Abstract: A boost inductor value reduction circuit is integrated into a traditional boost power converter to greatly reduce undesirable high frequency harmonics from being fed back to the input side of the boost power converter. The boost inductor value reduction circuit is very small when compared with traditional filter techniques, is less costly than traditional filter techniques, and does not degrade the boost power converter control performance. It can also be used to reduce the size of the boost inductor without compromising the converter performance for use in energy efficient sensitive applications such as photovoltaic inverters.

Abstract: An optically powered drive circuit and a method for controlling a first semiconductor switch are provided. The optically powered drive circuit includes a photovoltaic cell configured to receive a first light signal from a fiber optic cable and to output a first voltage in response to the first light signal. The optically powered drive circuit further includes an energy storage device electrically coupled to the photovoltaic cell configured to store electrical energy received from the first voltage and to output a second voltage. The optically powered drive circuit further includes an electrical circuit electrically coupled to both the photovoltaic cell and the energy storage device. The electrical circuit is energized by the second voltage. The electrical circuit is configured to receive the first voltage and to output a third voltage in response to the first voltage for controlling operation of the first semiconductor switch.

Abstract: An optically powered drive circuit and a method for controlling a first semiconductor switch are provided. The optically powered drive circuit includes a photovoltaic cell configured to receive a first light signal from a fiber optic cable and to output a first voltage in response to the first light signal. The optically powered drive circuit further includes an energy storage device electrically coupled to the photovoltaic cell configured to store electrical energy received from the first voltage and to output a second voltage. The optically powered drive circuit further includes an electrical circuit electrically coupled to both the photovoltaic cell and the energy storage device. The electrical circuit is energized by the second voltage. The electrical circuit is configured to receive the first voltage and to output a third voltage in response to the first voltage for controlling operation of the first semiconductor switch.

Abstract: A power module includes a substrate that includes an upper layer, an electrical insulator and a thermal coupling layer. The upper layer includes an electrically conductive pattern and is configured for receiving power devices. The electrical insulator is disposed between the upper layer and the thermal coupling layer. The thermal coupling layer is configured for thermal coupling to a heat sink. The power module further includes at least one laminar interconnect that includes first and second electrically conductive layers and an insulating layer disposed between the first and second electrically conductive layers. The first electrically conductive layer of the laminar interconnect is electrically connected to the upper layer of the substrate. Electrical connections connect a top side of the power devices to the second electrically conductive layer of the laminar interconnect.

Abstract: A ripple current reduction circuit is provided that reduces the ripple current of a transformer by providing a substantially opposite or inverse ripple of an auxiliary current that can be combined with the ripple current of the transformer for cancellation or reduction of the ripple current.

Abstract: An AC ripple current reduction circuit for an AC converter having: an AC voltage source at the input; a first capacitor across which the circuit output voltage is provided; a first, main inductor in series with the first capacitor and the input; an auxiliary circuit including a second capacitor and a transformer coupled to the main inductor, the secondary of the transformer being in series with the second capacitor; and a means for enabling the flow of a time varying voltage across the first and second capacitors that has a frequency much less than the ripple frequency of the current in the main inductor.

Abstract: A method of operating a system having a coil includes providing a switched amplified current to the coil, and adding a second current to the switched amplified current, wherein the second current is substantially out of phase with the switched amplified current such that the coil receives current with substantially no switching frequency ripple.

Abstract: A ripple current reduction circuit is provided that reduces the ripple current of a transformer by providing a substantially opposite or inverse ripple of an auxiliary current that can be combined with the ripple current of the transformer for cancellation or reduction of the ripple current.

Abstract: A low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.

Abstract: A low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.

Abstract: A high current inductor is constructed using two single-sided or double-sided printed circuit boards having patterned copper traces thereon, a magnetic toroidal core, and multiple interconnecting wires extending between the boards. Multiple turns for the inductor are created by suitably configuring the copper traces on the printed circuit boards. Vias are employed on each circuit board for electrically interconnecting the boards to each other. Multiple thick, solid-gauge wires are situated in the vias in order to provide a very large copper area, thus providing high current carrying capability.

