MODULAR JACK WITH IMPROVED MAGNETICS AND METHOD OF MANUFACTURING SAME
[0001] This Application claims priority to Provisional Application Serial No. 61/106,510, filed October 17, 2008, which is incorporated herein by reference in its entirety.
[0002] The disclosure relates generally to modular telecommunications jacks and, more particularly, to a high data rate capable modular jack.
[0003] Modular jack ("modjack") receptacle connectors mounted to printed circuit boards ("PCBs") are well known in the telecommunications industry. These connectors are typically used for electrical connection between two electrical communication devices. With the ever-increasing operating frequencies of data and communication systems and the increased levels of encoding used to transmit information, the electrical characteristics of such connectors are of increasing importance. In particular, it is desirable that these modjack connectors do not negatively affect the signals transmitted and where possible, noise is removed from the system. Based on these requirements and desires, various proposals have been made in order to improve modjack connectors used with communication or transmission links.
[0004] When used as Ethernet connectors, modjacks generally receive an input signal from one electrical device and then communicate a corresponding output signal to a second device coupled thereto. Magnetic circuitry can be used to provide conditioning and isolation of the signals as they pass from the first device to the second and typically such circuitry uses components such as a transformer and a choke. The transformer often is toroidal in shape and includes a primary and secondary wire coupled together and wrapped around a toroid so as to provide magnetic coupling between the primary and secondary wire while ensuring electrical isolation. Chokes are also commonly used to filter out unwanted noise, such as common-mode noise, and can be toroidal ferrite designs use in differential signaling applications. Modjacks having such magnetic circuitry are typically referred to in the trade as magnetic jacks.
[0005] In practice, it turns out that the manufacture of the transformer in combination with the choke is not easy to do well. For one thing, the process tends to be manual
(and is thus subject to variability) and for another, the intended signal-to-noise levels are low enough that the system is sensitive to external noise and other issues. Thus, the challenging manufacturing conditions, such as the need to wrap thin wires around a toroidal core in one configuration and then extend the wires in different configurations as they travel away from the toroid, have increased the difficulties in providing a modjack housing with the desired performance.
[0006] Furthermore, as system data rates have increased, increasing the data rate of signals that pass through the magnetic jacks has become an increasingly impacted by any inconsistency of the magnetics. In other words, the significance of the inconsistencies depends on the data rates at which the magnetic jacks are expected to perform. Magnetic subassemblies that operate within a predetermined range of electrical tolerances at one data rate (such as 1 Gbps) may have enough electrical inconsistencies so as to be out of tolerance or inoperable at higher date rates (such as 10 Gbps). The desire to operate at high date rates thus tends to increase the cost of the magnetic jack. Therefore, improvements in designs of magnetic jacks would be appreciated by certain individuals.
SUMMARY OF THE INVENTION
[0007] A signal conditioning assembly includes a toroidal core with an opening therein and a plurality of wires proximate the toroidal core to define a central winding section, a plurality of outer twisted wire sections and a plurality of wire proximity sections positioned between each outer twisted wire section and the central winding section. The central winding section includes a predetermined length of a predetermined number of wires configured in a predetermined twisted pattern to define a group of central twisted wires with the group of central twisted wires wrapped around the toroidal core and extending through the opening a predetermined number of times and defining a conductor of a primary side of a transformer and a conductor of a secondary side of a transformer. Each outer twisted wire section includes at least a pair of wires twisted together in a predetermined twisted pattern that are electrically connected to but spaced from the group of central twisted wires. Each wire proximity section is configured to maintain physical proximity between the conductor of the
primary side of the transformer and the conductor of the secondary side of the transformer as the wires exit the toroidal core. If desired, the assembly may be used with a modular jack or another type of connector.
