlocking features, such as snap-fit features, such that cover  672  may be attached to housing  670  after conductive elements  674 A and  674 B are inserted into housing  670 . 
     One or more cables are attached to each of the conductive elements  674 A and  674 B. In this example, cable groups  676 A and  676 B are attached to conductive elements  674 A and  674 B, respectively. Each cable group  676 A and  676 B includes one or more cables, and are here shown with four cables. However, the groups may have other than four cables and may have different numbers of cables than each other. Each of the conductive elements  674 A and  674 B has a first end to which the cables of a group are electrically and mechanically connected, such as by welding, brazing, soldering or crimping. A mating contact portion  656  is formed at a second end of each of the conductive elements  674 A and  674 B. 
     Housing  670  and/or cover  672  may be shaped to hold conductive elements  674 A and  674 B in position for mating to the complementary conductive elements at a mating interface  662 . Additionally, housing  670  supports latch  652 . Latch  652  is joined to housing  670  via flexible arm  658 , which may, for example, be integrally molded with the rest of housing  670  from a polymer such that flexing of arm  658  enables the hooked end  657  of latch  652  to pivot. Hooked end  657  may pivot during mating such that the hooked end  657  may engage a latching element of a mating connector. Pivoting may also support un-mating. As shown, latch  652  includes an actuation end  659  opposite hooked end  657 . Actuation end  659  is positioned for a user to press it towards housing  670 , causing the hooked end  657  to pivot away from, and disengage from a latching element of a mating connector. 
       FIGS.  6 D and  6 E  show a cable assembly formed by terminating cables groups  676 A and  676 B with a connector  650 . A second end of the cable assembly is not shown. However, the cable assembly may be used as a conductive interconnect as described herein. The second end of the cable groups  676 A and  676 B, for example, may be terminated with a conventional cable connector and mated to a conventional connector mounted at an interior location on a PCB to which the connector with power tap off is mounted. However, other connections are possible. 
       FIGS.  3 - 6    illustrate various configurations of a power tap off connector, differing in various details of construction including whether the power tap off interface is configured for mating to a cable assembly or one or more bus bars. These configurations also differ in the construction of the housing. In each case, however, the connectors include power terminals to make connections among a mating interface, a power tap off interface and a mounting interface.  FIGS.  7 - 12    illustrate techniques that may be used to manufacture reliable and low cost power terminals configured for making such connections. In these examples, the connector housings are configured for receiving at a mating interface a card edge, such as an edge of a PCB in a PSU. The power tap off interface is configured for mating with one or more bus bars, each configured to carry a single voltage. The bus bar, for example, may be a solid busbar. 
     In some embodiments, such a power terminal may be formed from two or more conductors that engage with one another through a mechanically rugged and low resistance coupling. In some embodiments, groups of one or more conductors may be held in a housing as a subassembly, and terminals may be assembled by engaging one subassembly to another. 
       FIG.  7    is an exploded view of a connector  700 . Connector  700  includes an insulative housing  740  that includes a slot ( 802 ,  FIG.  8 B ) that, like slot  412 , may serve as a mating interface  702 . Mating interface  702  may receive an edge of a PCB, for example. To make connections to the signal pads on the edge of the PCB, connector  700  may include a plurality of signal terminals  718 , with mating contact portions positioned at the mating interface  702  and tails extending to the mounting interface  704 . 
     Connector  700  also includes an insulative projection  708 , including a slot  710 , which may serve as a power tap off interface  706 . In this example the first slot  710  may be configured to receive one or more solid bus bars. 
