Abstract: A device (1) has a series circuit of submodules with a power semiconductor circuit and an energy accumulator connected in parallel with the power semiconductor circuit. Each submodule is associated with a short circuit device for shorting the submodule. The short circuit device is a vacuum switching tube. The device is cost-effective and at the same time enables safe bridging of a defective submodule.

Abstract: One form of the invention provides a method and apparatus for preventing an extraordinary electromagnetic pulse from reaching and rendering inoperative an electrical component of an electrical power system, wherein the component is located in a conductive path of the system that receives the pulse. The method and apparatus comprises the steps or means for detecting the presence of the pulse in the conductive path prior to the pulse reaching and rendering inoperative the electrical component. The pulse is diverted around the electrical component with a low inductance, high current capacity circuit relative to the electrical component before the pulse can reach and render the electrical component inoperative. The foregoing invention may beneficially utilize a high-speed current shunt comprising a flat conductive metal strap having a defined current-measuring region, a tapered parallel-plate transmission-line matching transformer attached to the current-measuring region and an output via a coaxial cable.

Abstract: A method and apparatus for mitigating arc faults in a power generation system includes reducing and/or eliminating voltage when an arc is present, to protect the system from associated damage.

Abstract: An electrical barrier for connecting a power supply to electrical equipment to be used in a potentially explosive area. The barrier includes a shunt zener diode for limiting the output voltage and a series resistance for limiting the current. In the arrangement shown, the shunt zener diode is a silicon carbide zener diode which has a higher resistance to large output current and/or operating temperature than zener diodes fabricated commercially.

Abstract: A fault detection and protection circuit can include a comparing circuit (e.g., a comparator or a detector) that can be connected to a power line supplying power to an electronic device being tested. The comparing circuit can be configured to detect a fault in which the power line is shorted to ground. For example, the electronic device being tested may have a fault in which its power terminals are shorted to ground. Upon detection of such a fault, the comparing circuit activates one or more switches that shunt capacitors or other energy storage devices on the power line to ground. The comparing circuit may alternatively or in addition activate one or more switches that disconnect the power supply supplying power to the electronic device under test from probes contacting the electronic device.

Abstract: A drive arrangement for a hand-guided working machine for agriculture, forestry and horticulture applications. The drive arrangement comprises an electric motor, a DC power source for electrical energy, and a control apparatus for the electric motor which is fed from the DC power source. The electric motor has a specific, in particular linear, characteristic curve between the electric current which is consumed by the electric motor and the rotational speed of an output shaft of the electric motor. The control apparatus has current-limiter which limits the current which flows through the electric motor to a maximum value in order to protect the electric motor against overloading. The control apparatus limits the current consumption of the electric motor in a range of low rotational speeds to values which are considerably smaller than the characteristic curve values which are given for these rotational speeds by the characteristic curve of the electric motor, as a function of the rotational speed.

Abstract: The resistance of an integrated circuit against ESD (electrostatic discharge) is improved without disturbing improvement of the performance and reduction of size of the integrated circuit. A protection circuit is interposed between an input and output terminals. When ESD is generated, the input and output terminals are short-circuited by the protection circuit, so that overvoltage application to the circuit is prevented. The circuit is electrically connected to the input and output terminals by a connection wiring. The circuit has a plurality of electrical connection portions between the circuit and the connection wiring, and the connection wiring is formed such that the wiring resistance between the input or output terminal and each of the connection portions is the same. Accordingly, if ESD is generated, voltage application on only one of the connection portions is prevented, whereby the possibility that the circuit will be broken by ESD is decreased.

Abstract: A circuit breaker for multi-phase power includes an opening-closing apparatus configured to open and close each phase of the multiphase power, a detection unit configured to detect a fault current in at least one phase of an electrical installation being protected by the circuit breaker, a plurality of connecting bars disposed on a load side of the circuit breaker, and a short circuiter disposed on the connecting bars and configured to produce a short circuit between the connecting bars if a fault current is detected by the fault-current detection unit. When a fault current occurs, a tripping signal can be transmitted by the detection system to the short circuiter. The circuit breaker is also fully operational, even without a function-activated short circuiter.

