Patent Publication Number: US-2021166860-A1

Title: Hybrid transformers for power supplies

Description:
TECHNICAL FIELD 
     The present subject matter relates to power supplies and, more particularly, to hybrid transformers therefor. 
     BACKGROUND 
     Often times, electronics and other applications call for power characteristics that are different from available power sources. Converters, transformers, and/or combinations thereof address the problem of mismatched power sources and power needs. A converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. A transformer is conventionally utilized to increase or decrease the alternating voltages in electric power applications. However, power conversion may be costly, in terms of component size, expense, noise introduction, manufacturing time, power consumption, thermal load, etc. 
     Power supplies that call for high input voltage and yield lower output voltage entail transformers with high primary to secondary turns ratios. Exemplary power supplies may be from 420V DC to 360V DC converted to 54V DC, 24V DC or 12V DC. Isolated DC-DC converters such as 54V DC converted to 12V or 10V DC have conventionally involved lower turns ratios. Further, such conventional low turns ratio transformers were frequently developed using planar transformers having both primary and secondary transformer windings disposed on high count, multilayer printed wiring boards (PWBs) or printed circuit boards (PCBs). The advances contemplated by the present disclosure take advantage of resonant topology and hybrid technologies to improve power density, decrease material usage, decrease cost, and improve efficiency. 
     Conventionally, transformer coils have been manufactured directly into the material of a PCB. A multilayer PCB with reinforced isolation between each turn of a coil requires approximately six weeks to manufacture. The manufacturing time and complexity results from safety requirements necessitating thick, three-layer, 16 millimeter dielectric layers separating the coil. Growing these dielectric layers is time consuming and labor intensive. A solution, like that described in the below disclosure, utilizing a surface mounted wire coil represents an improvement in the art because such a design reduces cost, accelerates time to market, and improves efficiency for DC-DC converters. 
     The description provided in the background section should not be assumed to be prior art merely because it is mentioned in or associated with the background section. The background section may include information that describes one or more aspects of the subject technology. 
     SUMMARY 
     According to an aspect of the present disclosure, a hybrid transformer may include first and second wire coils arranged on opposing surfaces of a printed circuit board (PCB), a core extending through the PCB, wherein the first and second coils are each wound around the core, and at least one header electrically coupling one of the first and second wire coils to the PCB. 
     According to another aspect of the present disclosure, a method of assembling a hybrid transformer, the method may include coupling a first wound conductor to a first surface of a printed circuit board (PCB), coupling a second wound conductor to an opposing second surface of the PCB, and positioning a core such that a central limb of the core extends through the first wound conductor, the second wound conductor, and the PCB. 
     Yet another aspect of the present disclosure describes a power supply may include a printed circuit board (PCB), a hybrid transformer, and a header. The hybrid transformer may include a core, a first coil, and second coil, wherein the first coil comprises a first wire and a first insulating material wound into the first coil and surface mounted to the PCB, and the header electrically coupling the first coil to the PCB. 
