Abstract: A sensor system includes a sensor head, an optical source, and a measurement apparatus. The sensor head includes a beamsplitter having first, second, third, and fourth ports, the beamsplitter being responsive to light selectively applied to the first, second and third ports for passing light of a first polarization state from the first port to the second port, for passing light of a second polarization state from the first port to the third port, for passing light of the second polarization state from the second port to the fourth port, and for passing light of the first polarization state from the third port to the fourth port. The optical source means provides light to the first port.

Abstract: A non-contact DC current sensor has a housing in which a pair of cantilevered compliant armatures are mounted. In one embodiment, a single magnet is mounted to a free end of one armature portion, and a nonmagnetic mass of the same moment and weight is mounted at the free end of the other armature to compensate for gravitational forces. Strain gages are mounted adjacent the magnet and the nonmagnetic mass on the pair of armatures. The strain gages are connected in a circuit to generate an output caused by a Lorentz force. The circuit includes provision for static gravity compensation, and in one embodiment l/r compensation.

Abstract: A noninductive shunt current sensor includes a cylindrical-shaped conductive element and a concentric conductive pipe electrically connected at one end by a conductor, such as a washer. Except for the conductor, the pipe and conductive element are electrically isolated from each other by insulation, such as Kapton.TM. or an air-gap. Sensing wires are electrically connected to contact points, each contact point being located on either the inner surface of the inner pipe or the outer surface of the outer pipe. The wires pass through a space where the magnetic field is substantially null, thereby reducing any mutual coupling effects.

Abstract: An apparatus for measuring at least one state variable of a brushless direct-current motor includes 2 * n pole segments, wherein n=1, 2, 3, etc.. The pole segments are integral with a rotor of a brushless direct-current motor and are formed of permanently magnetic material generating a magnetic field. At least one Hall-effect element supplies an output voltage and is disposed in the vicinity of the rotor for impressing the magnetic field of the permanently magnetic segments on the output voltage from the at least one Hall-effect element. A logic unit receives the output voltage from the at least one Hall-effect element for determining the temperature of the brushless direct-current motor.

Abstract: An alternating current sensor employing a mutually-inductive current sensing scheme comprises a conductive pipe and a cylindrical-shaped conductive element at least partially surrounded by the pipe. The pipe is substantially concentric to the conductive element and a conductor electrically connects a pair of corresponding ends of the pipe and conductive element to form a connected conductive path through the sensor. The pipe and the conductive element are spaced apart a predetermined radial distance to form a magnetic field in the space between the pipe and conductive element during current flow along the conductive path.

Abstract: A new electro-optic sampling probe with femtosecond resolution suitable for ultra-fast electro-optic sampling. The new probe is several times thinner and has a dielectric constant four times less than the best reported conventional bulk LiTaO.sub.3 probes. In addition, the ultimate bandwidth is 50 percent greater than an equivalent LiTaO.sub.3 probe. The probe is a thin film of Al.sub.x Ga.sub.1-x As used in both total internally reflecting and free-standing geometries. Here x is chosen for sufficient transmission of the crystal to the wavelength of the laser source being used for electro-optic sampling. The thickness of the film is a small fraction of the thickness of prior art probes and is chosen, for speed and sensitivity of electro-optic sampling, to be thin compared to the spatial extent of the laser pulse. The thin film probe eliminates many of the problems associated with the use of bulk crystals as electro-optic sensors.

Abstract: A clamp-on multimeter includes a body section, and a clamp section having a pair of clamp cores for clamping a conductor to be measured. The front ends of the clamp cores are capable of closing and opening. An input section receives signals introduced from a conductor. A display section simultaneously displays a first parameter corresponding to an induction voltage induced in the clamp section, and a second parameter corresponding to the measured signals input via the input section. A control section controls the simultaneously display of the first parameter and the second parameter on the display section.

