Abstract: A device for improving the shielding effectiveness of apertures used for mounting electrical component in an enclosure from Electromagnetic Interference (EMI). The device includes a hollow housing which contains and a disc with an aperture, where the disc is attached to an inner surface of the housing to define a first and second inner space. The device also includes a ferrite core which is fit into the second inner space.

Abstract: A permanent magnet assembly comprising an essentially tubular magnet element which is radially magnetized, inner and outer members of a magnetic material resting against inner and outer sides, respectively, of the magnet element, and an annular top plate placed on one end of the outer member. The annular top plate and an end portion of the inner member form an annular air gap which is axially separated from the magnet element and across which the magnetic flux of the magnet element extends radially. The inner member has a polygonal outer surface. The magnet element is divided axially into a number of separate magnet segments having inner surfaces fixed to corresponding outer surfaces of the inner member.

Abstract: An integrated electromagnetic device (112) provides increased inductance in a smaller area on a semiconductor substrate (130). A conduction path (140) is disposed on the substrate for developing the inductance. A first magnetic shield (142) is disposed between the substrate and the conduction path to concentrate the magnetic flux induced by current flowing along the conduction path, which increases the inductance. Inductance is further increased by shielding the magnetic flux from the substrate with the first magnetic shield, which reduces substrate eddy currents that oppose the applied current. A second magnetic shield (144) overlaying the conduction path is coupled to the first magnetic shield, further concentrating the magnetic flux and increasing the inductance.

Abstract: A travel sensor (10) is proposed which has a insertion body (11) consisting of non-ferromagnetic material with good conductive properties. The insertion body (11) is submerged into a measuring coil (15) through which alternating current flows. In addition, the travel sensor is enveloped by a shielding sleeve (16) consisting of ferromagnetic material. Due to the alternating effect between the magnetic field of the coil (15), through which an alternating current flows, and the two materials, at designated frequencies of the alternating current and the respective volume of the insertion body (11) or the shielding sleeve (16), it is possible to compensate the effects of the temperature in such a way that at varying temperatures the measuring curves of the travel sensor (10) extend nearly parallel across the entire measuring range.

Abstract: A system for supplying electric power to an electrically powered vehicle includes a feeder disposed along a structural member as a guide rail that guides the vehicle. The vehicle has an electric power receiving unit that receives electric power from the feeder on a non-contact basis. The electric power receiving unit has a ferrite core with a coil. A ferrite sheet is disposed on a surface of the structural member in such a manner that the ferrite sheet is opposite to the electric power receiving unit. The feeder is surrounded by the ferrite core and the ferrite sheet. When an AC current is supplied to the feeder, a magnetic flux that penetrates the ferrite core and the ferrite sheet varies, thereby causing electromotive force to occur in the coil.

Abstract: A plug cap incorporated type ignition coil is provided with a primary coil 20 and a secondary coil 30 inserted in a case 10. After a cushion member 80, a magnet 82, and then a core 40 are inserted in order in a primary coil bobbin 22 of a generally cylindrical bottomed shape, the case 10 is filled with potting resin 70. There is interposed a bottom wall portion of the primary coil bobbin 22 between one end 42 of the core 40 and the potting resin 70. Accordingly, even though stress resulting from the difference in thermal shrinkage between the core 40, the primary coil bobbin 22 and the potting resin 70 is caused, the stress is absorbed by elasticity of the primary coil bobbin 22 and as a result, the potting resin 70 is hard to cause a crack. Also, even though the core is affected by the thermal shrinkage, the magnet 82 is hard to destroy.

Abstract: A transformer in which a magnetic medium provides flux paths within the medium, two or more windings enclose the flux paths at separated locations along the paths, and an electrically conductive medium, arranged in the vicinity of the magnetic medium and the windings, defines a boundary within which flux emanation from the magnetic medium and the windings is confined and suppressed. In a transformer constructed in accordance with the present invention, both controlled values of leakage inductance and the benefits of separated windings can be achieved. The conductive medium can be configured to reduce the leakage inductance of a controlled-leakage inductance transformer (e.g. for use in a zero-current switching power converter), having separately located windings, by at least 25%, and can be configured to reduce the leakage inductance of a low-leakage inductance transformer (e.g. for use in a PWM power converter), having separately located windings, by at least 75%.

