Energy transfer element comprising a communication element

Abstract

An energy transfer element providing galvanic isolation in a power controller is disclosed herein. A magnetic core assembly has an aperture. A first power winding is positioned within the magnetic core assembly. A first communication winding and a second communication winding are positioned within the aperture such that the first and second communication windings are both perpendicular to the first power winding. Magnetic flux density produced by current in the first power winding is perpendicular to magnetic flux density produced by current in the first and second communication windings. The energy transfer element provides galvanic isolation between a controller having a reference input and a controller having a reference output for a power controller because the communication windings are electrically isolated from each other and from the magnetic core assembly.

Description

[0001] of

[0002] Application for U.S. Patent

[0003] Energy transfer element including a communication element

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 888,089, filed August 16, 2019, which is incorporated by reference herein in its entirety.

[0005] Related Applications

[0006] This patent application is related to patent application 62 / 888,194 - "Core Assemblies for Magnetic Saturation Detector without Requirement for DC Bias" and patent application 62 / 887,810 entitled "Magnetic Saturation Detector with Single and Multiple Transverse Windings," each of which was filed on the same date as the present application, each of which is assigned to the common assignee of the present application, and each of which has a common inventor. Each of the related applications is incorporated by reference herein in its entirety. BACKGROUND

[0007] 1. TECHNICAL FIELD

[0008] The present disclosure describes an apparatus for communication and energy transfer between galvanically isolated circuits. The apparatus transfers energy from an input to a galvanically isolated output. The communication can be between the galvanically isolated circuits. The communication is independent of the voltage and current involved in the energy transfer.

[0009] 2. DISCUSSION OF RELATED ART

[0010] In a switch-mode power supply (SMPS) that provides galvanic isolation between input and output, there is typically a magnetic energy transfer element having one or more input windings and one or more output windings. The input windings are galvanically isolated from the output windings, and the circuitry referenced to the return node on the input is galvanically isolated from the circuitry referenced to the return node on the output. In other words, a direct current (dc) voltage applied between the input windings and the output windings will produce negligible current. Similarly, a dc voltage applied between the nodes of any circuitry on the input and the nodes of any circuitry on the output will produce negligible current. The SMPS can have a first controller referenced to the input and a second controller referenced to the output. The two controllers can communicate with each other during operation of the power supply. For example, a request for the circuitry on the input to provide more power can originate from the control circuitry referenced to the output. In another embodiment, the input-referenced controller can receive feedback information from the output-referenced error amplifier regarding the state of the output to be regulated.

[0011] Furthermore, it can be desirable to communicate "housekeeping" data (e.g., device temperature, device identification, and / or power level, etc.) from the input-referenced controller to the output-referenced controller, and vice versa. Still further, it can be desirable to communicate information across an isolation barrier that separates the input circuitry from the output circuitry of the SMPS in either direction. The communication can be in analog or digital format.

[0012] Typically, one or more communication transformers, capacitive couplers, or opto-couplers are used to provide isolation in the communication interface of the SMPS. However, utilizing such isolation devices and associated components typically increases the component count and overall cost of the SMPS. There is a need to provide communication between the galvanically isolated circuits of the SMPS without increasing the component count. BRIEF DESCRIPTION OF DRAWINGS

[0013] Non-limiting and non-exhaustive embodiments of the present application are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views.

[0014] Figure 1 An embodiment of a power supply having an energy transfer element including first and second communication windings for communicating between a controller referenced to an input and a controller referenced to an output is illustrated in accordance with some embodiments.

[0015] Figure 2An example of a signal transformer having a flux density path in the first direction is shown.

[0016] Figure 3A An illustration is shown of a magnetic core including a signal transformer according to some embodiments, the signal transformer having a first communication winding and a second communication winding.

[0017] Figure 3B Examples are given based on some implementation schemes. Figure 3A It includes a first communication winding, a second communication winding, and a magnetic core with a flux density path in the first direction.

[0018] Figure 4A Examples are given based on some implementation schemes, such as Figure 3A and Figure 3B The magnetic core shown includes a first communication winding, a second communication winding, and a power winding for energy transfer.

[0019] Figure 4B Examples are given based on some implementation schemes. Figure 4A The exploded view of the magnetic core shown illustrates the placement of the first communication winding, the second communication winding, and the power winding for energy transfer.