[0008] A method of manufacturing a signal conditioning assembly may be used that includes the steps of providing a toroidal core having an opening therein and providing a plurality of wires, each having first and second ends. A predetermined length of the wires is twisted to define a group of twisted wires having a predetermined pattern. The group of twisted wires is wrapped around the toroidal core and through the opening a predetermined number of times to define a central twisted core of wires and establish a conductor of a primary side of a transformer and a conductor of a secondary side of a transformer. The conductors of the primary side of the transformer are secured in physical proximity to the conductor of the secondary side of the transformer as the wires of the central twisted core exit the toroidal core. The ends of at least a pair of wires may be twisted to define an outer twisted wire section that is electrically connected to but spaced from the central twisted core of wires.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various other objects, features and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views in which:
[0010] FIG. 1 is a front perspective view of a magnetic jack in accordance with a first embodiment;
[0011] FIG. 2 is a partially exploded rear perspective view of the magnetic jack housing of Fig. 1 with the internal modules in various stages of insertion therein;
[0012] FIG. 3 is an exploded view of one of the internal modules of Fig. 2;
[0013] FIG. 4 is perspective view of one of the component housings of Fig. 3 prior to insertion of the noise reduction components therein and with the windings removed for clarity;
[0014] FIG. 5 is a perspective view identical to that of Fig. 4 with the noise reduction components inserted therein and with the windings removed for clarity;
[0015] FIG. 6 is a side elevational view of the noise reduction components for use with the magnetic jack of Fig.1 ;
[0016] FIG. 7 is a side elevational view of the twisted wires used with the noise reduction components of the disclosed embodiment;
[0017] FIG. 8 is a perspective view of a transformer toroid with only the central winding section wound thereon;
[0018] FIG. 9 is a perspective view of the transformer toroid and central winding section similar to Fig. 8 but with the wires untwisted as they exit each end of the transformer toroid;
[0019] FIG. 10 is a perspective view of the transformer toroid and central winding section after certain of the wires are twisted in the retention twist section;
[0020] FIG. 11 is a perspective view of the transformer toroid with the completed central winding section, retention twist section and standard twisted section thereon;
[0021] FIG. 12 is a side elevational view of the transformer toroid with the completed winding thereon with the choke toroid slid onto a pair of the wires;
[0022] FIG. 13 is a perspective view of an alternate embodiment including a wire positioning clamp with four wires extending therethrough;
[0023] FIG. 14 is an end view of the alternate wire positioning clamp of Fig. 13;
[0024] FIG. 15 is a side elevational view of the transformer toroid, central winding section and retention twist section similar to Fig. 10 but with longer retention twist sections as part of an alternate embodiment;
[0025] FIG. 16 is a side elevational view of an additional twisting step after Fig. 15;
[0026] FIG. 17 is a side elevational view similar to Fig. 16 but with the additional twisting step performed on the wires extending from both sides of the transformer choke;
[0027] FIG. 18 is a perspective view similar to that of Fig. 11 but with the additional twists as depicted in Figs. 16 and 17;
[0028] FIG. 19 is side elevational view of the fully assembled noise reduction components of the alternate embodiment;
[0029] FIG. 20 is a side elevational view of the transformer toroid and central winding section with only the central winding section wound thereon as part of a still further alternate embodiment;
[0030] FIG. 21 is a side elevational view of the transformer toroid and central winding section of Fig. 20 together with a single twist section for positioning and controlling the wires;
[0031] FIG. 22 is a side elevational view of the transformer toroid, central winding section and single twist section of Fig. 21 together with the standard twist sections;
[0032] FIG. 23 is a side elevational view of the fully assembled noise reduction components of the still further alternate embodiment;
[0033] FIG. 24 is a front perspective view of a single port magnetic jack in which the improved noise reduction components may be used;
[0034] FIG. 25 is a partially exploded front perspective view of the magnetic jack housing of Fig. 24 with the internal module removed therefrom;
[0035] FIG. 26 is an exploded view of the internal module of Fig. 25; and
[0036] FIG. 27 is perspective view of the internal module of Fig. 26 prior to insertion of the noise reduction components therein and with the windings removed for clarity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] The following description is intended to convey the operation of exemplary embodiments of the invention to those skilled in the art. It will be appreciated that this
description is intended to aid the reader, not to limit the invention. As such, references to a feature or aspect of the invention are intended to describe a feature or aspect of an embodiment of the invention, not to imply that every embodiment of the invention must have the described characteristic. Furthermore, it should be noted that the depicted detailed description illustrates a number of features. While certain features have been combined together to illustrate potential system designs, those features may also be used in other combinations not expressly disclosed. Thus, the depicted combinations are not intended to be limiting unless otherwise noted.
