Soft iron

Cast iron

Cast steel

Stainless steel

Reduce the friction loss

Reduce the windage loss

Reduce the hysteresis loss

Reduce the eddy current loss

Shunt generator

Series generator

Differential compound generator

Cumulative compound generator

Minimizes rough commutation

Maintain constant output voltage

Neutralizes the demagnetizing effect

Decreases the excitation current of field coils

Output voltage is pulsating

Output voltage is above normal

Generator fails to build up voltage

Generator builds up voltage normally