     Other aspects and advantages of the present embodiments will become apparent upon consideration of the following detailed description and the attached drawings wherein like numerals designate like structures throughout the specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a high density isolated hybrid transformer for DC-DC converters; 
         FIG. 2  is a cross-sectional view of the hybrid transformer taken along line  2 - 2 ; 
         FIG. 3  is a another cross-sectional view of the hybrid transformer taken along line  3 - 3 , 
         FIG. 4  is an isometric view of a coil from the hybrid transformer of  FIG. 1 ; 
         FIG. 5  is an isometric view of a header from the hybrid transformer of  FIG. 1 ; 
         FIG. 6  is an isometric view of the header and coil of the hybrid transformer with an insulator disposed thereon; 
         FIG. 7  is an isometric view of the header, coil, and insulator of a hybrid transformer disposed on a PCB; 
         FIG. 8  is an isometric view of the header, coil, and insulator with a portion of a core disposed over a mirror image of the header, coil, and insulator arranged on an opposite side of the PCB; 
         FIG. 9  is an isometric view of a hybrid transformer omitting other electrical components otherwise disposed on the PCB; 
         FIGS. 10, 11, and 12  are graphical charts showing efficiency plotted against output current for an example hybrid transformer according to the present disclosure and supplied with input voltages of 405V, 410V, and 415V respectively; 
         FIGS. 13, 14, and 15  are graphical charts showing power dissipation plotted against output current for an example hybrid transformer according to the present disclosure and supplied with input voltages of 405V, 410V, and 415V respectively; 
         FIG. 16  is an enlarged cross-sectional view of one side of a solid wire model example of the hybrid transformer, similar to that shown in  FIG. 2 , with magnetic flux lines superimposed on the image; 
         FIG. 17  is an enlarged cross-sectional view of the coil and insulator shown in  FIG. 16 ; 
         FIG. 18  is a graphical chart showing resistance plotted against frequency for the solid wire model of  FIG. 16 ; 
         FIG. 19  is an enlarged cross-sectional view of one side of a litz wire model example of the hybrid transformer, similar to that shown in  FIG. 2 , with magnetic flux lines superimposed on the image; 
         FIG. 20  is an enlarged cross-sectional view of the coil and insulator shown in  FIG. 19 ; 
         FIG. 21  is a graphical chart showing resistance plotted against frequency for the litz wire model of  FIG. 19 ; 
         FIG. 22  is an enlarged cross-sectional view of one side of an offset coil, litz wire model example of the hybrid transformer, similar to that shown in  FIG. 2 , with magnetic flux lines superimposed on the image; 
         FIG. 23  is an enlarged cross-sectional view of the coil and insulator shown in  FIG. 22 ; and 
         FIG. 24  is a graphical chart showing resistance plotted against frequency for the offset coil, litz wire model of  FIG. 22 . 
     
    
    
     In one or more implementations, not all of the depicted components in each figure may be required, and one or more implementations may include additional components not shown in a figure. Variations in the arrangement and type of the components may be made without departing from the scope of the subject disclosure. Additional components, different components, or fewer components may be utilized within the scope of the subject disclosure. 
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various implementations and is not intended to represent the only implementations in which the subject technology may be practiced. As those skilled in the art would realize, the described implementations may be modified in various different ways, all without departing from the scope of the present disclosure. Still further, modules and components depicted may be combined, in whole or in part, and/or divided, into one or more different parts, as applicable to fit particular implementations without departing from the scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. 
     With reference to  FIGS. 1-24 , a high density isolated hybrid transformer  100  for DC-DC converters is described. The hybrid transformer  100  is designed for electrical applications, such as power supplies, that call for relatively high input voltages and relatively low output voltages, e.g., 415V DC to 380V DC converted to 54V DC, 24V DC or 12V DC. The hybrid transformer  100  may facilitate improved power density, decreased material usage, decreased expense, decreased time to market, improved customization, and improved efficiency, as compared with conventional transformers for high voltage input 
     Referring now to  FIGS. 1-3 , the hybrid transformer  100  is shown disposed on a PCB  102  along with a number of other electrical components  104 . The hybrid transformer  100  comprises first and second coils  106 ,  108  disposed on first and second sides  110 ,  112  of the PCB  102 . First and second insulators  114 ,  116  are disposed adjacent the first and second coils  106 ,  108  axially distal from the PCB  102 . In the exemplary embodiment of  FIGS. 2 and 3 , the PCB  102 , first and second coils  106 ,  108 , and first and second insulators  114 ,  116  are stacked according to the following order: the first insulator  114 , the first coil  106 , the PCB  102 , the second coil  108 , and the second insulator  116 . In other words, the first and second insulators  114 ,  116  sandwich the first coil  106 , the PCB  102 , and the second coil  108 . An interior opening or passageway  118  is disposed within the first and second coils  106 ,  108 , the first and second insulators  114 ,  116 , and the PCB  102 . A core  120  is disposed within the interior opening  118  and passes through each of the coils  106 ,  108 , insulators  114 ,  116 , and the PCB  102 . In the embodiments illustrated in  FIGS. 1-3, 8, and 9 , the core  120  is configured as a shell-type transformer core because the primary and secondary windings  106 ,  108  are arranged about a central limb  122  of the core  120 , while the core  120  considered as a whole, surrounds the coils  106 ,  108 . 
