Abstract: A fault indicator for indicating the occurrence of a fault in an electrical conductor is reset at a predetermined time after the fault is detected, such as about 4 hours. The fault indicator has a housing, a high capacity battery, a fault sensor, a display for indicating a fault condition, and a programmable controller with a sleep state that draws low quiescent current. As a result the battery is expected to last the lifetime of the fault indicator. The fault indicator may optionally include current inrush restraint and/or voltage inrush restraint to inhibit the controller from activating the display to the fault indicating condition during the inrush conditions. The electromagnetic field about the conductor causes an electrostatic sensor to develop a differential voltage signal between two electrodes of different areas for the voltage inrush restraint circuit. Auxiliary contacts are provided to remotely monitor the fault indicator.

Abstract: A method and system for remotely monitoring the magnitude and direction of net electrical power and current flow to or from a power generation facility over the transmission lines operably connected thereto allows for the estimation of the power output of that facility. The method includes detecting and measuring the magnetic field emanating from the monitored transmission line(s), and detecting a signal synchronized to the power system frequency, typically the electric field, emanating from the transmission lines. The method further includes evaluating, storing, and transmitting the data on the electromagnetic (EM) fields that are recorded.

Abstract: The invention relates to a method for generating an error signal which characterizes a fault current in an electrical conductor provided with two conductor ends and having charge measuring devices which are connected to each other by data lines. At least one device is attached to each end of the conductor. In the invention, charge measuring values are determined using charge measuring devices. The measured charge values take into account the direction of the charge flow and a total measured charge value is formed by addition. The error signal is generated when the total measured charge value exceeds a certain threshold value. In order to be able to detect errors in a more sensitive manner than had previously been possible, the threshold value is formed by taking into account the individual measuring tolerance of the individual charge measuring devices.

Abstract: A fault indicator for indicating the occurrence of a fault in an electrical conductor has a plurality of trip settings, such as in the range of 50 A to 1200 A, that is automatically calibrated. The fault indicator includes a housing, a battery, an illuminated display, such as LEDs, a current sensor for sensing the load current in the conductor and a microcontroller that receives a current signal from the current sensor to determine the load current. In the calibration mode, a known load current is passed through the conductor, the microcontroller selects the trip level that is related to the load current, determines the load current from the current signal, and sequentially calibrates each of the plurality of trip levels for the respective known load currents. The calibration information is stored in memory. The illuminated display provides a distinctive pattern to indicate that each trip setting has been calibrated.

Abstract: An electrical connection between a power source and a threaded aperture in a power device is made by means of a terminal lug and a bolt. In order to measure the current, a second electrical path is made in parallel with the bolted connection, and current in the second path is sensed. The bolt may carry the main current, or an insulating spacer may be used which prevents significant current flow in the bolt. In one embodiment, the parallel current path extends through a conductor arrangement including additional lugs through which the bolt passes, and in another arrangement the parallel path extends through traces of a printed circuit board.

Abstract: An apparatus that controls the supply of electrical power including one or more monitors adapted to sense a state of current flow supplied to a device, one or more controlled sockets, a power input; and a logic circuit. The logic circuit controls the supply of electrical power to at least one of the controlled sockets responsive to the sensed state of current flow supply to the sensed device.

Abstract: Measurement of power factor to diagnose the condition of high powered stand-off insulators, which include a roll of insulating material carrying an intermediate layer of conductor between layers of the insulating material around a central HV conductor in a hollow insulator body, is accomplished while the power system is subject to full voltage. Coupling means provides a capacitive voltage divider with a tap at a low voltage point on the conductor within the insulator structure. The divider with the coupling means is also provided with an external low voltage connector and a ground connector. A computer is connected to the external connections of the coupling means and contains software to convert a received analog signal to digital, and subject the digital signal to a fast Fourier transform analysis to produce an output signal representative of the power factor. The computer is arranged to calculate, process and store the bushing insulator power factor at periodic intervals.

