DC engine can be classified according to the electrical connections of the armature winding and the
field windings. The different ways in which these windings are connected lead to machines operating with
different characteristics. The field winding can be either self-excited or separately-excited, that is, the terminals
of the winding can be connected across the input voltage terminals or fed from a separate voltage source (as in
the previous section). Further, in self-excited motors, the field winding can be connected either in series or in
parallel with the armature winding.
Sammy