Based on Ampere’s Loop Law
Calculation of DC magnetic circuit
The first category: given the magnetic flux, the required excitation magnetomotive force of the ball.
The second category: given excitation magnetomotive force, the magnetic flux in the spherical magnetic circuit.
1. Simple series magnetic circuit
Excluding the influence of magnetic flux leakage, there is only one magnetic circuit without branch.
2. Simple parallel magnetic circuit
Consider the effect of magnetic leakage, or the magnetic circuit has more than two branches.