A magnetic circuit is a closed loop of magnetic flux, similarly to how an electric circuit is a closed loop of electric current. Magnetic flux is guided through the use of materials with very high permeability, which keep the flux contained within the material until it meets a dead-end, in which case it travels through air (or the vacuum). Since magnetic field lines are always closed (due to the Divergence of the magnetic field always being zero), magnetic circuits are always closed.
Component analogies#
Magnetic circuits are easiest to understand by comparing them to more familiar electrical circuits.
- Current becomes magnetic flux.
- Batteries that emit an electromotive force become coils traversed by a current wrapped around the material and produce a magnetomotive force.
- Resistances becomes magnetic reluctances.
- Electric potential becomes magnetic potential.
- Kirchhoff's laws have their own magnetic versions.