Abstract: A current measuring device includes first and second current transformers, having each a magnetic core, a primary conductor or winding and a secondary winding coupled with the magnetic core, the primary windings or conductors being connected to carry the current to be measured. The secondary windings of the first and second transformers have an equal number of turns and are connected in series with each other, and arranged so that the currents induced in the secondary windings by the current to be measured flow in the same direction. A current generator has an output connected to the secondary winding of the first current transformer for feeding to the same a current comprising a magnetizing current component capable of driving the corresponding core, alternately, in opposite states of saturation.

Abstract: A current sensing device includes a secondary coil positioned within the curved portion of a U-shaped primary conductor or coil. The secondary coil is surrounded by a non-ferromagnetic metallic shield to prevent capacitive coupling between the windings of the secondary coil and other nearby metallic objects. A nonconductive material is integrally formed about the U-shaped conductor and provides a cavity for receiving the secondary coil an shield in a predetermined position with respect to the U-shaped conductor. A flux guide of ferromagnetic metal, formed in an elliptical-cylindrical shape, surrounds the U-shaped conductor and the secondary coil to provide a flux steering effect to steer flux around the secondary or pick-up coil. The current sensing device is useful in measuring current in electrical utility power monitoring or watthour meter applications.

Abstract: The optical electric current sensor is composed of a birefringent light guide (2) coiled around an electric current conductor (1) and is characterized by a spatial modulation of the magnetic field or of the birefringence of the light guide, along the light guide, at a spatial period equal to a whole number of times the beat length of the guide.

Abstract: The invention relates to a current measuring transducer operating on the compensation principle, comprising two magnetic cores (C1, C2) with windows; windings wound thereon for both a current (Ip) to be measured and for a compensation current (Is); and means (Um, Nm, R1, D, IA) for generating the compensation current and adjusting the magnitude thereof. To compensate for induced interference voltages, a further winding (Nc1, Nc2) is arranged about both magnetic cores of the current transducer. To widen the frequency band, the windings (Nc1, Nc2) are series-connected in a closed loop through a frequency-dependent impedance (Z).

Abstract: A current ratio device is used for forming a current transformer that can accurately scale down high currents to usable metering levels. The transformer has associated circuitry that renders it capable of functioning not only with ac and a mixture of ac and dc, but also when dc alone is present in the primary winding. The device employs a toroidal core and winding assembly that is cut along a plane containing the toroidal axis through a pair of diametrically opposite sections of the assembly that contain no windings, in order to separate the device into a pair of sub-assemblies that can be readily placed over a single turn primary, e.g. a busbar, without dismantling the same.

Abstract: In an optical current transformer in which the Faraday rotation of light in a waveguide (2) enclosing the current is measured, the waveguide (2) is designed as an integrated-optics single-mode waveguide embedded in a substrate (1).Further elements of the measuring device, such as polarizers (13), mirrors (11) and Y couplers (12, 14), may likewise advantageously be integrated into the substrate (1).The integration leads to a sensor element (SE) which can be produced in a simple manner and is to a large extent insensitive to environmental influences such as temperature fluctuations and vibrations.

Abstract: A current sensor using a resonance directional magnetometer which includes a magnetic circuit having a gap and a device supplying a voltage representative of a magnetic field produced in the gap by a current when the current passes through the circuit. The value of the field is a function of the intensity of the current. The device is a resonance directional magnetometer having a sample with resonant spins placed in the gap and exposed to a magnetic field having a polarization parallel to the field produced in the gap or coinciding with this field and a measuring device for exciting the resonance and detecting the excited resonance and for supplying a voltage representative of the amount of excited resonance.

Abstract: A method and circuit for measuring direct and high duty factor current in a conductor (1) with minimal interference with the operation of a monitored circuit. Current flow in the conductor is magnetically sensed with a transformer T1 having a primary winding connected electrically in series with the conductor (1). The transformer T1 is driven into saturation during a first time interval and brought out of saturation during a second time interval. After the transformer T1 is brought out of saturation, an output signal is provided which is proportional to the flow of current in the conductor (1).

