Abstract: An apparatus and method that can accelerate the turn off time for a thyristor current interrupter. Following commutation of a load current from a main thyristor to an auxiliary turn-off unit, a capacitor of the auxiliary turn-off unit can provide a resonant current to create a zero current crossing for turning the main thyristor off, as well as provide a reverse bias voltage for the main thyristor. The auxiliary turn-off unit can hold the main thyristor off and facilitate sufficient time being available for main thyristor to block forward system voltage. A voltage level of another capacitor of the auxiliary turn-off unit can, with a switch of the auxiliary turn-off unit and the main thyristor turned off, be increased to a level that triggers at least one voltage-clamping unit to absorb electrical power from that capacitor.

Abstract: A circuit includes a first transistor, a second transistor and a first resistive load. The first transistor has a first terminal coupled to a first reference voltage terminal, a second terminal coupled to a second reference voltage terminal, and a control terminal coupled to the first reference voltage terminal. The second transistor has a first terminal coupled to the second reference voltage terminal, a second terminal coupled to the first reference voltage terminal and the control terminal of the first transistor, and a control terminal coupled to the second reference voltage terminal and the second terminal of the first transistor. The first transistor further comprises a third terminal coupled to the second reference voltage terminal through the first resistive load.

Abstract: An electronic apparatus, a power supply apparatus, and a power supply method. The electronic apparatus may include a controller to provide a control signal to generate a multiphase signal through conversion of an input power and to receive a feedback of an output voltage that is generated using the multiphase signal; and a power supply including a plurality of unit converters having upper and lower switching elements of a half or full-bridge type, being operated by the control signal, and configured to provide the output voltage by the multiphase signal generated according to driving of the plurality of unit converters, wherein the power supply detects whether the upper and lower switching elements are simultaneously turned on in the plurality of unit inverters and turns off the operation of the unit converters according to the detection result.

Abstract: A voltage source converter includes a converter limb having limb portions separated by an AC terminal and extending between DC terminals, each limb portion including a primary switching element to switch the limb portion into and out of circuit. The converter further includes an auxiliary limb. The primary switching element of each limb portion is switchable to switch the auxiliary limb into and out of circuit with the corresponding limb portion. The converter further includes a control unit to, in one mode, inject a circulation current that flows in one direction in one of the limb portions and minimize a current flowing in the opposite direction in that limb portion. Each primary switching element switches the respective limb portion into or out of circuit following the minimization of the limb portion current by the circulation current.

Abstract: A semiconductor module includes a printed circuit board, a ceramic substrate and a semiconductor chip. The printed circuit board includes an insulating material, a cutout formed in the insulating material, and a first metallization layer, which is partly embedded into the insulating material. The first metallization layer includes a conductor track projection projecting into the cutout. The ceramic substrate includes a dielectric, ceramic insulation carrier, and an upper substrate metallization applied to a top side of the insulation carrier. The semiconductor chip is arranged on the upper substrate metallization, and the first metallization layer is mechanically and electrically conductively connected to the upper substrate metallization at the conductor track projection.

Abstract: A controller connected to the gate, cathode and anode of a thyristor, may be configured such that in response to the anode being provided with a voltage, the controller activates the thyristor to allow current flow between the anode and the gate in a first instance and to allow current flow between the gate and the cathode in a second instance so as to provide the cathode with an enhanced voltage, the enhanced voltage being an enhancement of the voltage at the anode.

Abstract: The present disclosure provides a rectifier. The rectifier includes a N-type epitaxial layer, a plurality of P-type diffusion regions and a plurality of N-type diffusion regions. The P-type diffusion regions are disposed in the N-type epitaxial layer, and the N-type diffusion regions are respectively disposed in the P-type diffusion regions. Wherein, the P-type diffusion regions are electronically coupled to the N-type diffusion regions.

Abstract: An exemplary current switching device includes an integrated gate-commutated thyristor with an anode, a cathode, and a gate, wherein a current between the anode and the cathode is interruptible by applying a switch-off voltage to the gate; and a gate unit for generating the switch-off voltage. The gate unit and a connection of the gate unit to the gate establish a gate zcircuit having a stray impedance. The gate unit is adapted for generating a spiked switch-off voltage with a maximum above a breakdown voltage (VGRMAX) between the cathode and the gate, such that the switch-off voltage at the gate stays below the breakdown voltage (VGRMAX) due to the stray impedance of the gate circuit.

