Abstract: An ignition coil for an internal combustion engine includes a magnetically-permeable core extending along a core longitudinal axis, the core having a pair of end surfaces on axially-opposite ends thereof. The ignition coil also includes a primary winding disposed outward of the core, a secondary winding disposed outward of the primary winding, and a structure comprising magnetically-permeable steel laminations having a base and a pair of legs, the structure defining a magnetic return path. The core is disposed between the pair of legs such that the core longitudinal axis extends through the legs and the end surfaces face toward the legs and at least one of the end surfaces of the core is spaced apart from a respective one of the legs to define an air gap. The structure is over-molded with an over-molding material such that the over-molding material fills at least a portion of the air gap.

Abstract: This disclosure provides implementations of inductors, transformers, and related processes. In one aspect, a device includes a substrate having first and second surfaces. A first inducting arrangement includes a first set of vias, a second set of vias, a first set of traces arranged over the first surface connecting the first and second vias, and a second set of traces arranged over the second surface connecting the first and second vias. A second inducting arrangement is inductively-coupled and interleaved with the first inducting arrangement and includes a third set of vias, a fourth set of vias, a third set of traces arranged over the first surface connecting the third and fourth vias, and a fourth set of traces arranged over the second surface connecting the third and fourth vias. One or more sets of dielectric layers insulate portions of the traces from one another.

Abstract: A surgical navigation system for navigating a region of a patient includes a non-invasive dynamic reference frame and/or fiducial marker, sensor tipped instruments, and isolator circuits. The dynamic reference frame may be repeatably placed on the patient in a precise location for guiding the instruments. The instruments may be precisely guided by positioning sensors near moveable portions of the instruments. Electrical sources may be electrically isolated from the patient.

Abstract: A surgical navigation system for navigating a region of a patient includes a non-invasive dynamic reference frame and/or fiducial marker, sensor tipped instruments, and isolator circuits. The dynamic reference frame may be repeatably placed on the patient in a precise location for guiding the instruments. The instruments may be precisely guided by positioning sensors near moveable portions of the instruments. Electrical sources may be electrically isolated from the patient.

Abstract: A surface-mount air-core coil is provided in which a conductive wire covered with an insulation coating is wound into a spiral shape to form a cylindrically wound coil portion, conductive wires which are not covered with the insulation coating extend from both ends of the wound coil portion to form a pair of terminal portions, and the terminal portions are soldered onto electrode lands of a circuit board. A lower side of the wound coil portion which faces the circuit board is curved, an upper side thereof is formed in a flat shape, and the curved part is mounted on the circuit board.

Abstract: An eddy current probe having an increased depth penetration. The probe includes an eddy current test assembly formed in the outer surface of a shoe that rotates within a tubular test specimen. The eddy current test assembly includes a pair of differentially-connected electromagnetic coils whose axes are parallel and lie in a plane perpendicular to the direction of the axis of the tubular test specimen. The probe assembly further includes a magnetically permeable backing plate that is closely adjacent to the innermost ends of the two differentially-connected coils. The differentially-connected coils are driven with a signal having a predominant frequency that is less than the natural resonant frequency of the eddy current probe. Flaws and other non-uniformities in the tubular test specimen are detected as the differentially-connected coils travel pass the location of the flaw.

Abstract: A superconducting energy storage inductor having two D-shaped coils with their flat sides being adjacent and facing one another. The coils are restrained from moving relative to one another and are immersed in a cryogenic fluid. The coils are connected in series and when provided with current, the resulting magnetic fields of the coils oppose one another.

Abstract: Electrically conductive tubing for realizing induction coils having improved efficiencies comprises an outer peripheral portion of conductive material defined by a plurality of side walls and a single hollow passageway. Each side wall has an inner and outer surface. At least one side wall has a curved outer surface. The hollow passageway is defined by the inner surfaces and can be either centered within the tubing or spaced apart from the center of the tubing. The present invention also defines an induction coil and an induction furnace having an induction coil which utilizes such tubing. The curved outer surface has a radius of curvature which is defined substantially by a function of the tubing width in the axial direction, and spacing between turns of the induction coil. The cross section of the outer surface of the outer peripheral portion of the tubing taken along a transverse axis of the tubing defines a geometric figure.

Abstract: A search coil assembly for an inductive search device of the transmitter/receiver type is described having advantages relative to manufacture, repeat accuracy and sensitivity in operation. This is made possible by the utilization of printed-circuit board technology in search coil construction in which electrically conductive windings in the form of a conductor band of circuit tracks are arranged side-by-side at the periphery of partial areas on a carrier layer common to the partial areas.

Abstract: Method for fabricating a laminated coil conductor for a high current coil which includes wrapping a layer of insulation around a rotatable shaped mandrel and then winding a plurality of copper sheets over the insulation as the mandrel is rotated. Solder is interposed between the copper sheets and between coolant tubes positioned on each end of each coil conductor. The assemblage is then removed from the mandrel and raised to a temperature to bond the copper sheets and coolant tubes together. The assemblage is then placed in a structural box and a plastic is injected into the box to fill any voids between the coil conductor and the box.An assembly of a plurality of coil conductors arranged in a high current coil according to the method is illustrated.