Abstract: The present invention relates to a solution to the unpredictable, inrush voltage or current surge such as static electricity and eddy current phenomenon. The solution provides a circuit which can guide an unpredictable voltage or current surge into the circuit and let them dissipate in the circuit. The present invention also relates to a solution to a DC power source surge. The solution provides a protection circuit to divide an input power surge into DC and AC in which AC will be dissipated in the protection circuit and the safe DC is sent to the output. The present invention further relates to an energy discharge capacitor which can quickly dissipate the charge and the capacitor can be applied to our inventive circuits.

Abstract: The present invention relates to Lenz effect in a circuit. When a close loop is suddenly opened or closed, the Lenz voltage will be generated at inductor in the loop. The Lenz current generated by the Lenz voltage flows oppositely to the normal current and it usually comes with very high and broadband frequency. The design of a Lenz route parallel to an inductor in a circuit can dissipate the Lenz power to stabilize the circuit. The design of a Lenz route can also be applied to a switch to protect the switch against the Lenz effect.

Abstract: An overvoltage protection system and method including a control circuit and a bank of resistors to absorb the energy from a transient voltage without exceeding an allowed temperature for the resistors. The resistors in the bank are independently switched and configured such that upon detection of an overvoltage condition a combination of the resistors is switched into the circuit to dissipate energy. The resistance introduced by the combination of resistors prevents the voltage from rising to an unacceptable level that may damage the circuit being protected. As time progresses, the control circuit alters the combination of resistors in the bank of resistors so as to increase the effective load resistance value, thereby decreasing a load current.

Abstract: Circuit and method for providing over-current and overloading protection with a single additional pin. A converter controller circuit is provided that includes a voltage controlled oscillator and outputs upper and lower gating signals for driving the upper and lower driving transistors in a voltage converter, for example, in an inductor-inductor capacitor half-bridge circuit topology. A current sense input pin of the circuit receives a voltage corresponding to the current flowing in the half-bridge circuit. A feedback input pin has an external capacitor coupled to it and receives a voltage from an output voltage sensor at the output terminals. Over-current protection is provided by sensing the voltage at the current sense input pin with no external components needed. Overload protection is provided by utilizing the external feedback capacitor and the feedback input pin during overload conditions. Methods for providing over-current and overload protection are disclosed.

Abstract: A wiring fault correction circuit for determining wiring conditions of an AC supply system includes: input line and neutral conductors connectable to the AC supply system; output line and neutral conductors connectable to a load; first, second, third, and fourth single pole, single throw relays; a first driver circuit for controlling the first and second single pole, single throw relays to respectively connect the input line conductor to the output line conductor and the input neutral conductor to the output neutral conductor in response to a correctly wired AC supply system; and a second driver circuit for controlling the third and fourth single pole, single throw relays to respectively connect the input line conductor to the output neutral conductor and the input neutral conductor to the output line conductor in response to an incorrectly wired AC supply system in which line and neutral conductors are reversed.

Abstract: An interface system may be used to connect an electrical device to an electrical bus. The interface system may include a first end and a second end in electrical communication with the first end. Where the interface system is used to connect an electrical device to an electrical bus, the first end may be connected to the electrical bus and the second end may be connected to the electrical device. The interface system may also include a reverse current blocking circuit configured to block current from flowing from the second end to the first end. Additionally, the interface system may include a discharge circuit electrically connected between the first end and the second end for discharging the blocked current.

Abstract: An ESD protection circuit includes a silicon controlled rectifier coupled between a circuit pad and ground for bypassing an ESD current from the circuit pad during an ESD event. An MOS transistor, having a source shared with the silicon controlled rectifier, is coupled between the pad and ground for reducing a trigger voltage of the silicon controlled rectifier during the ESD event. The silicon controlled rectifier has a first diode serially connected to a second diode in an opposite direction, between the pad and the shared source of the MOS transistor, for functioning as a bipolar transistor. In a layout view, a first area for placement of the first and second diodes is interposed between at least two separate sets of second areas for placement of the MOS transistor.

