Abstract: A disclosed switching apparatus, such as a circuit breaker, includes a transistor switch circuit connected between a power input terminal and a load terminal, and, connected to the power input terminal and bypassing the transistor switch circuit, a switchable bypass leg that is optically switched by a series-connected photoconductive semiconductor switch (PCSS). The transistor switch circuit includes at least one cascade of three or more series-connected transistors, and at least one resistor network configured to divide a voltage from a voltage source across a cascade of series-connected transistors. Operating the switch apparatus includes detecting whether a sensed electric current is in a fault condition, opening the transistor switch circuit upon detecting a fault condition, and then closing the PCSS so that the electric current is diverted onto a switchable bypass path. The opening of the transistor switch circuit comprises turning OFF a normally-ON transistor switch circuit.

Abstract: A vertical gallium nitride (GaN) PN diode uses epitaxial growth of a thick drift region with a very low carrier concentration and a carefully designed multi-zone junction termination extension to achieve high voltage blocking and high-power efficiency. An exemplary large area (1 mm2) diode had a forward pulsed current of 3.5 A, an 8.3 m?-cm2 specific on-resistance, and a 5.3 kV reverse breakdown. A smaller area diode (0.063 mm2) was capable of 6.4 kV breakdown with a specific on-resistance of 10.2 m?-cm2, when accounting for current spreading through the drift region at a 45° angle.

Abstract: A method and system for determining the state of one or both of an electrical conductor or an associated system utilizing a non-invasive sensor and a magnetostrictive response from the current of the electrical conductor. The method includes providing a sensor assembly including a magnetostrictive resonator sensor and a signal detector. A state of one or both of the electrical conductor or the associated system is determined with the fault detector in response to a first frequency profile and a second frequency profile obtained with the magnetostrictive resonator sensor. A fault monitoring system utilizing a magnetostrictive resonator sensor is also disclosed.

Abstract: A vertical gallium nitride (GaN) PN diode uses epitaxial growth of a thick drift region with a very low carrier concentration and a carefully designed multi-zone junction termination extension to achieve high voltage blocking and high-power efficiency. An exemplary large area (1 mm2) diode had a forward pulsed current of 3.5 A, an 8.3 m?-cm2 specific on-resistance, and a 5.3 kV reverse breakdown. A smaller area diode (0.063 mm2) was capable of 6.4 kV breakdown with a specific on-resistance of 10.2 m?-cm2, when accounting for current spreading through the drift region at a 45° angle.

Abstract: A GaN diode EMP arrestor exhibits breakdown in <10 ns at reverse-bias voltage >20 kV. Additionally, the arrestor exhibits avalanche ruggedness at 1 kA/cm2 in a 1 mm2 device (i.e. 10 A absolute current) over a period of 500 ns following the onset of breakdown. Finally, the specific on-resistance in the forward direction is <20 m? cm2.

Abstract: A hybrid switched capacitor power converter for high-power applications is provided. The converter has a transistor-switched input-stage boost converter followed by a capacitor-and-diode ladder circuit. The converter is adapted to produce an output voltage of at least 5 kV at a power level of at least 0.5 kW. The ladder circuit includes one or more multi-stage rails.

Abstract: A DC power bus having reduced parasitic inductance and higher tolerable operating temperature is disclosed. In example embodiments, a bus structure overlies a printed circuit board, and an array of capacitors is arranged on a surface of the printed circuit board distal the bus structure. The bus structure comprises an upper metal plate, a lower metal plate, and a dielectric film interposed between the upper and lower metal plates. The capacitors are connected in parallel between conductive planes of the printed circuit board. The upper and lower metal plates of the bus structure are connected to respective conductive planes of the printed circuit board.