This latter plan is
65 preferable when current having high
number alternationsperunitof time em
ployed drive the motor. This principle operation,
which consists converting change of
connections otherwise double-circuit mo- no
tor one operating progressive shifting
of the poles into ordinary synchronizing-
motor may carried out many other
ways. For instance,instead using the switch
shown the previous figures, may use 115
temporary ground-circuit between the gen
erator and motor, order start the motor,
in substantially the mannerindicated Fig. have 105
found that this disposition the motor is
maintained rotation synchronism with
the generator.
From the common joint union between the
two circuits both the generator and the
motor earth connection established,
while the terminals ends the said circuits 130
are connected the line.401,520
polar projections the armature-core or
other similar and well-known features, the
properties synchronizing-motor.
Let this figure represent ordinary
alternating-current generator with, say, two 120
poles, M', and armature wound with
two coils, N', right angles and connected
in series.
L represent the conductors line from
5 alternating-current generator G. the path the bars the con
tact which forms one terminal the cir
cuit through coils and the contact 4,which
15 one terminal the circuit through coils B. Generally adjust the
conditions that the electro-motive force used
in each the motor-circuits that which is
required operate the motor when its cir
cuits are series.
Assuming the generator running, and
that desired start the motor, the switch
is shifted until its levers rest upon points 1
and The two motor-circuits are thus con-
45 nected with the generator-circuit; but rea
son the presence the resistance one
and the self-induction coil the other the
coincidence the phases the current is
disturbed sufficiently produce progression
50 the poles, which starts the motor rota
tion. 3. When the motor has attained
the proper speed, the switch shifted that
the levers cover the contacts and 9,thereby
connecting circuitsB and series. The plan which follow 75
in this case illustrated Fig. will ob
served that when this position and with
lever contact the current divides be
tween the two circuits which from their
difference electrical character produce 100
progression the poles that starts the motor
in rotation. the path of
the levers are two other contact-termi
nals, and The contact connected to
25 contact through, artificial resistance, I,
and contact with contact through self-
induction coil, that when the switch-le
vers are shifted onto the points and the
circuits coils and will connected in
30 multiple arc derivation the circuit I/,
and will include the resistance and self-in
duction coil, respectively. There are,how
ever, five contacts, which have designated
by the figures 5,6,7,8, and The motor-cir
cuits which include alternate field-coils,
are connected the terminals the follow- 85
ing order: One end circuit connected
to contact and contact through dead
resistance, One terminal circuit is
connected contact and contact 6
through self-induction coil, The oppo- 90
site terminals both circuits are connected
to contact 8.
One the levers, the switch made
with extension, otherwise, to
cover both contacts and 6when shifted into 95
the position start the motor. third position
of the switch that which the levers and
F' are shifted out contact with both sets of
35 points. Assuming that
the motor synchronizing-motor one
that has the capability running synch
ronism with the generator, but not start-
. In. The motor has, for example, four
poles wound with coils which are C021-
nected series and armature with polar 125
projections wound with closed coils E. this
diagram the motor has twelve poles and tlie
armature has polar projections wound with
closed coils The switch used sub
stantially the same construction that 80
shown the previous figure. this case the motor entirely out
of circuit. When the speed the motor has run
up synchronism with the generator, ap
proximately so, the switch shifted over onto
the points and thus cutting out the coils
55 and that the currents both circuits
have the same phase; but the motor now runs
as synchronous motor, which well known
to very desirable and efficient means of
converting and transmitting power.
60 will understood that when brought up
to speed the motor will run with only one of
the circuits connected with the main
or generator circuit, the two circuits may
be connected series.
Near the motor placed switch the ac
tion which that the one shown the
drawings, which constructed follows: F
F' are two conducting plates arms, pivoted
io their ends and connected insulating
cross-bar, shifted parallel
ism. such case the
starting the motor more difficult and the
dead and inductive resistances must take a
considerable proportion the electro-motive 70
force the circuits.
The opposite end the wire coils con
nected the wire bar F', and the corre
sponding end coils connected wire
L' and bar hence the bars shifted so
20 bear contacts and both sets of
coils will included the circuit L'
in multiple arc derivation.
The purpose and manner operating the
motor these devices are follows: The
normal position the switch, the motor be-
40 ing out circuit, off the contact-points
