Magnetic core

About: Magnetic core is a research topic. Over the lifetime, 30011 publications have been published within this topic receiving 155247 citations.

Treatment of amorphous magnetic alloys to produce a wide range of magnetic properties

Abstract: Amorphous magnetic metal alloys are processed by annealing at temperatures sufficient to achieve stress relief and cooling in directed magnetic fields or in zero magnetic fields. The ac and dc properties of magnetic cores produced in accordance with the processes of the invention may be tailored to match those of a wide range of magnetic alloys. Alloys processed in accordance with the invention provide improved performance in inductors, transformers, magnetometers, and electrodeless lamps.

A Novel Method to Predict the Real Operation of Ferrite Inductors With Moderate Saturation in Switching Power Supply Applications

Abstract: This paper presents a method to predict the real operation current wave-shape of Ferrite Core (FC) inductors in switching power supply applications involving a moderate inductor saturation. The method is based on a behavioral analytical model of inductance versus current saturation curve, obtained starting from the data provided by inductors manufacturers. The algorithm developed to solve the nonlinear model of the inductor can be applied to predict the range of the operating conditions involving a sustainable partial saturation for FC inductors, and the resulting method is best suited for the selection of minimum size inductors for high-power-density power supply design solutions.

Multipole electrical circuit breaker with improved interchangeable trip units

Abstract: A molded case multi-pole circuit breaker comprises an interchangeable trip unit having a magnetic circuit surrounding a main stationary conductor and provided with a U-shaped core secured to circuit-breaker assembly and a magnetic rod fastener to the trip unit. The rod is inserted between the legs of the core, and a single turn secondary winding surrounds the rod. A bimetal is attached to the winding, and the thermal tripping characteristics are independent of the relative position of the magnetic core and rod.

Horizontal field iron core magnetic resonance scanner

Abstract: A patient is disposed on a patient couch (A) and positioned longitudinally and vertically to bring a region of interest within the patient into a gap between a pair of magnetic pole pieces (20, 22). Magnetic field driver(s) (50', 50, 52) generates a magnetic field through a U-shaped ferrous member (B) connected with the pole pieces and through the gap therebetween. The U-shaped ferrous member extends below the gap such that open access is provided to the patient from above. Shielding coils (62, 64, 66) are disposed between the U-shaped ferrous portion and the gap to compensate for distortion of the magnetic field in the gap attributable to magnetic flux through the U-shaped member. Magnetic resonance is excited in the region of interest of the patient between the pole pieces and magnetic resonance signals emanating therefrom are received, such as with a crossed elliptical quadrature coil (72). The received magnetic resonance signals are processed by processing circuitry (E) and image representations for display on a monitor (82).

A fully integrated planar toroidal inductor with a micromachined nickel-iron magnetic bar

Abstract: A fully integrated toroidal inductor is realized on a silicon wafer by using a multilevel metallization technique to fabricate a wrapped coil wound around a micromachined bar of high-permeability magnetic material. In particular, efforts are made to minimize the coil resistance by using thick conductor lines and electroplated vias. In this structure, a 30 /spl mu/m thick nickel-iron permalloy magnetic core is wrapped with 40 /spl mu/m thick multilevel copper conductor lines, constructing a conventional toroidal inductor in planar shape. A closed magnetic circuit (i.e., toroidal) in this inductive component is adopted, where magnetic core bar and wrapped conductor lines are tightly interlinked, so that leakage flux and electromagnetic interference are minimized. For an inductor size of 4 mm/spl times/1 mm/spl times/130 /spl mu/m thickness having 33 turns of multilevel coils, the achieved inductance is approximately 0.4-0.1 /spl mu/H at 1 kHz-1 MHz, corresponding to a core permeability of approximately 800. The measured dc resistance of the conductor lines is approximately 0.3 /spl Omega/. Since this inductive component shows favorable magnetic characteristics as well as electrical properties, it is potentially very useful as a basic inductive component in applications for magnetic microsensors, microactuators, and micromagnetic power devices such as a dc/dc converter. >