Abstract: A high current inductor is constructed using two single-sided or double-sided printed circuit boards having patterned copper traces thereon, a magnetic toroidal core, and multiple interconnecting wires extending between the boards. Multiple turns for the inductor are created by suitably configuring the copper traces on the printed circuit boards. Vias are employed on each circuit board for electrically interconnecting the boards to each other. Multiple thick, solid-gauge wires are situated in the vias in order to provide a very large copper area, thus providing high current carrying capability.

Abstract: Non-destructive EMI susceptibility testing involves near-field injection of very high levels of instantaneous energy and low average power through localized injection of signals of very high field strength and low duty cycle. An electric field injector and a magnetic field injector are scanned, each in turn, over the equipment under test. For each injector, the amplitude and frequency of the induced localized electric or magnetic field, respectively, is varied such that the susceptibility locations, magnitudes, and frequencies can be identified and mapped. This approach localizes which section or subcircuit of the equipment under test is susceptible, the frequencies and field strengths of susceptibility, and whether susceptibility problems are created by magnetic fields, electric fields, or both.

Abstract: An IGBT is optimized for ZVS operation, thereby significantly reducing switching losses during ZVS operation. In effect, the IGBT is optimized to operate as a MOSFET with a very small bipolar transistor component. Switching losses are reduced by reducing the number of minority carriers injected into the device during conduction. Additionally, this ZVS IGBT structure allows for a small increase in stored charge as the operating temperature is increased, allowing the device to operate at higher temperatures with relatively low switching losses.

Abstract: An optimal phase-shifted control for a series resonant converter involves instantaneous monitoring of state variables (resonant capacitor voltage resonant inductor current and output voltage) and implementation of a control law for providing a quasi-squarewave-with-maximum-coasting (QSWMC) mode of operation. The control law uses the instantaneous resonant inductor current, the instantaneous resonant capacitor voltage and the output voltage to determine the optimal time to perform switching events in order to operate on a desired control trajectory. The QSWMC converter operates at a minimized frequency in a super-resonant mode with zero-voltage switching, minimized electrical stresses, and reduced electromagnetic interference due to nearly sinusoidal resonant tank currents.

Abstract: A bulk current injection (BCI) system and method for testing electromagnetic susceptibility of electrical apparatus includes an RF modulator in a BCI setup. The BCI setup with RF modulator injects high instantaneous currents with a very low, controllable duty cycle into a wire under test, thereby simulating an electromagnetic environment to which electrical equipment is exposed during an electrical transient event. The RF modulator provides an amplitude modulated envelope for removing undesirable transients. Injecting currents at selectable frequency, one frequency at a time, allows for frequency-amplitude electromagnetic susceptibility mapping for each major wire within an electrical apparatus.

Abstract: A control method and apparatus for reducing transformer core volume in a power converter of the type having a switching circuit coupled to a primary winding of the transformer for selectively coupling the primary winding to a dc voltage source, a secondary winding of the transformer being coupled to an output rectifier circuit for developing a relatively high dc voltage across an output capacitor. The apparatus includes a high voltage zener diode clamp for limiting the maximum voltage on the capacitor, and the rectifier circuit includes at least a pair of zener diodes connected for blocking reverse current flow through the rectifier circuit.

Abstract: A switching converter achieves improved regulation range by the use of a saturable reactor in series with a transformer primary. The saturable reactor uses a conventional magnetic pot core including a magnetic shell and center post. The location at which the post joins the shell is perforated to reduce the cross-section of magnetic material, so that, at low reactor currents, incremental inductance is established by the gap between post and lid, and at high reactor currents, the incremented inductance is established by saturation at the base of the post. Perforation at the base of the post also results in generation of heat at a location immediately adjacent the flat bottom of the pot core.

Abstract: A low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.