     The first coil  106  shown in  FIG. 4  is a wire wound planar coil comprising a suitable conductor such as litz wire, solid triple insulated wire, or another suitable wire. The first and second coils  106 ,  108  may be made of the same material or differing materials depending upon specifics of example applications. Forming the coils  106 ,  108  from windable material reduces time-to-market as compared with conventional methods of fabricating windings directly into a PCB. Particularly safety schemes may specify that one of or both of the coils  106 ,  108  may be made from particular materials that facilitate adequate insulation between conducting portions thereof. 
     Referring still to the coil  106  shown in  FIG. 4 , the conductor is arranged into a planar coil thereby forming the interior opening  118 . The winding of the coil  106  begins at a mutual starting point for both ends of the coil and is wound simultaneously in opposite directions. For example, to form a planar coil having twelve turns each side of such an example coil is looped or turned six times in both, opposing directions. 
     For high frequency applications litz wire may be desirable. Also, in examples, triple insulated wire may be desirable for applications calling for reinforced isolation. The size and shape of the coils,  106 ,  108  may be easily customized. Referring ahead to  FIGS. 22 and 23 , a first coil  106   c  of that example embodiment is formed with a larger diameter than a second coil  108   c . Alternative embodiments may include coils comprising rectangles, rounded rectangles, rounded triangles, ovals, ellipses, non-planar coils, and/or other suitable shapes depending upon the desired application. This feature further results in easy manipulation and customization of the first and second coils  106 ,  108  without necessitating changes to the PCB  102 . For example, the configuration of  FIGS. 22 and 23  may be manufactured on the same PCB  102  and about the same core  120  as the embodiment of  FIGS. 1-3  or, referring ahead once again,  FIGS. 8 and 9 . Still further, a turns ratio between the first and second coils  106 ,  108  may be easily manipulated and customized without extensive, or any, change to the PCB  102 . 
     Additionally, the exemplary planar coil  106  may use self-adhesive wires to hold the shape of the coil  106 , or tape may be employed to maintain the shape of the coil  106 . First and second wire leads  126 ,  128  may be mounted to a header  124  with surface mount pins  130 ,  132  extending therefrom, as illustrated by  FIG. 5 . The header  124  insulates and maintains separation between the wire leads  126 ,  128  and the surface mount pins  130 ,  132 . In exemplary embodiments, the header  124  is designed to meet clearance and creepage distances of the wire leads  126 ,  128  and the surface mount pins  130 ,  132  for compliance with applicable safety standards. The wire leads  126 ,  128  may operatively and electrically connect with the PCB  102  through the surface mount pins  130 ,  132  to through-hole or surface-mounted device (SMD) type connections on the PCB  102 . 
     Referring now to  FIG. 6 , the first insulator  114  is disposed on the first planar coil  106 . The first insulator  114  may have a corresponding or complementary fit relative the header  124  such that the first and second wire leads  126 ,  128  are partially surrounded and/or encapsulated by a combination housing of the first insulator  114  and the header  124 . The first and second insulators  114 ,  116  may be FR-4, Kapton, G-10, or another suitable material and/or board. The insulators  114 ,  116  disposed over the first and second coils  106 ,  108  supply a flat surface  134  for easy handling. 
     Combination of the coil  106 , the header  124 , and the first insulator  114  form a coil assembly  136 . The flat surface  134  facilitates pick and place manufacturing of the coil assembly  136  during fabrication of the hybrid transformer  100 . An analogous assembly  138  (see  FIGS. 2 and 3 ) may be constructed from components associated with the second coil  116 . During manufacturing, one or more of the coil assemblies  136 ,  138  may be picked and placed by machine (e.g., robot, automated arm, etc.) and surface mounted on one or another side of the PCB  102 , as illustrated in  FIG. 7 . 