Abstract: An insulated gate turn-off thyristor has a layered structure including a p+ layer (e.g., a substrate), an n? layer, a p-well, vertical insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. Some of the gate regions are first gate regions that only extend into the p-well, and other ones of the gate regions are second gate regions that extend through the p-well and into the n? layer to create a vertical conducting channel when biased. The second gate regions increase the beta of the PNP transistor. When the first gate regions are biased, the base of the NPN transistor is narrowed to increase its beta. When the product of the betas exceeds one, controlled latch-up of the thyristor is initiated. The distributed second gate regions lower the minimum gate voltage needed to turn on the thyristor.

Abstract: An integrated exciter-igniter architecture is disclosed that integrates compact, direct-mounted exciter electronics with an aerospace designed igniter to reduce overall ignition system complexity. The integrated exciter-igniter unit hermetically seals exciter electronics within a stainless steel enclosure or housing. The stainless enclosure enables the exciter electronics to remain near atmospheric pressure while the unit is exposed to vacuum conditions. The exciter electronics include a DC-DC converter, timing circuitry, custom-designed PCBs, a custom-designed main power transformer, and a high voltage ignition coil. All of which are packaged together in the stainless steel enclosure. The integrated exciter-igniter unit allows for efficient energy delivery to the spark gap and eliminates the need for a high voltage cable to distribute the high voltage, high energy pulses.

Abstract: In a circuit that turns off a fluorescent lamp, clamping circuitry is provided to dissipate energy stored in a ballast when the lamp is being turned off. In a normal state in which the lamp is on, or in a normal state in which the lamp is off, clamping is not performed as long the VDS of a power switch is below a voltage A. In a lamp turn off operation, the switch is turned on for a time period to extinguish the lamp, and is then made to operate as a clamp (operate in its linear region) for a second period of time to dissipate energy that was stored in the ballast. Clamping in the linear region continues for VDS voltages down to B as ballast energy is dissipated, where B is smaller than A. By clamping down to the lower voltage B, re-ignition of the lamp is prevented.

Abstract: An embodiment of a power device having a first current-conduction terminal, a second current-conduction terminal, a control terminal receiving, in use, a control voltage of the power device, and a thyristor device and a first insulated-gate switch device coupled in series between the first and the second conduction terminals; the first insulated-gate switch device has a gate terminal coupled to the control terminal, and the thyristor device has a base terminal. The power device is further provided with: a second insulated-gate switch device, coupled between the first current-conduction terminal and the base terminal of the thyristor device, and having a respective gate terminal coupled to the control terminal; and a Zener diode, coupled between the base terminal of the thyristor device and the second current-conduction terminal so as to enable extraction of current from the base terminal in a given operating condition.

Abstract: An electronic device includes a wide bandgap thyristor having an anode, a cathode, and a gate terminal, and a wide bandgap bipolar transistor having a base, a collector, and an emitter terminal. The emitter terminal of the bipolar transistor is directly coupled to the anode terminal of the thyristor such that the bipolar transistor and the thyristor are connected in series. The bipolar transistor and the thyristor define a wide bandgap bipolar power switching device that is configured to switch between a nonconducting state and a conducting state that allows current flow between a first main terminal corresponding to the collector terminal of the bipolar transistor and a second main terminal corresponding to the cathode terminal of the thyristor responsive to application of a first control signal to the base terminal of the bipolar transistor and responsive to application of a second control signal to the gate terminal of the thyristor. Related control circuits are also discussed.

Abstract: A method of controlling a static VAR compensator includes providing a static VAR compensator having a reactive component and a thyristor for switching the reactive component into and out of a power distribution network; monitoring a periodic waveform on the power distribution network and controlling operation of the thyristor on the basis of the harmonic frequency content of the waveform.