Abstract: A high-frequency appliance, which is allowed to have an ESD tolerance by using a small-sized and low-cost ESD protection circuit, and in particular, an antenna duplexer having a multi-band high-frequency switch function. There are provided a signal separation unit for separating a first frequency band signal from a second frequency band signal, the second frequency band being lower than the first frequency band, a first SAW filter for inputting the first frequency band signal outputted from the signal separation unit, a second SAW filter for inputting the second frequency band signal outputted from the signal separation unit, and a high-pass filter for permitting passing of the second frequency band signal, and limiting passing of a signal whose frequency band is lower than the second frequency band, the high-pass filter being located on a signal line connecting the signal separation unit and the second SAW filter to each other.

Abstract: To improve the ESD protection of a circuit receiving a signal. An inverter circuit INV1 is connected to ground wiring GND1 for supplying power, and is connected to power supply wiring VDD1 via a PMOS transistor MP5. An inverter circuit INV2 is connected to ground wiring GND2 and power supply wiring VDD2 for supplying power, and its input node is connected to an output node of the inverter circuit INV1. Further, the ground wiring GND1 and the ground wiring GND2 are connected via a protection element PE0. During normal operation, the output of an inverter circuit INV3 goes to an H level, the output of an inverter circuit INV4 goes to an L level, and the PMOS transistor MP5 is turned on. When ESD is applied, the power supply wiring VDD2 is place in a floating state, the output of the inverter circuit INV4 goes to an H level, the PMOS transistor MP5 is turned off, and a current that occurs when EDS is applied does not flow into the inverter circuit INV2.

Abstract: Provided are an abrupt metal-insulator transition (MIT) device for bypassing super-high voltage noise to protect an electric and/or electronic system, such as, a high-voltage switch, from a super-high voltage, a high-voltage noise removing circuit for bypassing the super-high voltage noise using the abrupt MIT device, and an electric and/or electronic system including the high-voltage noise removing circuit. The abrupt MIT device includes a substrate, a first abrupt MIT structure, and a second abrupt MIT structure. The first and second abrupt MIT structures are formed on an upper surface and a lower surface, respectively, of the substrate. The high-voltage noise removing circuit includes an abrupt MIT device chain connected in parallel to the electric and/or electronic system to be protected. The abrupt MIT device chain includes at least two abrupt MIT devices serially connected to each other.

Abstract: Systems and methods for auto-resetting span power protection are provided. In one embodiment, a method for deactivating a protective device is provided. The method comprises determining when an overload condition occurs on a communication medium; when the overload condition occurs, deactivating at least one protective device by applying, for a first predetermined period of time, a short-circuit to an output of a power supply that provides a holding current to the at least one protective device; and after the first predetermined period of time has elapsed, removing the short-circuit on the output of the power supply.

Abstract: A method of identifying an electrical fault in an electrical system may include coupling an electronic service tool to an electronic control module. The method may also include instructing the electronic control module to disable an enable condition and modify a trip condition set by the electronic control module. The method may further include monitoring the electrical system as a user wiggles a component of the electrical system. The method may further include providing the electronic control module with electrical system data, and generating a fault code when the electrical system data fulfills the modified trip condition. The method may further include communicating the fault code to the user.

Abstract: An over-current protection device is constituted of a current detection unit for detecting a current from a power-supply source to a load having a magnetism detection element with a magnetic impedance (MI) effect, an AC-current supply device for supplying an AC current to the detection element, a bias-current supply device for supplying a bias current to a bias coil, a peak detection device for detecting a peak of impedance of the magnetism detection element as a variation of voltage, and a switch corresponding to a phase for selecting an output of the peak detection device. In the current detection unit, a holding device for holding a switch output and an amplifier are disposed in common for detecting the current in each phase, thereby expanding a current detectable range and reducing power consumption and cost.

