REVIEW 463
and thus gives peculiar regulation characteristics, similar as the
Stanley induction generator. It has been proposed for steam-
turbine alternators, as it would permit higher turbine speed
(3000 revolutions at 25 cycles) but has not yet been used. As
motor it has the disadvantage that it is not self-starting.
Eickemeyer Inductively Compensated Single-phase Series
Motor.—193. Single-phase commutating machine with series
field and inductive compensating winding.
Eickemeyer Inductor Alternator.—160. Inductor alternator
with field coils parallel to shaft, so that the magnetic flux disposi-
tion is that of a bipolar or multipolar machine, in which the
multitooth inductor takes the place of the armature of the stand-
ard machine. Voltage induction then takes place in armature
coils in the pole faces, and the magnetic flux in the inductor re-
verses, with a frequency much lower than that of the induced
voltage. This type of inductor machine is specially adopted for
moderately high frequencies, 300 to 2000 cycles, and used in in-
ductor alternators and inductor converters. In the latter, the in-
ductor carries a low-frequency closed circuit armature winding
connected to a commutator to receive direct current as motor.
Eickemeyer Rotary Terminal Induction Motor.—XI, 101.
Single-phase induction motor with closed circuit primary winding
connected to commutator. The brushes leading the supply cur-
rent into the commutator stand still at full speed, but revolve
at lower speeds and in starting. This machine can give full maxi-
mum torque at any speed down to standstill, depending on the
speed of the brushes, but its disadvantage is sparking at the com-
mutator, which requires special consideration.
Frequency Converter or General Alternating-current Trans-
former.—XII, 103. Transforms a polyphase system into another
polyphase system of different frequency and where desired of differ
ent voltage and different number of phases. Consists of an induc-
tion machine concatenated to a second machine, which may be
an induction machine or a synchronous machine, thus giving the
induction frequency converter and the synchronous frequency con-
verter. (See " Concatenation.") In the synchronous frequency
converter the frequency ratio is rigidly constant, in the induction
frequency converter it varies slightly with the load, by the slip
of the induction machine. When increasing the frequency, the
second machine is motor, when decreasing the frequency, it is
generator. Above synchronism, both machine's are generators