Abstract: An embodiment of a power device having a first current-conduction terminal, a second current-conduction terminal, a control terminal receiving, in use, a control voltage of the power device, and a thyristor device and a first insulated-gate switch device connected in series between the first and the second conduction terminals; the first insulated-gate switch device has a gate terminal connected to the control terminal, and the thyristor device has a base terminal. The power device is further provided with: a second insulated-gate switch device, connected between the first current-conduction terminal and the base terminal of the thyristor device, and having a respective gate terminal connected to the control terminal; and a Zener diode, connected between the base terminal of the thyristor device and the second current-conduction terminal so as to enable extraction of current from the base terminal in a given operating condition.

Abstract: A housing for a semiconductor device is disclosed. In an exemplary embodiment of the present invention, the housing comprises a semiconductor substrate that is arranged between two contact elements, one contact element forming an anode contact element and another contact element forming a cathode contact element, the semiconductor substrate having, on at least one surface, a gate electrode that is contacted by a gate contact element, the first contact element forming a surface arranged across from the gate electrode and at a distance from the gate electrode. Also included is at least one driver unit for generating a gate current, the driver unit comprising a first terminal that is contacted with the gate contact element, and a second terminal that is contacted with a first of the two contact elements.

Abstract: An electronic device includes a wide bandgap thyristor having an anode, a cathode, and a gate terminal, and a wide bandgap bipolar transistor having a base, a collector, and an emitter terminal. The emitter terminal of the bipolar transistor is directly coupled to the anode terminal of the thyristor such that the bipolar transistor and the thyristor are connected in series. The bipolar transistor and the thyristor define a wide bandgap bipolar power switching device that is configured to switch between a nonconducting state and a conducting state that allows current flow between a first main terminal corresponding to the collector terminal of the bipolar transistor and a second main terminal corresponding to the cathode terminal of the thyristor responsive to application of a first control signal to the base terminal of the bipolar transistor and responsive to application of a second control signal to the gate terminal of the thyristor. Related control circuits are also discussed.

Abstract: Resonant gate driver circuits provide for efficient switching of, for example, a MOSFET. However, often an operation of the resonant gate driver circuit does not allow for an application where high switching frequencies are required. According to the present invention, a pre-charging of the inductor of the resonant gate driver circuit is performed. This allows for a highly efficient and fast operation of the MOSFETs.

Abstract: A housing for a semiconductor device is disclosed. In an exemplary embodiment of the present invention, the housing comprises a semiconductor substrate that is arranged between two contact elements, one contact element forming an anode contact element and another contact element forming a cathode contact element, the semiconductor substrate having, on at least one surface, a gate electrode that is contacted by a gate contact element, the first contact element forming a surface arranged across from the gate electrode and at a distance from the gate electrode. Also included is at least one driver unit for generating a gate current, the driver unit comprising a first terminal that is contacted with the gate contact element, and a second terminal that is contacted with a first of the two contact elements.

Abstract: The highest-power switches now available are based on thyristor-type devices: GTOs (Gate turn-off thyristors), MTOs (MOS controlled turn-off thyristors), IGCTs (Integrated gate commutated thyristors), and the new ETOs (Emitter turn-off thyristors). These devices handle kilovolts and kiloamperes for megawatt inverters/converters. Measurements by the inventors show that conduction losses of MOSFETs and switching losses of IGCTs are drastically decreased by cryo-cooling. IGCTs, ETOs, and MTOs, together with many small, low voltage MOSFETs for gate and emitter turn-off circuitry, are cryo-cooled to attain much higher switching speeds and a reduction in size, weight and cost of high-power (megawatt range) equipment.

Abstract: A gate driving circuit having: a direct current power source; a driving signal source for outputting signal; a main switch device, having a gate terminal in which the signal outputted from the driving signal source is inputted, for controlling a conduction state between a source terminal and a drain terminal; a load energized when the conduction state between the source and drain terminals becomes a conductive state; a reverse current blocking unit, connected between the driving signal source and the gate terminal; and a regenerative unit, connected between the gate terminal and a high potential side of the power source, which becomes a conductive state when the conduction state between the source and drain terminals is a non-conductive state. A gate-source threshold voltage to obtain the conductive state between the source and drain terminals is set higher than an output voltage of the power source.