Abstract: A semiconductor integrated circuit device is disclosed, which comprises power supply system circuits, in which power supply terminals and/or ground terminals are separated from each other between the power supply system circuits, an electrostatic discharge protecting circuit, an internal circuit provided in each of the power supply system circuits, an internal signal transmitting line, a surge input detecting circuit, and at least one of an input protecting circuit which is provided at an input side of the internal circuit and which limits a voltage of a signal transmitted from the internal signal transmitting line, and an output logic setting circuit which is provided at an output side of the internal circuit and which sets a logic level of a signal outputted to the internal signal transmitting line to a low level when the surge input detecting circuit has detected a surge input.

Abstract: An apparatus for electric braking and system protection for an electric generator includes a dynamic brake and a crowbar circuit designed for cooperation with power converters to dump power upon command. The dynamic brake includes at least one resistor and the crowbar circuit includes another at least one resistor for dissipating power from the electric generator. Methods for use of the electric braking and system protection calls for shunting the power to at least one of the dynamic brake, the crowbar circuit and the generator side power converter.

Abstract: A power amplifier protection circuit that includes protection circuitry to variably shunt an input radio frequency (RF) signal to AC ground, turn off bias to an output transistor of a power amplifier, and turn off the output transistor. The power amplifier protection circuit features an asymmetrical control that can quickly shut off a power amplifier, and turn on the power amplifier at a steady, controlled rate when an output transistor exceeds a predetermined threshold voltage.

Abstract: A protection device for non-common ground buses is disclosed. The protection circuit includes a controller, a level shifter, a first group of switches, and a second group of switches. The controller together with the level shifter controls the first group and second group of switches. The non-common ground buses will be isolated when at least one group of the switches are turned off in an abnormal condition.

Abstract: A fluid-heating apparatus for heating a fluid and method of operating the same. The fluid-heating apparatus includes a heating element for heating a fluid surrounding the heating element and a control circuit connected to the heating element and connectable to a power source. The control circuit includes a current path from the power source to the heating element back to the power source, a switch connected in the current path, and a current sensor. The method includes initiating a heating state of the fluid-heating apparatus, initiating a non-heating state of the fluid-heating apparatus, applying a voltage to the heating element during the non-heating state, sensing a leakage current of the heating element during the application of the voltage, and determining a degradation of the heating element with the sensed leakage current.

Abstract: The electrical equipment comprises electrical elements corresponding to at least one phase of the distribution network and housed in a tank. The equipment is insulated with a dielectric liquid wherein the elements are immersed. The equipment comprises an input for each phase in the tank, and also a protection device, associated with at least one failure detector and configured so that, in the event of detecting such a failure, a short circuit will be established in the phases. The protection device is situated so as to establish the short circuit in a position before any protection, control or transformer element of the electrical equipment.

Abstract: An electronic circuit for protecting a field effect transistor from high voltage includes a switching device having a first state in which the switching device turns the field effect transistor ON, and a second state in which the switching device turns the field effect transistor OFF. A charging device is connected to the switching device and receives an electrical charge when an electrode of the field effect transistor is shorted to a voltage source. The charging device applies the electrical charge to the switching device to thereby place the switching device in the second state.

Abstract: Control of an induction motor is carried out to limit damaging arcing stress and mechanical stresses placed on the control contactor assembly and the induction motor resulting from the simultaneous or synchronous breaking and making of contactors employed to connect the windings of the motor to a power supply. Asynchronously connecting the windings to the power supply via the asynchronous or non-simultaneous closing of the contactors of a modular contactor assembly reduces the potentially damaging transient current, the associated torque oscillations, and mechanical stresses. The present invention is particularly applicable to delta motors that are started with its windings in a star or wye configuration followed by the reconnection of the windings in a delta configuration when the motor is at normal running speed.