[0020] Figure 5 The magnetic cores shown in Figures 3 and 4 according to some embodiments are illustrated to illustrate the flux density paths of communication signals and the flux density paths of energy transfer signals.

[0021] Figure 6 An example is illustrated, according to some embodiments, a magnetic core having a power winding for energy transfer, a first communication winding coupled to a communication circuit to a reference input, and a second communication winding coupled to a communication circuit to a reference output.

[0022] Figure 7 An EE core according to some embodiments is illustrated, having a power winding for energy transfer, a first communication winding coupled to a communication circuit to a reference input, and a second communication winding coupled to a communication circuit to a reference output.

[0023] Figure 8 A low-profile RM core is illustrated according to some embodiments, having a power winding for energy transfer, a first communication winding coupled to a communication circuit to a reference input, and a second communication winding coupled to a communication circuit to a reference output.

[0024] In all of the several views of the drawings, corresponding reference characters indicate corresponding parts throughout the several views. The skilled artisan will understand that the elements in the drawings are illustrated for simplicity and clarity and not necessarily drawn to scale. For example, the dimensions of some of the elements in the drawings can be exaggerated relative to other elements to help improve the understanding of the various embodiments of the application. Also, common but well-understood elements that are useful in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the application. DETAILED DESCRIPTION

[0025] In the following description, numerous specific details are set forth to provide a thorough understanding of the application. Those of ordinary skill in the art will realize that the application can be practiced without the specific details

[0026] Reference throughout this specification to "one embodiment," "an embodiment," "one example," or "an example," means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "one example," or "an example" in various places throughout this specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable

[0027] Figure 1 is a schematic diagram 100 of an example power supply configured to operate using an energy transfer element that includes a communication element. Figure 1 The example power supply of receives an input voltage V IN 102 from a reference input return 104 and provides a regulated output to a load 148. The regulated output can be a voltage V O 154, a current I O 146, or a combination of both.

[0028] Figure 1The example power supply of FIG. 1 uses a flyback power converter to produce an output that is isolated from the input current. In other words, the voltage applied between the input return 104 and the output return 144 will produce a negligible current. Figure 1 The flyback power converter in the example power supply of FIG. 1 includes an energy transfer element LI 120 having an input power winding PI 118, an output power winding P2 122, a first communication winding K1 128, and a second communication winding K2 126. The power windings PI 118 and P2 122 are primarily involved in the transfer of energy between the input and the output, while the communication windings K1 128 and K2 126 are primarily involved in communication between a controller that references the input and a controller that references the output. In Figure 1 In the example power supply of FIG. 1, the controller 132 that references the input and the controller 152 that references the output send and receive signals between the current-isolated returns 104 and 144. The controller 132 that references the input can send and receive signals using the communication winding 128 in the form of a voltage V C1 130 or a current I C1 134. The controller 152 that references the output can send and receive signals using the communication winding 126 in the form of a voltage V C2 140 or a current I C2 142.

[0029] Figure 1 The notation for the energy transfer element LI 120 in FIG. 1 uses dot convention to indicate the voltage polarity on the windings. The circular dots on the power windings PI 118 and P2 122 indicate that the dotted end of the power winding has the same voltage polarity with respect to the undotted end of the same winding. For example, if the dotted end of one power winding is positive with respect to the undotted end, the dotted end of all power windings is positive with respect to their undotted ends. Similarly, the square dots on the communication windings K1 128 and K2 126 indicate that the dotted end of the communication winding has the same voltage polarity with respect to the undotted end of the same communication winding. The dots on the power windings have a different shape than the dots on the communication windings to indicate that the polarity of the power windings is not necessarily the same as the polarity of the communication windings, as will become apparent from later descriptions of the construction of the energy transfer element LI 120 in this disclosure.

[0030] The clamp circuit 106 is coupled in parallel to the input power winding PI 118. The input switch SI 110 is coupled between the input power winding PI 118 and the input return 104.

[0031] During operation, the reference input controller 132 receives signals from the reference output controller 152 via current-isolated communication windings K1 128 and K2 126 included in the energy transfer element L1 120 to generate drive signals for opening and closing the input switch S1 110. An open switch cannot conduct current, while a closed switch can. The reference input controller 132 senses the current I in the input switch S1 110. S1 108 senses the current sensing signal 114. In one operating mode, when the current I... S1 When the threshold is reached at 108, the reference input controller 132 can disconnect the input switch S1 110.