     Referring now to  FIGS. 7, 8, and 9 , the coil assembly  136  is placed on the PCB  102 , alongside the other electrical components  104  (see  FIG. 1 ) and solder may be re-flowed to establish operative and electrical connections to the PCB  102 . The core  120  is assembled about and through the first coil assembly  136  and the second coil assembly  138  (not shown in the view of  FIGS. 7, 8, and 9 ). In the exemplary embodiment of  FIGS. 8 and 9 , the core  120  is assembled as two separate portions, a first portion  140  and a second portion  142 . The second portion  142  is placed over and through the second coil assembly  138 , i.e. on the underside of the view of  FIGS. 8 and 9 . In this embodiment, first and second side openings  144 ,  146  are disposed in the PCB  102  along the coil assemblies  136 ,  138 . The second portion  142  of the core  120  has a shape that corresponds with the first and second side openings  144 ,  146  and the interior opening or passageway  118 , which extends through the PCB  102  and the coils  106 ,  108  and the insulators  114 ,  116 ; and wherethrough the central limb  122  of the core  120  is disposed. The first portion  140  of the core  120  has a shape mirroring that of the second portion  142 ; but, in the illustrated embodiment of  FIGS. 8 and 9 , the first portion  140  does not extend through the PCB  102  to contact the second portion  142 . Instead, the first and second portions  140 ,  142  meet within the interior passageway  118  relatively above the PCB  102  and inside a portion of the passageway  118  within the first coil assembly  136 . The first portion  140  may be fixedly attached to the second portion  142  by soldering, adhesive, and/or another method suitable for connecting the core  120 . The core  120  may substantially cover and/or surround an arcuate portion of the insulators  142 ,  144  and the coils  106 ,  108  as is typical for a shell-type transformer. Also, in examples, shown in  FIGS. 1-3 , the core may have a relatively thinner width co-extensive only with the interior opening  118  such that the insulators  142 ,  144  and the coils  106 ,  108  are still partially surrounding and covered by material of the core  120 , but to a lesser extent than in the examples of  FIGS. 8 and 9 . 
     Referring now to  FIGS. 10, 11, and 12 , one improvement realized by the hybrid transformer  100  described by the present disclosure may be efficient conversion of a high input voltage V in .  FIG. 10  compares the efficiency of power conversion, when the V in  is 405V, across a range of possible output currents from less than two amperes to approximately ten amperes of output current for an output voltage V o  of 12V. It is notable that efficiency is improved by the hybrid transformer  100 , as compared to conventional transformers, for each current output. Embodiments utilizing litz wire improve efficiency across a range of input voltage and load conditions as compared with solid wire windings.  FIGS. 11 and 12  illustrate a similar trend in efficiency improvements for input voltages V in  of 410V and 415V transformed to produce the same current output range as in  FIG. 10 . 
     Referring now to  FIGS. 13, 14, and 15 , another improvement realized by the hybrid transformer  100  described by the present disclosure may be decreased power dissipation during conversion of a high input voltage V in .  FIG. 13  compares the power dissipated during power conversion when the V in  is 405V across a range of possible output currents from less than two amperes to approximately ten amperes of output current for an output voltage V o  of 12V. It is notable that power dissipation is improved, i.e., decreased, by the hybrid transformer  100 , as compared to conventional transformers, for each current output.  FIGS. 14 and 15  illustrate a similar trend in power dissipation improvements of approximately 1.25 watts to 1.5 watts for input voltages V in  of 410V and 415V transformed to produce the same current output range as in  FIG. 13 . 