Abstract: A current measuring circuit for a PWM driver. The current measuring device measures the high side and low side currents of a PWM driver circuit before the currents reach the driver. A first measuring circuit measures the high side of the circuit and a second measuring circuit measures the low side of the circuit. The second measuring circuit also receives a signal from the first measuring circuit containing the current measurement measured by the first circuit and the second circuit then adds this current to the second circuit current and transmits a signal of the summed currents to a receiving device.

Abstract: Accurate harmonic measurements on electrical power systems where the main instrument transformers are of the capacitor coupled voltage type (CVT type) is made possible by the provision of one or more current sensors (PQCS1, PQCS2). CVTs typically have a high voltage capacitor bank (CH) and a low voltage capacitor bank (CL). One or more current sensors (PQCS1, PQCS2) is/are positioned so as to measure capacitor current and from that the input voltage (Vin) of the CVT can be determined for each frequency.

Abstract: A current control that employs a magnetic amplifier and an active feedback circuit. The feedback circuit establishes the effective operating current of the amplifier at a fixed point. The magnetic amplifier includes a pair of oppositely wound gate windings, a bias winding and a control winding. The gate windings are driven by an oscillator driver that generates a gate winding current and a gate winding voltage. A reference voltage and the gate winding voltage are applied to a feedback amplifier and the feedback circuit. When the gate winding voltage becomes equal to the reference voltage, the feedback circuit is stable and the gate winding current is set to a desired zero current operating point.

Abstract: A voltage divider (102) for high voltage and other applications uses a high voltage impedance element (104) and a low voltage impedance element (106) to isolate a sample node (110) from which to measure current, voltage, frequency response and other characteristics. The high voltage impedance element (104) includes a resistive network for reducing high voltages, for instance power line voltages of 20 kV or more, down to instrument levels to take measurements on insulation or other materials. The high voltage impedance element (104) is surrounded by one or more capacitive guard elements (118) which shunt stray capacitive currents to ground, improving frequency response and other characteristics. The voltage divider (102) be connected to a current receiver (112) for purposes of instrumentation.

Abstract: A fault indicator for indicating the occurrence of a fault in an electrical conductor has a housing, a high capacity battery, a display for indicating the occurrence of a fault, a current sensor for sensing the load current in a monitored conductor a microcontroller for determining the load current, for selecting one of a plurality of trip settings, such as in several steps between 50 A and 1200 A, based upon the determined load current and for determining that a fault condition occurred when the load current exceeds the trip setting. The selected trip setting is stored in memory. The load current is periodically sampled and the trip setting is changed if the load current falls in a different range. The display may include permanent and temporary fault indicating LEDs and additional internal LEDs that cause the housing to glow or flash at nighttime, or a target style display may be used. Upon the load current exceeding the trip setting, the microcontroller begins flashing the permanent fault LEDs.

Abstract: The invention relates to a method for generating an error signal which characterizes a fault current in an electrical conductor provided with two conductor ends and having charge measuring devices which are connected to each other by data lines. At least one device is attached to each end of the conductor. In the inventive method, charge measuring values are determined using charge measuring devices. The measured charge values take into account the direction of the charge flow a total measured charge value is formed by addition. The error signal is generated when the total measured charge value exceeds a certain threshold value. According to the invention, the measured charge values are determined synchronously and determined repeatedly at regular intervals in such a way that the time interval between each sequential determination is smaller than the predefined measuring period.

Abstract: A panelboard having an enclosure includes at least one busbar having a plurality of electrical distribution connection points, and a current transformer module having a current transformer integral with and in signal communication with each of the busbars. A signal path is associated with and in signal communication with each current transformer for communicating a signal therefrom. In application, a load current passing through each of the busbars within the panelboard results in a signal, representative of the associated load current, at the associated current transformer and signal path.

Abstract: A system for measuring power of a circuit on a printed circuit board (PCB) including first and second circuits, a power strip, a power plane, and a calibration strip. The power strip is connected to the power plane to the first circuit, is embedded in the PCB during the manufacturing process, and also has at least two vias for measuring a voltage drop. The calibration strip is also embedded in the PCB during the manufacturing process and has at least two vias for measuring a voltage drop. The second circuit is configured to measure a voltage drop across the power strip as a first voltage and a voltage drop across the calibration strip as a second voltage, and to calculate the power being fed to the first circuit based on the first voltage and the second voltage.

