Magnetic core

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

A Novel Linear Permanent-Magnet Vernier Machine With Improved Force Performance

Abstract: In this paper, a linear permanent-magnet vernier machine is proposed, in which both magnets and armature windings are placed in the short mover, while the long stator consists of an iron core only. Hence, it is suitable for long-stroke applications such as urban rail transit. The proposed machine integrates two magnetization directions of magnets together, which can reduce leakage flux and enhance flux density. Meanwhile, since different topologies and different slot/pole number combinations have an effect on the winding factor, several general rules are established. It is revealed that the thrust force ripple of the proposed machine is lower than its cogging force ripple, which is explained by a built analytical model. Both the analytical model and the finite-element results are validated by experiments based on a prototype machine.

Partial gap magnetic core apparatus

Abstract: Potted wire-wound loop-core structures are based on cores which include partial gapped inductors or transformers with their reduced dependence of inductance on current during operation. Total enclosure of gaps by encircling core material is both magnetic and physical, thereby avoiding fringing magnetic fields as well as joint failure due to differential expansion of potting material.

Methods and apparatus for coupling and decoupling portions of a magnetic core

Abstract: Aspects of the subject disclosure may include, regulating an alternating magnetic flux in a magnetic core having a first portion separable from a second portion of the magnetic core. The regulation of the alternating magnetic flux causes a coupling force between the first portion of the magnetic core and the second portion of the magnetic core. Responsive to detecting a signal, modifying the regulation of the alternating magnetic flux to reduce the coupling force between the first portion of the magnetic core and the second portion of the magnetic core. Other embodiments are disclosed.

Antenna and radio timepiece using the same, keyless entry system, and rf id system

Abstract: A highly sensitive magnetic sensor-type antenna provided in a metallic housing, a radio timepiece into which the antenna is integrated, a keyless entry system, and an RF ID system, where a problem of eddy current loss is eliminated from the antenna without increasing installation area and volume. The antenna is constructed by bending an end section of a magnetic core of the antenna in the direction to separate from a metallic housing, or by providing an auxiliary magnetic path member having a smaller specific magnetic permeability than the magnetic core, or by receiving the magnetic core in a case made from a magnetic material.

Filters with inductance cancellation using printed circuit board transformers

Abstract: Capacitor parasitic inductance often limits the high-frequency performance of filters for power applications. However, these limitations can be overcome through the use of specially-coupled magnetic windings that effectively nullify the capacitor parasitic inductance. This paper explores the use of printed circuit board (PCB) transformers to realize parasitic inductance cancellation of filter capacitors. Design of such inductance cancellation transformers is explored, and applicable design rules are established and experimentally validated. The high performance of the proposed inductance cancellation technology is demonstrated in an EMI filter design.