Abstract: A combined current and voltage measuring sensor for measuring voltage and current on a primary conductor, the sensor including a cast resin body having therein a aluminum support, the support having an aluminum encasement mounted thereto. An air core coil is encapsulate with the encasement within the cast resin body adjacent a grooved portion in the cast resin body for maintaining the primary conductor in the top of the cast resin body. The groove and the aluminum encasement cooperate to precisely locate the primary conductor with respect to the air core coil. A keeper assembly mechanically maintains and locates the primary conductor in the groove and further provides an electrical connection from the primary conductor to the voltage measuring apparatus of the sensor. A corona shield encapsulated within the cast resin body is at the same potential as the conductor and is interposed between the air coil and the groove of the cast resin body.

Abstract: A current sensing system includes a number of remote current sensors for measuring the magnetic field surrounding each conductor of an electrical transmission system to independently monitor the current flowing through the conductors. A generally U-shaped mounting fixture is provided for supporting the current sensors in a fixed, predetermined orientation relative to each of the conductors. An electronic compensation circuit is provided for conditioning the output of each the sensors with the output of the other of the sensors to isolate the influence of the magnetic field induced by the current flowing through only one of the conductors.

Abstract: In the case of a fiber optics arrangement for measuring the intensity of an electric current while utilizing the Faraday effect in which the magnetic field surrounding the conductor 1 through which the current flows affects the polarization condition of the light, the path of which leads through the core of an optical fiber 2 which surrounds the conductor 1 in the form of a coil, the light coupled out of the optical fiber 2, by means of a beam splitter 9, being divided into two partial light beams, the intensities (I.sub.1, I.sub.2), after passage through one polarizer 12, 11 respectively, being measured by one photodetector 14, 13 respectively, the object of expanding the measuring range of the arrangement is achieved by the fact that the polarizers 12, 11 are rotated symmetrically with respect to one another in comparison to the conventional angle of 45 degrees, the angle (.alpha.

Abstract: Method and apparatus for determining the current in a defibrillation pulse discharge circuit 30 which has an inductor 38 with a characteristic inductance for shaping the defibrillation pulses. A sense winding 136 is wound around the inductor with at least one turn between ends of the winding for developing a sense voltage between the ends in response to the current in the inductor as a defibrillation pulse is discharged by the circuit. This sense voltage is measured, and based on the sense voltage and the characteristic inductance of the inductor, the current in the defibrillation discharge pulse is determined.

Abstract: An AC/DC current detection method that can detect small and large changes in current, by employing a high-frequency excitation current applied to a coil wrapped around an annular iron core. The change in this value is determined for operation in the region of the coercive force of the iron core or as the change in an extreme value thereof.

Abstract: An isothermal current shunt device with excellent temperature coefficient of resistivity characteristics stability for use in a power measuring circuit having a wide temperature and dynamic range and particularly for customers of electric utility companies, and it includes a first arm having a first flange portion, a second arm having a second flange portion, and a bridge means coupling the first arm to the second arm wherein the bridge means is a monolithic sintered powdered-metal piece having a block portion and a loop portion. The block portion has a first face juxtaposed to and electrically coupled to the first flange portion of the first arm and a second opposing face juxtaposed to and electrically coupled to the second flange portion of the second arm. This configuration allows a majority of electrical current to conduct between the first arm and the second arm. The loop portion is outside the first face and the second face of the block portion and conducts a minority of current.

