Abstract: A secondary magnetic excitation generator-motor device that inputs a first ignition pulse command to a three-level NPC power converter such that a detected excitation current value corresponds with an excitation current command value, the secondary magnetic excitation generator-motor device having a function of identifying a first phase, a second phase, or a third phase in descending order of a current absolute value, wherein a pulse switch to output an ignition pulse command to the three-level NPC power converter switches the ignition pulse command to the second ignition pulse command when a current absolute value exceeds a set overcurrent level 1, and switches the ignition pulse command to the first ignition pulse command when current absolute values for three phases are all equal to or smaller than a set overcurrent level 2.

Abstract: A power harvesting system including multiple parallel-connected photovoltaic strings, each photovoltaic string includes a series-connection of photovoltaic panels. Multiple voltage-compensation circuits may be connected in series respectively with the photovoltaic strings. The voltage-compensation circuits may be configured to provide respective compensation voltages to the photovoltaic strings to maximize power harvested from the photovoltaic strings. The voltage-compensation circuits may be include respective inputs which may be connected to a source of power and respective outputs which may be connected in series with the photovoltaic strings.

Abstract: A capacitive element has its terminals coupled together by two thyristors electrically in antiparallel. The discharge of the capacitive element is controlled by the application of a gate current to one thyristor of the two thyristors which is in a reverse-biased state in response to a voltage stored across the terminals of the capacitive element. The reverse-biased thyristor responds to the applied gate current by passing a leakage current to discharge the stored voltage.

Abstract: The present invention relates to a power supply circuit (400) for a breaking circuit (100), the power supply circuit (400) comprising a first connecting point (CP1) arranged to be connected to an input (102) of the breaking circuit (100) and a second connecting point (CP2) arranged to be connected to an output (104) of the breaking circuit (100).

Abstract: Embodiments herein relate to a three-phase paralleled passive front-end drive, that includes a rectifier bridge, a coupling reactance operably connected to the rectifier bridge and configured to transfer power from the rectifier to a first direct current (DC) bus, and a bus coupler operably coupling the first DC bus to a second DC bus. The paralleled drive also includes a first inverter operably connected to the first DC bus; a second inverter operably connected the second DC bus, the first inverter and second the inverter each configured to provide a plurality of motor excitation signals, respectively. The paralleled drive also includes a plurality of interphase inductors operable to combine the plurality of motor excitation signals from the first inverter with the plurality of motor excitation signals from the second inverter.

Abstract: A respiratory apparatus includes components to protect operations of the apparatus. For example, in some versions, the apparatus may include a power supply, a motor powered by the power supply, and a transient absorption diode circuit between the motor and the power supply. The transient absorption diode circuit may be configured to absorb energy generated by the motor from rotational kinetic energy. Such absorption may serve to protect the components of the apparatus. In some examples, the apparatus may include a fault mitigation integrated circuit (IC). The IC circuit may be included in the respiratory apparatus to detect one or more faults based on physical and system parameters of the apparatus. The fault mitigation integrated circuit may generate a signal to stop the motor based on the detected fault, and may digitally communicate with a processor information about the detected fault.

Abstract: The invention relates to an inverter circuit for the alternating connection of the phases of a three-phase load to a DC source, having pairs of electronic switches connected in parallel with one The two switches of each pair are connected in series, and wherein the connection for the respective phase of the load is provided at the connection of the two electronic switches belonging to the pair. An intermediate circuit capacitor is connected in parallel to the DC source. Electric connections are provided between the intermediate circuit capacitor and the power module for the connection of the switch pairs. The circuit arrangement has a buffer capacitor connected to a connection of the switch pairs. A first diode connects the buffer capacitor to the other connection of the switch pairs. A step-down controller connects the buffer capacitor to the intermediate circuit capacitor.

Abstract: A power supply monitoring device, comprising a monitoring circuit that includes a first charge comparing unit configured to generate a first comparison result based on a first pulsating signal, a second charge comparing unit configured to generate second comparison result based on a second pulsating signal, and a power interruption detection unit configured to output a detection signal based on whether the first and second comparison results indicate a supply of power has been interrupted.