[0032] The switching of switch S1 110 generates a pulsating current I in the corresponding power windings P1 118 and P2 122 in the energy transfer element L1 120. P1 116 and I P2 124, and the corresponding pulsating voltages V1 and V2 across the windings. When the switch is open, clamping circuit 106 prevents excessive voltage on input power switch S1 110. Output winding current I from output power winding P2 122. P2 124 is rectified by diode 136 and by output capacitor C. O 138 filters are used to generate the output voltage V at load 148. O 154 and output current I O 146. Output voltage V O 154. Output current I O 146 or a combination thereof can be sensed by the reference output controller 152 as an output sensing signal 150. The reference output controller compares the sensed output quantity with a reference value and communicates with the reference input controller 132 via current-isolated communication windings K1 128 and K2 126 to appropriately switch the input switch S1 110 to obtain the desired output value.

[0033] Figure 2 An example of a signal transformer constructed from a toroidal coil 255 of magnetic material is illustrated. A first communication winding 228 and a second communication winding 226 pass through an aperture 245 at the center of the toroidal coil. The windings are electrically insulated from the core and from each other, thus isolating them from current. In response to the voltage on the communication windings 226 and 228, a magnetic flux density B is established in a direction 235 perpendicular to the axis of the aperture 245, passing through the region defined by the loop of each winding. C The voltage applied to a winding produces a flux density B. C rate of change dB CThe rate of change of / dt 215 creates a voltage on the other winding. The ratio of the two voltages is approximately the same as the ratio of the number of turns of their respective windings. In Figure 2 embodiments where each winding has a single turn, the voltage V C1 230 is approximately the same as the voltage V C2 240. Thus, a galvanically isolated circuit can communicate over the galvanically isolated windings 226 and 228 by transmitting and receiving voltages on the communication windings. Similarly, a voltage on the windings can generate a current in the windings that a circuit can interpret as a communication signal.

[0034] Figure 3A A perspective view 300A illustrates a magnetic core assembly including a signal transformer having a first communication winding 328 and a second communication winding 326. Figure 3A The assembly in FIG. 3 includes an upper core piece, such as upper half core 339, and a lower core piece, such as lower half core 349, each having a cylindrical section forming a center post 329. The assembly also includes a gap 359 in the center post 329. An aperture 326 passes through the center post 329 in each half core to form a toroidal coil similar to the toroidal coil of the signal transformer of FIG. 2. Figure 2 The communication windings 328 and 326 pass through the aperture in each half core of FIG. 3 to form a signal transformer within the center post of the assembly. Figure 3A The communication windings 328 and 326 pass through the aperture in each half core of FIG. 3 to form a signal transformer within the center post of the assembly.

[0035] Those skilled in the art will appreciate that magnetic assemblies and parts of magnetic assemblies can be described by a variety of terms that are not necessarily technically accurate and precise. For example, almost any piece of magnetic material can be referred to as a magnetic core. A complete assembly of magnetic parts that does not include windings can also often be referred to as a magnetic core. An assembly of a magnetic core often includes two core pieces. In many assemblies of magnetic cores, such as in the embodiment of FIG. 3, the two core pieces can be nearly identical. Thus, each core piece can often be referred to as a core member or a half core. In fact, the gap in the center post, such as gap 359 in FIG. 3, can be referred to as a center post gap. Figure 3A Figure 3A ​The gap 359 in the assembly of components can be formed by removing material from the center post of only one of the two identical half-cores. Each core component is still referred to as a half-core even though the piece that formed the gap is no longer identical to the piece that did not have material removed. The assembly can also be referred to as a core pair. In this disclosure, the term half-core can be used to refer to one of the two nearly identical pieces in an assembly to distinguish the assembly from an alternative assembly that includes pieces that are clearly not identical. For example, an assembly of two E-shaped pieces can have the same geometric features and magnetic properties as an assembly that uses one E-shaped piece and one I-shaped piece. Although each assembly includes two core members, the EE assembly includes two half-cores while the EI assembly does not. It should be noted that in the practice of the art, each of the magnetic core pieces, magnetic core members, magnetic core elements, magnetic half-cores, and magnetic core assemblies can be referred to as a magnetic core.