Abstract: An electrostatic discharge protection network comprising electrostatic discharge (ESD) clamp devices distributed between turns of a coil shaped inductor. The inductance of the coil shaped inductor and parasitic capacitance of the ESD clamp devices form a low pass filter structure having a very high cut-off frequency. Below the low pass filter cutoff frequency, the capacitive influence of the ESD clamp devices are cancelled by the series inductance of the coil shaped inductor. The turns of the coil shaped inductor may be fabricated on insulation layers proximate to one another so as to achieve close magnetic coupling there between, thereby achieving a larger inductance value for a given sized coil structure. Improved input and output impedance matching is also achieved by adjusting the inductive and capacitive components of the low pass filter structure formed by the coil shaped inductor and capacitance of the ESD clamp devices.

Abstract: A current sensor which constitutes an overload protection apparatus and senses a current supplied from a power source to a load is constituted by providing a magnetic sensor having the effect of magnetic impedance (MI), an AC supply means which impresses AC on this sensor, a bias current supply means which supplies a bias current to a bias coil, a peak sensing means which senses the peak or a change in impedance of the magnetic sensor as a change in voltage, and a switch which selects the output of the peak sensing means in accordance with each phase. A holding means which holds switch outputs one after another and an amplification means are provided in common to enable current sensing for each phase. Thus, a range of current sensing is enlarged to reduce power consumption and cost.

Abstract: A method, apparatus, and system for routing signals in a microelectronic device are disclosed. The system includes a plurality of chip components, such as transient suppression regulators, that are configured to include a transmission path that is routed through the chip component for transmission of any signal, for example, a signal from a communication bus of the microelectronic device.

Abstract: A protection relay for determining whether or not a fault point of a power system exists in a predetermined range including a filter section for inputting sampling data of a voltage and a current in the power system to a digital filter having a predetermined transfer function and outputting a first voltage data and a first current data, and a second voltage data and a second current data normal to the first voltage data and the first current data, respectively, a calculator for calculating a predetermined measurement value based on the first and second voltage data, and the first and second current data at a first time and the first and second voltage data, and the first and second current data at a second time different from the first time, and an operation decision section for performing an operation decision based on the predetermined measurement value obtained by the calculator.

Abstract: In an ESD protection device using a LVTSCR-like structure, the holding voltage is increased by placing the p+ emitter outside the drain of the device, thereby retarding the injection of holes from the p+ emitter. The p+ emitter may be implemented in one or more emitter regions formed outside the drain. The drain is split between a n+ drain and a floating n+ region near the gate to avoid excessive avalanche injection and resultant local overheating.

Abstract: A self diagnostic solid state relay for converting a low current input into a high current output and providing the combined functions of silent switching and visual indication of circuit status. A three dimensional polygonal shaped housing encloses a printed circuit board. A MOSFET field effect transistor, a pair of female circuit board terminals, and a pair of LED elements are electrically communicable with a first side of the printed circuit board, the LED elements further being viewable from an exterior location of the housing. A fuse including first and second spaced apart and extending blade portions engage, respectively, with the first and second female terminals through openings defined in the housing. A plurality of male circuit board terminals are in electrical communication with a second side of said printed circuit board and extend from further selected exterior locations of the housing.

Abstract: The present invention relates to a method for providing improved reliability in a protective circuit. Specifically, embodiments of the present invention provide improved reliability by coupling the outputs of functional elements of redundant protective circuits through OR gates to the inputs of subsequent functional elements. By this cross-coupling of individual circuit output signals between redundant circuit blocks, a failure of any functional element can be bypassed, allowing any non-failed functional element to supply the signal missing from a failed functional element.

Abstract: A protection circuit (10) is formed to protected a load (11) when a short circuit develops during operation of the load (11). A load transistor (18) is formed to couple the load to a voltage return terminal. A disable transistor (19) is formed to disable the load transistor (18) when a short circuit occurs.