[0038] As noted above, it is generally desirable to minimize electrical inconsistencies in the magnetic properties of a magnetic jack. In addition, tolerances associated with the magnetics of high speed magnetic jacks are typically very tight. It has been determined that inconsistent winding of the twisted wires that are wrapped around the transformer toroid will result in electrical inconsistencies from one wound core to the next and such variability can cause some transformers to be out of tolerance. More specifically, the length and manner in which the twisted wires extend through the toroid can greatly impact the electrical performance of the magnetic subassembly. Furthermore, due to the fact that the magnetically coupled wires are untwisted at some point as they exit the toroid and, the wires tend to untwist inside the toroid. If the untwisting is not controlled, the wires will untwist in an inconsistent manner due to various factors such as wire size, insulation material, presence of epoxy, how the assembly is handled and twists per unit length of the wires. The relatively uncontrolled untwisting of the wires and their locations relative to the toroid make it difficult to control the coupling between the primary and secondary wires and therefore causes variability in the electrical characteristics of one transformer to the next. For example, it has been determined that the characteristics of two otherwise identical transformers can be significantly different if in one case the wires were untwisted only outside of the toroid while in the other case the wires were slightly untwisted within the toroid. The result of the inconsistent untwisting of the twisted wires is an increased variability in the magnetic coupling of the primary side of a transformer to the secondary side of the transformer, which can result in degraded performance of the magnetics (e.g., the coupling can be less efficient and likely will be unpredictable).
[0039] Fig. 1 illustrates the front side of a multiple input, magnetic, stacked jack 100 having a housing 102 made of an insulating material such as a synthetic resin (for example, PBT) and includes front side openings or ports 103 that are each configured to receive an Ethernet or RJ-45 type jack (not shown). The magnetic jack 100 is configured to be mounted on circuit board 104. A metal or other conductive shield assembly 106 surrounds the magnetic jack housing 102 for RF and EMI shielding purposes as well as for providing a ground reference. It should be noted that, as shown in Figs. 24 - 27, a similar configuration is possible in instances in which only a single unit magnetic jack is desired.
[0040] It should be noted that in this description, representations of directions such as up, down, left, right, front, rear, and the like, used for explaining the structure and movement of each part of the disclosed embodiment are not intended to be absolute, but rather are relative. These representations are appropriate when each part of the disclosed embodiment is in the position shown in the figures. If the position or frame of reference of the disclosed embodiment changes, however, these representations are to be changed according to the change in the frame of reference of the disclosed embodiment.
[0041] Shield assembly 106 includes a front shield component 106a and a rear shield component 106b. These joinable shield components are formed with interlocking tabs 108 and openings 110 for engaging and securing the components together when the shield assembly 106 is placed into position around the magnetic jack 100. Each of the shield components 106a, 106b includes ground pegs 112, 114, respectively, that extend into through-holes 116 on the circuit board 104 when mounted thereon. As shown in Fig. 2, the rear portion of the magnetic jack housing 102 includes relatively large openings 115 that are sized and shaped to receive internal subassembly modules 118. These modules 118 provide the physical contacts for engaging the Ethernet plugs (not shown) and also provide the electrical filtering functionality of the jacks.
[0042] Referring to Fig. 3, subassembly module 118 includes a contact module 120 that is electrically connected to a top PCB 122. The top PCB 122 is mounted to a component housing 126, which includes magnetic circuits and filtering components.
Bottom PCB 124 is mounted on the bottom of component housing 126. The top and bottom PCBs 122, 124 include the resistors, capacitors and any other components associated with the chokes and transformers located inside the component housing 126, which together comprise the filtering circuitry of the magnetic jack.
[0043] Contact module 120 includes a top contact assembly 121a and a bottom contact assembly 121 b for providing a stacked jack, or dual jack, functionality. The top contact assembly 121a provides physical and electrical interfaces, including upwardly extending contact terminals 128, for connecting to an Ethernet plug. The bottom contact assembly 121 b is physically connected to the top contact assembly 121a and includes downwardly extending electrically conductive contact terminals 130. The contact module 120 is electrically connected to the top PCB 122 through leads 132, which are soldered, or electrically connected by some other means, such as welding or conductive adhesive, to a row of PCB pads 134 that are positioned along the top of PCB 122 along one edge thereof and a second, similar row of PCB pads (not shown) on a lower surface of top PCB 122.