[0036] Figure 3B is Figure 3A a front view 300B of the magnetic core assembly of C1 and the voltage V across the second communication winding 326 that produces a flux density 315 that varies in a direction 335 that is perpendicular to the axis of the aperture C2 . Figure 3B It is also illustrated that the flux density produced by the communication windings is essentially limited to the magnetic material of the aperture that surrounds the center of the structure. In other words, the portion of the half-core that extends radially beyond the center post has negligible flux density from the communication windings.

[0037] Figure 4A is a perspective view 400A of a magnetic core that includes a first communication winding 428, a second communication winding 426, and a power winding 418 as illustrated in Figure 3A and Figure 3B The power winding 418 represents one or more windings that participate in storing or transferring energy, such as, for example, a power winding 418 that is used to store energy in a transformer or to transfer energy in a power inductor. Figure 1In the power supply, the power transfer elements L1 120 contain P1 118 and P2 122. In actual components, the turns of the power winding are typically placed on a separate spool, sometimes called a bobbin or coil former, which is mounted on a center post for easy assembly. The communication winding can then be threaded through the opening. Because the communication windings 426 and 428 are perpendicular to the turns of the power winding, and the core intended for the power transfer elements is typically optimized to hold the power winding, the communication windings can be referred to as lateral windings—describing their physical orientation relative to the power winding of a conventional core. It should be understood that the lateral windings do not necessarily have to be geometrically perpendicular to the power winding. Any conductor that passes completely through a turn of the power winding in one direction at any angle can be a lateral winding. Ordinary cores used in power supplies typically do not have an opening 445 to accommodate the communication winding. The power transfer elements will typically have openings such as... Figure 3A The gap 359 in the central column of the assembled half-core shown is used to set electrical parameters corresponding to the desired amount of stored energy.

[0038] Figure 4B Examples Figure 4A The perspective view 400B of the magnetic core shown has an upper half-core 439 and a lower half-core 449 to show the lateral communication windings 426 and 428 passing through the opening in the lower half-core 448.

[0039] Figure 5 yes Figure 4A The figure shows a front view 500 of the magnetic core assembly, illustrating the direction and path of the flux density. The accompanying drawing illustrates the flux density B generated in the central post 529 of the upper core 539 and lower core 549. C The current I in the corresponding communication windings 528 and 526 of 535 C1 534 and I C2 542. Flux density B C The direction of 535 is perpendicular to the axis of the opening in the central post 529. Flux density B C The rate of change of the size of 535 dB C / dt and the voltage V across the corresponding communication windings 528 and 526 C1 530 and V C2 540 is proportional.

[0040] Figure 5 The accompanying drawing also shows the number of turns of the power winding 518 surrounding the central post 529. The current I in the power winding 518... P1 516 generates flux density B in central column 529. P 565. In the central column 529, the flux density B generated by the power winding 518P 565perpendicular to the flux density B C 535generated by the communication windings 528 and 526 Figure 5 The accompanying drawings show the flux density B C 535and B P 565in the center leg 529 is a right angle of 90 degrees. Figure 5 shows that when current is passed through the power winding, a first magnetic flux density B P 565is generated in the magnetic core assembly, and when current (I C1 518or I C2 542) is passed through the communication winding (528 or 526, respectively), a second magnetic flux density B C 535is generated in the magnetic core assembly, such that the first magnetic flux density B P 565is perpendicular to the second magnetic flux density B C 535.

[0041] When the energy transfer element is operating in its linear region - in which the magnitude of the flux density has a negligible effect on the properties of the magnetic material of the core, the flux densities B P 565and B C 535have a negligible effect on each other. Thus, the rate of change dB P 565in the magnitude of the flux density B P / dt does not generate a significant voltage on the communication windings 528 and 526. Conversely, the rate of change dB C 535in the magnitude of the flux density B C / dt does not generate a significant voltage on the power winding 518.

[0042] Figure 5 shows that the power winding flux density B P 565in the center leg is divided into two approximately equal portions in the horizontal and outer vertical portions of the core as it traverses the closed path between the upper and lower halves. Although the portion of the power winding flux density B P 565in the horizontal section of the half cores is not everywhere perpendicular to the communication winding flux density B C 535, any contribution to the voltage on the communication winding in the top half core 539 is completely cancelled by the opposite contribution in the bottom half core 549, so the net contribution from the power winding to the voltage in the communication winding is zero. In other words, the flux density of the communication signal and the flux density of the energy transfer signal are oriented by the geometry of the energy transfer element such that the voltage and current involved in the communication are independent of the voltage and current involved in the energy transfer.

