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Match Document Document Title
8085519 Circuit arrangement for providing a DC operating voltage  
The invention relates to a circuit arrangement for providing an operating DC voltage from a mains voltage, more particularly to operating circuits comprising a clocked electronic converter. Such...
7508643 System for overvoltage suppression for construction equipment  
An overvoltage suppression system is disclosed, such as for construction equipment, for protecting the construction equipment from overvoltages that may occur in day to day operations. An...
7388765 Method and arrangement in connection with a half-controlled network bridge  
A method and an arrangement for controlling phase-specific thyristors of a half-controlled network bridge, the method comprising identifying a thyristor to be controlled on the basis of the...
7164562 Configuration and method for protecting converter means  
A protection configuration for converter means which comprise a plurality of controllable switches, the protection configuration comprising a protection circuit coupled to the alternating voltage...
7009828 Semiconductor switching device  
Self-quenching switching elements are connected in series in a semiconductor switching device. Snubber circuits including a diode, a capacitor, and a non-linear circuit are connected in parallel...
6952335 Solid-state DC circuit breaker  
A high-speed, solid-state circuit breaker is capable of interrupting high DC currents without generating an arc, and it is maintenance-free. Both the switch and the tripping unit are solid-state,...
6947270 Building block for series connection in high power converter  
A converter includes building blocks, each building block being a switching unit. Each building block must be able to receive high power at an elevated switching frequency with low power...
6870202 Surge protection semiconductor device  
A pnpn thyristor element Thy1 and six pn diode elements D1, D2, D3, D4, D5, and D6 are formed in a semiconductor substrate of a first conductivity type, and separated into six regions by a...
6594130 Method and circuit for the protection of a thyristor  
Circuits and methods for protecting thyristors in a bridge configuration are provided. A circuit comprises a line reactor in series with the input of the bridge and the input of the diametric cell,...
6567253 Apparatus to sense a silicon controlled rectifier short circuit  
An apparatus to sense an SCR short circuit failure and prevent overheating of solid-state power supply equipment, such as a welder, during an occurrence of the short circuit failure is provided....
6342994 Protective device against excessive currents, in particular for resettable protection of a controlled switch  
A protective device against excessive currents occurring in an electric circuit between a voltage source and a load mounted downstream of said device, comprising a first triggering component with...
6275093 IGBT gate drive circuit with short circuit protection  
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...
6204493 Fault tolerant electric current regulator  
The present invention is a fault tolerant apparatus for regulating the flow of electricity. The apparatus comprises a light radiating circuit which includes a first light source for radiating a...
6169672 Power converter with clamping circuit  
A power converting apparatus comprising a group of semiconductor switches and DC terminals electrically connected to the group of semiconductor switches, in which a clamping circuit is connected to...
5946178 Protective circuit for series-connected power semiconductors  
A semiconductor assembly with overvoltage protection is provided. The semiconductor assembly comprises at least two series connected power semiconductors, each of which is protected by at least one...
5815359 Semiconductor device providing overvoltage protection against electrical surges of positive and negative polarities, such as caused by lightning  
An overvoltage protection device, particularly for protecting equipment against electrical surges caused by lightning, wherein the protective device includes a first protection element for...
5781392 Balanced overvoltage protector for a dual-wire system  
A balanced overvoltage protector for a dual-wire system comprising a single semiconductor substrate including two breakover thyristors located in sufficiently close proximity so that current in one...
5621599 Switched MOV device  
A metal oxide varistor in series with a semiconductor switch forms a protection circuit that reduces the steady-state voltage across the metal oxide varistor during normal operation, During an...
5570260 Overvoltage protection circuit  
An overvoltage protection circuit including a plurality of series connected thyristors having an overvoltage protection function and a plurality of impedance circuits. Each of the impedance...
5532638 Superconducting energy storage apparatus  
In a superconducting energy storage apparatus including an AC-DC converter unit, a superconducting coil, a quench protection unit and a mechanical type persistent current switch, a self-firing type...
5436786 Isolator surge protector for DC isolation and AC grounding of cathodically protected systems  
An isolator surge protector for use with corrosion protection systems which are an inherent part of or coupled to an electrical power system, for power transformers, and for DC transmission...
5212619 Method and system for protecting a gate controlled thyristor against unacceptable overvoltage  
Protecting a gate fully controlled thyristor that is controlled by a drive circuit including a turn-on circuit and a turn-off circuit against overvoltage, is accomplished by monitoring the anode...
5155673 Thyristor converter protection method and apparatus  
A method and apparatus for protecting thyristors in a power converter from overvoltages. Voltage detectors determine if the forward voltage of each thyristor has increased in the converter. If such...
4947282 Thyristor valve with improved gate pulse generating scheme  
A thyristor valve circuit protected having an arrester to protect it from an overvoltage. The circuit includes a voltage detector for detecting a forward voltage level applied to the thyristor...
4885657 Thyristor with turn-off facility and overvoltage protection  
In a thyristor with turn-off facility (AT) and overvoltage protection, the voltage limitation is achieved by a parallel-connected controllable resistor, in particular in the form of a J-FET (JF)...
4876620 Protection devices and arrangements for telephone lines  
A two-wire telephone subscriber line protection arrangement consists of two protection devices each comprising a pair of complementary thyristors connected in reverse parallel with one another...
