Experimental determination of optimum coil pitch for a planar mesh-type micromagnetic sensor

To overcome the directional properties of a planar meander-type sensor, a new planar micromagetic sensor having mesh-type configuration is reported in this paper. Analytical models are usually used for the characterization of the planar-type sensors. Sensors having mesh-type configuration have been fabricated for the derivation of the optimum coil pitch

A comparison between a two-material and three-material magnetic current limiter

This paper investigates the inductance versus current characteristics of a two-material and a three-material magnetic current limiter. The two-material device consists of a NdFeB permanent magnet, a high saturation flux density magnetic material, and a high saturation flux density magnetic pole piece placed on both sides of the magnet. The three-material device consists of a NdFeB permanent magnet, a high saturation flux density magnetic material, and a low saturation flux density material. Finite-element results for the three-material device agree with the results obtained using design equations. In contrast, the results obtained for the two-material device show that the transition current is overestimated and that the ratio of the maximum safe current and transition current, as well as the unsaturated inductance is underestimated. Extending the magnet beyond the adjoining surfaces improves the sharpness of the transition characteristics when the ratio of the core length to the core width is large. © 1998 American Institute of Physics

A comparison between a two-material and three-material magnetic current limiter

This paper investigates the inductance versus current characteristics of a two-material and a three-material magnetic current limiter. The two-material device consists of a NdFeB permanent magnet, a high saturation flux density magnetic material, and a high saturation flux density magnetic pole piece placed on both sides of the magnet. The three-material device consists of a NdFeB permanent magnet, a high saturation flux density magnetic material, and a low saturation flux density material. Finite-element results for the three-material device agree with the results obtained using design equations. In contrast, the results obtained for the two-material device show that the transition current is overestimated and that the ratio of the maximum safe current and transition current, as well as the unsaturated inductance is underestimated. Extending the magnet beyond the adjoining surfaces improves the sharpness of the transition characteristics when the ratio of the core length to the core width is large. © 1998 American Institute of Physics

Measurement and Visualization of Three-Dimensional Radial and Vectored Magnetic Field Distribution by Usue of the Magnetic CT Method

金沢大学環日本海域環境研究センター生体機能計測研究部

Design Improvements to a Three-Material Passive Magnetic Current Limiter

This paper shows that flux nonuniformity in a passive magnetic fault current limiter softens the transition characteristics from the saturated to the unsaturated state. Soft transition characteristics lead to higher core losses and a derating in the maximum nominal operating current. Flux uniformity is improved by using a combination of extended magnets and an anisotropic saturable core. The use of distributed permanent magnets or an extended magnet leads to larger differential inductance ratios