Figure2 Field connections for dc generators:(a)separately excited generator;(b)self-excited,shunt generator;
(c)series generator;(d)compound generator;short-shunt connection;(e)compound generator,long-shunt
connection.
The shunt field contains many turns of relatively fine wire and carries a comparatively
small current, only a few percent of rated current. The series field winding, on the other hand,
has few turns of heavy wire since it is in series with the armature and therefore carries the
load current.
Before discussing the dc generator terminal characteristics, let us examine the relationship
between the generated voltage and excitation current of a generator on no load. The generated
EMF is proportional to both the flux per pole and the speed at which the generator is driven,
EG=kn. By holding the speed constant it can be shown the EG depends directly on the flux.
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