Magnetic circuit

About: Magnetic circuit is a research topic. Over the lifetime, 15707 publications have been published within this topic receiving 118099 citations.

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. >

Magnetic trip device with wide tripping threshold setting range

Abstract: A magnetic trip device having two plunger cores cooperating respectively with polar parts of a fixed magnetic circuit excited by a coil. The effects of the plunger cores are opposing, and by adjusting the inital position of the moving core assembly constituted by these two plunger cores, the tripping thereshold can be adjusted with a large amplitude.

Magnetic Adder Based on Racetrack Memory

Abstract: The miniaturization of integrated circuits based on complementary metal oxide semiconductor (CMOS) technology meets a significant slowdown in this decade due to several technological and scientific difficulties. Spintronic devices such as magnetic tunnel junction (MTJ) nanopillar become one of the most promising candidates for the next generation of memory and logic chips thanks to their non-volatility, infinite endurance, and high density. A magnetic processor based on spintronic devices is then expected to overcome the issue of increasing standby power due to leakage currents and high dynamic power dedicated to data moving. For the purpose of fabricating such a non-volatile magnetic processor, a new design of multi-bit magnetic adder (MA)-the basic element of arithmetic/logic unit for any processor-whose input and output data are stored in perpendicular magnetic anisotropy (PMA) domain wall (DW) racetrack memory (RM)-is presented in this paper. The proposed multi-bit MA circuit promises nearly zero standby power, instant ON/OFF capability, and smaller die area. By using an accurate racetrack memory spice model, we validated this design and simulated its performance such as speed, power and area, etc.

A Simple Nonlinear Magnetic Analysis for Axial-Flux Permanent-Magnet Machines

Abstract: This paper presents a simple nonlinear magnetic analysis for axial-flux permanent-magnet machines as an assistant design tool of 3-D finite-element analysis (3D-FEA). The proposed analysis consists of an equivalent magnetic circuit and an analytical model of air-gap permeances, including saturable permeances in the core. The proposed analysis is capable of calculating the flux distribution and torque characteristics under heavy operating conditions. We verify the accuracy of the proposed analysis by comparing the results with those of 3D-FEA for various design free parameters. After verifying the accuracy of the analysis, we present our analysis-based optimum design, which realizes the maximum torque density while maintaining efficiency at the desired value. Compared to the traditional 3D-FEA, the design method proposed here has the same accuracy, while the computation time is as short as 1/21.

Modeling and Analysis of a Novel Transverse-Flux Flux-Reversal Linear Motor for Long-Stroke Application

Abstract: In this paper, a transverse-flux flux-reversal linear motor (TF-FRLM) is proposed. With magnets on the primary side, the proposed motor is suitable for long-stroke application, benefiting from easy manufacturing and low-cost secondary cores. First, the basic structure and operating principle of the proposed motor are presented. Then, the expressions of back electromotive force (EMF) and electromagnetic thrust are obtained by an equivalent magnetic circuit model. Third, for saving computation time, a simplified half-phase model with a symmetry boundary is employed in the 3-D finite-element analysis (FEA) to investigate the TF-FRLM, and the field distribution, the back EMF, the detent force, as well as the thrust force are emphasized. Finally, a prototype is constructed, and experiments show good agreement with the FEA results.