4796146 Protection circuit for a thyristor converter  
A protection circuit is provided which digitally detects the presence/absence of individual forward voltages across all thyristors at a level low enough compared to the allowable voltage, judges a...
4757417 Monitoring system for load-driving switch circuits  
Disclosed is a monitoring system for a load-driving switch circuit, in which a switch circuit arranged in a circuit for driving an electrical load is controlled and opened or closed by a fail-safe...
4745513 Protection of GTO converters by emitter switching  
A fault current protection arrangement for a power converter circuit utilizes gate turn-off thyristors as electronic switching devices. A gate turn-off thyristor is connected between relatively...
4710699 Electronic switching device  
An electronic switching device having a detection circuit or input circuit powered by an external source and load is described. The external source and load are in a series circuit with a power...
4694315 CMOS overvoltage protection circuit utilizing thyristor and majority carrier injecting anti-parallel diode  
A semiconductor device comprises a semiconductor circuit of CMOS type and an overvoltage protective circuit integrated therewith. The CMOS circuit and the overvoltage protective circuit are formed...
4665458 Acceleration power supply  
An acceleration power supply includes a series-connected semiconductor switches with voltage dividing elements and another semiconductor switch coupled in series to the series-connected...
4651251 Protective circuitry for a thyristor  
A protection circuit for use with a thyristor having several break over diode, BOD, elements is connected between the anode and the gate of a thyristor providing static and dynamic overvoltage...
4638138 High frequency inverter circuit for melting and induction heating  
A two-pole inverter bridge has an inductor mounted between the two controlled switches in each pole and a resonant load is connected across the poles between ends of the inductors which are...
4613932 Method and circuit for reduction of stress in thyristors operating in the individual emergency firing mode  
The invention is a method and a circuit for the emergency firing of individual thyristors in a thyristor valve that have a protection circuit for providing an emergency gate control signal for...
4571535 VAR Generator having controlled discharge of thyristor switched capacitors  
A device is taught for controlling the residual charge on a thyristor switched capacitor. A capacitor is in series circuit relationship with at least two bidirectional back-to-back thyristor...
4555754 Equalizer circuit for switches connected in series  
An equalizer circuit for switches connected in series between a voltage source (21) and a load (16), each switch (4, 11) being connected in parallel with a respective equalizing capacitor (2, 9)...
4546401 Two-pole overcurrent protection device  
A two-pole overcurrent protection device arranged to interrupt the current flowing in a conductor if the current exceeds a predetermined level employs a semiconductor wafer on which is formed a...
4536816 Thyristor apparatus employing light-triggered thyristors  
A thyristor apparatus employing light-triggered thyristors comprises forward voltage detecting circuits (15) and a thyristor number detecting circuit (17). The forward voltage detecting circuits...
4503477 Method and arrangement for protecting a thyristor switch of a pulse generator  
A method and apparatus for protecting switching elements, and, in particular, thyristor switching elements, which are used in a pulse generator to supply pulsed electrical voltage to a capacitive...
4475139 Thyristor-switched capacitor apparatus  
A protective circuit for a plurality of series connected thyristors where each thyristor has in parallel with it a resistance, capacitance type snubber circuit and a metal oxide varistor. The...
4473858 Firing circuit for power thyristors  
A firing circuit for two antiparallel-connected power thyristors. Each of the power thyristors has a gate terminal; the gate terminals being connected by a series combination of auxiliary...
4437133 Current source inverter commutation-spike-voltage protection circuit including over-current and over-voltage protection  
An adjustable-frequency three phase motor control system (2, CSI, M) is provided with a spike voltage clamp (SVC) to control the magnitude of voltage spikes generated during commutation of the...
4414599 Arrester and a semiconductor circuit arrangement with a protection device including the same  
An arrester is provided including series connected first and second nonlinear resistance elements and a by-pass circuit. The by-pass circuit is connected in parallel with the second nonlinear...
4400755 Overvoltage protection circuit  
An overvoltage protection circuit for a circuit array including one or more semiconductor devices such as thyristors derives its energization solely from the voltage across the array. A...
4377835 Recovery protection device for a thyristor valve  
In a thyristor valve having a plurality of series-connected thyristors, each thyristor has an individual recovery protection device arranged in its entirety at the potential of the thyristor. For...
4371909 High voltage converter apparatus having overvoltage protection circuits for thyristors  
A high voltage converter apparatus having overvoltage protection circuits for thyristors is disclosed in which, in order to protect series-connected thyristors in the converter against overvoltage,...
4367418 Combining thyristor circuits of various circuit configurations  
Thyristors included in circuit configurations are, in turn, connected in series circuit fashion such that n circuit configurations are so interconnected, where n is a real integer equal to or...
4301801 Electrosurge failsafe system  
An electrosurge generator, which is energized by a power supply to produce n output voltage of a desired level, includes a failsafe system at its output to prevent any excessive high DC voltage...
4297739 Device for exciting synchronous machine  
A device for exciting a synchronous machine, comprises an exciter electrically connected to an exciting winding of the synchronous machine, a starting unit connected in parallel with the exciter...
Matches 1 - 50 out of 72 1 2 >