Abstract: According to one aspect, embodiments of the invention provide a power supply system comprising an input configured to receive input AC power from an input power source, an output configured to provide output AC power to a load, a converter coupled to the input and configured to convert the input AC power into converted DC power, a first DC bus coupled to the converter and configured to receive the converted DC power, an inverter coupled to the first DC bus and the output and configured to convert DC power from the first DC bus into the output AC power, a first DC switch circuit coupled between the first DC bus and neutral and a controller coupled to the first DC switch circuit and configured to operate the first DC switch circuit such that voltage on the first DC bus is zero during switching operation of the converter and the inverter.

Abstract: A power unbalance mitigating polarity correction circuit is presented comprising a first and a second polarity correction circuit, each comprising: an input for receiving an input current, an output for providing a rectified output current, at least a first current path, for conducting the received current when the received current is of a first polarity, and a second current path, for conducting the received current when the received current is of a second polarity, wherein the first current path comprises a passive rectification component as an asymmetric conductance component of a first type and the second current path comprises an active rectification component as an asymmetric conductance component of a second type different from the first type; the power unbalance mitigating polarity correction circuit further comprising a controller, wherein the controller is arranged for controlling the active rectification component to operate in a power unbalance mitigation mode when the current received by the firs

Abstract: Multilevel power converters, power cells and methods are presented for selectively bypassing a power stage of a multilevel inverter circuit, in which a single relay or contactor includes first and second normally closed output control contacts coupled between a given power cell switching circuit and the given power cell output, along with a normally open bypass contact coupled across the power stage output, with a local or central controller energizing the coil of the relay or contactor of a given cell to bypass that cell.

Abstract: A regulator rectifier device and a method for regulating an output voltage of the same which takes input from three phase alternating current voltage generating device with each phase including a positive cycle and a negative cycle. A first rectifying unit with a first gate terminal, connected to the generating device to rectify the positive cycle of said three phase alternating current voltage. A second rectifying unit with a second gate terminal, connected to said generating device to rectify the negative cycle of said three phase alternating current voltage, wherein said second rectifying unit switches between rectification mode and shunt mode depending on the load condition.

Abstract: A power supply apparatus includes a main power processing circuit and an alternating current power detection circuit. The alternating current power detection circuit is electrically connected to the main power processing circuit. The alternating current power detection circuit includes a rectifying unit and a frequency processing unit. The rectifying unit is electrically connected to the main power processing circuit. The frequency processing unit is electrically connected to the main power processing circuit and the rectifying unit. The rectifying unit rectifies an alternating current power to obtain a rectified power. When a frequency of the rectified power is greater than a predetermined frequency, the frequency processing unit informs the main power processing circuit, so that the main power processing circuit processes the alternating current power to obtain an output direct current power.

Abstract: A switch failure detector, configured to be installed in an electric system including an electric storage device, includes at least one electronic switch connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, at least one rectifier for passing a discharging current by bypassing the electronic switch when the electronic switch is turned off, and a controller for sending an on-command signal to the at least one electronic switch to turn on the electronic switch, and determining whether a switch failure detection process is executable based on a voltage of the electric storage device.

Abstract: A switch failure detector configured to be installed in an electric system including an electric storage device, the switch failure detector includes at least one electronic switch connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, at least one rectifier for passing a discharging current by bypassing the electronic switch when the electronic switch is turned off, a switch voltage detection circuit configured to detect a voltage drop caused by the at least one electronic switch, and a controller for sending an on-command signal to the at least one electronic switch to turn on the electronic switch, and receiving the voltage detected by the switch voltage detection circuit while the on-command signal is sent to the electronic switch.

