The stator-fed a.c. commutator machine with induction regulator control

The paper presents a theory of the stator-fed a.c. commutator machine with fixed brushes and induction regulator to provide the variable voltage and/or phase-shifting effect in the rotor circuit for both shunt and series connection. Circle diagrams are developed using a minimum of mathematical treatment without, however, sacrificing accuracy, whilst a maximum of conclusions useful in practice are drawn. A number of regulator systems of known and recently developed design are also described.