SINGLE-PHASE COMMUTATOR MOTORS

341

winding were massed together in a single coil, as shown diagram-
matically in Fig. 161. Repulsion motors are still occasionally
built in which field and compensating coils are combined in a
single distributed winding, as shown in Fig. 162. Soon after the
first repulsion motor, conductively and inductively compensated
series motors were built by Eickemeyer, with a massed field
winding and a separate compensating winding, or cross coi],
either as single coil or turn or distributed in a number of coils or
turns, as shown cliagrammatically in Fig. 163, and by W. Stanley.

FIG. 162.—Repulsion motor with
distributed winding.

FIG. 163.—Eickemeyer inductively
compensated series motor.

For reversible motors, separate field coils and compensating
coils are always used, the former as massed, the latter as dis-
tributed winding, since in reversing the direction of rotation
either the field winding alone must be reversed or armature and
compensating winding are reversed while the field winding re-
mains unchanged.
IV. Types of Varying-speed Single-phase Commutator Motors
194. The armature and compensating windings are in induc-
tive relations to each other. In the single-phase commutator
motor with series characteristic, armature and compensating
windings therefore can be connected in series with each other, or
the supply voltage impressed upon the one, the other closed upon
itself as secondary circuit, or a part of the supply voltage im-
pressed upon the one, and another part upon the other circuit,
and in either of these cases the field winding may be connected
in series either to the compensating winding or to the armature
winding. This gives the motor types, denoting the armature by