       FIG. 16  is an enlarged cross-sectional view of one side of a solid wire model embodiment  100   a  of the hybrid transformer  100 , similar to the embodiment shown in  FIG. 2 , with magnetic flux lines superimposed on the image and coils  106   a ,  108   a  formed from solid copper wire.  FIG. 17  shows a further enlarged, cross-sectional view of the coil  106   a  and the insulator  114  shown in  FIG. 16 . As noted hereinabove, the hybrid transformer  100  is a shell-type transformer, wherein the core  120  surrounds the primary and secondary windings  106   a ,  108   a . In a shell-type transformer, magnetic flux concentrates on the central limb  122 . This operation is illustrated in  FIGS. 16 and 17 , showing the central limb  122  of the core  120  experiencing relatively large magnetic flux within the passageway  118  through the first and second coils  106   a ,  108   a . Current is prevented from flowing in the presence of magnetic flux. Furthermore, at high frequencies, current primarily travels near a surface of a wire because of the skin effect. The skin effect results in increased loss of power, particularly in high frequency applications such as typical applications of the presently disclosed hybrid transformer  100 . A gap  148  in the central limb  122  of the core  120  between the first portion  140  and the second portion  142  is disposed at a location relatively removed from the primary and secondary windings  106   a ,  108   a  to minimize fringing loss generated thereby. The gap  148  is similarly located along the central limb  122  in the embodiments of  FIGS. 19 and 22 . 
     Stranded wire, such as litz wire, reduces negative outcomes from the skin effect by increasing the total surface area available for conduction as compared to the surface area of the equivalent solid wire. However, stranded wire may exhibit higher resistance than an equivalent solid wire of the same diameter because the cross-section of the stranded wire is not all copper; but, instead introduces gaps between the strands. Referring ahead to  FIGS. 19, 20, 22, and 23 , litz wire comprises gaps  150  between individual strands  152  and insulating material  154  (see  FIGS. 22 and 23 ) surrounding each of the strands  152  partially fills the gaps  150 . 
       FIG. 18  is a graphical chart showing resistance plotted against frequency for the solid wire model shown in  FIGS. 16 and 17 . Simulated AC-AC resistance of the windings  106   a ,  108   a  is shown in  FIG. 18  for the operating frequency range of an LLC converter of the solid wire model embodiment  100   a  of the hybrid transformer  100 . A total AC resistance  160  of the primary winding  106   a  is shown in Ohms, and an AC resistance is shown in mOhms for each layer  162   a - 162   f  in the secondary winding  108   a . The total AC resistance of the secondary winding  108   a  parallels all of the other illustrated resistance curves in the 5.6 mOhm range. 
       FIG. 19  is an enlarged cross-sectional view of one side of a litz wire model embodiment  100   b  of the hybrid transformer  100 , also similar to that shown in  FIG. 2 , with magnetic flux lines superimposed on the image and coils  106   b ,  108   b  formed from litz wire. For the purposes of simulation, it may be useful to simulate litz wire as comprising air gaps, rather than insulation, between each individual strand of the litz wire. Spacing between strands of the windings  106   b ,  108   b  influences the operation of the hybrid transformer  100 .  FIG. 20  is a further enlarged, cross-sectional view of the coil  106   b  shown in  FIG. 19 . The solid wire model  100   a  and the litz wire model  100   b  both are shown with a first, primary winding  106   a ,  106   b , comprising a mean turn length of 1.63 inches. This results in the coils  106 ,  108  utilizing 2.03 feet of wire for 15 turns. 
     As noted hereinabove, the skin effect results in power loss, particularly at high frequencies. Litz wire introduces the insulated strands  152  to increase surface area with the objective of decreasing power loss. However, as can be seen in  FIG. 21 , which is a graphical chart showing resistance plotted against frequency for the litz wire model  100   b  of  FIG. 19 , resistance exhibited by the litz wire model  100   b  is similar to that of the solid wire model  100   a . Simulated AC-AC resistance of the windings  106   b ,  108   b  is shown in  FIG. 21  for the operating frequency range of an LLC converter of the litz wire model  100   b . A total AC resistance  164  of the primary winding  106   b  is shown in Ohms, and an AC resistance of each layer  166   a - 166   f  in the secondary winding  108   b  is shown in mOhms. The total AC resistance of the secondary winding  108   b  parallels all of the individual illustrated resistance curves of the layers  166   a - 166   f.    