[0044] Component housing 126 is a two piece assembly having a right housing 136a and left housing 136b for holding the magnetics 151. A two piece shock absorbing foam insert 150a, 150b for holding and cushioning the magnetics is provided as well. A metal shield 153 is positioned within component housing 126 between foam inserts 150a, 150b and the magnetics 151 contained within each housing half 136a, 136b. The left and right housings halves 136a, 136b are formed from a synthetic resin such as LCP or other similar material and are physically identical for reducing manufacturing costs and increased ease of assembly. A latch projection 138a extends from the right sidewall 142 of each housing. A latch recess 138b is located in the left sidewall 140 of each housing and lockingly receives latch projection 138a therein. Each housing half 136a, 136b, is formed with a large box-like receptacle 144 (Fig. 6). This receptacle 144 receives the filtering magnetics 151 therein.
[0045] The magnetics 151 provide impedance matching, signal shaping and conditioning, high voltage isolation and common-mode noise reduction. This is particularly beneficial in Ethernet systems that utilize cables having unshielded twisted
pair ("UTP") transmission lines as these lines are more prone to noise pickup than shielded transmission lines. The magnetics help to filter out the noise and provide good signal integrity and electrical isolation. The magnetics 151 include four transformer and choke subassemblies 152 associated with each port 103. The choke is configured to present high impedance to common-mode noise but low impedance for differential- mode signals. A choke is provided for each transmit and receive channel and each choke can be wired directly to the RJ-45 connector.
[0046] Referring now to Figs. 3 - 5, after the transformer and choke subassemblies 152 are assembled as described below, the component housings 126 are assembled. Each housing 136a, 136b receives four magnetic subassemblies 152, and wire leads are connected to electrically conductive metal pins 154 such as by soldering as is known in the art. One of the foam shock absorbing inserts 150a, 150b is placed inside each of the housing halves 136a, 136b. The inserts 150a, 150b are sized such that a significant portion thereof partially extends out from the opening 144 of the housing halves and contacts a central conductive metal shield 139 that is positioned within housing halves 136a, 136b and is sandwiched between foam inserts 150a, 150b.
[0047] During assembly of the housings halves 136a, 136b, the shock absorbing foam inserts 150a, 150b compress against the magnetics 151 and central shield 139 so that the inserts 150a, 150b are deformed to the point of filling in spaces and crevices between the various transformers and chokes. The foam inserts 150a, 150b also press the transformers and chokes against the sidewalls of the opening 144 of their respective housings to hold the magnetics in place and reduce the likelihood that a sudden or hard movement could possibly break the components or cause the windings to break.
[0048] As described above, the magnetics 151 include four transformer and choke subassemblies 152 associated with each port 103 of the connector. Referring to Fig. 6, one embodiment of a magnetic subassembly 152 can be seen to include a one-piece, magnetic ferrite transformer toroid 160, a magnetic ferrite choke toroid 190, transformer windings 170 and choke windings 191. Transformer winding 170 includes a central winding section 172, a retention twist section 174, and a standard twist section 176.
[0049] FIG. 7 illustrates a group of four wires 178 that are initially twisted together and wrapped around the transformer toroid 160. Each of the four wires is covered with a thin, color-coded insulator to aid the assembly process. As used herein, the four wires 178 are twisted together in a repeating pattern of a red wire 178r, a natural or copper-colored wire 178n, a green wire 178g, and a blue wire 178b. The number of twists per unit length, the diameter of the individual wires, the thickness of the insulation as well as the size and magnetic qualities of the toroids 160 and 162, the number of times the wires are wrapped around the toroids and the dielectric constant of the material surrounding the magnetics are all design factors utilized to establish the desired electrical performance of the system magnetics.
[0050] As shown in Fig. 8, the four twisted wires 178 are inserted into a central bore or opening 162 that extends through transformer toroid 160 in order to form central winding section 172. The twisted wires 178 are wrapped around the outer surface 164 of transformer toroid 160 and re-threaded through central bore 162 and this process is repeated until the twisted wire group 178 has been threaded through the central bore the desired number of times. As depicted, the twisted wire group 178 extends through the central bore 162 four times. As a result, the twisted wires 178 wrap around the outer surface 164 of toroid 160 three times. In some instances, it may be desirable to evenly space apart the twisted wires 178 of the central winding section 172 that extend along the outer surface 164 of transformer toroid 160 so that, for example, with three wraps or turns around the toroid 160, the twisted wires are positioned approximately one hundred twenty degrees from each other.