Abstract: A weld current switch includes a channel-shaped core, a shunt, and a magnetic reed switch. The magnetic reed switch and shunt are placed across the core poles. An electrical conductor carrying high current passes through the core. Upon deenergization of the electrical current, a residual magnetism remains in the core. The residual magnetism is normally high enough to prevent the magnetic reed switch from opening. However, the shunt directs sufficient magnetic flux from the switch such that the switch senses a much lower level of magnetic flux than if the shunt were not present. As a result, the switch opens, even with the high residual flux in the core. The increased reliability of the switch upon decreasing current at electrical conductor deenergization enables the weld current switch to use a higher sensitivity switch than was formerly possible.

Abstract: A method and circuit for measuring direct and high duty factor current in a conductor (1) with minimal interference with the operation of a monitored circuit. Current flow in the conductor is magnetically sensed with a transformer T1 having a primary winding connected electrically in series with the conductor (1). The transformer T1 is driven into saturation during a first time interval and brought out of saturation during a second time interval. After the transformer T1 is brought out of saturation, an output signal is provided which is proportional to the flow of current in the conductor (1).

Abstract: A current sensor is provided with a flux concentrator which is made of two or more annular laminae. The laminae, or lamina plate, each are provided with a gap formed in its circumferential length. Each lamina has a gap which is defined by two opposing faces. The laminae are stacked with their planar surfaces in contact and in such a way so as to define a central opening. The gaps of the laminae are arranged proximate each other. One lamina is rotated relative to another to change the width of the effective gap by misalign the faces of the one gap relative to another. The lamina is rotated during the manufacture of the current sensor while an output voltage signal is measured as a function of a current passing through an opening of the flux concentrator. The degree of rotation of the lamina is determined as a function of the output signal to achieve a preselected current/voltage relationship.

Abstract: The current transformer of an electronic house-service meter has a ferromagnetic core which, except for an air gap, is closed. A measuring coil is inserted in the air gap and is fastened, and dimensioned so that it lies within the cross sectional area of the core.

Abstract: An electric current sensor assembly and method. A housing containing a Hall effect device is provided with at least one curved, concave surface for placement against a wire carrying a current. The housing is attached to the wire by a strap that fastens around the housing and the wire and fits in grooves in the housing. When the assembly is installed, the Hall effect device is positioned so that the magnetic field produced by current in the wire passes through the Hall effect device and produces an electric signal proportional to the amplitude of the current in the wire. A set screw is movably mounted in the housing adjacent the Hall effect device to adjust the sensitivity of the current sensor assembly.

Abstract: Two groups of magnetic field transducers shielded from electric fields and at a known distance from each other are contained in a portable instrument. Each group consists of 3 magnetic field transducers each sensitive to the magnetic field at a single point but according to three orthogonal orientations. Rapid reading of the magnetic field values measured by all 6 coils allows evaluation of the current in a straight electrical conductor relatively near to the apparatus on the basis of the direction and amplitude of the magnetic field vectors measured at the position of each group of 3 coils. Assuming that the conductor under scrutiny is the dominant magnetic influence in the area, the determination of both current and distance of the conductor is exact within a wide range of distances between apparatus and conductor and within a large number of orientations of the apparatus with respect to the conductor because of internal computational compensations performed by a microprocessor.

Abstract: In the present current intensity transformer device, a magnetic circuit having an air-gap provided with a Hall cell, is coupled with a conductor for the current to be measured and with a measuring winding. An electric measuring circuit provides a first voltage which is a function of the magnetic field in the air-gap, and a second voltage which is a function of the current in the measuring winding. Both voltages are added together to provide a measure of variable currents, such as pulse currents or periodic currents of a strongly asymmetrical wave form, as well as direct currents or low frequency alternating currents with superposed strong high frequency undulation.

Abstract: In a gas-insulated switchgear having an isolated-phase bus, a current-carrying bus (2) with a given external radius R.sub.1 is arranged coaxially in a cylindrical enclosure with a given external radius R.sub.2, the voltage of the current carrying bus is measured using optical fiber voltage transducers. For this purpose, at least three identical piezoelectric sensor elements are provided. They are arranged essentially at a distance corresponding to the internal radius R.sub.2 from an axis of the current carrying bus in the enclosure at identical angular distances. The sensor elements are preferably accommodated together with an optical fiber curent transducer in a metal ring that can be inserted into the enclosure.