Abstract: A highly accurate electromagnetic-induction-type conductivity and dielectric constant meter is obtained by using a calibration box (instrument) and a structure as below. The conductivity and dielectric constant meter employs an electromagnetic inductive probe which includes a primary transformer composed of a toroidal core with a wound primary coil, a secondary transformer composed of a toroidal core with a wound secondary coil, an electrostatic shield shielding the transformers, and cables that connect the probe to a meter. To eliminate the electrostatic capacity produced by causes other than electromagnetic induction, the structure of the probe is symmetrical. In a first embodiment, the secondary transformer is placed between two parts of the primary transformer, which has two cores of the same shape that are placed symmetrically.

Abstract: A magnetism sensor is disclosed that includes a substrate, a SQUID including a washer of an oxide superconductor thin film formed on a principal surface of the substrate, a hole shaped a similar figure to the washer at the center of the washer, a slit formed between one side of the washer and the hole and a Josephson junction by which portions of the washer at the both sides of the slit are connected across the slit. The magnetism sensor further includes a superconducting flux transformer of an oxide superconductor thin film including an input coil arranged on the SQUID but isolated from the SQUID and a pickup coil arranged on the principal surface of the substrate far from the SQUID, which are connected in parallel and a magnetism shield which excludes flux penetrating into the Josephson junction of the SQUID.

Abstract: A ferrite chip bead includes a ferrite substrate, a plurality of outer electrodes formed at opposite sides of the ferrite substrate, and a plurality of conductive leads each extending transversely through the ferrite substrate and having opposite ends protruded outwardly of opposite side surfaces of the ferrite substrate and connected to corresponding outer electrodes. Conductive leads are embedded in the ferrite substrate by introducing conductive leads in a central portion of a nozzle for extruding the ferrite substrate such that the conductive leads are embedded in the ferrite substrate being extruded, or by introducing conductive leads between ferrite substrate sheets being fed to be bonded together for forming the ferrite substrate such that the conductive leads are interposed between the ferrite substrate sheets being bonded. The ferrite chip has no tendency for outer electrodes to short-circuit from the ferrite substrate upon carrying the chip bead on a circuit board.

Abstract: A rotary transformer assembly of a rotary head drum device, comprising a plurality of concentric circular shielding walls for isolating adjacent pairs of channels from each other so as to prevent a leakage of electromotive force between the pairs of channels and a plurality of concentric circular slots for receiving the ends of the shielding walls so as to isolate the adjacent pairs of channels from each other in combination with the shielding walls. The shielding walls are provided at one of the transformer rotor and the transformer stator as protruding at the outer side of the outermost channel, at the inner side of the innermost channel and at a position between each adjacent pairs of channels. The slots are provided at portions, corresponding to the shielding walls, of the other of the transformer rotor and the transformer stator.

Abstract: A distribution transformer (58) is assembled using a core (18) having a core surface (36) including an inner circumferential surface (40) defining an open eye region (38), an outer circumferential surface (42), and end surfaces (24, 26). Wedged-shaped core supports (20, 22), secured to the end surfaces of the core, are used to support the core during conductor winding operations and to mount the finished transformer within a transformer container (66). The core supports do not extend into the open eye region and allow virtually the entire inner circumferential surface to be covered by the electrical conductors (34, 56). The layers of electrical conductors are wound on top of one another so that each successive layer of electrical conductors conforms to the core surface and any previously wound conductors. Electrical insulation (54) is provided between each conductor layer.