     Connector  700  includes a plurality of power terminals to make connections among the mating interface  702 , mounting interface  704  and the power tap off interface  706 . In this example, each of the power terminals has mating contact portions positioned in each of the slots forming the mating interface  702  and power tap off interface  706 . In this example, the mating contact portions include spring fingers on opposite sides of a slot that press against a member inserted into the slot. As all components of each terminal are electrically connected, the opposing spring fingers are configured for mating to a flat member, such as a solid bus bar, that has contact areas that are part of the same power circuit on opposing sides. However, other terminal configurations are possible. Groups of one or more terminals may be electrically isolated within connector  700 . In the illustrated embodiment, electrical isolation is provided by inserting mating members that are connected to different power circuits in different portions of the mating interfaces, such as is described above in connection with  FIG.  4   . In the example of  FIG.  7   , each of the terminals is electrically isolated from the other terminals. 
     In the example of  FIG.  7   , each of the terminals is formed from a plurality of terminal subassemblies, here illustrated by terminal subassemblies  750  and  760 . In this example, terminal subassemblies  750  and  760  each contains conductors, with the conductors of terminal subassemblies  750  and  760  extending in orthogonal directions such that they intersect. Housing  740  includes passages  742  that open into the slot ( 802 ,  FIG.  8 B ) forming mating interface  702 . A mating contact portion of a subassembly  760  may be inserted into each of the passages  742 . Insulative projection  708  may contain similar passages, opening into slot  710  which may be orthogonal to the passages  742  that open into the slot ( 802 ,  FIG.  8 B ) forming mating interface  702 . Mating contact portions of subassemblies  750  may extend into the passages of projection  708 . 
     Terminal subassembly  750  contains at least one conductor that has a mating contact portion positioned in the tap off interface  706  and tails that extend to mounting interface  704 . Terminal subassembly  760  includes at least one conductor that has a mating contact portion positioned in the mating interface  702 . The conductors of the subassemblies engage such that each terminal makes electrical connections between mating interface  702 , mounting interface  704  and power tap off interface  706 . In the example illustrated, the conductor(s) of terminal subassembly  760  each have a body portion  762  and the conductors of subassembly  750  pass through and engage that body portion. 
     Additional details of terminal subassemblies  750  and  760  are illustrated in connection with  FIGS.  8 A and  8 B . In the illustrated example, each of the terminal subassemblies includes a plurality of conductors held in an insulative member. In this example, each of the terminal subassemblies is formed from four conductors, each stamped from a sheet of metal, such as a copper alloy. The insulative member is molded over the conductors to hold the conductors together. 
     For example, subassembly  760  has four conductors, conductors  862 ,  864 ,  866 , and  868 . Those conductors are held together by an insulative member  860 . Each of the conductors may include one or more alignment features, such as notches  872 , that may be aligned by an assembly tool before insulative member  860  is molded over the conductors. 
     In the illustrated example, each of the conductors of subassembly  760  has mating contact portions at a first end and a body portion with holes  870  at a second, opposing end. In this example, the mating contact portions are formed by spring fingers cut in a metal sheet forming the conductor. The mating contact portions face inwards, towards the center of slot  802  forming the mating interface. In the illustrated example, conductors on opposite sides of the slot  802  have opposing contacts, with conductor  862  opposing conductor  866  and conductor  868  opposing conductor  864 . 
     Each of the conductors  862 ,  864 ,  866 , and  868  may have a different shape. Conductors  862  and  866  are illustrated to be longer than conductors  864  and  868 . Accordingly, the distal ends of conductors  862  and  866  extend closer to the entry  804  of slot  802  of mating interface  702  than the distal ends of conductors  864  and  868 . Additionally, the conductors are here shown to be asymmetrical. In this example, the asymmetry positions the body portions with holes  870  near the mounting interface  704 . In this example, this configuration is achieved by jogged portions in conductors  862  and  864 , which jog their body portions towards the body portions of conductors  866  and  868 . With this jog at an intermediate portion of the conductors, opposing ends of the conductors are in different planes. In contrast,  866  and  868  have their ends in the same plane. Conductors  866  and  868 , adjacent the surface of slot  802  nearer the mounting interface  704 , have straight bodies such that the conductor bodies are stacked one on top of the other adjacent mounting interface  704 . The body portions of conductors  866  and  868  are parallel to the body portions of conductors  862  and  864 , such that the body portions of conductors  862  and  864  and conductors  866  and  868  may be stacked side-by-side in parallel, as illustrated. 
