Given three coils whose surface normals are co-planar, with any two coils having a 120° displacement from each other, we can find the (set of) excitation inputs to the coils that should produce a rotating magnetic field (or vector) in any direction. The aim of this paper is to find such excitation inputs for a set of three coils having coplanar surface normal vectors (or simply coplanar coils) with arbitrary spatial orientation. In doing this, the idea of "Sequence Components" of a three-phase system is generalized to any three-phase system with arbitrary spatial orientation. In addition, we define a "Sequence Matrix" and discuss some of its properties.