Abstract: A fiber-optical current transformer including a sensor coil, operated in reflection mode, with a sensor fiber (5) for detecting a current utilizing of the Faraday effect. A light source (1) couples light into an incoming first HB fiber (2a). At the end of the first HB fiber (2a), a fiber-optical polarizer (4) is preferably located which ensures a direction of polarization in parallel with a given birefringence axis of the first HB fiber (2a). A Y splitter (3) couples, on the one hand, the supplied light of the first HB fiber (2a) into the sensor fiber (5) and, on the other hand, the light coming from the sensor fiber (5) into an outgoing second HB fiber (2b). The second HB fiber (2b) is rotated with its birefringence axes by 45.degree. with respect to the birefringence axes of the first HB fiber (2a).

Abstract: A device for rapidly measuring voltages by electro-optic or magneto-optic ans which exhibits a substantially linear response over much of its operating range. The device employs the Pockels effect in which the orientation of polarized light is altered in direct response to applied voltages. The response of the subject device is made substantially more linear by dividing the polarized light into two beams and retarding the phase of the second beam by one-quarter wavelength, attenuating its intensity by a factor of approximately four, and passing it through a second Pockels cell having a transducer constant of one half that of the first Pockels cell and then recombining, or superpositioning, the first and second beams of light, thus yielding a substantially linear response over much of the applied voltage range.

Abstract: At both ends parts of a specified section of a high tension line and close to it, a first Faraday device and a second Faraday device are disposed, and an output end of the first Faraday device is connected to the input end of the second Faraday device through a polarization plane retaining type optical fiber. A light having a linear-polarized polarization plane is inputted from a polarizer to the input end of the first Faraday device. The light output from the second Faraday device is led through an analyzer to a photoelectric device, whose output is processed by an electric circuit consisting of only one band-pass filter, only one DC filter, only one divider, and a judgment circuit.

Abstract: A current measuring method in which a magnetic sensor is a torodial core having a conductor for carrying a current to be measured passing through the hollow portion of the toroid. A coil on the core is excited with an AC voltage such that the positive and negative voltages induced in the coil are equal in amplitude when the conductor is not carrying current. Current in the conductor generates a change in magnetic flux which change is measured by detecting the algebraic sum of the amplitudes of the positive and negative voltages. Simultaneously, the amplifier output is applied to the input side of the AC voltage or a second coil disposed in the magnetic sensor so as to establish a magnetic equilibrium. Current measuring apparatus according to this invention include two types of apparatus composed of hardware to which the above-mentioned current measuring method is applied.

Abstract: An optical instrument transformer can measure both current and voltage of the primary conductor. Measurement of current is made through modulation effect of a light signal by the optical magnetic-field sensor, and measurement of voltage is made through modulation effect of a light signal by the optical electric-field sensor, by measuring the voltage between a conductor member and an upper flange the of the a bushing, which has a value divided in a dividing ratio determined by the capacitance between the conductor member (4a) and the upper flange and the capacitance between the upper flange and ground.

Abstract: An optical current transducer for measuring current in a high voltage transmission line includes a temperature compensated light source of nominal predetermined intensity and wavelength, a Faraday rotation device where Faraday rotation impressed on the light exiting the light source is proportional to the intensity of the electrical current to be measured. A hermetic tank encloses the Faraday rotation device to provide protection from the environment. An electronic circuit converts the optical output of the Faraday rotation device to an electrical signal in direct proportion to and in phase with the current to be measured.

Abstract: A power line post insulator has a housing that encloses two inductive sensors that transversely straddle a recess which receives the power conductor. Wires connect the sensors additively with respect to voltages induced by currents in the conductor between the sensors. The sensors may each include one or two additively connected coils.

