Abstract: A magnetic assembly formed by a custom magnetic core and its bobbin with interconnection pins is presented. This magnetic assembly leads to a higher power density of magnetic assembly and a better utilization of the volume inside a power converter, allowing a higher power density of the power converter and a higher efficiency through the minimization of the parasitic inductances.

Abstract: A magnetic structure in a power converter includes at least two multilayer boards, such as a primary board containing the primary windings and some auxiliary windings, and a secondary board containing the secondary windings and some auxiliary windings. The primary and secondary boards are on top of each other. On the layer on the primary board adjacent to the secondary board, is a dual function shield to reduce the total common mode noise in the converter towards zero. The controlled dual function shield can be placed on the secondary board on the layer adjacent to the primary board, and in some embodiments can be placed on both primary and secondary board on the layers adjacent to the other board. The embodiments herein offer a very good solution for cost reduction of the planar transformers and offers an avenue for total elimination of the common mode noise in a power converter.

Abstract: A switching power conversion apparatus for converting power from an input voltage source to a load includes first and second switches connected to a switching node. An inductive element has a magnetizing current connected to the node, and the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles. A capacitance connected to the node resonates with the inductive element to cause parasitic oscillation. A clamp subcircuit across the inductive element contains an auxiliary switch to trap energy and prevent parasitic oscillation, wherein the auxiliary switch is complementary to the first switch. A controlled voltage source injects energy in the inductive element, when the auxiliary switch turns off to discharge the parasitic capacitance by using trapped energy in the inductive element in addition to injected energy from the controlled voltage source.

Abstract: A switching power conversion apparatus includes an input voltage source, an output load, a first switch connected to a switching node, and a second switch connected to the switching node. An inductive element has a magnetizing current connected to the switching node. The inductive element delivers energy via the first and second switches from the voltage source to the load during power conversion cycles. A capacitance connected to the switching node can resonate with the inductive element during a portion of the power conversion cycles to cause a parasitic oscillation. A first clamp subcircuit is across the inductive element and contains a unidirectional auxiliary switch to trap energy from the inductive element and store it into the storage capacitor and prevent parasitic oscillation. The auxiliary switch is complementary to the first switch. A current source discharges the storage capacitor and uses the energy in the switching power conversion apparatus.

Abstract: A switching power conversion apparatus for converting power from an input voltage source to a load includes first and second switches connected to a switching node. An inductive element has a magnetizing current connected to the node, and the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles. A capacitance connected to the node resonates with the inductive element to cause parasitic oscillation. A clamp subcircuit across the inductive element contains an auxiliary switch to trap energy and prevent parasitic oscillation, wherein the auxiliary switch is complementary to the first switch. A controlled voltage source injects energy in the inductive element, when the auxiliary switch turns off to discharge the parasitic capacitance by using trapped energy in the inductive element in addition to injected energy from the controlled voltage source.

Abstract: A magnetic and electrical circuit element including magnetic-flux-conducting posts, and a multi-layer structure formed with an electrically-conductive material. The multi-layer structure includes multiple layers forming a stack of layers along a length of the posts, said multi-layer structure configured as primary and secondary windings of a transformer. The primary winding is embedded in the multi-layer structure and wound around the magnetic-flux-conducting posts in such a way that a magnetic field induced in each of the magnetic-flux-conducting posts has a magnetic field polarity opposite to a polarity of the respective magnetic field of the magnetic-flux-conducting post adjacent the respective magnetic-flux-conducting post. Around each of the magnetic-flux-conducting posts, there is a respective one of the secondary windings connected to a semiconductor device.

Abstract: A two-transistor forward switching cell includes two primary switching elements connected between an input voltage source and a primary winding of a transformer. The switching elements are connected to the primary winding at opposite ends of the winding. Reset diodes are connected between one of the opposite ends of the primary winding and one termination of the voltage source, and between another of the opposite ends of the primary winding and another termination of the voltage source. The transformer has at least a secondary winding connected to drains of synchronous rectifiers. One of the rectifiers is on during at least a portion of a time when the switching elements are on. The other of the rectifiers is a freewheeling rectifier, is connected to at least one controlled current source, and is off when the switching elements are on. Both rectifiers are on for a common predetermined time.

Abstract: This specification discusses the concept of energy injection in a resonant circuit with initial conditions which is part of almost all of the present topologies. It presents in detail several methods of energy injection in a resonant circuit with initial conditions and how it applies to different topologies. It patent presents also a simple and economical method of driving the clamp switch in a flyback topology operating in discontinuous mode and a bias circuit in a flyback topology wherein the output voltage varies over a large range.

Abstract: A magnetic assembly formed by a custom magnetic core and its bobbin with interconnection pins is presented. This magnetic assembly leads to a higher power density of magnetic assembly and a better utilization of the volume inside a power converter, allowing a higher power density of the power converter and a higher efficiency through the minimization of the parasitic inductances.

Abstract: Systems and method for optimizing the efficiency of operation of electronic circuits, configured structured according to a true soft-switching phase-shifted full-bridge topology (where all the primary switching elements turn on at zero voltage and the secondary switching elements turn off at zero current with no ringing and no spikes across the secondary switching elements) with the use of unique current-injection approaches. An additional advantage of the embodiments of this invention is that the true soft switching feature applies regardless of the leakage inductance in the transformer.