Abstract: A switch failure detection device configured to be installed in an electric system including an electric storage device, the switch failure detection device including at least one electronic switch to be connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, the at least one electronic switch including a first electronic switch, at least one rectifier for passing a discharging current by bypassing the electronic switch when the electronic switch is turned off, the at least one rectifier including a first rectifier being connected parallel to or being parasitic to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, a switch voltage detection circuit configured to detect a voltage drop caused by the at least one electronic switch, and a controller.

Abstract: Power conversion apparatus for controllably converting alternating current (AC) to direct current (DC). An example apparatus includes multiple AC sources, galvanically isolated from one another, and multiple bridge rectifier circuits, including one or more controllable bridge rectifier circuits, where each bridge rectifier circuit has respective AC-side terminals and DC-side terminals and each bridge rectifier circuit is connected to a corresponding one of the AC sources via its AC-side terminals. The DC-side terminals are connected so that the outputs of the bridge rectifier circuits are combined in series.

Abstract: An apparatus/method is provided. The power conversion apparatus includes: a rectifying unit including a silicon-controlled rectifier thyristor (SCR) for rectifying single-phase power externally inputted; a power factor correcting unit configured to correct a power factor of the power rectified by the rectifying unit; and a control signal generating unit configured to detect a zero-crossing point based on the single-phase power inputted and generate a pulse single of which a width increases as time elapses based on the detected zero-crossing point. The rectifying unit rectifies the single-phase power by using the pulse signal inputted to a gate terminal of the SCR.

Abstract: A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

Abstract: A converter includes a converter bridge (101) adapted to transfer electrical energy between the AC terminal (102) and the DC terminal (103) of the converter. The converter also includes electrical paths bypassing the converter bridge for conducting overvoltage transients occurring in the AC terminal around the converter bridge to the DC terminal. Each electrical path includes a unidirectionally conductive semiconductor component (104a, 104b, 104c), such as a diode, and a voltage-limiting component (105) for which the ratio of voltage change to current change is small when the voltage of the voltage-limiting component is greater than a predetermined threshold voltage. Because of the overvoltage protection thus achieved, AC chokes can be omitted from the AC terminal or at least they can be designed smaller, reducing the load-dependent voltage drop of the DC terminal.

Abstract: A method and apparatus for controlling the feed rate of a rectified AC pulses via a gated rectifier in a low DC voltage and current power supply is disclosed. The gated rectifier outputs gated AC pulses to an input capacitor via a current control diode and/or a zener diode and/or a resistor for charging the input capacitor to a voltage level and a charge capacity commensurate with the low voltage regulator and the low DC current drain. A gate capacitor for accumulating incremental charges of rectified AC pulses fed via a divider network is pre-configured to trigger the gated rectifier, timed by discharging the aggregated charge of a predetermined number of charges to the gate. The input capacitor charged by the gated AC pulses at a rate of one per said determined number to the input capacitor feeds the voltage regulator for powering a low DC current consuming device.

Abstract: A rectifier building block has four electrodes: source, drain, gate and probe. The main current flows between the source and drain electrodes. The gate voltage controls the conductivity of a narrow channel under a MOS gate and can switch the RBB between OFF and ON states. Used in pairs, the RBB can be configured as a three terminal half-bridge rectifier which exhibits better than ideal diode performance, similar to synchronous rectifiers but without the need for control circuits. N-type and P-type pairs can be configured as a full bridge rectifier. Other combinations are possible to create a variety of devices.

Abstract: An alternating current-to-direct current (AC-DC) converter is provided. The converter may include a transformer having a primary side and a secondary side. A first bi-directional switch and a first inductor may be connected in series between a positive terminal of an AC source and a first terminal of the primary side of the transformer. A second bi-directional switch and a second inductor may be connected between the positive terminal of the AC source and a second terminal of the primary side of the transformer and connected in parallel with the first bi-directional switch.

Abstract: An apparatus/method is provided. The power conversion apparatus includes: a rectifying unit including a silicon-controlled rectifier thyristor (SCR) for rectifying single-phase power externally inputted; a power factor correcting unit configured to correct a power factor of the power rectified by the rectifying unit; and a control signal generating unit configured to detect a zero-crossing point based on the single-phase power inputted and generate a pulse single of which a width increases as time elapses based on the detected zero-crossing point. The rectifying unit rectifies the single-phase power by using the pulse signal inputted to a gate terminal of the SCR.