     Subassembly  760  may include features that engage complementary features in housing  740 . In this example, insulative member  860  includes one or more projections  894  that extend into openings  896  when a subassembly  760  is inserted into housing  740 . 
     Subassembly  750  may comprise an insulative member  850  and conductors  852 ,  854 ,  856 , and  858 . In the example, each of the conductors has, at one end, contact fingers and at an opposite end contact tails  950  ( FIG.  9 A ). In this example, there are three contact fingers, but conductors with more or fewer contact fingers may be used. In the example of  FIGS.  8 A,  8 B,  9 A,  9 B and  9 C , conductors  852 ,  854 ,  856 , and  858  have mating contact portions that are formed in the same way as the mating contact portions of  862 ,  864 ,  866 , and  868 . For example, conductors  852  and  856  are longer than conductors  854  and  858 , such that conductors  852  and  856  extend closer to the opening of slot  710  than conductors  854  and  858 . 
     Further housing  850  of subassembly  750  has a different shape than the housing  860  of subassembly  760 . In this example, housing  850  is shaped to fit within an opening of projection  708 . To hold subassembly  750  within projection  708 , attachment features may be present on either or both of projection  708  and housing  850 . In this example, housing  850  has one or more projections  890  that extend into openings  892  of projection  708  to hold the subassembly in projection  708 . 
     In this example, the portions of the conductors of subassembly  750  at an end opposite the mating contact portions include features that engage with the conductors of subassembly  760 . In the illustrated example, those features may be tails  950  extending from a body of the conductors. As shown in  FIGS.  9 B and  9 C , each conductor may have multiple tails. Three tails are shown in this example. Each of the tails may have a distal portion  954  shaped for attachment to a printed circuit board. In this example, distal portions  954  are shaped as solid pins for pin-in-hole mounting. 
     Tails  950  may further include an engagement portion, configured to engage with conductors of subassembly  760 . The engagement portion may make an interference fit with openings in conductors of subassembly  760 . In the example of  FIGS.  9 B and  9 C , engagement portion  952  may have, for example, a rectangular cross section. Here, a square cross section is illustrated, so as to make an interference fit with circular openings  870  of the conductors of subassembly  760 . An interference fit, for example, may be created with engagement portions  952  that have a diagonal that is larger than the diameter of the openings  870 . The conductors of each may be configured to provide a low resistance electrical connection between the conductors of the two subassemblies while enabling that connection to be formed without excessive force. The resistance, for example, may be less than 5 Ohms, and less than 1 Ohm in some embodiments. The diagonal in cross section of engagement portion  952  may be larger than the diameter of openings  870  by between 3% and 20%, for example, or between 3% and 10% in some examples. 
       FIG.  10    shows an alternative construction of a connector with terminals formed by engaging multiple subassemblies. In this example, the mating interface, the mounting interface and the tap off interface of connector  1000  may be the same as for connector  700 . Accordingly, housing  740  and projection  708  may be as described above. Connector  1000 , however, may differ from connector  700  with respect to the shape of the conductors in the subassemblies that form terminals. 
       FIG.  11 A  is an enlarged view of the portion of the card-edge connector of  FIG.  10    indicated by circle B. 
     The conductors  1052 ,  1054 ,  1056  and  1058  of subassembly  1050  may have mating contact portions that are as described above for connector  700  and may similarly be held in a subassembly housing. The tails of conductors  1052 ,  1054 ,  1056  and  1058 , however, may be configured to engage with conductors of subassembly  1060 , which have a different configuration than conductors  862 ,  864 ,  866  and  868  of connector  700 . 
     In this example, the conductors of subassembly  1060  on opposing sides of slot  802  are symmetrical. Conductors  1062  and  1066  have the same shape as each other, for example. Conductors  1064  and  1068  also have the same shape as each other. The conductors with the same shape are mounted on opposite sides of slot  802  such that they are symmetrical across the axis of insertion of PCB  200  into slot  802 . 