Abstract: A method and apparatus for determining a critical current of a conductor at least including superconducting material conveys the conductor in a superconducting state through a varying external magnetic field. A part of at least a first contact-free measurement of a magnetic field that results from influence of the external magnetic field on the conductor that is out of phase with the external magnetic field is determined for determining the critical current of the conductor.

Abstract: A method and system for remotely monitoring the magnitude and direction of net electrical power and current flow to or from a power generation facility over the transmission lines operably connected thereto allows for the estimation of the power output of that facility. The method includes detecting and measuring the magnetic field emanating from the monitored transmission line(s), and detecting a signal synchronized to the power system frequency, typically the electric field, emanating from the transmission lines. The method further includes evaluating, storing, and transmitting the data on the electromagnetic (EM) fields that are recorded.

Abstract: The invention relates to a resistor arrangement (1), especially for current measurement in a vehicle electrical system, with two plate-shaped connection elements (6, 9) separated from each other and a plate-shaped first resistive element (2), which is arranged between the two connection elements (6, 9) and is electrically and mechanically connected to these elements. According to the invention, at least one of the other plate-shaped resistive elements (3), which are separated from the first resistive element (2) and which are arranged between one of the two connection elements (6, 9) of the first resistive element (2) and another connection element (10) is connected electrically and mechanically to these connection elements (6, 10).

Abstract: A current sensor has a yoke with an air gap, a magnetic field probe arranged in the air gap, a circuit carrier on which the magnetic field probe is mounted, the magnetic field probe being mounted so that overlap a recess of the circuit carrier, and a magnetic flux of the yoke being oriented in the recess substantially perpendicularly to the circuit carrier.

Abstract: A constant input impedance AC coupling circuit for a current probe measurement system has a resistive-capacitive network that includes a capacitor for coupling the current output signal of a current measurement probe to the low input impedance measurement instrument and the resistive terminating element disposed in the measurement instrument. The resistive-inductive network includes a resistor and a synthesized inductor having a high inductive value, large current carrying capacity and an L/R time constant equal to the RC time constant of the resistive capacitive network. The resistive-inductive network is coupled to the resistive-capacitive network and receives the current output signal from the current measurement probe for terminating DC and low frequency signal components of the current output signal below the low frequency cutoff of the resistive-capacitive network in the same low input impedance of the measurement instrument.

Abstract: A system for measuring power of a circuit on a printed circuit board (PCB) including first and second circuits, a power strip, a power plane, and a calibration strip. The power strip is connected to the power plane to the first circuit, is embedded in the PCB during the manufacturing process, and also has at least two vias for measuring a voltage drop. The calibration strip is also embedded in the PCB during the manufacturing process and has at least two vias for measuring a voltage drop. The second circuit is configured to measure a voltage drop across the power strip as a first voltage and a voltage drop across the calibration strip as a second voltage, and to calculate the power being fed to the first circuit based on the first voltage and the second voltage.

Abstract: It is possible to avoid the effects of floating capacitance, and to measure a voltage with a simple operation and in a non-contact manner, without measuring the floating capacitance.

Abstract: An electrical energy meter comprises an electrically insulating housing (10) for securing relative to least two mains cables (22,24) each having a conductive core surrounded by a sheath of insulating material. The housing includes respective electrical contacts for piercing the insulating sheath of each cable, a current probe for measuring current flowing in at least one of the cables, and circuit means for calculating and displaying electrical energy as a function of the voltage across the contacts and the output of the current probe. An improved current probe is employed comprising a series of Rogowski coils equally spaced around the circumference of a circle, with the gap between two adjacent coils permitting the current-carrying conductor to be introduced into the loop. An alternative current probe employs two such concentric loops of coils, enabling compensation for the effects of external current source pickup.