[0051] Referring now to Fig. 9, the transformer toroid 160 together with the completed central winding section 172 is shown. The twisted wires 178 are shown after the portions thereof exiting central bore 162 have been untwisted so that the individual wires may be rerouted or re-twisted as desired to complete the magnetics assembly. This, however, may create a potential problem in that the magnetics 151 were designed so that the twisted wires 178 would electrically couple to one another for a fixed length as they wrap around toroid 160. The individual wires 178r, 178n, 178g, and 178b are untwisted adjacent the end surfaces 166a, 166b of toroid 160, and hence it is difficult to
prevent the wires 178 from untwisting while still inside central bore 162. If this occurs, the electrical properties of the magnetics 151 will be negatively affected as the untwisted wires 178 will become less magnetically coupled and, for example, potentially decrease the efficiency of the transformer.
[0052] In order to ensure that the desired coupling of wires 178 is maintained in a consistent manner exit central bore 162, the red wire 178r and blue wire 178b are twisted together in a retention twist area 182 (to create red and blue retention twist 178rb) as they leave central bore 162 adjacent end surface 166 of transformer toroid 160. (Fig. 13) Similarly, the green wire 178g and natural wire 178n are also twisted together (to create green and natural retention twist 178gn) as they exit from central bore 162 adjacent end surface 166a within retention twist area 182. The red and blue twisted wires 178rb and the green and natural twisted wires 178gn extend in opposite directions (left and right, respectively, as viewed in Fig. 10) from end surface 166a of toroid 160. The same untwisting of the twisted wires 178 occurs at opposite end surface 166b of the toroid. Similarly, the red wire 178r and the blue wire 178b are twisted together to create another retention twist 178rb as are the green wire 178g and the natural wire 178n to create green and natural retention twist 178gn. It should be noted, however, that while the red and blue retention twist 178rb and the green and natural retention twist 178gn extend to the left and right as viewed in Fig. 10 from end surface 166a, the red and blue retention twist 174rb and the green and natural retention twist 174gn extend from the opposite end surface 166b in the opposite direction (to the right and left as viewed in Fig. 10). That is, the red and blue retention twist 174rb at one end surface 166a extends in the same direction as the green and natural retention twist 174gn extending from the opposite end surface 166b. This can best be seen in Fig. 14 in which the retention twists 174rb, 178gn are longer as compared to those in Fig. 10.
[0053] The retention twist section 174 is included to ensure that the desired electrical characteristics of twisted wires 178 are maintained in a consistent manner as they exit central bore 162 and to maintain the desired coupling between the primary side of the transformer and the secondary side of the transformer. By creating the retention twist section 174 through the twisting of the green and natural wires 178g, 178n to create
green and natural retention twist 174gn and twisting of the red and blue wires 178r, 178b to create red and blue retention twist 174rb, the desired electrical characteristics and coupling between the primary and secondary sides of the transformers are maintained in a consistent manner. More specifically, each retention twist includes one wire (178r or 178g) from the primary side of the transformer and one wire (178b or 178n) from the secondary side of the transformer in order to maintain the coupling within the transformer for as long as possible and in as consistent a manner as possible, preferably right up to the point where the primary and secondary wires are intentionally directed in different directions. Through the use of the retention twist, the un-twisting of the twisted wires 178 as they exit the central bore 166 may be precisely controlled and thus the coupling of the primary and secondary sides of the transformer may be controlled in a consistent manner which permits control over manufacturing variability of the magnetics 151. Accordingly, the resultant magnetic jacks can consistently provide the industry desired high data rates.
[0054] In tests performed comparing a transformer having the retention twist windings to a transformer that did not, it was found that forward return loss, reverse return loss, forward insertion loss and reverse insertion all were improved by controlling the proximity of the primary and secondary wire as they exited the toroid. More specifically, return loss was 2.5dB better at 400 MHz and insertion loss was 0.5dB better at 400 MHz. Since improved electrical performance of the magnetics 151 is beneficial in providing a design that is manufacturable and can reliably operate at high speeds such as 10 Gigabits per second, improvements in the performance and consistency of the magnetics are especially helpful.