     The symmetrical configuration results in the body portions of conductors  1068  and  1066  jogging toward the body portions of conductors  1062  and  1064 . As a result, the body portions  1162  of conductors  1062 ,  1064 ,  1066  and  1068  are stacked, one on top of the other near the mounting interface  704 , but at a further distance from the mounting interface  704  than in connector  700 . 
       FIG.  11 B  is a cross section of the card-edge connector of  FIG.  10   , mounted to a first PCB and mated with a second PCB, from the perspective indicated by line B-B in  FIG.  11 A . 
     The tails of the conductors of subassembly  1050  are shaped to engage the body portions of conductors of subassembly  1060 . As shown in  FIGS.  12 A,  12 B, and  12 C  each of the conductors of subassembly  1050  has multiple tails  1250 . As with the conductors of connector  700 , each of the tails  1250  may have a distal portion  1256 , shaped for attachment to a printed circuit board, and an engagement portion  1252 , shaped to engage conductors in another subassembly. Additionally, each of the tails  1256  may include an intermediate portion  1254  between the engagement portion and the distal portion. Here, intermediate portion  1254  is shown to have a shape different than each of distal portion  1256  and engagement portion  1252 . In other implementations, intermediate portion  1254  may have the same shape as either distal portion  1256  or engagement portion  1252 . 
     Connector  1000  may include a tail organizer  1180  that has openings sized and positioned to receive the intermediate portions  1254  of one or more terminals. In this example, there is one organizer, here shown as a plate, for all of the terminals in the connector, but in other configurations, there may be multiple organizers. Conversely, the organizers collectively may not be coextensive with the tails of all of the terminals in connector  1000  such that the tails of some terminals may not pass through an opening of an organizer. Organizer  1180  may be made of an insulative material. 
     The openings in organizer  1180  may align the tails  1250  in a predetermined pattern matching the pattern of holes in organizer  1180 . The pattern of holes in organizer  1180 , for example, may match the pattern of holes in PCB  240  to which connector  1100  may be mounted and/or the pattern of holes in the body portions through which the tails  1250  pass. In some embodiments, connectors, such as connector  700 , with asymmetrical conductors may additionally include an organizer. In other embodiments, the holes in body portions  762  may provide the function of an organizer. 
     Having thus described several embodiments, it is to be appreciated various alterations, modifications, and improvements may readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only. 
     Various changes may be made to the illustrative structures shown and described herein. 
     For example, construction techniques for forming connectors with power tap offs as described herein may be combined in embodiments not expressly illustrated. For example, the mating contact portions may have other configurations. For example, rather than conductors terminating in spring fingers, mating contact portions may be shaped as blades. Further, the number of conductors on each side of a slot may be varied. Moreover, conductors may be positioned on only one side of a slot forming a mating interface or the conductors on opposite sides of a slot may be electrically insulated from each other within the connector. Further, any of the configurations for which a bus bar is used as a conductive interconnect for a power tap off may alternatively or additionally be formed using a cable assembly as the conductive interconnect. 
     As another example of a possible variation, embodiments of an electronic system were described in which a printed circuit board  300  was designed to mate with a power supply unit through connector  310 . In such a configuration, electrical power may be sourced from the power supply unit and used by components on printed circuit board  300 . However, it should be appreciated that the techniques described herein are applicable to systems in which power flows in either direction through connector  310 , and the techniques are useful with systems to couple power in any direction. 
     In some embodiments, one of the mating interfaces of the connector may be a card edge connector, which may be configured to receive a card edge, or similarly sized structure, from a power supply. In other embodiments, a mating interface of the connector may be configured for mating with a mating connector, which might, in turn, have a mounting interface for connection to a printed circuit board or other substrate. 
