The present application claims the benefit of U.S. patent application Ser. No. 14/140,421, filed on Dec. 24, 2013, for a “Common Mode Choke and Integrated Connector Module Automation Optimization” by William F Edwards.
The subject technology relates to improved common mode choke (CMC) and integrated connector module (ICM) designs, and in particular, provides design improvements to optimize CMC and ICM process automation.
Suppression of electromagnetic interference (EMI) has become a major concern in the transmission, reception, and processing of electronic signals and data. Modern communication systems are often designed as an interconnection of functional blocks and connections made using cables or wiring harnesses. Such interconnections often present opportunity for common mode current loops between devices that can lead to EMI regulatory failure.
Due to EMI concerns, Ethernet devices, such as Ethernet ICM transformers (ICMts), are often coupled with a common mode choke (CMC). A CMC can comprise two coils wound on a single core and may be useful for EMI and Radio Frequency interference (RFI) prevention from, for example, power supply lines and other sources. A CMC can pass differential currents (e.g. equal but opposite), while blocking common-mode currents. Thus, when properly operated, CMCs filter common mode currents without causing signal degradation. Therefore, the addition of CMCs, e.g., in conjunction with a connector such as an ICM, can provide filtration of mode currents, while also allowing passage of desired signals.
In some traditional configurations, CMCs and ICMs are bundled together, for example into a common ICM housing. By way of example, CMC and ICM components can be bundled into “pigtail” components, which provide connections between the CMC and ICM as well as a shared housing. Bundling of the ICM and CMC into the pigtail is a labor intensive process and makes it nearly impossible to later separate the ICM/CMC from the pigtail to make component modifications or adjustments.
For example, the ICM can include an Ethernet transformer that is configured (tuned) to block ground currents, e.g., of a corresponding Ethernet transceiver or “PHYreceiver.” In contrast, the CMC is generally tuned to filter noise produced by other device components in which the ICM is disposed. Because noise resulting from the other components can vary with the life of the device, or as device changes are made, it is not uncommon to require re-tuning of the CMC. To simplify the ability to tune/re-tune the choke, some Ethernet implementations provide physically decoupled CMC and ICM modules (as opposed to pigtails in which the respective components cannot be easily decoupled).
In such configurations, separate CMC and ICM components are physically separated but electrically coupled, for example, via a printed circuit board (PCB). The physical decoupling of CMC and ICM components can provide the groundwork for several advantageous modifications to conventional CMC and ICM architecture.
Aspects of the subject technology provide a common mode choke (CMC) component including a housing, the housing including an upper chassis element and a lower chassis element, the upper chassis element comprising a first plurality of comb structures vertically disposed around an edge of the upper chassis element. In certain aspects, the lower chassis element includes a second plurality of comb structures vertically disposed around an edge of the lower chassis element, the second plurality of comb structures configured to interlock with the first plurality of comb structures to form an enclosure when the upper chassis element is mechanically coupled with the lower chassis element. Additionally, in some implementations, a mechanical coupling between the upper chassis element and the lower chasses element forms a wire gap between an inside of the enclosure and an outside of the enclosure.
In yet another aspect, the subject technology relates to an integrated connector module transformer (ICMt), including a wafer configured to hold a plurality of toroid elements, and wherein the wafer is comprised of a two or more mechanically coupled wafer portions. In certain implementations, the ICMt can further include a plurality of tie-off pins configured to protrude from at least one of the two or more wafer portions, and wherein the tie-off pins are disposed at an angle between two and eighty-eight degrees with respect to the at least one of the two or more wafer portions.
It is understood that other configurations of the subject technology will become readily apparent to those skilled in the art from the following detailed description, wherein various configurations of the subject technology are shown and described by way of illustration. The subject technology is capable of other and different configurations and its several details are capable of modification in various respects without departing from the scope of the subject technology. Accordingly, the detailed description and drawings are to be regarded as illustrative and not restrictive in nature.
Certain features of the subject technology are set forth in the appended claims. However, the accompanying drawings, which are included to provide further understanding, illustrate disclosed aspects and together with the description serve to explain the principles of the subject technology. In the drawings:
The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a more thorough understanding of the subject technology. However, it will be clear and apparent that the subject technology is not limited to the specific details set forth herein and may be practiced without these details. In some instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology.
As shown in
As discussed in further detail below, the physical separation of CMC 110 and ICM 120 is instrumental in realizing design advantages for each respective component.