Abstract: An impedance dropping dc power supply having an impedance controlled converter whose impedance adaptively changes as a function of the power supply's load impedance, to maintain the ac voltage across the primary winding of its power transformer below a predetermined maximum level, and to minimize the waste heat generated by the power supply that would otherwise have to be dissipated.

Abstract: A switched-mode power supply unit includes a mains input connecting the power supply to a primary supply voltage; an input circuit including a shared electrical path connected to the mains input and including a first mains filter, a first electrical path, connected in series with the shared electrical path, including a second mains filter, a second electrical path connected in series with the shared electrical path and connected in parallel with the first electrical path, and a first switching element that opens the first electrical path; a supply output that provides a filtered primary supply voltage; a switched-mode converter coupled to the supply output that converts the filtered primary supply voltage to a secondary supply voltage; and a control circuit that selectively switches the power supply unit to a first mode of operation with a high power output or a second mode of operation with a reduced power output.

Abstract: A method and apparatus for controlling the feed rate of a rectified AC pulses via a gated rectifier in a low DC voltage and current power supply. The gated rectifier outputs gated AC pulses to an input capacitor via a current control diode and/or a zener diode and/or a resistor for charging the input capacitor to a voltage level and a charge capacity commensurate with the low voltage regulator and the low DC current drain. A gate capacitor for accumulating incremental charges of rectified AC pulses fed via a divider network is pre-configured to trigger the gated rectifier, timed by discharging the aggregated charge of a predetermined number of charges to the gate. The input capacitor charged by the gated AC pulses at a rate of one per said predetermined number to the input capacitor feeds the voltage regulator for powering a low DC current consuming device.

Abstract: The present invention relates to a circuit minimizing standby power in a power adapter with a power-frequency transformer (T1), which includes a sensing circuitry (1), a driving circuitry (2), a switching circuitry (3) and a resistive element (Z). When the sensing circuitry (1) senses a power supply signal of the power-frequency transformer (T1) in work mode, the switching circuitry (3) shorts the resistive element (Z); and when the power-frequency transformer (T1) is in standby mode, the electronic switch (3) is switched off and the resistive element (Z) is coupled to the power-frequency transformer (T1). The circuit attached to the power adapter reduces the standby power consumption very much, and achieves energy-saving effect with low cost.

Abstract: Systems and/or methods that facilitate controlling a rate of voltage change across an inductively loaded thyristor when switched are presented. Based on a received control signal indicating a thyristor is to be switched, a control component controls the rate of voltage change across a thyristor associated with an inductive load when the thyristor is switched from a first state to another state to facilitate controlling noise emissions during switching based in part on a predefined noise criteria, without using a filter. A capacitor component is connected to the inductive load and thyristor. The control component employs a voltage-controlled current sink comprising a transistor to facilitate discharging voltage from the capacitor component until the capacitor component is discharged to a predefined voltage level, where at or near such point a gate component can send a signal to the thyristor gate to switch the thyristor to the desired state.

Abstract: A method and a circuit for controlling a thyristor (V1) into conducting state, the thyristor (V1) being in a rectifier, which rectifier supplies DC voltage to a DC voltage circuit. The circuit comprising a trigger capacitor (C2) adapted to be charged from the voltage difference across the thyristor (V1) when the anode-to-cathode voltage of the thyristor is positive, a zener diode (V5) adapted to be triggered with the voltage of the trigger capacitor (C2), when the voltage of the trigger capacitor (C2) exceeds the breakdown voltage of the zener diode (V5), and an auxiliary thyristor (V3) adapted to be triggered with the current from the trigger capacitor (C2) flowing via the zener diode (V5), wherein the cathode of the auxiliary thyristor (V3) is connected to the gate of the thyristor (V1) for triggering the thyristor (V1) with the current from the trigger capacitor (C2) flowing via the auxiliary thyristor (V3) for using the thyristor (V1) in a diode mode.