Abstract: A reactor having a coil surrounded by a magnetic shield formed of laminated magnetic sheets. Connecting members pass through the central opening of the coil and are clamped between sheets of the magnetic shield. Each connecting member comprises a pair of connecting plates having opposite ends expanded. They are inserted from opposite sides of the central opening of the core, and are fixed together. The expanded parts at both ends of the connecting member increases the friction, and reduces vibration and noises.

Abstract: A ferrite composition comprising ferrite, borosilicate glass, and optionally boron oxide can be fired at a relatively low temperature of up to 950.degree. C. into a sintered body having improved mechanical strength and electromagnetic properties. The sintered ferrite body is used to form a chip inductor. The inductor is combined with a capacitor to form a composite LC part.

Abstract: A shielded inductor is formed by winding a coil of wire around an axial leaded form, and disposing a magnetic shield around the axial leaded form and the coil of wire. In a preferred embodiment, the magnetic shield is epoxied to the coil of wire. In a further preferred embodiment, a premold is formed around the axial leaded form and the coil of wire, and the magnetic shield is epoxied to the premold, the premold serving to position the magnetic shield concentrically with respect to the axial leaded form and the coil of wire. In a still further embodiment, the premold is provided with a shoulder against which the magnetic field abuts, thus positioning the magnetic shield along the axis of the axial leaded form.

Abstract: A vibration detector for sensing imbalance of a part in a balancing machine uses an eddy current proximity detector for sensing vibration movement of a portion of the machine. To prevent spurious signals due to magnetic fields varying at the part rotation frequency, a mu-metal can is secured to the vibrating portion of the machine, an electrically conductive coupon is attached inside the can for vibrating movement therewith, and the proximity detector is spaced from the coupon by a small gap for producing AC signals representing the vibration amplitude.

Abstract: A superconducting gradiometer for measuring weak magnetic fields for a measuring device comprising a SQUID (Superconductive Quantum Interference Devices), a gradiometer coil, a coupling coil, a cryosystem and a signal processing device, in which the well-defined gradient of a magnetic field to be measured is detected by means of the gradiometer. A coil of the gradiometer is made of superconducting wire, arranged about a carrier body in axial and circumferential grooves cut in the carrier body, the grooves being coated with a superconducting thin film. The thin film in the circumferential grooves is interrupted by slots. The wire in the respective circumferential grooves comprises loops wound in opposing directions connected by a twisted pair of connecting leads secured in the axial groove.

Abstract: An electromagnetic pickup has a coil and a core. A noise shielding cylindrical member of magnetic material is provided around the coil to form an open magnetic circuit between the noise shielding member and the core.

Abstract: In a transformer including a low-voltage input coil, a high-voltage output coil disposed coaxially of the low-voltage input coil, and a core for magnetically connecting both of the coils together; the improvement comprising a first bobbin around which the low-voltage input coil is wound which first bobbin has an inner-diameter hole, wherein the core comprises a rod portion to be inserted into the inner-diameter hole of the first bobbin and a flange portion provided at one axial end of the rod portion. In another aspect of the invention, the transformer further comprises a second bobbin around which the high-voltage output coil is wound, and a connector adapted to be connected to an ignition plug which connector is mounted on an end surface of the second bobbin on the opposite side of the flange portion of the core in such a manner that a mounting direction of the connector substantially coincides with an axial direction of the second bobbin.

Abstract: A transformer system for measuring electrical current includes an electrical conductor having first and second conductor portions. The first conductor portion conducts electrical current in one direction and the second conductor portion conducts the electrical current in an opposite direction. The first conductor portion produces a magnetic field H.sub.a and the second conductor portion produces a magnetic field H.sub.b. A coil having a non-ferromagnetic core is positioned between the first and second conductor portions so that the axis of the coil is substantially parallel to the magnetic fields H.sub.a and H.sub.b. The separation between the outer circumferential surface of the coil and the first and second conductor portions is the minimum distance for avoiding a voltage breakdown therebetween for a predetermined maximum electrical current in the conductor portions. At least one ferromagnetic shield surrounds the first and second conductor portions for shielding the coil from external magnetic fields.