Common Mode Choke Geometry:
One problem in conventional CMC designs relates to the way in which toroid wire management is performed throughout assembly. In conventional deigns, toroid wires are jumbled together and left to protrude from a single opening of the CMC enclosure, and must then be manually sorted and separated before being tied off. This wire management process is both cumbersome and time consuming, adding to the difficulty and cost of CMC manufacture. As such, there is a need for an improved CMC housing geometry, which facilitates toroid wire management.
Another problem in conventional CMC designs relates to the way in which toroid wires (of a magnetic toroid element) are tied off, for example, onto pegs external to the CMC housing. In conventional CMC designs, the pegs are of a circular or square shape and distend from the outer housing surface. These pegs are configured to receive the ends of the toroid wires, which are wrapped around the pegs and broken off during the assembly process. However, the force produced from stretching (and breaking) the wire often causes the supporting (symmetrical) peg to shear off from the housing. Accordingly, an improved peg geometry is needed to enhance overall durability of the CMC housing and to provide pegs that are strong enough to resist greater shear forces.
Aspects of the technology address both of the foregoing problems by providing a CMC enclosure that facilitates toroid wire management, as well as an improved peg geometry that provides strengthened bonds between the pegs and supporting CMC chassis.
Lower chassis element 202 includes comb structures 204 that are configured to alternating integrate with comb structures 214 of upper chassis element 212. Lower chassis element also includes a clip insert 219 which is configured to mate with clip 218 to the hold upper chassis element 212 and lower chassis element 202 together. More specifically, the interlocking of comb structures 204 with comb structures 214 operates to provide a wire-gap, as discussed in further detail below. As further illustrated, lower chassis element also includes pegs 206, each of which correspond with respective solder pads 220. In the illustration of
In operation, wires from toroid elements 207 pass from the toroid (on the interior of the CMC enclosure), through an adjacent wire-gap provided by the coupling of comb structures (204,214), and out of the CMC enclosure. Wires protruding out from the CMC housing through the wire-gap are then tied off on an adjacent peg (e.g., one of pegs 206). As discussed below, assembly of the CMC involves ablating the wire wrapped on pegs 206 using an incident laser, to remove any lacquer or insulation. Subsequently, a solder joint is formed between the wrapped wire and a corresponding solder pad (e.g., solder pad 220).
By way of example, a preferred peg geometry can include a shape that is larger in the middle (or center) to improve peg strength. Additionally, in some implementations, a top surface of the peg is larger (e.g., of a greater surface area) compared to that of the bottom surface. An increased surface area on the top side of the peg can increase exposure of the corresponding wire wrap to laser light incident on the top surface (e.g., for removal of lacquer or insulation) during the CMC manufacture process. In contrast, a more narrow shape (e.g., smaller surface area) on the bottom side of the peg helps to provide an angular shape that is more conducive to the formation of strong solder joints, e.g., as between the wrapped toroid wire and the corresponding solder pad, e.g., solder pad 220 illustrated in
Lower chassis element further includes separator 224 which provides a non-conductive barrier between toroids 207. The configuration of separator 224 and comb structures 204 mechanically restrains toroids 207, without the use of epoxy or silicone bonding agents, which affect the electrical and/or magnetic properties of toroids 207. By eliminating the need for conductive toroid restraints, the dielectric of toroids 207 remains equal to that of the air filling the gaps in the CMC housing. As such, the mechanical restraint features of CMC 110 serve to enhance the electrical properties of conditions in and around the CMC housing.
Additional features of the CMC housing, including additional restraint mechanisms, are provided when upper chassis element 212 is coupled with lower chassis element 202.
Specifically, in
In certain aspects, cooperation between upper chassis element 212 and lower chassis element 202, (e.g., to form the CMC housing) is accomplished using a mechanical locking mechanism. By way of example, clip 218 of upper chassis element 212 is configured to connect with lower chassis element 202 using clip insert 219.
In certain aspects, upper chassis element 212 also includes restraint features for imparting a force on toroids 207, to provide further mechanical support. For example, upper chassis element 212 includes spring fingers 216 that are disposed on the inner surface of upper chassis element 212. When upper chassis element 212 is lowered on onto lower chassis element 202, spring fingers 216 contact with, and mechanically secure toroids 207.
A further illustration of the contact between spring fingers 216 and toroids 207 is provided by
As further shown in
Specifically,
In operation, wire cutting mechanism 222 facilitates the severance of wires as they are pulled from peg 206 during the CMC assembly process. For example, after the completion of toroid wire wrapping, the wire is pulled against cutting mechanism 222, causing the wire to sever and break off. By providing cutting mechanism 222, smaller forces can be exerted to break/cut the wrapped toroid wire, reducing the likelihood that the peg will shear or twist off from the supporting chassis element.