     A mating interface for power tap off may similarly be configured like a card edge connector, but may receive a busbar or similarly sized terminal of a power cable. In other embodiments, the power tap off mating interface may have terminals that mate with terminals in a connector terminating a power cable assembly. 
     As an example of another possible variation, power connectors in which conductors of two subassemblies engage by the conductors of a first subassembly, forming a power tap off interface, passing through conductors of a second subassembly, forming a mating interface. In other embodiments, the conductors of the second subassembly may pass through conductors of the first subassembly. 
     As a further example, terminal subassemblies were described in which bodies of multiple conductive members were aligned via features such as a notch and/or protrusion. In some examples, the alignment features may comprise one or more holes in one or more of the conductive members having a member, separate from the tails of the plurality of conductive members passing therethrough. 
     As yet another example, conductors with tails for pin in hole mounting are illustrated. Tails in other configurations, such as press fit or surface mount solder, for example, may alternatively or additionally be used. 
     As another example of a variation, the power portion  471  of a PCB may comprise a blade of conductive material. For example, the power portion  471  may comprise any of the following: a solid piece of elemental metal having high conductivity (e.g., Cu, Al); a solid piece of an alloy of metals (e.g., a Cu alloy); or a solid plate or core clad with a high-conductivity metal (e.g., a Cu plate clad with Au, a steel plate clad with Cu, a resin plate clad with Cu); or a laminate with layers of high conductivity material interspersed with lower conductivity materials. 
     Alternative construction techniques for bus bars may also be used. The busbar may be, for example: a solid piece of copper; a core that is clad with a thick layer of copper; a core that is clad with a thick layer of copper and a surface layer of gold; a core that is clad with a thick layer of copper, a layer of silver, and a surface layer of gold; a laminated structure with a thin insulative layer separating two thicker conductive layers; etc. As will be appreciated, the high-conductivity material may be a metal alloy. The core may be made of any material having properties that enable it to be formed into a blade-like shape and that may be clad with another material without adversely reacting with the other (cladding) material. For example, the core may be made of aluminum. 
     Moreover, a busbar with two portions supporting two electrically separate paths was illustrated to provide an exemplary busbar. Such a busbar may be used, for example, in an electronic device with one high current power circuit. Some electronic devices may have more than one high current power circuit, and may therefore have a busbar with more than two portions, such as 4, 6 or more portions. Each portion of the bus bar may have a mating portion, such as an exposed surface that may be inserted into a card edge connector as pictured above. 
     Manufacturing techniques may also be varied. For example, embodiments are described in which power conductive elements are formed into terminal subassemblies, which are then inserted into a connector housing. In some embodiments, power conductive elements may be separately inserted into a connector housing. 
     Connector manufacturing techniques were described using specific connector configurations as examples. A parallel board, right angle connector, that mates with a card edge was described as an example of a first connector. A second connector was illustrated as a vertical card edge connector. Either or both of these connectors may have other forms, including, for example, backplane connectors, cable connectors, stacking connectors, mezzanine connectors, I/O connectors, chip sockets, etc. 
     In some embodiments, contact tails were illustrated as posts suitable for a pin in holder solder attachment. However, other configurations may also be used, such as surface mount elements, press fits, etc., as aspects of the present disclosure are not limited to the use of any particular mechanism for attaching connectors to printed circuit boards. 
     As an example embodiment, a power connector may comprise a terminal, the terminal comprising: a first conductor comprising one or more tails; a second conductor comprising one or more openings; wherein: a cross sectional shape of the one or more tails and a shape of the one or more openings are different; and the one or more tails pass through and engage the one or more openings such that the first and second conductors are electrically coupled. 