Abstract: A surface mountable electronic device and method of making same wherein a discrete electronic device is encapsulated in a body of electrical insulating material having opposite ends and mounting surface extending between the ends, and an electrode is provided on each end. Each electrode includes a portion on the end of the body in electrical contact with the corresponding lead of the discrete electronic device and a contact portion extending along the mounting surface for making electrical connection to a circuit portion defined on a surface to which the device is mountable. The discrete electronic device is manufactured, prior to encapsulation, by known techniques. Preferably the body is a rectangular solid with each of the four sides having electrode contact portions thereon to serve as one of four possible mounting surfaces each with substantial mechanical stability.

Abstract: In a transformer (1) comprising an E-I laminated core (2) with transformer windings (7) wound around the central limb (5), at least two metal-strip loops (10, 11) are provided for magnetic screening. The magnetic strips (10,11) extend around the corners (12) of the laminated core (2) at an as constant as possible distance from one another and perpendicularly to the lamination direction of the laminated core (2) and are welded (17) to the laminated core (2) at side areas where the magnetic field strength is low.

Abstract: A cutlery detector device is provided for detecting metal objects discarded as trash along with non-metallic trash material. The detector device includes a metal detecting ring or the like mounted at the top of a trash receptacle, in combination with circuitry adapted to trigger an alarm upon passage of a metal object such as a cutlery item into the trash receptacle. A counter may also be provided to count the number of metal objects placed into the trash receptacle.

Abstract: An electronic component such as a chip inductor, in particular an air core coil, RF choke and transformer is disclosed having a solid core portion (1) of the ferromagnetic or electrically nonconducting material, with a winding space to be wound in one or more courses and recessed relative to parallel end faces (2, 2) of the core portion. The end faces (2, 2) have dovetail-shaped cutouts (3, 3) located within the outside portion of these end faces for receiving tab-like electric contact elements (5, 5). These electrical contacts may be glued or wedged into these cutouts and retained therein under the action of resilient properties of the cutout elements.

Abstract: An induction cooking apparatus or a ceramics hob which heats conductive food and/or a conductive pan through hysteresis loss and/or eddy current loss by exciting a coil with high frequency power, comprises a casing, a coil mounted on a coil support, and an insulation cover plate between the coil and food to be cooked. The coil support is made of ferro-magnetic material of mixture of insulation resin and ferrite powder which occupies 75-85 weight %, instead of a prior mere insulation resin so that no flux leaks below the coil support. Preferably, the coil support has a plurality of longitudinal ferrite ribs extending radially under the coil support, and still preferably, the coil support has a plurality of holes at the central portion of the same so that permeability at the central portion is essentially smaller than that at the outer portion to provide uniform flux.

Abstract: A ferromagnetic eddy current probe apparatus having a double shielded magnetic coil to reduce the size of the magnetic filed and to generate a sharply focused electromagnetic field. A ferromagnetic steel alloy provides a double shield effect for greater concentration of the electromagnetic field onto a test specimen, and also to prevent probe tip wear and deformation when used to inspect fastener holes with a high speed designed feature maintenance the size setting of the probe (coil-end) diameter. An expansion slot in the end of the probe provides a spring action during probe radiation to keep a constant contact with the wall of a fastener hole. The ferromagnetic probe portion is removeable from the shank-end (a non-metallic portion of the probe) for easy repair or replacement and provides electrical isolation to prevent shorting of the signal.

Abstract: There is provided a polyphase assembly for controlling A.C. devices and capable of producing an electrical impedance of a substantial resistive component. The assembly has a plurality of windings, separate for each phase, wound on and along a single, axially directed core. The core is constituted by at least one ferromagnetic body. The air boundary to air boundary thickness of at least the portions of the core covered by the windings is greater than 1.6 mm.