[0055] After the green and natural retention twist 174gn and the red and blue retention twist 174rb are created, the wires (178r, 178n, 178g and 178b) proceed to the standard twisting section 176, as best seen in Fig. 11. At the standard twist sections, the wires are twisted in order to properly associate each wire as desired for the final assembly. More specifically, the blue wire 178b from one end surface 166a of toroid 160 is twisted with the natural wire 178n that extends form the opposite end surface 166b of toroid 160 to create final twist wires 176bn. The red wire 178r that was twisted
with the blue wire 178b in the retention twist winding section 174, and which extends from end surface 166a of toroid 160, is then twisted with the green wire 178g that extends from the other end surface 166b and that was twisted with the natural wire 178n in the retention twist winding section 174 extending from the other end surface 166b to create final twist wires 176rg. Similarly, the natural wire 178n that extends (left as viewed in Fig. 11 ) from the first end surface 166a is twisted with the blue wire 178b that extends from the opposite end surface 166b of toroid 160 to create final twist wires 176bn. Finally, the green wire 178g that extends from the first end surface 166a is twisted with the red wire 178r that extends from the opposite end surface 166b to create final twist wires 176rg. As viewed in Fig. 11 , the red and green final twist wires 176rg that extend to the left will have their insulation stripped therefrom so that they are interconnected together as a center tap of the transformer circuit. Likewise, the blue and natural final twist wires 176bn that extend to the left as viewed in Fig. 11 also will have their insulation stripped therefrom so that they are electrically connected and also act as a center tap of the secondary circuit of the transformer.
[0056] In some instances, it is desirable to minimize the length in which any of the wires 178 extend in a solitary or individual manner. As the wires 178 extend through transformer toroid 160 in the twisted manner as depicted in Fig. 7, the wires are coupled together in a consistent manner. As the wires exit the central bore 162, pairs of wires are twisted together to form the retention twist sections 174 which includes coupling the primary and secondary sides of the transformers. The pairs of wires forming the retention twist sections are then separated and further pairs of wires are created and twisted together to form the standard twist sections 176 which results in the formation of twisted pair wires for sending differential signals and the center taps. In doing so, it may be desirable to form the transition from the retention twist sections 174 to the standard twist sections 176 in such a manner to minimize the distance that any wires extend without coupling to another wire. Referring to Fig. 11 , it can be seen that the wires extending to the left from the retention twist section (formed by wires 178gn) immediately transition (at 175a) into the standard twist sections (formed by wires 178bn, 178rg). On the other hand, it can be seen that the transition from the retention twist section formed by wires 178rb,178gn to the right in Fig. 11 do not immediately transition
into the standard twist sections (formed by wires 178bn, 178rg) but rather the wires extend alone (at 175b) for some distance until beginning the standard twist sections. Depending on the sensitivity of the system and other factors, the distance that the wires travel alone during this transition could result in reduced system performance (e.g., reductions in efficiency) and thus the configuration on the right may be less desirable. In other words, increasing the consistency of the proximity between the primary and secondary wires and where it ends has been determined to tend to provide a more reliable assembly.
[0057] As shown in Fig. 12, the choke toroid 190 is slid downward relative to the transformer in the direction of arrow "A" so that the upper red and green final twist wires 176rg extend through the central opening 192 of choke toroid 190 until the lower surface 194 thereof is adjacent the intersection 196 between the red and green final twist wires 176rg and the blue and natural final twist wires 176bn. The green and red final twist wires 176rg are then looped around the outer surface 198 of choke toroid 190 and the end of the green and red final twist wires 176rg is then threaded back through the central bore 192 of choke toroid 190. This process is repeated until the red and green final twist wires 176rg are wound around the outer surface 198 of choke toroid 190 the desired number of times (eight as depicted in Fig. 12) and the turns around the outer surface 198 of choke toroid 190 are evenly spaced as seen in Fig. 6.
[0058] Additional structures to accomplish the goal of retention twist winding section 174 (i.e, ensure consistent and close physical positioning and coupling of the primary and secondary sides of the transformer as the twisted wires 178 encircle transformer toroid 160) are also possible. For example, as shown in Figs. 13 and 14, an elastomeric clamp or open ring 200 could be applied around the twisted wires 178 adjacent end surfaces 166a, 166b of toroid 160. Clamp 200 is an annular ring-shape with a central bore 202 and an opening 204 through which the twisted wires 178 pass as they are pressed into central bore 202. Central bore 202 is sized so as to have a diameter slightly smaller than the diameter of the group of twisted wires 178 so that the clamp 200 is compressed in the order to retain the twisted wires 178 therein. Opening 204 is sized so as to permit insertion of the twisted wires 178 yet permit the clamp 200
to surround or encircle the twisted wires sufficiently to hold them in place. While the clamp 200 is shown with ends 206 that are spaced apart in a circumferential direction and extend approximately 300 degrees around the circumference, depending on the flexibility of the clamp 200, the ends could be closer together or even overlap and lie in different planes so long as clamp 200 is sufficiently flexible to permit the twisted wires to pass between the ends of the clamp yet retain the twisted wire 178 in the central bore 202. Such clamp could be manufactured of Hytrel, silicone rubber or some other sufficiently flexible material. In addition, other structures to hold the wires in place could be utilized such as tape, rubber bands or cable ties.