Abstract: The integrated gate dual transistor (IGDT) has two controllable gates (G1, G2), a first gate (G1) being provided on the cathode side and being driven via a low-inductance first gate terminal with a first gate current, and a second gate (G2) being provided on the anode side and being driven via a low-inductance second gate terminal with a second gate current. In the switch-off operation of the IGDT, the rate of rise of the voltage across the IGDT is limited via the two gates. Limiting the rate of rise of the voltage across the IGDT prevents voltages from building up at different speeds in a series circuit of IGDTs, and thus unequal loads from overheating and destroying the individual IGDTs.

Abstract: A family of emitter turn-off thyristors and their drive circuit comprise a gate turn-on (GTO) thyristor, a first switch, the drain of the first switch being connected to the cathode of the GTO thyristor, and a second switch connected between the gate of the GTO thyristor and the source of the first switch. The first switch consists of many paralleled metal oxide semiconductor field effect transistors (MOSFETs). The anode of the GTO thyristor and the source of the first switch serve as the annode and the cathode, respective, of the emitter turn-off thyristor. The emitter turn-off thyristor has four control electrodes: the gate of the GTO thyristor, the control electrode of the second switch, the gate of the first switch, and the cathode of the GTO thyristor. The drive circuit comprises a current source circuit, a voltage clamp circuit, a current direction detector, and a control circuit. The ETO thyristor further comprises a current sensing and over-current detector circuit.

Abstract: A novel gate driver apparatus in which an energy recovery circuitry is incorporated in a square-wave gate driver. The energy recovery circuitry has a first loop circuit for discharging the energy from the gate capacitor to an inductor when the gate driver is turned off, and a second loop circuit for discharging the energy from the inductor to the power supply. Thus, the energy of the gate capacitor is transferred to the power source when the gate driver is turned off, and the gate driver apparatus still maintains its operating flexibility as the square-wave driver and is independent of switching frequency.

Abstract: A gate-controlled switch includes a gate turn-off thyristor in series with a diode. By using the diode in series with the GTO, the switch significantly increases the turn-off voltage that can be used for the current commutation. The unity turn-off gain and the snubberless turn-off capability are demonstrated.

Abstract: This invention relates to a pressure-contact type semiconductor device (1) having a ring-shaped gate terminal, and aims at overcoming such a technical problem that a gate current is not uniformly supplied to a semiconductor substrate (4) due to a connection structure for the device (1) and an external gate driver (2). For this purpose, a ring-shaped gate terminal (10) is structured as a resistor whose resistivity is at least 0.1 m&OHgr;·cm in the present invention. Thus, a voltage drop by the aforementioned resistor enlarges in a concentrated part of the gate current, and it follows that the gate current is shunted to another non-concentrated part. The present invention is utilizable as a high-power element in a power applied device.

Abstract: A gate terminal plate (1) of a GCT thyristor (90), a connecting substrate (70) of a driving device and a cathode electrode plate (10) are interposed between a set of metal rings (7A) and (7C) fastened to each other with a screw (8). The cathode electrode plate (10) is connected to a cathode post electrode (31) of the GCT thyristor (90). The screw (8) is electrically insulated from the metal ring (7A) and the gate terminal plate (1) through an insulator (9). By this structure, the gate terminal plate (1) and the cathode electrode plate (10) are directly connected to a first metallized layer (5) and a second metallized layer (6) which are provided on two main surfaces of the connecting substrate (70) of the driving device, respectively. Thus, resistance and inductance components in a path for a gate current are reduced and an assembly is simplified.

Abstract: An IGBT gate driver circuit includes means for detecting when the collector-to-emitter voltage (Vce) of a turned-on IGBT, intended to be operated in the saturation region, increases above a preset level, indicative of a fault condition, such as a short circuit. In response to such an increase in the Vce of a turned on IGBT, the IGBT is turned-off in two steps. First, the turn-on gate drive is decreased to a level that is still above the threshold (turn-on) voltage of the IGBT in order to decrease the current flowing through the IGBT and hence, the peak power dissipation. This decrease in the current through the IGBT and the peak power dissipation increases the length of time the IGBT can withstand a fault condition such as a short circuit. Then, after decreasing the gate drive to the IGBT, the gate drive is gradually decreased until the IGBT is completely turned off.