Abstract: Methods and systems provide pulsed-power to a load utilizing high temperature superconductors (HTS) within multiple pulsed-power devices. According to embodiments described herein, each pulsed-power device includes a HTS mounted on a rotor and an armature coil mounted on a stator. The rotor is positioned to allow a magnetic field within the HTS to induce a voltage in the armature coil when the rotor is rotating and to allow a magnetic field created by passing current through the armature coil to charge the HTS. Current created from the operation of a first pulsed-power device is routed to the armature coil in a second pulsed-power device to charge the associated HTS to a higher value. Subsequently, the second pulsed-power device is operated to produce current that is used to further charge the HTS in the first pulsed-power device. This bootstrapping procedure is repeated until all HTSs are fully charged.

Abstract: A power converter that converts an AC power outputted from a generator into a DC power and supplies it to a battery (load). The power converter includes a thyristor (switch unit) connected between an output unit of the generator and the battery (load); and a gate control unit (control unit) for generating a triangle wave voltage having a constant peak voltage corresponding to each cycle of the AC power outputted from the generator, generating a differential voltage between the voltage supplied to the load via the switch unit and a predetermined target voltage, and controlling the conductive state of the switch unit based on the triangle wave voltage and the differential voltage.

Abstract: An improved DC bus regulator that utilizes more transistor packs for power conversion at some times and diode, SCR, and resistor packs at other times. The conversion technology is selected by the regulator based on the current load capacity and response required. For example, transistor packs may be used in low power load conditions. Through use of this hybrid system, the system obtains the desirable effects of transistor pack systems including fast response time, ability to regulate current, and bi-directional power conversion while mitigating the high costs and fragile nature of a system based solely on transistor packs.

Abstract: An apparatus for generating electronic signals for application in subsea electromagnetic exploration. A surface generated high-voltage low-current source signal stabilized at a first frequency is supplied to a deep-tow vehicle (18) via an umbilical cable (16). The high-voltage low-current signal is transformed at the deep-tow vehicle to a high-current low-voltage a.c. signal by a transformer (52) within a cycloconverter (30). A semiconductor relay bridge (104) provides switchable rectification of the high-current low-voltage a.c. signal to provide a quasi-square wave at a second frequency, lower than the first frequency, for supply to a transmitting antenna (22) towed by the deep-tow vehicle. The times of the rectification switching are dependent on zero crossings of the high-current low-voltage a.c. signal. Allowable rectification switching times may be gated to occur only within pre-determined time windows to avoid noise-induced zero-crossing switching.

Abstract: An AC-DC converter includes a DC reference voltage generation unit that creates a DC reference voltage waveform based in part on a feedback signal. The AC-DC converter also includes an SCR firing unit that receives a variable frequency power output from the generator and that provides firing signals. The AC-DC converter further includes SCRs arranged as a positive bank of SCRs and a negative bank of SCRs. The AC-DC converter further includes a modulator unit that receives the firing signals and the DC reference voltage waveform, and that respectively outputs SCR gate signals to the SCRs. The AC-DC converter also includes a filter unit provided between the positive and negative banks of SCRs. The AC-DC converter also includes a voltage feedback path for feeding back the DC output voltage as the feedback voltage waveform.

Abstract: The novel circuit arrangement is used for the static generation of a variable electric output, as is common in static reactive-power compensation systems. According to the invention, a voltage is applied to a consumer, i.e. to a capacitor and/or an inductor, and a transformer (T) has at least two power-control windings (W1, W2) in a secondary circuit, said windings being connected electrically in series via bridge circuits (B1, B2). In their branches, the bridge circuits contain static switches (BSS1 . . . 4) in an inverse-parallel connection, said switches can be selectively connected or disconnected.

