There are several ways to define the gauge condition in the A - phi me
thod for the 3-D eddy current analysis: e.g. the Coulomb gauge, the Lo
rentz gauge, etc. Unlike the Coulomb gauge, the physical meaning of th
e potentials in the Lorentz gauge is not obvious. Therefore this paper
introduces a novel physical meaning of the Lorentz gauge, and describ
es the relationship between these gauge conditions in the A - phi meth
od systematically from a physical viewpoint.