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Figure 3.5 - Configuration of DC machines

This configuration is rarely used for generators, since the
generated voltage and the load voltage must always differ by the
voltage drop across the field coil, which varies with the load
current.
Thus, a series generator would have poor (large) regulation.
However, series-connected motors are commonly used in
applications not more than about 1 kW output, or if we are talking
about bigger motors – they are used for electric locomotives.
The third type of DC machine is the compound-connected
machine, which consists of a combination of the shunt and series
configurations. Figure 3.5 (d) and (e) shows the two types of
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