Abstract: According to one embodiment, an apparatus is described. The apparatus includes a vacuum chamber and an electrical transformer to induce an electromagnetic field within the vacuum chamber. The transformer includes a primary winding, a secondary winding formed by the plasma loop, and a separate secondary winding implemented to measure the voltage along the plasma loop. The apparatus also includes a current transformer to measure the current flow through the plasma loop.

Abstract: The current draw of a pump driven by an electric motor, especially a centrifugal pump such as a heating-system circulating pump, is measured by detecting the voltage drop across a conductor segment connecting the power side and hence the power line to the motor control circuit. This eliminates the need for a separate measurement resistor.

Abstract: A mounting structure for current detection resistor device has a feature that voltage detection terminal wiring is configured so as to extend along a current path in the resistor body first, and then, to bend at right angles to the current path, while maintaining electrical isolation from a resistor body of the current detection resistor device. The voltage detection terminal wiring connecting to the voltage detection terminals on the circuit board is disposed to extend for some distance in the same direction as the current path so as to cause mutual-inductance between that section of the voltage detection terminal wiring and the resistor body. This causes cancellation of induced voltage caused by the self-inductance of the resistor body, so that it is possible to nullify detection error generated by the voltage induced by the resistor body from the viewpoint of the measuring system.

Abstract: An apparatus for sensing the current in a power line of a power system and systems incorporating the apparatus are disclosed. The apparatus may comprise an enclosure providing a window operable to permit the passage of the power line therethrough. The apparatus may further comprise an active current transformer set within the enclosure and operative to produce a scaled version of the current. The apparatus may further comprise an amplifier coupled with the active current transformer and operative to reduce the phase shift and ratio error between the current and the scaled version of the current. The apparatus may further comprise a powering current transformer set within the enclosure and operative to receive power from the power line on a primary winding and deliver power on a secondary winding.

Abstract: A current detector for detecting or measuring an electric current includes two Hall effect devices each for generating a voltage proportional to magnetic field strength and two current path terminals for the inflow and outflow, respectively, of a current to be detected or measured.

Abstract: A device for measuring current in a line supplied by a voltage with noise includes a shunt mounted in series in the line, a floating shunt signal amplifier, a floating supply to supply the floating amplifier with a voltage that follows the supply voltage of the shunt, and a differential amplifier whose inputs are connected, on the one hand, to an input terminal of the shunt, and, on the other hand, to the output of the floating amplifier.

Abstract: A current sensing device and a residual current detection device are described having a temperature compensation capability so that residual current can be directly measured to a high degree of precision in the background of a high load current. The residual current device comprises a plurality of resistive shunts for connection in respective ones of a plurality of lines through which current can flow to and from a load, and a detector means sensitive to the voltage developed across each of the shunts to detect any imbalance between the currents flowing through the shunts.

Abstract: While a power transistor which is positioned in an upper arm with respect to an inductive load and a power transistor which is positioned in a lower arm are both controlled to be OFF by a controller, reverse currents flowing in current mirror circuits which respectively correspond to these power transistors positioned in the upper arm and the lower arm are detected by current detectors. Since the currents which flow in the current mirror circuits are proportional to the currents which flow in the power transistors provided corresponding thereto, it is possible to detect the load current based upon the reverse currents which are detected by the current detectors.

Abstract: A residual current detection device comprising a plurality of resistive shunts for connection in respective ones of a plurality of lines though which current can flow to and from a load, and detector means sensitive to the voltage developed across each of the shunts to detect any imbalance between the currents flowing though the shunts.

Abstract: A jump bar shunt structure 30 includes a base 32 constructed and arranged to be mounted to a substrate and to function as a current shunt; a pair of first legs 34 and 36 integral with the base and being constructed and arranged to be connected between terminals of at least two power devices such as MOSFETs; and a pair of second legs 50 and 52 integral with the base and being constructed and arranged to be connected to a printed circuit board so as to define a current sensing connection. The jump bar shunt structure is a single component that carries high current between two or more power devices and converts current into voltage that is used by the current measurement circuitry. The advantage of the jump bar shunt structure is that no high current (motor current) flows through a control PCB.

