Abstract: The stator windings of a dynamo electric machine include three phase and single phase output windings for generating alternating current output power at different voltages. The machine output voltage is kept relatively constant by means of a brushless exciter having control and compounding field windings which are energized through stationary rectifier circuits. The rectifier circuit for energizing the field windings of the exciter is connected to or near the neutral leads of the stator windings to maintain a low voltage between the diodes of the rectifier and ground. The energization of the compounding field winding is controlled by means of a variable resistor in dependence upon whether the load connected to the dynamo electric machine is supplied with single phase or three phase current.

Abstract: A dynamo electric machine including an alternating current generator and a brushless exciter for the generator field, wherein control and compounding field windings of the exciter are energized from the generator stator winding through stationary rectifier circuits, the rectifier circuit for the compounding field making connection with the generator stator winding in the vicinity of its neutral point to avoid impressing high voltage to ground on rectifiers of the circuit.