Abstract: In a gate circuit having a turn-off gate circuit composed of: OFF gate power source Eoff of which one terminal is connected to the emitter of semiconductor switching element 81, and switch SWoff that connects the other terminal of OFF gate power source Eoff and the gate of semiconductor switching element S1 via resistor Rg, the gate circuit is provided with second switch SWoff2 that connects the other terminal of OFF gate power source Eoff and the gate of semiconductor switching element S1. By closing second switch SWoff2 at the timing at which the turn-off operation is completed, it will connect to OFF gate power source Eoff without passing through a resistor.

Abstract: A one-way switching circuit of the type including a gate tun-off thyristor biased to be normally on, further includes, between the gate and a supply line, a capacitor and a controllable switch connected in parallel.

Abstract: In an FET device having a pair of input terminals, a pair of output terminals, a plurality of FETs and driving circuits, the driving circuit has such a circuit structure that source electrodes of the FETs are electrically connected to each other. Each of gate electrodes of the FETs is independently connected to a photo-diode array. The gate electrodes of the FETs are not electrically short-circuited to each other. The FETs are tuned on and off in response to a single control signal.

Abstract: In a gate driver device, cathode conductor 2, gate conductor 3, and positive and negative conductors 8 and 9 between the principal turn-on and turn-off capacitors and MOSFET switching elements Q11-Q1i and Q21-Q2j are disposed on a wide plate. A thin insulation layer is inserted between conductor 3 and conductors 8 and 9. Numerous chip-type ceramic capacitors C11-C1m and C21-C2n to be used as principal capacitors are arranged in rows in the space between conductor 2 and conductors 8 and 9. The gate voltage of switching elements Q11-Q1i is reduced exponentially by time constant circuit TC, and the leak inductance of transformer Thf is employed to smooth the charging current.

Abstract: The switching di/dt and switching dv/dt of a MOS gate controlled ("MOS-gated") power device are controlled by respectively controlling the voltage and current waveforms. Open loop control of the turn-on of the MOS-gated device is provided by coupling a common terminal of a current generator circuit, which provides a current to the gate of the MOS device, to a first resistor for controlling the switching dv/dt. At the detection of a negative dv/dt, the common terminal of the current generator circuit is then coupled to a second resistor for controlling the switching di/dt. The first and second resistors are, in turn, coupled to the source terminal fo the MOS-gated device. An analogous operation provides turn-off control of the MOS-gated power device. Closed loop control is also provided by measuring the switching dv/dt and the switching di/dt which are then fed back to the circuit to control the current supplied to the gate of the MOS-gated device.

Abstract: In a method and apparatus used for detecting and handling a short circuit in a circuit having a plurality of power semiconductors connected in series the voltage is divided across the electrodes and each power semiconductor and the magnitude of a small proportion of the voltage is measured. The magnitude of the voltage is compared to a reference voltage at least from when the power semiconductor is turned on. The reference voltage is higher than the maximum voltage across the power semiconductor during normal operation. A short circuit is detected when the magnitude of the measured voltage exceeds the reference voltage.

Abstract: The invention provides a silicon controlled rectifier having an anode and a cathode and including an NPN transistor and a PNP transistor. The NPN transistor has an emitter coupled to the cathode, a base and a collector. The PNP transistor has a base coupled to the NPN collector, an emitter coupled to the anode, a first collector coupled to the NPN base and a second collector coupled to the NPN collector.

Abstract: A power semiconductor circuit provides a simple gate drive for switch components for the use in parallel-connected half-bridges, taking into consideration a gate voltage limitation to achieve short-circuit resistance. The circuit consists of drive circuits and main power circuits. The present invention contributes to solving the problems of the influence of the main power circuit on the drive circuit. According to the invention, switching transistors connected in parallel to the driver through separate activation and deactivation resistors, the former of relatively low resistance and the latter of relatively high resistance. Each of the switching transistors has an emitter resistor connected in parallel with a respective clamping diode to a sum point at ground, the cathode to the emitter. Each of the activation resistors is connected in series to the driver through a respective diode whose cathode is connected to the activation resistor.