Abstract: An integrated current sensor includes a magnetic field transducer such as a Hall effect sensor, a magnetic core, and an electrical conductor. The conductor includes features for receiving portions of the Hall effect sensor and the core and the elements are dimensioned such that little or no relative movement among the elements is possible.

Abstract: An industrial power delivery system configured in a modular architecture and having a plurality of modules. The modules interconnect via digital communication links and exchange data using a digital format. The modularity of the system enables the system to be scaled to vary future content of the product.

Abstract: A jump bar shunt structure 30 includes a base 32 constructed and arranged to be mounted to a substrate and to function as a current shunt; a pair of first legs 34 and 36 integral with the base and being constructed and arranged to be connected between terminals of at least two power devices such as MOSFETs; and a pair of second legs 50 and 52 integral with the base and being constructed and arranged to be connected to a printed circuit board so as to define a current sensing connection. The jump bar shunt structure is a single component that carries high current between two or more power devices and converts current into voltage that is used by the current measurement circuitry. The advantage of the jump bar shunt structure is that no high current (motor current) flows through a control PCB.

Abstract: A combined fuse holder and shunt has a shunt integrated into a one-piece assembly between a fuse holder and a circuit connector. The housing for the connectors is made in two halves that are heat staked together after the connectors are inserted therein. Slots and ribs in the housing retain the connectors therein without requiring supplemental fasteners.

Abstract: The invention concerns a device and a process for testing for functionality of loudspeakers, in which the electro-magnetic alternating fields produced by the loudspeaker are received via an antenna, the received signals are evaluated for signal components in the transmission range of loudspeakers using a unit for analysis, and in the case of the existence of the functionality this is displayed using a display unit.

Abstract: A current transformer to be installed around a current-carrying conductor. The transformer has a split core with two parts, which can be opened to allow the transformer to be installed around or removed from the current-carrying conductor. A winding wound on the core is operatively connected to a switch so that the winding can be shorted prior to opening the split core when the transformer is removed from the current-carrying conductor in order to reduce the magnetic force holding the split core parts together. The winding is shorted by the switch prior to closing the split core parts when the transformer is installed around the conductor in order to minimize the damage to the core due to the induced magnetic force thereon. A mechanical tool is used to open or close the split-core parts. The switch can be linked to the tool for shorting and opening the winding.

Abstract: A system for monitoring respective electrical currents in a plurality of conductors, such as wires. The system may include first and second current sensors, each suitable for sensing the current in a respective conductor. The first sensor may provide a first signal representative of the current it senses to a current monitor. The second signal may provide a second signal representative of the current it senses to the first current sensor, which in turn, may provide the second signal to the current monitor.

Abstract: A current sensor arrangement for measuring electrical current flow (subject flow) includes an elongated conductor for carrying the subject flow through a region. A magnetic field sensing device is located in the region, and produces a sensed voltage representative of the magnitude of the magnetic field in the region. A test generator generates a magnetic field component having “known” magnitude in the spatial region. The test generator is gated, so that the magnetic field changes when the test generator is ON. If the test generator generates its magnetic field by passing a test current through the spatial region, the change in the magnetic field, which is expressed in the sensed voltage, is related to the test current. Simple control circuit processing determines the subject current from the sensed magnetic field and the known magnitude of the test current.

Abstract: An apparatus for remotely sensing the currents flowing in a set of substantially parallel conductors carrying N independent AC currents comprises N magnetic field sensors M1, M2 positioned to take mutually independent measurements of the magnetic field generated by the conductors and provide corresponding signals. Processing means 12′ or 12″ derive further signals, respectively corresponding to the conductor currents, based upon the sensor signals and the location and angular orientation of each sensor relative to each conductor.