       FIG. 22  is an enlarged cross-sectional view of one side of a coil offset, litz wire model embodiment  100   c  of the hybrid transformer  100 , also similar to that shown in  FIG. 2 , with magnetic flux lines superimposed on the image and coils  106   c ,  108   c  formed from litz wire.  FIG. 23  is an enlarged cross-sectional view of the coil  106   c ,  108   c  and insulating material  154  shown in  FIG. 22 . Here, the primary coil  106   c  is offset relative the secondary coil  108   c  and separated from the central limb  122  of the core  120 . In this embodiment, the primary winding  106   c  has a mean turn length of 2.22 inches and utilizes 2.38 feet of wire for 15 turns.  FIG. 24  is a graphical chart showing resistance plotted against frequency for the offset, litz wire model of  FIG. 22 . In this example, the resistance experienced by the litz wire is considerably decreased by the offset arrangement. Simulated AC-AC resistance of the windings  106   b ,  108   b  is shown in  FIG. 24  for the operating frequency range of an LLC converter of the coil offset, litz wire model embodiment  100   c . A total AC resistance  168  of the primary winding  106   c  is shown in Ohms, and an AC resistance of each layer  170   a - 170   f  in the secondary winding  108   c  is shown in mOhms. The total AC resistance of the secondary winding  108   c  parallels all of the individual illustrated resistance curves of the layers  170   a - 170   f.    
     The offset decreases interference with conduction of the coil  106   c  from magnetic flux by moving the coil  106   c  away from a region near the central limb  122  of the core  120  that experiences the strongest flux outside of the core  120 . In exemplary embodiments, the first coil  106   c  is spaced farther from the central limb  122  of the core  120  than the second coil  108   c . For example, the first coil  106   c  may be farther away from the central limb  122  radially than the second coil  108   c . Alternatively, modifying the shape of one or both of the coils  106   c ,  108   c  may otherwise facilitate movement of the first coil  106   c  and/or the second coil  108   c  away from a region proximal the central limb  122  that experience an undesirable level of magnetic flux. In another example, the first coil  106   c  may be wound vertically, according to a stacked coil arrangement, and/or otherwise take a shape different from the planar coil shown hereinthroughout. In still other embodiments, both of the coils  106   c ,  108   c  may be spaced apart from the central limb  122  of the core  120 , rather than adjacent the central limb  122  as illustrated in  FIGS. 16 and 19 . A number of desired turns for a particular coil may further be considered in determining the shape of the coils  106 ,  108 . 
     The embodiment(s) detailed hereinabove may be combined in full or in part, with any alternative embodiment(s) described. While some implementations have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the disclosure, and the scope of protection is only limited by the scope of the accompanying claims. 
     Headings and subheadings, if any, are used for convenience only and do not limit the embodiments. The word exemplary is used to mean serving as an example or illustration. To the extent that the term include, have, or the like is used, such term is intended to be inclusive in a manner similar to the term comprise as comprise is interpreted when employed as a transitional word in a claim. Relational terms such as first and second and the like may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
     Phrases such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof and alike are for convenience and do not imply that a disclosure relating to such phrase(s) is essential to the subject technology or that such disclosure applies to all configurations of the subject technology. A disclosure relating to such phrase(s) may apply to all configurations, or one or more configurations. A disclosure relating to such phrase(s) may provide one or more examples. A phrase such as an aspect or some aspects may refer to one or more aspects and vice versa, and this applies similarly to other foregoing phrases. 
     The disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular implementations disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative implementations disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. 
     It should be understood that the described instructions, operations, and systems can generally be integrated together in a single software/hardware product or packaged into multiple software/hardware products. 
     The use of the terms “a” and “an” and “the” and “said” and similar references in the context of describing the embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. An element proceeded by “a,” “an,” “the,” or “said” does not, without further constraints, preclude the existence of additional same elements. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.