Abstract: A method includes providing a transformer with primary and current injection windings, a primary switch connected to the primary winding, a parasitic capacitance reflected across the primary switch, a secondary rectifier means, and a current injection circuit including a current injection switch connected to the current injection winding, and a unidirectional current injection switch connected to the current injection winding. The method includes switching on the current injection switch to start a current injection flowing from a controlled voltage source, through the unidirectional current injection switch and further through the current injection winding. The current injection reflects into the primary winding, thereby discharging the parasitic capacitance reflected across the primary switch. The method includes turning on the primary switch with a delay time after the current injection switch turns on and turning off the current injection switch after the current injection reaches zero amplitude.

Abstract: A magnetic and electrical circuit element including magnetic-flux-conducting posts, and a multi-layer structure formed with an electrically-conductive material. The multi-layer structure includes multiple layers forming a stack of layers along a length of the posts, said multi-layer structure configured as primary and secondary windings of a transformer. The primary winding is embedded in the multi-layer structure and wound around the magnetic-flux-conducting posts in such a way that a magnetic field induced in each of the magnetic-flux-conducting posts has a magnetic field polarity opposite to a polarity of the respective magnetic field of the magnetic-flux-conducting post adjacent the respective magnetic-flux-conducting post. Around each of the magnetic-flux-conducting posts, there is a respective one of the secondary windings connected to a semiconductor device.

Abstract: A magnetic assembly formed by a custom magnetic core and its bobbin with interconnection pins is presented. This magnetic assembly leads to a higher power density of magnetic assembly and a better utilization of the volume inside a power converter, allowing a higher power density of the power converter and a higher efficiency through the minimization of the parasitic inductances.

Abstract: A magnetic structure in a power converter includes at least two multilayer boards, such as a primary board containing the primary windings and some auxiliary windings, and a secondary board containing the secondary windings and some auxiliary windings. The primary and secondary boards are on top of each other. On the layer on the primary board adjacent to the secondary board, is a dual function shield to reduce the total common mode noise in the converter towards zero. The controlled dual function shield can be placed on the secondary board on the layer adjacent to the primary board, and in some embodiments can be placed on both primary and secondary board on the layers adjacent to the other board. The embodiments herein offer a very good solution for cost reduction of the planar transformers and offers an avenue for total elimination of the common mode noise in a power converter.

Abstract: Power converter electronic circuitries configured to harvest and store energy from at least the parasitic oscillation occurring during the operation thereof. Methodologies of using such energy for the current injection, carried out by discharging the parasitic capacitance across the switching elements to achieve zero voltage switching condition for these switching elements. In a specific case, the methodology of current injection (with the use of so harvested and stored energy) is self-adjusting, causing the optimization of the energy required to discharge the parasitic capacitance.

Abstract: A magnetic and electrical circuit element including magnetic-flux-conducting posts, and a multi-layer structure formed with an electrically-conductive material. The multi-layer structure includes multiple layers forming a stack of layers along a length of the posts, said multi-layer structure configured as primary and secondary windings of a transformer. The primary winding is embedded in the multi-layer structure and wound around the magnetic-flux-conducting posts in such a way that a magnetic field induced in each of the magnetic-flux-conducting posts has a magnetic field polarity opposite to a polarity of the respective magnetic field of the magnetic-flux-conducting post adjacent the respective magnetic-flux-conducting post. Around each of the magnetic-flux-conducting posts, there is a respective one of the secondary windings connected to a semiconductor device.

Abstract: A system for reducing common-mode noise includes a switch mode power supply having primary and secondary sides, primary and secondary side grounds, an input voltage source, a primary switch, a transformer, a core, and a power output. The primary and secondary sides each have a quiet termination. The transformer includes a primary winding, a secondary winding, and an active shield winding between the primary and secondary windings. The active shield winding has two terminations, is wound in a same direction as the secondary winding, and occupies a same axial position on the core as the secondary winding. One of the terminations of the active shield winding is connected to the quiet termination of the primary side, so that the terminations of the secondary winding and the active shield winding that are adjacent each other carry alternating voltages of a same polarity and a same amplitude.

Abstract: A magnetic structure in a power converter includes at least two multilayer boards, such as a primary board containing the primary windings and some auxiliary windings, and a secondary board containing the secondary windings and some auxiliary windings. The primary and secondary boards are on top of each other. On the layer on the primary bard adjacent to the secondary board, is a dual function shield to reduce the total common mode noise in the converter towards zero. The controlled dual function shield can be placed on the secondary board on the layer adjacent to the primary board, and in some embodiments can be placed on both primary and secondary board on the layers adjacent to the other board. The embodiments herein offer a very good solution for cost reduction of the planar transformers and offers an avenue for total elimination of the common mode noise in a power converter.

Abstract: Electronic circuitry and method of operating the same to shape and reduce the circulating current through the active clamp in a flyback converter and to harvest most of the leakage inductance energy to provide the bias power. Methodologies for minimizing the circulating energy in the clamp circuit in order to improve efficiency of operation of the same. A method for using a portion of the leakage inductance energy in order to create zero voltage switching conditions at the main primary switch.

Abstract: A system for reducing common-mode noise includes a switch mode power supply having primary and secondary sides, primary and secondary side grounds, an input voltage source, a primary switch, a transformer, a core, and a power output. The primary and secondary sides each have a quiet termination. The transformer includes a primary winding, a secondary winding, and an active shield winding between the primary and secondary windings. The active shield winding has two terminations, is wound in a same direction as the secondary winding, and occupies a same axial position on the core as the secondary winding. One of the terminations of the active shield winding is connected to the quiet termination of the primary side, so that the terminations of the secondary winding and the active shield winding that are adjacent each other carry alternating voltages of a same polarity and a same amplitude.