[0059] In addition, alternate wire twisting structures could be utilized. For example, referring to Fig. 15, the retention twist sections 174 could be lengthened as compared to those of Fig. 10. The longer red and blue retention twist 174rb' from one end 166a of the transformer toroid 160 may be twisted with the longer green and natural retention twist 174gn' from the other end 166b of the transformer toroid to create an additional twist 210rbgn (Fig. 16). Similarly, the longer green and natural retention twist winding 174gn' from the first end 166a of the toroid 160 may be twisted together with the longer red and blue retention twist 174rb' from the opposite end 166b of toroid 160 to create a second additional twist 210rbgn (Fig. 17). After creating the additional twists, the wires are then separated and re-twisted in order to create the red and green final twist wires 176rg that extend from opposite ends 166a, 166b of toroid 160 and the blue and natural final twist wires 176bn that also extend from opposite ends 166a, 166b of toroid 160 as shown in Fig. 18 and similar to those shown in Fig. 11. At that point, the choke toroid 190 is slid onto the upper red and green final twist wires 176rg and processed as shown in and described relative to Fig. 12 in order to create the alternate transformer and choke subassembly 215 as shown in Fig. 19. By creating the additional twists, the coupling between the primary and secondary sides of the transformer are consistently coupled and the transition to the final twist wires is simplified. Thus, after the coupled primary and secondary wires extend beyond an interior of the transformer toroid, some minimum predetermined number of twists between the primary and second wires can be used to control variations in the coupling between the primary and secondary wires in the transformer. Furthermore, if the proximity of the primary and secondary wires is
controlled until the primary and secondary wires are intended to go in different directions (e.g., the turn is completed), the efficiency of the transformer can be further improved. Thus, it has been determined that for many circumstances the closer to the point of completing the turn the proximity is carefully controlled, the better the transformer will function.
[0060] Still a further embodiment of a twisting structure for retaining the wires 178 in their desired locations is shown in Figs. 20-23. Fig. 20 shows a transformer toroid 160 with twisted wires similar to that of Fig. 8 but with a different number of wraps or turns of twisted wires 178 around the toroid. The wrapped transformer toroid 160 of Fig. 20 is assembled in the same manner as that of Fig. 8 but the wires 178 are threaded through central bore 162 one additional time as compared to Fig. 8. In the embodiment shown, toroid 160 will ultimately have the twisted wires 178 wrapped around its outer surface 164 five times. At the stage of assembly depicted in Fig. 20, the twisted wires 178 are positioned around the outer surface 164 four times and positioned approximately seventy-two degrees from each other except that the two groups of wires spaced farthest apart are approximately one hundred forty-four degrees apart to define an alignment location 168 (Fig. 21 ) that is approximately seventy-two degrees from and between the two farthest spaced apart groups of twisted wires.
[0061] One end of the twisted wires 178 extends from each of the top and bottom surfaces 166a, 166b of toroid 160. The first end 178a of the twisted wires is moved laterally so that it is generally positioned above the outer lateral (left as viewed in Fig. 21 ) surface of toroid 160 and aligned with the alignment location 168 . The second or opposite end 178b of the twisted wires 178 is then bent upward along the lower surface 166b and outer surface 164 aligned with alignment location 168 on the outer surface 164 of toroid 160 and wrapped around first end 178a of twisted wires 178 once to create a single twist 220 that includes all of the wires of the second end 178b wrapped around all of the wires of the first end 178a. As depicted in Fig. 21 , the second end 178b of twisted wires 178 extends across the top surface 166a of toroid 160 and away from alignment location 168.
