Magnetic core

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

Contribution of magnetostriction to transformer noise

Abstract: An important source of transformer noise is magnetostrictive vibration of the magnetic core. This paper outlines some important effects of mechanical building stress on magnetostriction. Harmonic analysis of magnetostriction is necessary to quantify its influence on acoustic noise but it implied here that the most important magnetostrictive parameter has not yet been identified. A route is proposed for obtaining a definite, quantified relationship between defined magnetostrictive characteristics of core laminations and noise by systematically assessing noise and vibration modes of simple, small transformer cores.

Fuel injection device

Abstract: A method of controlling a fuel injection device that can control a small amount of injection is provided. A fuel injection device for use in an internal combustion engine, includes: a valve body that can open and close a fuel passage, a needle that transfers a force with the valve body, and executes valve opening/closing operation, and an electromagnet that includes a coil and a magnetic core provided as a driver for driving the needle, and a cylindrical nozzle holder disposed on an outer periphery of the magnetic core and the needle, in which a current is supplied to the coil to exert a magnetic attractive force between the magnetic core and the needle to open the valve body.

Method of manufacturing iron core and apparatus suitable for the method

Abstract: PROBLEM TO BE SOLVED: To provide a method and an apparatus of largely improving workability of punching/fixing step of an iron core when fixing a normal magnetic steel sheet using an adhesive. SOLUTION: The method of manufacturing a laminated iron core includes, in the step of punching the magnetic steel sheet in a predetermined shape and fixing as a unit iron core, the steps of (1) punching a steel sheet in a predetermined shape with a mold, (2) laminating the punched unit iron cores, (3) coating a paste-like adhesive in a point-like or a linear-like manner on the surface of the iron core during laminating or after the lamination, and then (4) integrating the laminated iron core. COPYRIGHT: (C)2005,JPO&NCIPI

A Bearingless Switched-Reluctance Motor for High Specific Power Applications

Abstract: A 12-8 switched-reluctance motor (SRM) is studied in bearingless (or self-levitated) operation with coil currents limited to the linear region to avoid magnetic saturation. The required motoring and levitating currents are summed and go into a single motor coil per pole to obtain the highest power output of the motor by having more space for motor coil winding. Two controllers are investigated for the bearingless SRM operation. First, a model-based controller using the radial force, which is adjusted by a factor derived from finite element analysis, is presented. Then a simple and practical observation-based controller using a PD (proportional-derivative) control algorithm is presented. Both controllers were experimentally demonstrated to 6500 rpm. This paper reports the initial efforts toward eventual self levitation of a SRM operating into strong magnetic core saturation at liquid nitrogen temperature.