Abstract: The invention relates to a current sensor which works with a toroidal body, through which at least one conductor to be evaluated is extended and from which a measuring signal is taken. The toroidal body (1) comprises a magnetostrictive material and conductor runs (2) of length-dependent resistance material are applied over at least one ring region of the toroidal body (1). The resistance changes of the conductor runs are evaluated to determine a value representative of the current (I) to be measured.

Abstract: An optical current transformer particularly useful for a fault location system for a power supply system and substation, including a casing which can be detachably secured to a plurality of wire conductors which conduct currents of the same phase. Within the casing a plurality of Rogowsky coils are arranged such that when the casing is secured to the wire conductors, each Rogowsky coil is wound around respective wire conductors. The Rogowsky coils are connected in series with an air-core coil and an optical current sensor having a Faraday element is arranged within a space of the coil such that the Faraday element is subjected to a magnetic flux generated by the coil. A magnitude of the magnetic flux is optically detected by the Faraday element to measure a total sum of currents conducting along the wire conductors.

Abstract: In a sensor for sensing current in a conductor, a magnetic laminar arrangement adapted to surround the conductor passes through a coil. Inside the coil the laminar arrangement forms a gap with two projections extending transverse to lamina within the arrangement and facing each other. In one embodiment the coil drives a display to form part of a fault indicator.

Abstract: An AC current sensor comprising a generally C-shaped main coil with a fixed gap between its ends. A pair of compensating coils are positioned at fixed locations in the main coil's gap. The longitudinal axes of the compensating coils lie on an imaginary straight line which extends between the centers of the main coil's ends; and their electrical centers are each spaced the same distance from their respective ends of the main coil. A compensating coil gap is defined between the electrical centers of the compensating coils. The main coil defines a measuring recess in which the sensed AC current carrying conductor is located when a measurement is taken. When the ratio of the size of the main coil gap to the size of the compensating coil gap is equal to the square root of three, the AC current sensor's accuracy and outside signal rejection increase most rapidly with increased distance of the sensed AC current carrying conductor from the compensating coil gap, and the AC current sensor's size can be minimized.

Abstract: A sensor in a faulted current indicator includes a coil and a magnetic arrangement passing through the coil and around a current-carrying conductor for coupling the coil to the conductor. The magnetic arrangement has given magnetic reluctance and forms a higher reluctance section, such as a gap, within the coil. Preferably the magnetic arrangement includes a U-shaped laminate and two core laminations joined to the U-shaped laminate by two gaps to allow for installation around the conductor. The ferromagnetic plate outside the coil shields the coil. The sensitivity of the sensor is increased by coating the inner surface of the U-shaped laminate and the core lamination surfaces contacting the U-shaped laminate with a high Ni content ferromagnetic material.

Abstract: A non-intrusive DC current monitor is presented which emulates the theoretical operation of an AC transformer. A conductor, carrying the current to be measured, acts as the primary of a DC current transformer. This current is passed through the center of a secondary coil, and core positioned thereabout, and produces a magnetic flux which induces a current in the secondary proportional to the current flowing in the primary. Means are provided to periodically "reset" the transformer core such that the measurement inaccuracies associated with core saturation are obviated. A reset current is caused to periodically flow through the secondary coil which produces a magnetic flux oppositely polarized to the flux created by the current in the primary, thus allowing ongoing measurements to be made.

Abstract: A sensing device for measuring electric current and electric power including a plurality of magneto-electric transducers for detecting a magnetic field about a conductor carrying the electric current. The magneto-electric transducers can include Barber-Pole type elements, each element being positioned on a substrate at approximately the same distance from the central point of a substrate.