Abstract: An improved turbine engine ignition exciter circuit. Energy stored in an exciter tank capacitor is subsequently switched to the load (igniter plug) through a novel thyristor switching device specifically designed for pulse power applications. The switching device is designed and constructed to include, for example, a highly interdigitated cathode/gate structure. The semiconductor switching device is periodically activated by a trigger circuit which may be comprised of either electromagnetic or optoelectronic triggering circuitry to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. Likewise, the present invention allows new flexibility in the output PFN (Pulse Forming Network) stage, eliminating need for specialized protective output devices such as saturable output inductors. Due to considerably higher di/dt performance of the device, true high voltage output pulse networks may be utilized without damage to the semiconductor switching device.

Abstract: A circuit for discharging of a photovoltaic power source has a first and a second terminal and the circuit comprises a discharge circuit which is connected between the first and second terminal of the power source which comprises a controllable current source which is controlled by a band gap reference.

Abstract: An inductance in a path (R1) from a gate electrode (3G) of a GTO (3) through a gate driver (4) and a node (13) to a cathode electrode (3K) is determined so that a turn-off gain may be not more than 1. At a turn-off, a main current (I.sub.A) is entirely commutated from the gate electrode (3G) towards the node (13) through the gate driver (4) in a direction reverse to a turn-off control current (I.sub.G) A peak voltage suppressing circuit (5) clamps an anode-cathode voltage (V.sub.A-K) which rises on, to a prescribed voltage value for a prescribed time. This prevents losses caused by a snubber circuit. Commutation of a main current to the gate prevents locally concentrating in the cathode side of the semiconductor switching element, to thereby increase the turn off capability of the semiconductor switching element. Further, this prevents or reduces dissipation of large amount produced by a discharge of the electric charges from a snubber capacitor.

Abstract: An apparatus for use in the simultaneous deactivation of a set of series-connected switching devices includes gate command control logic to generate a gate command signal for application to a selected switching device of the set of series-connected switching devices. A command compensation circuit processes the gate command signal. The command compensation circuit includes a time differential measurement module that forms a time differential signal indicative of the time from the previous turn-off of the selected switching device and the previous turn-off of the last switching device in the set of series-connected switching devices. A time difference processing module of the command compensation circuit process the time differential signal and creates a delay signal. A delay module of the command compensation circuit delays the gate command signal in response to the delay signal. Each switching device of the set of series-connected switching devices includes a command compensation circuit.

Abstract: A thyristor, controllable by logic signals independent of its cathode voltage, includes a thyristor, a PNP transistor between the gate and the anode of the thyristor, and an NPN transistor between the base of the PNP transistor and a terminal connected to ground through a resistor, the base of the NPN transistor receiving the logic signals.

Abstract: A GTO gate driver circuit includes a GTO; a MOS gate driver; a turn-on rectifier for receiving power from a high voltage isolation transformer; a turn-on capacitor coupled in parallel with the turn-on rectifier; and a turn-on MOSFET having a drain coupled to a first side of the turn-on capacitor, a gate coupled to the MOS gate driver, and a source coupled to a gate of the GTO. In one embodiment the circuit includes a turn-off rectifier coupled to the turn-on rectifier; a turn-off capacitor coupled in parallel to the turn-off rectifier with a cathode of the GTO being coupled to a second side of the turn-on capacitor and a first side of the turn-off capacitor; and a turn-off MCT having a gate coupled to the MOS gate driver, an anode coupled to the source of the MOSFET and a cathode coupled to a second side of the turn-off capacitor.

Abstract: An improved turbine engine ignition exciter circuit. Energy stored in an exciter tank capacitor is subsequently switched to the load (igniter plug) through a novel thyristor switching device specifically designed for pulse power applications. The switching device is designed and constructed to include, for example, a highly interdigitated cathode/gate structure. The semiconductor switching device is periodically activated by a trigger circuit which may be comprised of either electromagnetic or optoelectronic triggering circuitry to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. Likewise, the present invention allows new flexibility in the output PFN (Pulse Forming Network) stage, eliminating need for specialized protective output devices such as saturable output inductors. Due to considerably higher di/dt performance of the device, true high voltage output pulse networks may be utilized without damage to the semiconductor switching device.