[0043] The communication winding need not pass through an opening in the center leg to realize the benefits of the present invention. The communication winding can pass through an opening at any other location in the magnetic core that places the flux density from the communication winding perpendicular to the flux density from the power winding. For example, the communication winding can be positioned in an opening in the center leg of the structure in Figure 5 The opening in the center leg of the structure in

[0044] The sum of the flux densities B C 535 and B P 565 is a vector in the magnetic material. In practical applications, it is often desirable to keep the sum of the vectors of the flux densities less than a threshold that marks the boundary between the linear region and the beginning of magnetic saturation. By timing the signaling interval to occur when the flux density from the power winding is relatively low, the magnetic core can be effectively shared between communication and energy transfer.

[0045] Figure 6 is a connection diagram 600 showing a perspective view of an example energy transfer element when the example energy transfer element can be applied in an example power supply of Figure 1 Some mechanical details have been omitted to avoid obscuring the present invention. Figure 6 The energy transfer element in includes upper and lower half-cores 639 and 649, each having a center leg 629. A power winding 618 encircles the center leg 629 and conducts current I P1 616. Communication windings 628 and 626 pass through openings 645 in the center legs of the two half-cores. A reference input communication circuit 632 and a reference output communication circuit 652 send and receive signals between galvanically isolated return loops 604 and 644. The reference input communication circuit 632 can use the communication winding 628 to send and receive signals in the form of a voltage V C1 630 or a current I C1 620. The reference output communication circuit 652 can use the communication winding 626 to send and receive signals in the form of a voltage V C2 640 or a current I C2 642.

[0046] Figure 7 is a connection diagram 600 showing a perspective view of an example energy transfer element when the example energy transfer element can be applied in an example power supply of Figure 1FIG. 7 is a connection diagram 700 of a perspective view of the improved EE half-core in the example power supply of FIG. 6. The assembly of energy transfer elements in the previous figures is presented as a general embodiment to show the salient features of the construction of an energy transfer element that includes a communication winding in an opening transverse to a conventional power winding. Figure 7 The example energy transfer element in FIG. 8 is constructed from two standard RM type ferrite half-cores, an upper half-core 839 and a lower half-core 849. A hole 845 in the center of the center post of each half-core is an off-the-shelf option intended to accommodate a ferrite slug to adjust the inductance of the power winding after assembly. In accordance with the teachings of the present invention, communication windings 828 and 826 can pass through the adjustment hole instead of a ferrite slug to form an integrated signal transformer. Other types of ferrite cores can have openings for other purposes, such as assembly hardware that can be adapted for communication windings. In cores not equipped with suitable openings, a hole can be drilled through the center post. P1 716.

[0047] The reference input communication circuit 832 can use the communication winding 828 to send and receive signals in the form of a voltage V C1 830 or a current I C1 820. The reference output communication circuit 852 can use the communication winding 826 to send and receive signals in the form of a voltage V C2 840 or a current I C2 842.

[0048] Figure 8 FIG. 8 is a connection diagram 800 of a perspective view of the example energy transfer element when it can be applied in the example power supply of FIG. 7. Figure 1 The hole 845 in the center of the center post of each half-core is an off-the-shelf option intended to accommodate a ferrite slug to adjust the inductance of the power winding after assembly. In accordance with the teachings of the present invention, communication windings 828 and 826 can pass through the adjustment hole instead of a ferrite slug to form an integrated signal transformer. Other types of ferrite cores can have openings for other purposes, such as assembly hardware that can be adapted for communication windings. In cores not equipped with suitable openings, a hole can be drilled through the center post.

[0049] The reference input communication circuit 832 can use the communication winding 828 to send and receive signals in the form of a voltage V C1 830 or a current I C1 820. The reference output communication circuit 852 can use the communication winding 826 to send and receive signals in the form of a voltage V C2 840 or a current I C2 842.

[0050] While the figures in the present disclosure illustrate embodiments of magnetic core assemblies using identical upper and lower core halves, other standard structures such as, for example, EI assemblies having non-identical upper and lower core pieces, can be modified to have holes drilled through the E and I pieces to form an opening through the center post. Further, it will be apparent to those skilled in the art that the core assembly can include more than two pieces to form equivalent structures.

