Magnet Formulas

A small web site devoted to the vanishing art of practical magnet design without FEA (Finite Element Analysis).

Experimental! Read Magnet Formulas as live IPython notebooks using binder.

The Basics

• Maxwell and His Equations
• The Law of Biot Savart

Simple Magnetic Field Formulas

• Field due to electric current in an infinitely long, straight wire
• Field inside an infinitely long, straight, air-core solenoid
• Field inside an air-core toroid
• On-axis field due to a current loop
• On-axis field due to a thin shell solenoid
• On-axis field due to a solenoid

Off-Axis Magnetic Field Formulas

• Off-axis field due to a current loop
• Off-axis field due to a magnetic dipole moment
• Off-axis, axial field component due to a solenoid

Helmholtz Coil Formulas

• Axial field of an ideal Helmholtz coil
• Axial field of a non-ideal Helmholtz coil

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Magnet Formulas, © 2018 by Eric Dennison. Source code and license on Github