Abstract: In a power-supply unit for a microwave tube, voltage between a helix power supply terminal and a cathode power supply terminal is divided into voltage slightly lower than the voltage of a collector power supply terminal. Uni-directional conductive means is provided between a voltage dividing point and the collector power supply terminal, and when the voltage of the collector power supply terminal is about to be lower than voltage at the voltage dividing point while the voltage approximates the voltage of the cathode power supply terminal, the uni-directional conductive means conducts and clamps the voltage of the collector power supply terminal so that the voltage is substantially equal to the voltage at the voltage dividing point.

Abstract: An apparatus and method are provided for preventing buffers used to reduce delays on long lines of an IC from being damaged due to charge that collects on the buffers during manufacturing. In accordance with the present invention, a protection diode is included directly in at least each buffer that is used for this purpose, i.e., for the purpose of preventing delays on long lines of the IC. By including a protection diode in at least each buffer that is used for this purpose, the present invention obviates the need for having to use tools during the IC design process to determine a suitable location for a protection diode.

Abstract: A semiconductor integrated circuit device is disclosed that can provide greater flexibility of layout while essentially ensuring circuit characteristics, and at the same time providing an minimum electrostatic discharge breakdown withstand value according to Charged Device Model (CDM) at all input/output (I/O) terminals. For each I/O terminal a size of a CDM protective device can be optimized in response to reference electric potential wiring resistance between an input protective device, a MOSFETs that can constitute an internal circuit, and an input resistance.

Abstract: A cross-pin electro-static-discharge (ESD) protection device protects against ESD zaps between two I/O pins. Pin A is connected to a drain of a bus-switch transistor and pin B is connected to the transistor's source. An ESD protection device on pin A has an n-channel shunting transistor to an internal ground bus. The gate of the shunting transistor is a cross-gate node that is capacitivly coupled to pin A, and has a leaker resistor to ground. An n-channel cross-grounding transistor has its gate connected to the same cross-gate node, but it connects the internal ground bus to pin B, which is grounded in the pin-to-pin ESD test. An ESD pulse on pin A drives the cross-gate node high, turning on both the shunting transistor and the cross-grounding transistor. The floating internal ground bus is connected to ground by pin B, grounding the substrate of the bus-switch transistor to prevent its turn-on.

Abstract: Metal oxide varistors (MOVs) are employed in surge protection devices, such as overvoltage protection devices, between signal lines and ground to reduce the capacitance and the capacitive imbalance introduced by the overvoltage protector, thereby improving higher frequency transmissions, such as xDSL communications, over a twisted-pair telecommunications network. The MOVs can be stacked electrically in series to reduce the capacitance of each MOV and to reduce the variability, tolerance or spread of the capacitance between MOVs. Asymmetrical MOVs with electrodes having different surface areas can also be used to reduce capacitance and to reduce capacitive imbalance between MOVs. Furthermore, Asymmetrical MOVs, as well as MOVs with electrodes having the same surface area, can be stacked electrically in series. Such series stacked, asymmetrical, and series stacked asymmetrical MOVs can be used in parallel with a gas discharge tube to form, for example, a station protector for use at a customer premises.

Abstract: A semiconductor device that includes an integrated circuit and an HBM structure formed on different semiconductor substrates is provided. The HBM structure may include input or output or input/output circuitry coupled to the integrated circuit and protection structures coupled to the input or output or input/output circuitry. In an embodiment, the integrated circuit may include input or output or input/output structures spaced across an area of the integrated circuit. The input or output or input/output circuitry of the HBM structure may be coupled to the input or output or input/output structures of the integrated circuit. A method for developing a design for an HBM structure is also provided. The method may include coupling an HBM structure formed on a first semiconductor substrate to an integrated circuit formed on a second semiconductor substrate. The method may also include testing the HBM structure and altering the HBM design based on the testing.