In some implementations, after toroid wrapping is complete, the wrapped toroid wire is subjected to laser stripping e.g., by laser light incident on the top of the peg surface. Laser stripping removes insulation from the wrapped toroid wire. In certain aspects, peg geometries, such as that of pegs 206, facilitates the laser stripping process, for example, by providing a flatter and larger surface area on the top side of the peg which can be reached with laser light. Additionally, the substantially flat top outer surface of the peg can help to reduce reflection of incident light, increasing the efficacy of laser ablation on the top surface. Thus, the geometry of pegs 206 not only improves mechanical integrity, but also facilitates the preparation and soldering of toroid wire. Further advantages of the subject peg geometry are illustrated by the view provided in
Specifically,
A more detailed view of the ICM wafer assembly is shown in
By using a mechanical mechanism to couple the multiple wafer portions, an ICM of the subject technology eliminates the need for adhesives such as epoxy or silicon, which can alter the electrical properties of toroids 302 and slow the ICM production process. As such, waferization of the ICM chassis provides several advantages, including improving the dielectric properties of toroids 302 (e.g., by eliminating conductive bonding media) and streamlining the ICM production process.
Aspects of the subject technology also provide an improved process and ICM geometry for relieving mechanical strain placed on toroid wires that are tied off on pins 304. Specifically, in some implementations, as illustrated in
Once pins 304B are in their final (angled) positions, the separate wafer assemblies are combined. It is understood that the angle of pins 304B with respect to the supporting chassis (or wafer) can vary with implementation. For example, pins 304B can come to rest at an angle that is greater than zero, but less than ninety degrees, with respect to the supporting chassis body.
As discussed above with respect to
Turning to
In certain aspects, first routing path 402 and second routing path 404 are provided on different layers of PCB 130. By way of example, first routing path 402 can be configured to cross over second routing path 404 using an orthogonal (i.e., 90 degrees) crossover e.g., to reduce cross-talk interference. By implementing two-layer routing in PCB 400, the subject technology can serve to reduce manufacturing costs, without realizing unacceptable levels of EMI or cross talk interference in PCB 400.
In another implementation, a PCB of the subject technology can be implemented using single layer routing. For example,
In some implementations, a PCB board of the subject technology provides a unique channel routing e.g., for Ethernet channel routing.
Although the number of channels carried by the channel slices, as well as the width of each individual channel slice can vary with implementation, in certain aspects first channel slice 504A, second channel slice 504B and third channel slice 504C will carry a combined total of eight differential Ethernet pairs at an approximately 75 ohm impedance.
In another aspect, a PCB of the subject technology (e.g., PCB 130), provides straight runs from a front of the board to the back of the board. For example, with reference to
In operation, first contact fingers 601A-E are configured to make electrical contact between an external chassis or case (not shown), when the case is fitted over ICM assembly 600. Accordingly, first contact fingers 601A-E an electrical coupling from ICM wrapper 605 and a case ground. The electrical connection between contact fingers 601A-E and the case provides a path by which stray EMI currents can be safely dissipated, without affecting other device components.
Similarly, the second set of contact fingers (e.g., 603A-603F) provide a ground connection between an ICM (not shown), and PCB 601. In certain aspects, the additional ground path provided by contact fingers 603A-F provides a low-impedance ground path from the ICM into the PCB, and eliminates the need for portions of the ICM wrapper, which would otherwise provide a similar function. That is, the addition of contact fingers 603A-F increases the availability of an electrical ground connection between the PCB and the supported ICMs.
By eliminating portions of the ICM wrapper, the subject technology provides ICM grounding configurations that reduce manufacturing costs while maintaining safety compliance.
In yet another aspect, the CMC and ICM configurations of the subject technology provide PCB layout configurations that facilitate the placement of lights, such as LEDs, at symmetrical positions around the ICM. By way of example, an ICM of the subject technology may be flanked by LEDs, which are used to signal to an external operator or user, that a corresponding connection if the illuminated ICM is active. In some implementations, a light-pipe or tube can be used to transmit light from the surface of the PCB (where the LEDs are mounted), and an external surface of the case or enclosure, so that they are visible to the user.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.”
A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A phrase such as a configuration may refer to one or more configurations and vice versa.
The word “exemplary” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs.
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Number | Date | Country | |
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Number | Date | Country | |
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Parent | 14140421 | Dec 2013 | US |
Child | 15408063 | US |