     Optionally, the first conductor may further comprise a first mating contact portion; the second conductor may further comprise a second mating contact portion; and the one or more tails, the first mating contact portion, and the second mating contact portion may be electrically connected. The cross sectional shape of the one or more tails may be rectangular and the cross sectional shape of the one or more openings may be circular. The one or more tails and the one or more openings may be sized to make an interference fit between each of the plurality of tails and a respective opening of the one or more openings. The terminal may further include a third conductor comprising one or more openings aligned with the one or more openings of the second conductor; and the one or more tails may pass through and engage the one or more openings of the third conductor such that the first, second and third conductors are electrically coupled. The second conductor may comprise a first alignment feature, and the third conductor may comprise a second alignment feature, aligned with the first alignment feature whereby the one or more openings of the third conductor are aligned with the one or more openings of the second conductor. The first alignment feature may be one of a protrusion and a notch, and the second alignment feature may be the other of the protrusion and the notch. The second conductor may comprise a first end, a second end, and an intermediate portion joining the first end and the second end; the second conductor may comprise a mating contact at the first end and the one or more openings of the second conductor may be disposed at the second end; and the intermediate portion of the second conductor may be jogged such that the first end and the second end of the second conductor are in different planes. 
     Optionally, the third conductor may comprise a first end, a second end, and an intermediate portion joining the first end and the second end; the third conductor may comprise a mating contact at the first end and the one or more openings of the second conductor may be disposed at the second end; the second end of the third conductor may be parallel and adjacent to the second end of the second conductor; and the intermediate portion of the third conductor may be straight. Alternatively or additionally, the third conductor may comprise a first end, a second end, and an intermediate portion joining the first end and the second end; the third conductor may comprise a mating contact at the first end and the one or more openings of the second conductor may be disposed at the second end; the second end of the third conductor may be parallel and adjacent to the second end of the second conductor; and the second conductor and the third conductor may be asymmetrical such that the second ends of the second and third conductors are closer to a distal end of the one or more tails of the first conductor than the first end of the second conductor. Alternatively or additionally, the third conductor may comprise a first end, a second end, and an intermediate portion joining the first end and the second end; the third conductor may comprise a mating contact at the first end and the one or more openings of the second conductor may be disposed at the second end; the second end of the third conductor may be parallel and adjacent to the second end of the second conductor; and the intermediate portion of the third conductor may be jogged such that the first end and the second end of the third conductor are in different planes. The second conductor and the third conductor may be symmetrical. 
     Optionally, the cross sectional shape of the one or more tails and the cross sectional shape of the one or more openings may be configured such that the one or more tails and the one or more openings hold the first and second conductors together via an interference fit. The first conductor may be orthogonal to the second conductor. 
     As an example embodiment, a power connector may comprise: a housing comprising a first slot, a second slot and a mounting face; a terminal comprising a first mating portion in the first slot, a second mating portion in the second slot and one or more tails extending through the mounting face, wherein: the terminal comprises: a first conductor comprising the one or more tails and a mating contact portion positioned in the first slot; and a second conductor comprising a mating contact portion positioned in the second slot and one or more openings; and each of the one or more tails passes through and electrically engages a respective opening of the one or more openings such that the first conductor and the second conductor are electrically connected. 
     Optionally, the second slot may comprise a card edge connector mating interface. The first conductor may be one of a plurality of first conductors, each first conductor of the plurality of first conductors may comprise one or more tails and a mating contact portion positioned in the first slot; the second conductor may be one of a plurality of second conductors, each second conductor of the plurality of second conductors may comprise a mating contact portion positioned in the second slot and one or more openings; and the one or more tails of each of the plurality of first conductors may pass through and electrically engage a respective opening of the one or more openings in each of the plurality of second conductors such that the plurality of first conductors and the plurality of second conductors are electrically connected. The plurality of second conductors may comprise alignment features that engage with one another to align the at least one opening in each of the plurality of second conductors. The alignment features may comprise protrusions and indents. The one or more tails and the one or more openings may be configured to fit together via an interference fit. The first slot may be orthogonal to the second slot. 