Abstract: Methods and apparatuses are disclosed for protecting solar cells from cellular degradation caused by an electrostatic discharge pulse. In one embodiment, a diode may bypass current generated from an electrostatic discharge so that the pulse current does not reverse bias the solar cell. Advanced diodes, capacitors and/or multiple diodes located on multiple bypass current paths, may be used. In another embodiment, the transient impedance of the current path that reverse biases the solar cell is increased by using inductors placed along the reversing current path. In another embodiment, the pulse current rise rate is reduced by extending the harness length of cell contacts. In another embodiment, solar cells in a serpentine pattern may be protected from electrostatic discharge damage by coupling bypass current paths to the open ends of the serpentine. Inductors may also be placed in series with the serpentine series of cells.

Abstract: An electronic thermal protection circuit is for high currents which can occur in the start-up phase in lighting converters. The circuit is associated with a power device having an output terminal connected to an electric load and at least one control terminal receiving a predetermined driving current value by a driving circuit portion. Advantageously, an integrated temperature sensor is provided to detect the temperature of the power device, and an output stage is connected downstream of the sensor to switch off the driving circuit portion when a predetermined operation temperature is exceeded.

Abstract: A method and apparatus for remotely operating a circuit protection device, such as a circuit breaker, to move the circuit protection device to an open condition to disconnect a load from a power source. The apparatus includes a control circuit positioned externally from the circuit protection device. The control circuit includes an impedance limiter and a switching device connected in series with each other. The impedance limiter and switching device are positioned in parallel with the load. The switching device can be remotely actuated to move between an open position and a closed position. When the switching device is in the closed position, the impedance limiter draws a supply of current through the impedance limiter. The size of the impedance limiter is selected such that the current drawn from the power source is greater than the trip current required to move the circuit protection device to the open position. Thus, the switching device can be used to remotely actuate the circuit protection device.

Abstract: The directional element, following enablement under selected input current conditions, calculates a zero sequence impedance, in response to values of zero sequence voltage and zero sequence current. The current value is selected between two possible values, one being the value from an associated current transformer, the other being the sum of the currents IA+IB+IC. The calculated zero sequence impedance is then compared against sensitive selected threshold values, established particularly for ungrounded systems. A forward fault indication is provided when the calculated zero sequence impedance is above a first established sensitive threshold value, and a reverse fault indication is provided when the calculated zero sequence impedance is below a second established sensitive threshold value.

Abstract: A circuit for controlling a silicon-controlled rectifier includes a high breakdown voltage metal-oxide semiconductor field-effect transistor (MOSFET) connected to drive the gate of the silicon-controlled rectifier. The high breakdown voltage MOSFET is itself controlled by a gate voltage. The power requirements for the gate trigger circuit of a series string silicon-controlled rectifier are greatly reduced by using the high breakdown voltage MOSFET as a gate triggering circuit for the silicon-controlled rectifier. Because the MOSFET consumes little power, a limited power source, such as a snubber capacitor voltage that is developed during the OFF-state of the silicon-controlled rectifier, can be used to power the gate trigger circuit.

Abstract: A device is provided for preventing high voltage from acting on a load driven by a bicycle dynamo. The device comprises a sensor circuit and a control circuit. The sensor circuit senses an operating signal derived from the dynamo, wherein the operating signal corresponds to a voltage generated by the dynamo. The sensor circuit also provides a control signal when the operating signal passes a threshold value. The control circuit is operatively coupled to the sensor circuit and is adapted to be coupled between the dynamo and the load to control the current delivered to the load in response to the control signal.

Abstract: In a device for the short-circuiting of a first electrical line (1) with a second electrical line (2) by at least one mechanical switching device (SM), at least one first electronic switching device (SE1) is arranged in parallel with the mechanical switching device (SM) and at least one second electronic switching device (SE2) is arranged reverse-connected in parallel with said first electronic switching device, by means of which a voltage difference that occurs between the first electrical line (1) and the second electrical line (2) can be bridged. Such a device is constructed in a simple manner and has short response times.