Abstract: A method is described in which load current present in a thyristor device may be detected by monitoring the characteristic voltage found on the gate of the thyristor. Load status information may be used in various ways such as, to turn off the output, to signal a load voltage, or to act as a lamp-fail reset on an aircraft passenger reading light.

Abstract: A gate drive circuit for a voltage-driven type power switching device, including a control device for generating a gate voltage for the voltage-driven type power switching device, and a correction device connected to the control device for receiving the gate voltage and for correcting an effect of a magnetic flux resulted from a main circuit current flowing in the voltage-driven type power switching device applied to the gate voltage to generate a corrected gate voltage. The corrected gate voltage is applied to a gate of the voltage-driven type power switching device.

Abstract: In a method and a circuit arrangement for driving semiconductor switches in a series circuit, in which a voltage limiting device is assigned to each semiconductor switch, the power losses of the voltage limiting devices are detected by a control equipment for equalizing the voltage distribution across the semiconductor switches. The control equipment generates modified control pulses for each semiconductor switch from a common control pulse on the basis of the detected power losses of the voltage limiting devices. By this means, the power loss of the voltage limiting devices is controlled to a minimum.

Abstract: An a.c. switch includes across first and second main terminals a first thyristor disposed in parallel with, but in an opposite direction of, a first diode and in series with a second thyristor disposed in parallel with but in an opposite direction of, a second diode. The first thyristor has a gate terminal connected to its gate area. The second thyristor and second diode are vertically realized in the same substrate, their conduction areas being closely interlaced, whereby a polarity inversion following a conduction period of the second diode causes the second thyristor to become conductive.

Abstract: An improved turbine engine ignition exciter circuit. Energy stored in an exciter tank capacitor is subsequently switched to the load (igniter plug) through a novel thyristor switching device specifically designed for pulse power applications. The switching device is designed and constructed to include, for example, a highly interdigitated cathode/gate structure. The semiconductor switching device is periodically activated by a trigger circuit which may be comprised of either electromagnetic or optoelectronic triggering circuitry to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. Likewise, the present invention allows new flexibility in the output PFN (Pulse Forming Network) stage, eliminating need for specialized protective output devices such as saturable output inductors. Due to considerably higher di/dt performance of the device, true high voltage output pulse networks may be utilized without damage to the semiconductor switching device.

Abstract: A photo SI thyristor driving circuit which has a good switching characteristic suitable to be used for a photo relay, and a protection circuit therefor for protecting a photo SI thyristor element from being broken down due to a thermal runaway. The photo SI thyristor driving circuit comprises a photo SI thyristor, a MOS transistor provided in a gate circuit of the photo SI thyristor to draw charges accumulated at the gate of the photo SI thyristor when the photo SI thyristor is turned off, and a plurality of photo electromotive force elements provided in a gate circuit of the MOS transistor to generate a photo current for biasing the MOS transistor. The protection circuit includes a snubber circuit connected between the anode and the cathode of the photo SI thyristor and a light emitting element for irradiating light to the photo electromotive elements in response to an output from the snubber circuit.

Abstract: An inductance in a path (R1) from a gate electrode (3G) of a GTO (3) through a gate driver (4) and a node (13) to a cathode electrode (3K) is determined so that a turn-off gain may be not more than 1. At a turn-off, a main current (IA) is entirely commutated from the gate electrode (3G) towards the node (13) through the gate driver (4) in a direction reverse to a turn-off control current (IG) A peak voltage suppressing circuit (5) clamps an anode-cathode voltage (VA-K) which rises on, to a prescribed voltage value for a prescribed time. This prevents losses caused by a snubber circuit. Commutation of a main current to the gate prevents locally concentrating in the cathode side of the semiconductor switching element, to thereby increase the turn off capability of the semiconductor switching element. Further, this prevents or reduces dissipation of large amount produced by a discharge of the electric charges from a snubber capacitor.