  We consider a model of topological solitons where charged particles have
finite mass and the electric charge is quantised already at the classical
level. In the electrodynamic limit, which physically corresponds to
electrodynamics of solitons of zero size, the Lagrangian of this model has two
degrees of freedom only and reduces to the Lagrangian of the Maxwell field in
dual representation. We derive the equations of motion and discuss their
relations with Maxwell's equations. It is shown that Coulomb and Lorentz forces
are a consequence of topology. Further, we relate the U(1) gauge invariance of
electrodynamics to the geometry of the soliton field, give a general relation
for the derivation of the soliton field from the field strength tensor in
electrodynamics and use this relation to express homogeneous electric fields in
terms of the soliton field.
