shunt-excited DC generator

A shunt-excited DC generator is a type of electric generator that uses its own output to supply its field current, eliminating the need for an external power source. This self-excitation process begins with residual magnetic flux in the iron poles, which generates a small voltage as the machine starts. This voltage then creates a field current, strengthening the magnetic flux and increasing the generated voltage until the iron reaches saturation, limiting further voltage buildup. The stable voltage can be adjusted using a resistor in series with the field coil. DC generators were historically important for tasks like battery charging and in electrolytic systems, and they have the advantage of being able to operate as motors as well.1