Magnetic circuit

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

A switched reluctance motor model with mutual coupling and multi-phase excitation

Abstract: A novel switched reluctance motor (SRM) magnetic equivalent circuit model with mutual coupling and multiphase excitation is presented which successfully predicts the magnetic behavior of an SRM with multiple phase at a time excitation. The model is new in that it spreads the saturable elements throughout the machine rather than at the tooth tips. This allows the dominant mutual coupling effect, core saturation during multi-phase excitation, to be modeled. The authors describe methods for calculating or functionally representing values for the circuit elements given the machine geometry and a minimum number of finite-element models, a method for modeling saturable materials, and a method for solving the resulting mesh for flux values given excitation levels. The model results are compared with intermediate finite-element results. >

Numerical analysis of transient magnetic field in a capacitor-discharge impulse magnetizer

Abstract: A method for analyzing the magnetic field in a capacitor-discharge impulse magnetizer is established by modifying the finite element method. The effects of charging voltage, capacitance and resistance on the behaviour of the localized fluxes in the Impulse magnetizer are analyzed quantitatively. As the detailed distribution of the flux density can be obtained, the optimum design of the magnetizer which produce desired magnet will be possible using our new method.

Concealed magnetic ID code and antitheft tag

Abstract: The invention relates to a special type of magnetic tag that serves both as an identifier of the article to which it is attached and as an antitheft device. The former attribute is especially important should stolen property be recovered. Identification comes about through the use of an array of individual magnetic elements that are closely spaced, preferably along and perpendicular to an amorphous wire or strip. The magnetic elements can take the form of magnetic ink, high coercivity wire, thin foil, or amorphous wire. The array may be personalized (coded) by leaving out elements of the array or driving selected elements to saturation while others remain demagnetized. The elements can also be in the form of a double array to constitute `1`s and `0`s to form a code. Reading of the elements is accomplished with a special reading head consisting or one or more small magnetic circuits coupled to one or more pickup loops. A longer length of soft magnetic wire or thin strip is used to trigger an anti-theft alarm when activated by an external field from a magnetic gate.

Magnetic shielding of wireless power transfer systems

Abstract: This paper deals with the magnetic shielding of the field generated by a wireless power transfer (WPT) system at the frequency of 20 kHz. Different shielding techniques are examined and discussed based on the use of conductive and magnetic material panels. The performances of the WPT system and the magnetic field shielding effectiveness (SE) in presence and in absence of shield panels are calculated and measured.

Magnetic thin film memory element utilizing GMR effect, and recording/reproduction method using such memory element

Abstract: It provides a magnetic thin film memory element utilizing the GMR effect. The memory element comprising a first magnetic layer with a closed magnetic circuit structure, a second magnetic layer with a closed magnetic circuit structure having a coercive force higher than that of the first magnetic layer, and a non-magnetic layer disposed between the first and second magnetic layers, at least a part of which is made of an insulating material. It also discloses methods for recording and reproducing information in and from such memory element.