Abstract: A device for measuring alternating current in a conductor comprising an even number of identical coils (C1) to (C14) mounted on an electrically insulating coil support member (10). Half the coils (C1) to (C7) are equally spaced around a first notional circle and are connected in series by a first conductive track (12) and the other half of the coils (C) to (C14) are equally spaced around a second notional circle, concentric with the first, and are connected in series by a second conductive track (14). The support member (10) has a recess (16) to allow a conductor under test to be introduced into the centre of the concentric circles. The device further includes means (R1, R2, 20) for deriving the alternating current in the conductor as a function of the voltages induced in the first and second sets of series-connected coils. The coils (C1) to (C14) and the support member are manufactured by printed circuit or thick film technology.

Abstract: A method and apparatus for simultaneously measuring voltage and current in a primary high voltage conductor. A current and a voltage from the primary conductor is monitored. The current and voltage information present on the current transformer secondary winding is separated. The voltage information present on the current transformer secondary winding is used to provide a voltage measurement output proportional to the voltage present on the primary conductor. The current information present on the current transformer secondary winding is used to provide a current measurement output proportional to the current flowing on the high voltage conductor.

Abstract: System for measuring a thickness of a circuit component on a printed circuit board (PCB). The system includes a first circuit, a power plane, a power strip, a calibration strip, a temperature sensor, and a second circuit. The power plane is coupled to the first circuit. The power strip is for providing power to the power plane and is disposed in the PCB connected to the power plane. The power strip has at least two vias. The calibration strip has a predetermined width and is disposed in said PCB. The calibration strip has at least two vias for measuring a voltage drop. The temperature sensor is coupled to the calibration strip and configured to measuring a temperature of the calibration strip. The second circuit is coupled to the temperature sensor and configured to determine the thickness of the calibration strip based on at least the temperature of the calibration strip.

Abstract: A method for remotely monitoring the magnitude and direction of net electrical power and current flow to or from a facility over a prolonged period of time. The method includes detecting and measuring the magnetic field emanating from the monitored line(s), and detecting a signal synchronized to the power system frequency, typically the electric field, emanating from the power lines. The method further includes evaluating, storing, and transmitting the data on the electromagnetic (EM) fields that are recorded.

Abstract: The present invention relates to a pole transformer load monitoring system using a wireless Internet network. The load monitoring system is capable of measuring, in real time, a variety of load parameters (phase voltages, phase currents and temperatures) of a pole transformer placed on a distribution line. The results of the measurements are transferred to an operator in a branch operating station over the wireless Internet network so as to prevent losses resulting from overloaded and unbalanced states, thereby enhancing the quality of power supply and efficiently managing a distribution load.

Abstract: The present invention discloses a method for remotely monitoring the magnitude and direction of net electrical power and current flow to or from a facility over a prolonged period of time. An apparatus that accomplishes this monitoring activity is also disclosed. The apparatus comprises at least one device for detecting and measuring the magnetic field emanating from the monitored line(s), and another device for detecting a signal synchronized to the power system frequency, typically the electric field, emanating from the power lines. The apparatus also comprises a device for evaluating, storing, and transmitting the data on the electromagnetic (EM) fields that are recorded.

Abstract: A powerline sensor including a housing physically and electrically connectable to a powerline; a number of voltage sensing devices spaced peripherally about the housing, each voltage sensing device having an outer plate, an inner plate, and a dielectric material between the inner and out plates, the inner plates electrically connectable to the powerline, the outer plates electrically isolated form the powerline; and circuitry for sensing the voltage potential between the inner and outer plates to determine the voltage on the powerline.

Abstract: A device for detecting impedance disturbance points in symmetrical data transmission lines includes an evaluation unit having at least two magnetosensitive elements. One of these elements is positioned in the proximity of the first conductor strand and a second one is positioned in the proximity of the second conductor strand. The evaluation unit contains furthermore an evaluation circuit which is connected to the magnetosensitive elements and supplies at an output terminal a fault signal which provides information on impedance disturbance points in the data transmission lines.

Abstract: A process for improving the corrosion resistance of an iron or steel part having a phosphate conversion coating, said method comprising contact of said part with a solution containing ions selected from the group of cobalt ions and nickel ions. Preferably, the solution also contains stannous ions. Contact may be by immersion or spraying.