[0051] The above description of the illustrated embodiments of the application, including what is described in the abstract, is not intended to be exhaustive or to be limiting to the precise forms disclosed. While specific embodiments of, and examples for, the application are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the application, as those skilled in the relevant art will recognize. Indeed, various examples of the application are possible as will be readily apparent to those skilled in the art. The specific examples provided herein are by way of example only and should not be construed as limiting the scope of the application. It is intended that the description of the application contained herein should be considered in all respects as illustrative and not restrictive, and that the scope of the application should be determined by the appended claims and their equivalents.

[0052] While the application is defined in the claims, it is understood that the application can be alternatively defined in accordance with the following embodiments:

[0053] Embodiment 1 : An energy transfer element comprising: a magnetic core assembly having an opening; a first power winding positioned within the magnetic core assembly; and a first communication winding and a second communication winding positioned within the opening such that the first and second communication windings are both perpendicular to the first power winding, wherein when current is transferred through the power winding a first magnetic flux density is generated in the magnetic core assembly and when current is transferred through the communication windings a second magnetic flux density is generated in the magnetic core assembly such that the first magnetic flux density is perpendicular to the second magnetic flux density.

[0054] Embodiment 2: The energy transfer element of embodiment 1, the magnetic core assembly further comprising: a lower core piece having a center section; and an upper core piece having a center section, aligned with the lower core piece such that the center section of the lower core piece and the center section of the upper core piece form a center post, wherein the center post has the opening therethrough, and wherein the first and second communication windings pass through the opening.

[0055] Embodiment 3: The energy transfer element of embodiment 2, wherein the lower core piece comprises a lower half core and the upper core piece comprises an upper half core.

[0056] Example 4: The energy transfer element of Example 1, further comprising: a second power winding, wherein the first power winding is an input power winding and the second power winding is an output power winding.

[0057] Example 5: A controller comprising: an energy transfer element comprising, a magnetic core assembly having an aperture; a first power winding positioned within the magnetic core assembly; and a first communication winding and a second communication winding positioned within the aperture such that the first and second communication windings are both perpendicular to the first power winding, wherein when current is transferred through the power winding a first magnetic flux density is generated in the magnetic core assembly and when current is transferred through the communication windings a second magnetic flux density is generated in the magnetic core assembly such that the first magnetic flux density is perpendicular to the second magnetic flux density; a reference output communication circuit coupled in parallel to the second communication winding and configured to sense an output sense signal, compare the output sense signal to a reference value, and generate a switching signal; and a reference input communication circuit coupled in parallel to the first communication winding and configured to generate a drive signal, wherein the first and second communication windings transmit a communication signal.

[0058] Example 6: The controller of Example 5, the magnetic core assembly further comprising: a lower core piece having a center section; and an upper core piece having a center section, aligned with the lower core piece such that the center section of the lower core piece and the center section of the upper core piece form a center post, wherein the center post has the aperture therethrough, and wherein the first and second communication windings pass through the aperture.

[0059] Example 7: The controller of Example 6, wherein the lower core piece comprises a lower half core and the upper core piece comprises an upper half core.

[0060] Example 8: The controller of Example 5, the magnetic core assembly further comprising: a second power winding, wherein the first power winding is an input power winding and the second power winding is an output power winding.

[0061] Example 9: The controller of Example 8, further comprising galvanic isolation placed between the reference input communication circuit and the reference output communication circuit.

[0062] Example 10: The controller of example 9, wherein the first and second communication windings are electrically isolated from each other and from the magnetic core assembly, and the electrical isolation comprises the galvanic isolation.

[0063] Example 11 : The controller of example 9, wherein the communication signal is between the communication circuit of the reference input and the communication circuit of the reference output.

[0064] Example 12: The controller of example 11, wherein the communication signal is selected from the group consisting of a voltage signal and a current signal.

[0065] Example 13: The controller of example 5, wherein the energy transfer element is included in a power converter.

[0066] Example 14: The controller of example 13, wherein the power converter is a flyback converter.

[0067] Example 15: The controller of example 14, the flyback converter further comprising: galvanic isolation placed between the communication circuit of the reference input and the communication circuit of the reference output.

[0068] Example 16: The controller of example 14, the flyback converter further comprising the first and second communication windings are electrically isolated from each other and from the magnetic core assembly, wherein the electrical isolation comprises the galvanic isolation.