Abstract: A transformer (3) having a ferromagnetic core (5, 7) provided with windings and a metal screening device which comprises a screening sheath surrounding the core (5, 7). The screening device comprises supporting caps (25, 27) which are placed on the transformer from opposite directions and between which the screening sheath (13) is clamped at a distance from the core. The screening device may also serve as a holder for the transformer on a chassis of an apparatus.

Abstract: An inductor having an air gap in its magnetic core is provided with a magnetic shield which surrounds the inductor air gap to not only reverse bias the inductor magnetic circuit so as to increase the amount of current required to achieve inductor saturation but also to return any stray flux radiating from the inductor back into the inductor magnetic circuit to reduce the radiated electromagnetic interference.

Abstract: An electrical shunt reactor coil comprises a rectangular magnetic frame in the form of two vertical members (1,2) interconnected at their ends by two horizontal yoke members (3,4). The frame members are constituted by respective stacks of magnetic laminations. A central core (7) extends across the middle of the frame parallel to the vertical members, and an electrical winding (6) is situated around the core. The horizontal yoke members are of width L which is less than the diameter of the winding and which is close or equal to the diameter of the central core. Magnetic shunts (20 to 23) are placed across the outside of the horizontal yoke members. The shunts are longer than the width L of the yoke members so that they overhang both sides thereof. The magnetic shunts are constituted by respective stacks of laminations extending parallel to the axis of the central core and at right angles to the laminations of the yoke members.

Abstract: An a-c current sensor for measuring the current which flows in a conductor has an insulating frame having a central compartment open at its upper end and encompassed by a U-shaped receptacle for a bent portion of the conductor. A coil is housed in the central compartment. The frame is slidingly mounted within a sleeve made of a soft magnetic material and having two assembled half-shells. The voltage generated by the current across the coil is proportional to the intensity of current flow.

Abstract: A transformer including a lamination core of band iron and a magnetic screen which consists of a wound iron band arranged around the lamination core (5) and which is secured to the core by means of expansion wedges provided in the space between the core and the screen 13. The expansion wedges (7) extend transversely of or at an angle with respect to the winding direction of the wound iron band.

Abstract: An inductive measuring transducer impermeable to pressure media for use with a fluidic adjusting member such as a multiple position valve as a receiving casing of non magnetic working material for receiving a magnetic core, coils surrounding the casing which are, in turn, surrounded by a housing. An operating rod passes into the casing through a connecting member and operates the core. The casing is formed as continuous, hollow cylindrical tube with a closing member or plug inserted in one end and attached in fluid tight relationship. The other end of the receiving casing is tightly connected with the connecting member which is formed as a separate part from the receiving casing.

Abstract: A non-contacting position sensor has an exciting coil disposed in a plane and has a sensing coil located in an intersecting plane so that portions of the sensing coil are disposed symmetrically around a portion of the exciting coil in mutually inductive relation to that portion of the exciting coil. Ferrite means magnetically shield those sensing coil portions from other portions of the exciting coil and housing means are provided to mount the sensor so that those coil portions are conveniently positioned for relative movement with respect to magnetically permeable or electrically conductive inductance-modifying means on an object whose position is to be monitored. Movement of the inductance-modifying means as the object moves then modifies the mutual inductance between the respective sensing coil portions and the exciting coil portion so that, when the exciting coil is driven, the sensing coil provides a signal which is accurately and reliably representative of the object position.

Abstract: A transformer characterized by groups of low voltage and high voltage windings inductively related to a core member, and a shunt of magnetizable microlaminations disposed between the low and high voltage windings, whereby the shunts independently adjust the transformer impedance.

Abstract: Apparatus for sensing the arrival of a motor vehicle at the pick-up window of a drive-thru business and providing a visual display of the length of time that the motor vehicle is present at the window. Visual and audible alarms apprise operating personnel that the vehicle has been present for a predetermined length of time. The apparatus also totals and displays the number of vehicles as well as the total duration of stay of all vehicles arriving at the pick-up window.The motor vehicles are sensed by means of a vertically oriented rectangular loop detector positioned beneath the pick-up window adjacent the vehicle approach lane. The detector senses the metallic sides of the approaching vehicle, and is shielded to prevent spurious signals.The apparatus finds particular application for improving the working efficiency of operating personnel of the drive-in business.