Abstract: Method for fabricating a laminated coil conductor for a high current coil which includes wrapping a layer of insulation around a rotatable shaped mandrel and then winding a plurality of copper sheets over the insulation as the mandrel is rotated. Solder is interposed between the copper sheets and between coolant tubes positioned on each end of each coil conductor. The assemblage is then removed from the mandrel and raised to a temperature to bond the copper sheets and coolant tubes together. The assemblage is then placed in a structural box and a plastic is injected into the box to fill any voids between the coil conductor and the box.

Abstract: Magnetic stimulator coils having a definable region wherein magnetic field intensity is greater than at other regions of the coil are disclosed. The definable region is formed by one or more corners in a coil and/or by a higher concentration of windings in one region of the coil. Because the magnetic field produced at the definable region of the windings is higher than at other regions, the location where stimulation is to occur is better defined when the definable region of a coil formed in accordance with the invention is suitably positioned on the skin of a patient and energized by a suitable power source. Preferably, the windings are splayed because splayed winding stimulator coils are more efficient than concentrated winding stimulator coils. Efficiency is better because magnetic field intensity is reduced where windings are splayed due to a reduction in mutual inductance.

Abstract: An inductor with high inductance to resistance ratio capable of handling megamp currents. Sixteen coil assemblies are radially arranged into four quadrants of four coil assemblies each and jumpers are utilized to connect the quadrants in different configurations for different inductance values. Each coil assembly is made up of a plurality of nested essentially D-shaped copper conductors collectively nested within an aluminum structural support plate in which eddy currents are minimized by a interruption in the plate. The individual conductors of each coil assembly are transposed throughout a quadrant for balanced current flow. Coil bus bars as well as an input and output bus bar are connected to predetermined ones of the coil assemblies with the input and output bus bars being connected to system input and output leads. The unit is operated at cryogenic temperatures by immersion in a liquid nitrogen filled cryostat.

Abstract: An improved magnetic core for an electrical transformer, and a method and apparatus for forming the core, are disclosed wherein the corners of core windows are configured to decrease the magnetic path length, thereby reducing the core losses and the amount of material necessary to construct the core. One exemplary embodiment includes a core window opening having an outer corner radii that are larger than the inner corner radii. Alternatively, the core window may have corners of a non-constant radii, with the outer corners having a more gradual or gentle curvature. These and other disclosed embodiments also enhance the ease of assembly of the transformer core and thus decrease or eliminate damage to the magnetic material during assembly.

Abstract: Apparatus comprising a toroidal magnet whose conductive layers closest to the axis of symmetry are supported everywhere by a structural material of high mechanical strength, and synchronous press means exerting a compressive force parallel to the said axis of symmetry, the apparatus achieving, in use, quasi-isotropy of the stress tensor in the most critically loaded part of the magnet.

Abstract: A superconductive coil assembly has a housing formed of an inner shell and an outer shell, and a superconductive coil situated in a space defined between the shells. A plurality of spring elements arranged in a mosaic-like pattern on a surface area of one of the shells between the superconductive coil and the shell. Each spring element has a first flat member being of a material having a relatively small dilatation and a second flat member being of a material having a relatively large dilatation. The first and second flat members are inseparably bonded to one another. The spring elements have an effective thickness that is greater at a relatively low temperature than at a relatively high temperature.

Abstract: A transformer winding, made as a layered winding with striplike conductor insulated with at least one strip of insulation folded about the conductor, and a process for making the same, are disclosed. To make possible a fully automatic manufacture of the winding with sufficient mechanical strength and uniform impregnation, the insulation strip, in addition to insulation of the conductor, constitutes likewise the insulation of the layers. At the periphery of a winding layer there are punctate bonding places at predetermined distances only on the outside of the conductor insulation. The cross section of the layered winding may be essentially trapezoidal with the transition to the free outer end comprising one or more circular arcs with different radii.

Abstract: A superconducting coil, suitable for generating a magnetic field within a nuclear reactor, wherein a structurally continuous disk helix is utilized to carry a plurality of parallel superconductor windings thereon. The structure provides an improved support to the superconductor windings to more positively prevent stresses or small movements that would cause the superconductor to go normal.

Abstract: At least one spiraled semi-circular shaped coil is printed on each surface of a wafer. The coil on a first surface of the wafer is arranged in such a manner that it is rotated 90 degrees with respect to the coil on a second surface thereof. In one embodiment, two such printed coils are symmetrically provided on each surface of the wafer, and the pattern of the printed coils on the first surface is arranged to be rotated 90 degrees with respect to the pattern of the printed coils on the second surface thereof. The spiraling directions of the coils on the same surface are inverse or opposite each other. The inner terminals of the coils on each surface are connected and an output is taken out from the outer terminals thereof, or vice versa. A printed coil is employed, for example, in a moving coil type pick-up cartridge.

Abstract: The conducting path width of a spiral printed circuit coil is reduced for the inside of the spiral coil to obtain more inductance in the same space without substantial sacrifice in Q. In another form of spiral coil with non-constant path width, the path width is reduced in a sector of the coil located between the inner and outer terminals to reduce the distance between terminals with minimum sacrifice in inductance or Q.