Abstract: A method for making an energy transfer element provides a magnetic core having a gap in a magnetic path, positions in the gap magnetizable material that produces an initial flux density, cures the suspension medium, and wraps one or more power windings around the magnetic path. When the magnetizable material is magnetized, a flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material comprises a mixture of a suspension medium that includes uncured epoxy and magnetizable particles. The magnetizable particles are capable of permanent magnetic properties when magnetized. The particles of magnetic material having magnetic permeability of at least 1000?o. The particles of magnetic material that have a magnetic permeability of at least 1000?o and the particles of magnetizable particles are uniformly distributed in the suspension medium.

Abstract: A housing or surface of a housing containing at least one heat dissipating device configured to be grasped or otherwise held by a user. The housing includes a first housing wall portion with a plurality of grasping features that protrude from the first housing wall portion and a second housing wall portion with a second plurality of grasping features that protrude from the second housing wall portion. The first plurality of grasping features and second plurality of grasping features prevent a user from contacting the first housing wall portion and the second housing wall portion.

Abstract: An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: A magnet comprising a center disc having a center disposed as a center of the magnet, a face of the center disc is substantially perpendicular to a central axis of the magnet. The magnet further comprises a first plurality of outer discs disposed around the center disc in a bundled rod construction, a face of each of the first plurality of outer discs substantially perpendicular to the central axis of the magnet, wherein the center disc and each disc of the first plurality of outer discs is electrically insulated from every other disc.

Abstract: Magnetic core assemblies include a skewing feature that introduces transverse components into the power flux density vector are disclosed herein. A magnetic core assembly comprises a lower core having a center section and an upper core having a center section. The center sections are aligned to form a center post. A power winding that receives current is wrapped around the center post. The core assembly further comprises a power flux density vector that has transverse and non-transverse components. The transverse components have a higher magnetic reluctance than the non-transverse components. When the assembly is used with a transverse winding, the transverse components from the magnetic core assembly produce a transverse voltage waveform on the transverse winding. The transverse voltage waveform may be observed to detect a change in the sign of the slope of the transverse voltage waveform. The change in the sign of the slope indicates magnetic saturation.

Abstract: An energy transfer element that provides 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 both the first and second communication windings are perpendicular to the first power winding. The magnetic flux density produced by current in the first power winding is perpendicular to the magnetic flux density produced by current in the first communication winding and the second communication winding For a power controller having an input-referenced controller and an output-referenced controller, the energy transfer element provides galvanic isolation between the controllers because the communication windings are electrically insulated from each other and from the magnetic core assembly.

Abstract: Magnetic saturation detectors for power converters are presented herein. An energy transfer element has an input power winding wrapped around a center post. Single or multiple transverse windings are positioned perpendicular to the input power winding and coupled to receive a transverse current that provides a transverse magnetic flux density within the energy transfer element. The transverse magnetic flux density produces a transverse voltage waveform. A voltage detection circuit is configured to receive the transverse voltage waveform and detect a change in the sign of the slope of the transverse voltage waveform. The change in the sign of the slope indicates magnetic saturation. The voltage detection circuit is configured to detect an occurrence of an extremum in the transverse voltage waveform. The extremum indicates the change in the sign of the slope.

Abstract: A method for making an energy transfer element provides a magnetic core having a gap in a magnetic path, positions in the gap magnetizable material that produces an initial flux density, cures the suspension medium, and wraps one or more power windings around the magnetic path. When the magnetizable material is magnetized, a flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material comprises a mixture of a suspension medium that includes uncured epoxy and magnetizable particles. The magnetizable particles are capable of permanent magnetic properties when magnetized. The particles of magnetic material having magnetic permeability of at least 1000?o. The particles of magnetic material that have a magnetic permeability of at least 1000?o and the particles of magnetizable particles are uniformly distributed in the suspension medium.

Abstract: An energy transfer element comprises a U-shaped core of powder core, the U-shaped core having two legs and a gap in a magnetic path, a bar comprising magnetizable material positioned in the gap such that the magnetic core and magnetizable material form a rectangular toroid, and one or more power windings wrapped around the magnetic path. The magnetizable material is capable of being magnetized. When the magnetizable material is unmagnetized, the magnetizable material has an initial flux density. When the magnetizable material is magnetized, the flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material is an unmagnetized magnet or a suspension medium such as epoxy with magnetized magnetizable particles and powder core. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: Presented herein are methods and apparatus for biasing magnetic circuits to reduce audible noise from a switching power supply. A magnetic component (e.g., a magnet) is constructed and provided to a core (e.g., a ferromagnetic core) to offset (i.e., bias) an applied magnetomotive force. By selecting and/or manufacturing the magnetic component based on a circuit operating condition, the offset may be tailored to advantageously shift a frequency of mechanical deformation outside the audible noise range. In a switching power supply with fixed peak current, the offset to the applied magnetomotive force may be determined, at least in part, by the fixed peak.