Abstract: The invention relates to a high-voltage transformer consisting of conventional elements disposed in two different groups, namely positive voltage elements (1-5) and negative voltage elements (1′-5′), both types of elements being separated by a single insulating barrier (6). One of the ends of all elements has a ground level or “zero voltage” increasing progressively towards the other end in the positive voltage elements and decreasing progressively in the negative voltage elements in such a way that the elements in each group have equipotential voltages at the same level or distance from the ground level. Said structure eliminates parasitic capacitances and makes it possible to mount the elements very close to each other thereby considerably reducing size and consequently costs.

Abstract: An ac-dc converter using bi-directional thyristor valves made up of back-to-back connected thyristors as converter valves. The bi-directional thyristor valves permit operation of the converter as a rectifier or an inverter with both polarities of the voltage across the dc terminals of the converter. The bi-directional valves can be used to prevent the reversal of the polarity of the dc voltage across the dc terminals of the converter or to minimize the magnitude of the reverse voltage. The bi-directional thyristor valves can be used to provide protection against overvoltage across the converter valves and eliminate or reduce the energy rating of converter valve arresters.

Abstract: A method for controlling fault interruption in a high voltage electrical energy transmission system semiconductor high voltage electrical energy transmission switching system which includes a multiple stack of power semiconductor SCR thyristor circuit sections arranged for single phase or three-phase operation with each section of the stack comprising; a pair of input and output terminals, a plurality of switching thyristors connected in series between the input and output terminals, an auxiliary power transformer having at least three windings with first and second windings interconnecting the input and output terminals of one section to the respective output and input terminals in each adjacent section of the stack such that the voltage difference between the first and second transformer windings is limited to the maximum voltage across the section.

Abstract: A regulator system includes a circuit regulating the output of a power supply such as a capacitive input filter power supply and preferably also a transformer and full-wave diode bridge.

Abstract: A method and system for determining zero current level occurrences in a reversible power converter without requiring additional component complexity and costs. A digital controller selectively determines the line to line voltage for the most recently fired thyristor pair. The selected line to line voltage is identified as the bridge reconstruction voltage and is compared against the actual bridge output voltage for the conducting bridge. The difference between the two voltage signals is identified as the bridge error voltage and the sign of its magnitude is indicative of a load current zero level occurrence. A zero current level occurrence happens whenever the bridge error voltage drops below zero. This indication is positive and substantially instantaneous and safely enables the reversal of power flow without the risk of line faults due to cross-bridge short circuits.

Abstract: The invention relates to an apparatus for initial charging of the output capacitors of a three-phase three-point pulsed rectifier system. According to the invention, a thyristor is arranged in each phase between the input terminal and is connected in the current flow direction to the anode of the freewheeling diode, and an initial charging path is connected in parallel with this thyristor. The circuit for actuating the thyristor is activated after completion of the initial charging; the reference voltage is applied to the negative input of the comparator.

Abstract: An apparatus and method for generating slow rise-time, high voltage electrical pulses to a load, preferably using an existing transformer/rectifier set or power supply to charge an inversion or high voltage switching circuit to produce the pulsed voltage. An energy recovery circuit (100, 102) is used to return unused energy from the load (24) back to the means for producing pulsed voltage (110, 130). A load matching circuit (120) uses a blocking diode and a capacitor for charging the load. An additional blocking diode (32) inhibits load voltage discharge back through the slow pulse generating circuit. A transformer (20) can be used to step-up voltage from the inversion circuit, or high voltage switching circuit, to the load. One or more magnetic switch stages are used to transfer energy from the inversion circuit, or high voltage switching circuit, to the load matching circuit. A fire-on voltage controller (66) triggers the inversion or high voltage switching circuit.

Abstract: A phase-shift thyristor trigger circuit, including a synchronous signal sampling circuit, a waveform shaping, integrating and comparator circuit, a high-frequency modulating pulse distributor circuit, a power amplification and high frequency pulse rectifier output circuit, characterized in that said synchronous signal sampling circuit includes a transformer, wherein its secondary inductance and a capacitor form a LC resonance circuit for selecting (via transformer coupling) synchronous signal from the main circuit. The trigger circuit connecting with a thyristor main circuit can make up a unified thyristor integrated module. The module is small in size, strong in antiinterference ability, has no requirements for phase sequence and number, and has a broad voltage adaptive range.

