...are another way of approaching Open Boundary problems. This page presents values necessary to implement really high-order IABCs.

Mathics is a Computer Algebra System that uses Mathematica-like syntax. A Windows installer is now available.

In a

Improved Continuum Skin/Prox Model

FEMM Overview

An example of how one might go about connecting to FEMM as an out-of-proc ActiveX server from a client written in C#.

A parameter that FEMM requests as part of the definition of a laminated material is the lamination fill factor or "stacking factor". This note aggregates guidance for selecting the stacking factor depending upon lamination thickness.

FEMM users have expressed an interest for BH curves that are defined up to very high levels of saturation and come from a well-documented source. This note discusses materials described in the Metals Handbook, 8th ed, Vol. 1 that are now included in the standard FEMM magnetic materials library. This source presents BH curves for a wide range of materials up at field intensities up to about 300,000 A/m. Electrical conductivities for these materials (along with the sources for the values) are also tabulated.

A very simple example of how one might go about connecting an Excel spreadsheet to FEMM using ActiveX.

For the purposes of developing an intuitive feel for the fashion in which energy is stored in a permanent magnet and its environment, it is useful to use analogies to other types of physical consideration. In this note, the magnetic circuit representation of a magnet driving an external reluctance will be reviewed. Then, capacitive and mechanical analogies to a permanent magnet will be considered. These analogies have an equivalent circuit representation that is identical to the one used to describe a permanent magnet.

Magnetic circuit representation of a PM cylinder including expressions for stored energy, coenergy, and magnetometric demagnetization factor

A note that considers an intuitive approach to computing the energy stored in permanent magnets based on the magnetic circuit representation of a permanent magnet.

A fairly widely used analytical formula for the diameter of bare wire as a function of AWG wire gauge is:

d_{wire} = (0.324861*inch)*exp(-0.115943*AWG)

A Mathcad worksheet that implements this function (and a few other functions related to wire resistance and weight calculation) is linked below.

- AWG Table in the form of a Mathcad worksheet
- AWG Table in the form of a SMath Studio worksheet
- PDF printout of AWG Table worksheet

Lua is distributed with double precision numbers as the standard number type. However, for many scientific applications (

A note that examines the effect of eddy current effect in thin disks of NdFeB.

Attachment | Size | Date Added | |

wire.sm | 9.56 KB | 3/20/2015 1:34 pm | |

FEMM_Presentation.pdf | 963.89 KB | 11/17/2015 8:53 am | |