[0062] The individual wires from the first and second ends 178a, 178b are then untwisted immediately beyond (or above as viewed in Fig. 21 ) the single twist 220. The individual wires are then twisted to create the desired standard twist sections 176 (Fig. 22) for the final assembly in a manner similar to those shown in Fig. 11. More specifically, the blue wire 178b from first end 178a of twisted wire 178 is twisted with the natural wire 178n of second end 178b of twisted wire 178 to create final twist wires 176bn. The red wire 178r from first end 178a of twisted wire 178 is then twisted with the green wire 178g of second end 178b of twisted wire 178 to create final twist wires 176rg. Similarly, the natural wire 178n from first end 178a of twisted wire 178 is twisted with the blue wire 178b of second end 178b of twisted wire 178 to create final twist wires 176bn. Finally, the green wire 178g that extends from first end 178a of twisted wire 178 is twisted with the red wire 178r of second end 178b of twisted wire 178 to create final twist wires 176rg. The red and green final twist wires 176rg that extend to the right in Fig. 22 will have their insulation stripped therefrom so that they are interconnected together as a center tap of the transformer circuit. Likewise, one of the blue and natural final twist wires 176bn that extends to the right as viewed in Fig. 22 also will have their insulation stripped therefrom so that they are electrically connected and also act as a center tap of the secondary circuit of the transformer.
[0063] Red and green final twist wires 176rg that extend upward as viewed in Fig. 22 are then slid into central opening 192 of choke toroid 190 until the lower surface 194 thereof is generally adjacent the single twist 220. The green and red final twist wires 176rg are looped around the outer surface 198 of choke toroid 190 and the end of the green and red final twist wires 176rg is then threaded back through the central bore 192 of choke toroid 190. This process is repeated until the red and green final twist wires 176rg are wound around the outer surface 198 of choke toroid 190 the desired number of times and the turns around the outer surface 198 of choke toroid 190 are evenly spaced as depicted in Fig. 23.
[0064] FIG. 24 illustrates the front side of an alternate embodiment of the present invention in its fully assembled form. As shown, magnetic jack 300 is a single port jack for receiving multiple Ethernet or RJ-45 type of plugs (not shown). Inasmuch as many
of the components of single port magnetic jack 300 are identical to those of multi-port magnetic jack 100, like numbers are used for like elements. Magnetic jack 300 includes a magnetic jack housing 302 made of an insulating material such as a synthetic resin and includes a single front side opening or port 303 that is configured to receive an Ethernet or RJ-45 type jack (not shown). The magnetic jack 300 is configured to be mounted on circuit board 304. A metal or other conductive shield assembly 306 is used to surround the magnetic jack housing 302 for RF and EMI shielding purposes as well as for providing a ground reference. Shield assembly 306 is a one piece member having a rear flap 306a that folds down over housing 302 to fully enclose and shield the housing as is known in the art.
[0065] Referring to Figs. 25 and 26, subassembly module 318 includes a contact module 320 that is electrically connected to a PCB 322. The PCB 322 is mounted to a component housing 326, which includes magnetic circuits and filtering components. The PCB 322 includes the resistors, capacitors and any other components associated with the chokes and transformers located inside the component housing 326, which together comprise the filtering circuitry of the magnetic jack.
[0066] Contact assembly 321 provides physical and electrical interfaces, including contact terminals 328, for connecting to an Ethernet plug. The contact module 320 is electrically connected to the PCB 322 through leads 332, which are soldered, or electrically connected by some other means, to a row of holes 334 that are positioned along one edge 335 thereof.
[0067] Referring to FIGS 27 and 28, component housing 326 is a one piece member for holding magnetics 151 therein. As described above, the magnetics 151 provide impedance matching, signal shaping and conditioning, high voltage isolation and common-mode noise reduction. The structure of the transformer and choke subassemblies 152 are identical to those described above and shall not be repeated. However, rather than inserting the transformer and choke subassemblies 152 into the sides of component housings 126 as described above, the transformer and choke subassemblies 152 are inserted through an opening 344 in the bottom of component housing 326. The wires 178 associated with the transformer and choke subassemblies
152 are soldered to electrically conductive metal pins 354 as described above. After the leads are soldered, epoxy may be inserted into the opening 344 if desired. Finally, the PCB 322 is mounted on the component housing 326 to complete the assembly of contact module 320 and such module may be inserted into magnetic jack housing 302.
[0068] Although the disclosure provided has been described in terms of illustrated embodiments, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. For example, the colors of the wires may be changed and/or the wire grouped together differently. Accordingly, numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.