Abstract: A current conductor is provided with opposing notches to produce a restricted section and with magnetic flux sensors on opposite sides of the restricted current section. The flux sensors are connected to differential amplification circuitry. The restricted section increases the concentration of magnetic flux sensed, and the differential amplification circuitry eliminates the sensing of currents in external conductive paths. An electrostatic shield is provided between the shaped conductor and the magnetic flux sensors to elminate electrostatic effects on the output signal. The flux sensors and differential amplification circuitry is fabricated in an integrated circuit chip. For small currents, the shaped conductor may be deposited on the chip; otherwise a shaped conductor is formed and a mounting substrate of insulating material, such as ceramic, is used to support the integrated circuit chip on the shaped conductor with each of the two sensors centered respectively within the two opposite notches.

Abstract: A measuring system (40) for measuring a magnitude of a quantity in accordance with the invention includes a light source (52) for providing a light beam (58); a polarization controller (44), optically coupled to the light beam, for rotating a plane of polarization of the light beam through an angle in response to a control signal, which is proportional to the magnitude of the quantity being measured to provide a first rotated polarized beam of light; a sensor (46), coupled optically to the first rotated polarized beam of light and to the quantity being measured, which rotates the plane of polarization of the first rotated polarized beam through an angle proportional to the quantity being measured to provide a second rotated polarized beam of light; an analyzer (42), coupled optically to the second rotated polarized beam of light, having a constant plane of polarization for detecting the second rotated polarized beam of light produced by the quantity being measured; and a feedback and output circuit, coupled t

Abstract: A current sensor for measuring relatively high currents in a semiconductor power switching device includes a coil wound around a nonmagnetic toroidal core situated about the conductor through which the current to be measured is flowing. The voltage between the open terminals of the coil winding is proportional to the time derivative of the current flowing in the conductor passing through the toroid. This voltage is provided to an integrator which supplies the corresponding current at its output. A control circuit resets the integrator once per cycle when the current in the switching device is zero. For a bidirectional switching device, a pulse width control circuit ensures that the integrator is reset for a fixed time before the current therein reverses direction. Any accumulation of errors, due to DC and relatively low-frequency components of current, is avoided and current measurements are reliable.

Abstract: A current sensing apparatus includes a first transformer having a core which is cyclically driven into forward and reverse saturation, and a second transformer having a separate core. The sensing apparatus includes circuitry for separating the sensed current component from the magnetizing current in the secondary winding of the first transformer. The apparatus may also include correction circuitry to cancel the effects of ripple current on the output due to both the magnetization current and errors due to the presence of the ripple cancellation circuitry itself. The present sensing apparatus provides electrical isolation between the primary circuit and the sensing circuit, has wide bandwidth, and is sensitive to temperature, temperature gradient, mechanical forces, aging (creep) and noise.

Abstract: A current sensing device is disclosed for measuring a current flowing in a primary conductor. The primary conductor is coupled with a magnetic circuit, and a device for measuring the magnetic flux in that circuit is provided. The primary conductor comprises U-shaped portions arranged over the magnetic circuit in the manner of a rider and connected by their ends, in the form of pins, to a printed circuit. The printed circuit includes conductor elements, arranged so as to connect certain of said pins together and form together with the U-shaped portions a primary winding of a desired number of turns.

Abstract: A current and voltage detector for a distribution system is provided with a lower section, an upper section and a fastener for combining the lower and upper sections into one body. The lower section comprises: a first groove for receiving an electric wire of the distribution system; an optical type current sensor; an optical type voltage sensor; and a potential divider for supplying a voltage to the voltage sensor. The upper section comprises: a second groove for receiving the electric wire; and a U-shaped magnetic core for applying a magnetic field to the current sensor.

Abstract: In the disclosed fault detector, a casing has a u-shaped portion for receiving a cable and a portion extending from the u-shaped portion. A screw is mounted on said portion. A pressure device is mounted on the end of the screw and directed toward the u-shaped portion for holding the cable in the u-shaped portion. A magnetic lamination passes through the u-shaped portion. The pressure device is made of a magnetic material and a coil surrounds said laminations.