     As an example embodiment, an electrical connector may comprise a mating interface, a power tap off interface and a mounting interface, the electrical connector comprising a plurality of terminals, each of the plurality of terminals comprising: a first terminal subassembly comprising a plurality of first conductive members, each of the plurality of first conductive members comprising a mating interface portion disposed at the power tap off interface and tails configured for mounting to a substrate disposed at the mounting interface; a second terminal subassembly comprising a plurality of second conductive members, each of the plurality of second conductive members comprising a mating interface portion at the mating interface and a body portion comprising a plurality of holes; wherein: the tails of the plurality of first conductive members pass through respective holes of the plurality of second conductive members, making an electrical connection between the plurality of first conductive members and the plurality of second conductive members. 
     Optionally, the body portions of the plurality of second conductive members may be stacked side-by-side in parallel. The mating interface may comprise a slot comprising an entry, and for a first subset of the plurality of second conductive members, the mating interface portion may be a first distance from the entry and for a second subset of the plurality of second conductive members, the mating interface portion may be a second distance from the entry, the first distance being less than the second distance. For a third subset of the plurality of second conductive members, the mating interface portion may be on a first side of the slot and for a fourth subset of the plurality of second conductive members, the mating interface portion may be on a second side of the slot, opposite the first side. Alternatively or additionally, conductive members of the third subset of the plurality of second conductive members may be symmetrical with respect to conductive members of the fourth subset of the plurality of second conductive members. Alternatively or additionally, conductive members of the third subset of the plurality of second conductive members may be asymmetrical with respect to conductive members of the fourth subset of the plurality of second conductive members. The body portions of the conductive members of the third subset of the plurality of second conductive members may jog towards the mounting interface. Alternatively or additionally, the body portions of the conductive members of the fourth subset of the plurality of second conductive members may be straight. 
     Optionally, the power tap off interface may comprise a second slot comprising a second entry, and for a first subset of the plurality of first conductive members, the mating interface portion may be a third distance from the second entry and for a second subset of the plurality of first conductive members, the mating interface portion may be a fourth distance from the second entry, the third distance being less than the fourth distance. For a third subset of the plurality of first conductive members, the mating interface portion may be on a first side of the second slot and for a fourth subset of the plurality of first conductive members, the mating interface portion may be on a second side of the second slot, opposite the first side. 
     Optionally, for each of the plurality of terminals, an insulative member may be molded over the plurality of first conductive members. For each of the plurality of terminals, an insulative member may be molded over the plurality of second conductive members. The electrical connector may further comprise an insulative housing, the insulative housing comprising: a first portion comprising a first slot, wherein the power tap off interface comprises the first slot; and a second portion comprising a second slot, wherein the mating interface comprises the second slot. The electrical connector may further comprise an insulative plate at the mounting interface, the insulative plate comprising a plurality of holes therethrough, wherein the tails of the plurality of first conductive members for a plurality of terminals extend through the holes. For each of the plurality of terminals, each of the plurality of second conductive members may comprise a registration feature, the registration feature comprising a hole having a member, separate from the tails of the plurality of conductive members passing therethrough. Alternatively or additionally, for each of the plurality of terminals, each of the plurality of second conductive members may comprise a registration feature, the registration feature comprising a notch along an edge of the second conductive member. 
     Various aspects of the present disclosure may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments. 
     Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. 
     Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments or examples. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. Accordingly, the foregoing description and drawings are by way of example only. 
     Terms such as “horizontal” and “vertical” were used to distinguish interfaces of an L-shaped connector. Horizontal and vertical directions may be determined relative to a surface of a printed circuit board to which the connector is mounted or, when the connector is not mounted to the board, the plane that a printed circuit board would occupy. However, such terms indicate relative direction and the horizontal and/or vertical directions may be determined relative to other reference planes. 
     The present disclosure is not limited to the details of construction or the arrangements of components set forth in the foregoing description and/or the drawings. Various embodiments are provided solely for purposes of illustration, and the concepts described herein are capable of being practiced or carried out in other ways. Also, the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having,” “containing,” or “involving,” and variations thereof herein, is meant to encompass the items listed thereafter (or equivalents thereof) and/or as additional items.