Abstract: Switching losses are distributed equally between multiple switching devices in a rectifier bridge (50) in which the rectifier bridge comprises at least a first pair of serially connected switching devices (56A, 56B) connected between positive and negative DC output buses (52, 54) and a second pair of serially connected switching devices (58A, 58B) connected in parallel with the first pair of switching devices. Only one of the switching devices in each pair of switching devices is pulse width modulated at any time at a frequency substantially higher than a frequency of the AC power applied to the rectifier bridge while another of the switching devices in each pair of switching devices is operated in synchronism with the waveform of the AC power applied to the bridge. Operation further involves periodically alternating the PWM operation of the switching devices between switching devices in each pair of switching devices so as to distribute the losses.

Abstract: A power supply includes a diode bridge rectifier. The diode bridge rectifier output provides direct current to a primary capacitor. A current-limiting resistor is connected in series with the rectifier output and the primary capacitor. The current-limiting resistor acts to limit inrush current to the primary capacitor when the power supply is turned on. A triac is coupled in parallel with the current-limiting resistor. When charged, the primary capacitor provides a primary signal and primary current to a switched load, which includes a first winding of a transformer and a load switching device. The transformer also has a second winding connected in series with the triac's gate terminal. When the primary signal reaches a satisfactory level, the load switching device switches the load, causing current transients in the first winding. The first winding current transients, in turn, induce current in the second winding and in the triac gate terminal.

Abstract: The present invention relates to a device for controlling a composite bridge including two anode-gate thyristors, the cathodes of which are connected together to a positive output terminal, the gates of the two thyristors being interconnected. The device includes a single-throw switch, controllable to be turned off and on, connected on the one hand to the two thyristors and on the other hand to a reference potential, and control means to turn on the switch only in a predetermined voltage range around the zero voltage of an a.c. voltage of the composite bridge.

Abstract: A plant for transmitting electric power between a direct voltage network and an alternating voltage network through a power station. A converter of a station has two current valves connected in series, each having one turn-on and turn-off type breaker and a diode connected anti-parallel therewith. Circuits are provided to detect the direction and the intensity of the current through the converter, as well as the current valve through which it flows to actuate the control apparatus on the basis of the detected current level and the identity of the valve carrying the current. The control apparatus operates to commutate current through the valve which is not carrying current when a detected current level in the current carrying valve exceeds a first predetermined level.

Abstract: A power supply for a CW magnetron, devoted for use in microwave heating equipment. A power supply according to the present invention (FIG. 1) has a high-voltage line transformer (1) with secondary winding (2) which is connected through a voltage doubling rectifier circuit to the magnetron cathode (4). The voltage-doubling rectifier circuit comprises a high-voltage diode (7) and a capacitor (3). The distinctive feature of the present invention is that the diode (7) of voltage doubler is connected in-series with the at least one thyristor-capacitor network (8) which is composed of a high-voltage thyristor which has its anode and cathode connected together with an additional capacitor (Cd) or with series connection of said capacitor with a resistor (Rs).

Abstract: A three-level NPC converter includes at least one phase leg including four series coupled electrical switches having a first pair junction between the first two switches and a second pair junction between the second two switches. First and second inner switch snubber capacitors are coupled in series at a neutral junction. First and second inner switch snubber diodes are respectively coupled to the first and second pair junctions and respectively coupled at first and second inner diode-capacitor junctions to the first and second inner switch snubber capacitors. First and second inner switch snubber resistors are respectively coupled between the first and second inner diode-capacitor junctions and respective portions of a DC bus. In one embodiment, the NPC converter further includes first and second outer switch snubber diodes coupled between respective first and second inner diode-capacitor junctions and respective portions of the DC bus.