[0069] Example 17: The controller of example 16, wherein the communication signal is between the communication circuit of the reference input and the communication circuit of the reference output.

[0070] Example 18: The controller of example 17, wherein the communication signal is selected from the group consisting of a voltage signal and a current signal.

Claims

1. An energy transfer element comprising: a magnetic core assembly having an aperture; a first power winding positioned within the magnetic core assembly; and a signal transformer comprising a first communication winding and a second communication winding positioned within the aperture such that the first and second communication windings are both perpendicular to the first power winding, wherein the first and second communication windings are galvanically isolated from each other and from the first power winding, wherein when current is transferred through the power winding, a first magnetic flux density is generated in the magnetic core assembly, and when current is transferred through the communication windings, a second magnetic flux density is generated in the magnetic core assembly such that the first magnetic flux density is perpendicular to the second magnetic flux density, wherein the magnetic core assembly further comprises: a lower core piece having a central section, and an upper core piece having a central section aligned with the lower core piece such that the central section of the lower core piece forms a central column with the central section of the upper core piece, wherein the central column has the aperture through the central column in each of the lower core piece and the upper core piece within which the signal transformer is positioned, and wherein the first and second communication windings pass through the aperture in each of the lower core piece and the upper core piece.

2. The energy transfer element of claim 1, wherein the lower core piece comprises a lower half core and the upper core piece comprises an upper half core.

3. The energy transfer element of claim 1, further comprising: a second power winding, wherein the first power winding is an input power winding and the second power winding is an output power winding.

4. A controller comprising: an energy transfer element comprising, a magnetic core assembly having an aperture; a first power winding positioned within the magnetic core assembly; a first communication winding and a second communication winding positioned within the aperture such that the first and second communication windings are both perpendicular to the first power winding, wherein the first and second communication windings are galvanically isolated from each other and from the first power winding, wherein when current is transferred through the power winding, a first magnetic flux density is generated in the magnetic core assembly, and when current is transferred through the communication windings, a second magnetic flux density is generated in the magnetic core assembly such that the first magnetic flux density is perpendicular to the second magnetic flux density; a reference output communication circuit coupled in parallel to the second communication winding and configured to sense an output sense signal, compare the output sense signal to a reference value, and generate a switching signal; and a reference input communication circuit coupled in parallel to the first communication winding and configured to generate a drive signal, ​ ​ wherein the first and second communication windings transmit a communication signal sent and received by the communication circuit of the reference output and the communication circuit of the reference input, wherein the communication signal is configured such that a vector sum of the first and second magnetic flux densities is less than a threshold marking a boundary between a linear region and a beginning of magnetic saturation in the magnetic core.

5. The controller of claim 4, the magnetic core assembly further comprising: a lower core piece having a central section; and an upper core piece having a central section, aligned with the lower core piece such that the central section of the lower core piece forms a central column with the central section of the upper core piece, wherein the central column has the aperture through the central column in each of the lower core piece and the upper core piece, and wherein the first and second communication windings pass through the aperture in each of the lower core piece and the upper core piece.

6. The controller of claim 5, wherein the lower core piece comprises a lower half core and the upper core piece comprises an upper half core.

7. The controller of claim 4, the magnetic core assembly further comprising: a second power winding, wherein the first power winding is an input power winding and the second power winding is an output power winding.

8. The controller of claim 7, further comprising galvanic isolation between the communication circuit of the reference input and the communication circuit of the reference output.

9. The controller of claim 8, wherein the first and second communication windings are galvanically isolated from each other and from the magnetic core assembly.

10. The controller of claim 8, wherein the communication signal is between the communication circuit of the reference input and the communication circuit of the reference output.

11. The controller of claim 10, wherein the communication signal is selected from the group consisting of a voltage signal and a current signal.

12. A power converter comprising the controller of claim 4, wherein the energy transfer element is included in the power converter.

13. The power converter of claim 12, wherein the power converter is a flyback converter.

14. The power converter of claim 13, the flyback converter further comprising: galvanic isolation between the communication circuit of the reference input and the communication circuit of the reference output.

15. The power converter of claim 13, wherein the first and second communication windings are galvanically isolated from each other and from the magnetic core assembly.

16. The power converter of claim 15, wherein the communication signal is between the communication circuit of the reference input and the communication circuit of the reference output.

17. The power converter of claim 16, wherein the communication signal is selected from the group consisting of a voltage signal and a current signal.

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