Abstract: A residual current transformer comprises an annular magnetic core which has not a gap nor sectional part crossing said magnetic core but has one or more narrow sectional area parts.

Abstract: In a transformer or a reactor having at least one winding of foil-formed electrical conductor material, a magnetic-flux-controlling spirally-wound sheet of highly permeable ferro-magnetic material is arranged axially outside each end of the winding. The ends of the sheet are galvanically connected to the foil winding. By division of the magnetic material in the sheet, a high resistance in the longitudinal direction of the sheet, and thus lower losses, are obtained.

Abstract: Disclosed are improved constructions for power transformers and reactors having windings of tape-formed conductor material which tend to reduce additional losses in the windings. In the improved construction for a power transformer or reactor comprising a core containing magnetic material and having legs and a yoke and comprising windings including a tape-formed conductor material arranged concentrically around the core legs, the innermost of the windings has a first portion located nearest the core leg which has an axial length greater than the length of the portion of the winding located radially outside said first portion. The first portion thereby forms a cylindrical shield for controlling the magnetic leakage flux appearing outside the ends of the winding.

Abstract: A magnetic circuit for inductive electrical devices, preferably reactors, comprises a frame consisting of yokes and side walls, the frame having a preferably rectangular cross-section and being manufactured from laminated magnetic material. At least one core leg having a preferably circular cross-section and composed of laminated magnetic material is arranged in the frame between the two yokes. Between the ends of the core leg and the yokes are arranged cross-flux plates of laminated magnetic material in order to distribute the flux between the legs and yokes. The laminations in the cross-flux plates are oriented to be perpendicular to the laminations in the yokes. Each cross-flux plate covers at least the full width of the yoke and at least the complete width of the core leg. The width of each plate is suitably as great as the diameter of the winding which is arranged around the core leg. Each plate will thus act as a mechanical support for the ends of the winding.

Abstract: Improved end clamping members are used in transformers having a horizontal magnetic circuit which is preferably of rectangular cross-section.Each end clamping member is embodied by juxtaposed longitudinal beams--side beams (4) comprising magnetic laminations on edge over substantially their whole thickness, and intermediate beams (5) comprising magnetic laminations on edge over only some of their thickness, the end clamping member being embodied for the rest by a longitudinal flat iron member (15), and each group or set of magnetic laminations has at its center the longitudinally extending wedge-shaped member and on each side another longitudinally extending flat iron member of the same width.The invention is of use more particularly for high-power shell type transformers in a form-fit tank.

Abstract: Efficient electromagnetic shielding envelopes made of wound metallic glass filaments are disclosed. They are made by winding the filaments around a suitably shaped mandrel and embedding the filaments in a matrix. These shielding envelopes have high shielding ratios at low magnetic fields and are easily manufactured.

Abstract: In an induction cooking apparatus, an electrostatic shield is interposed between the work coil and the location of the cooking vessel upon the sheet forming a cook top to reduce the capacitive coupling between the coil and the cooking vessel to accordingly reduce the voltage between the vessel and ground.

Abstract: In order to provide an electrically insulated and fluid-tight assembly for securing a current transformer to the inside of a dynamoelectric machine housing, a screw is inserted through an aperture in the machine's housing to secure the current transformer to a portion of the inner surface of the housing wherein a first insulating material is used to insulate the current transformer from the housing; a second insulator is used to insulate the screw from the housing; and an insulating cap is secured over the top of the screw. An O-ring provides a fluid-tight seal between the cap and the machine housing and a retaining ring is utilized to secure the cap over the screw's head within the machine housing. Secured to the lower part of the current transformer is a soft iron magnetic shield which is threaded to engage the screw and serves to support the current transformer.