Abstract: A magnet comprising a center disc having a center disposed as a center of the magnet, a face of the center disc is substantially perpendicular to a central axis of the magnet. The magnet further comprises a first plurality of outer discs disposed around the center disc in a bundled rod construction, a face of each of the first plurality of outer discs substantially perpendicular to the central axis of the magnet, wherein the center disc and each disc of the first plurality of outer discs is electrically insulated from every other disc.

Abstract: Presented herein are methods and apparatus for biasing magnetic circuits to reduce audible noise from a switching power supply. A magnetic component (e.g., a magnet) is constructed and provided to a core (e.g., a ferromagnetic core) to offset (i.e., bias) an applied magnetomotive force. By selecting and/or manufacturing the magnetic component based on a circuit operating condition, the offset may be tailored to advantageously shift a frequency of mechanical deformation outside the audible noise range. In a switching power supply with fixed peak current, the offset to the applied magnetomotive force may be determined, at least in part, by the fixed peak.

Abstract: A method for sensing the current in a high-electron-mobility transistor (HEMT) that compensates for changes in a drain-to-source resistance of the HEMT. The method includes receiving a sense voltage representative of the current in the HEMT, receiving a compensation signal representative of a drain-to-source voltage of the HEMT, and outputting as a compensated sense voltage a linear combination of the sense voltage and the compensation signal.

Abstract: A transformer for use in a power converter includes a first winding including a plurality of layers wound around a magnetic core. A first exclusionary winding is wound around the magnetic core forming a first exclusionary winding layer. A first section of the plurality of layers of the first winding is wound closer to a center of the magnetic core than the first exclusionary winding layer. A second exclusionary winding is wound around the magnetic core forming a second exclusionary winding layer. The first and second exclusionary windings have an equal number of turns around the magnetic core. A second section of the plurality of layers of the first winding is wound around the magnetic core between the first exclusionary winding layer and the second exclusionary winding layer.

Abstract: A power converter includes an energy transfer element, a switched element, a secondary control circuit, a primary switching, and a primary control circuit. The secondary control circuit generates a voltage pulse across a secondary winding of the energy transfer element while the secondary winding provides current to an output. The secondary control circuit is coupled to vary a voltage across the switched element to generate the voltage pulse across the secondary winding in response to an output of the power converter. The primary control circuit is coupled to the primary switch and a third winding of the energy transfer element. The primary control circuit is coupled to switch the primary switch to regulate the output in response to the voltage pulse. The secondary winding is coupled to reflect the voltage pulse onto the third winding which is on the same side of the energy transfer element as a primary winding.

Abstract: A method for sensing the current in a high-electron-mobility transistor (HEMT) that compensates for changes in a drain-to-source resistance of the HEMT. The method includes receiving a sense voltage representative of the current in the HEMT, receiving a compensation signal representative of a drain-to-source voltage of the HEMT, and outputting as a compensated sense voltage a linear combination of the sense voltage and the compensation signal.

Abstract: A power converter includes an energy transfer element, a switched element, a secondary control circuit, a primary switching, and a primary control circuit. The secondary control circuit generates a voltage pulse across a secondary winding of the energy transfer element while the secondary winding provides current to an output. The secondary control circuit is coupled to vary a voltage across the switched element to generate the voltage pulse across the secondary winding in response to an output of the power converter. The primary control circuit is coupled to the primary switch and a third winding of the energy transfer element. The primary control circuit is coupled to switch the primary switch to regulate the output in response to the voltage pulse. The secondary winding is coupled to reflect the voltage pulse onto the third winding which is on the same side of the energy transfer element as a primary winding.

Abstract: A signal averaging circuit includes a plurality of switched weighted current sources to generate a total amount of charge. The total amount of charge is representative of a weighted sum of a plurality of input signal samples during an active period of a read enable signal. A timing control signal generator is coupled to receive an input signal and the read enable signal and sequentially switch the plurality of switched weighted current sources to adjust the total amount of charge in response to the input signal during the active period of the read enable signal. A storage circuit is coupled to the plurality of switched weighted current sources to convert the total amount of charge into a voltage representative of an output signal.