Abstract: A Break Over Diode (“BOD”) device is a gate-less two terminal high power semiconductor switch in which transitions from a blocking state to a conducting state are triggered by a dV/dt pulse to the anode. The BOD device can be thought of as two cross-coupled PNP and NPN transistors, and includes both anode and cathode shorts which reduce the gain of the NPN and PNP transistors by shunting some current away from their bases directly to their emitters, thereby improving blocking. Moreover, the anode and cathode shorts in conjunction with the device blocking junction form PN diodes which are distributed throughout the bulk of the material and function as anti-parallel diodes to the base-emitter junctions of the PNP and NPN transistors, which enables the BOD device to handle a larger current reversal for a longer period of time. The P base layer may be made thin to decrease the voltage fall time from full blocking to full conduction, and the cathode and anode shorts may be provided in a honeycomb pattern.

Abstract: A Break Over Diode (“BOD”) device is a gate-less two terminal high power semiconductor switch in which transitions from a blocking state to a conducting state are triggered by a dV/dt pulse to the anode. The BOD device can be thought of as two cross-coupled PNP and NPN transistors, and includes both anode and cathode shorts which reduce the gain of the NPN and PNP transistors by shunting some current away from their bases directly to their emitters, thereby improving blocking. Moreover, the anode and cathode shorts in conjunction with the device blocking junction form PN diodes which are distributed throughout the bulk of the material and function as anti-parallel diodes to the base-emitter junctions of the PNP and NPN transistors, which enables the BOD device to handle a larger current reversal for a longer period of time. The P base layer may be made thin to decrease the voltage fall time from full blocking to full conduction, and the cathode and anode shorts may be provided in a honeycomb pattern.

Abstract: Apparatus and methods for ethanol production use shock waves to increase the conversion of starch and/or cellulosic material into sugar. The shock waves may also control bacteria levels in the ethanol production facility. The shock waves may be generated by a shock wave generator that includes a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: Apparatus and methods for ethanol production use pulsed electric fields to increase the conversion of starch and/or cellulosic material into sugar. The pulsed electric fields may also control bacteria levels in the ethanol production facility. The pulsed electric fields may be generated by a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: Apparatus and methods for ethanol production use shock waves and pulsed electric fields to increase the conversion of starch and/or cellulosic material into sugar. The shock waves or the pulsed electric fields may also control bacteria levels in the ethanol production facility. The shock waves and the pulsed electric fields may be generated, at least in part, by a pulsed electric field generator such as a Marx generator, which may have one or more semiconductor switches.

Abstract: Semiconductor switches, such as thyristors, may be light activated by introducing the light into the switch via a groove having a sloped surface to receive the triggering light. The use of a sloped surface increases the surface path length between points of different electrical potential in the groove and, therefore, reduces the likelihood of electrical breakdown on the groove wall. In one particular embodiment, a light-activated thyristor includes a semiconductor anode layer, an n-base layer, a p-base layer and a semiconductor cathode layer disposed parallel to a thyristor plane. A thyristor axis lies perpendicular to the thyristor plane. A groove having a light refracting side wall extends into the thyristor from the anode layer. A portion of the light refracting side wall is disposed non-parallel to the thyristor plane and to the thyristor axis, and extends in the n-drift layer.

Abstract: Semiconductor switches, such as thyristors, may be light activated by introducing the light into the switch via a groove having a sloped surface to receive the triggering light. The use of a sloped surface increases the surface path length between points of different electrical potential in the groove and, therefore, reduces the likelihood of electrical breakdown on the groove wall. In one particular embodiment, a light-activated thyristor comprises a semiconductor anode layer, an n-base layer, a p-base layer and a semiconductor cathode layer disposed parallel to a thyristor plane. A thyristor axis lies perpendicular to the thyristor plane. A groove having a light refracting side wall extends into the thyristor from the anode layer. A portion of the light refracting side wall is disposed non-parallel to the thyristor plane and to the thyristor axis, and extends in the n-drift layer.