Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1917-03-10

EblHcI Tue CuttNut VI pCoehIc Hes
vary in value, the hfherS rsmaining
practically esnf ~ H1aEy
however. a
tain either
called the Won
ticalIy consAM \ M giving
two main types 80, known as
the constant yoltN g. constant cur.
rent system, respectively.
There are four different methods OF
regulating the 1QtRt Of a gene1for
and theyIpag kitJed as II ws !:
s: !: s.! =: =: ! ! 4. s: s.
Ing parts. in this class are uded
cumulative and dffferentia Ieries
Held windiTgs and type Of orator
! having one or moN brushes I add
Mon to0aose 'td ID In delivering a
current In I'D cry and kno as
a third brusnl Chine The fia' cur.
| rent for the ppt winding ID ken
from the third brush and enc OF the
main brushes.
Purpose Of Eleetro-Mapnets
(b) Electromagnetic Regulation.
This type Of regulation is produced by
the action of electrpm magnets, which
Aay act to increasesthe resistance OF
the shunt field circuit or to open the
field circuit or to change the connec-
lions OF the field winnings.
(c) Mechanical Regulation. This
type of regulation Is produced by the
action OF centrifugaliy operated COVER
nors, which may act TO prevent the
speed of the generator increasing
above q certain definite value or to
insert q resistance In series with the
field winding or in series with the
generator and the battery.
(d) Regulation by Amphere Hour
Meter. This type OF regulation Is pro-
duced by means of On ampere-hour
meter, which changes the resistance
of the field circuit, depending upon
the number Of ainpere hours that may
pass into or out OF the storage bait
terry.
Ali the above types q regulation
are found IN many different applica.
iions and Ia combination with each
other. giving rise TO numerous iistinc-
tive types as used by the different
manufacturers OF motor car sener.
ators.
Cumulative Action Of Winnings
When the magnetizing action Of the
current In the series and shunt field
winnings Of generator are both In
IN esame direction the action Is said
to be cumulative, Gnd the generator
A. oarloa n.,,,. IN 49, .o-n~o,,d
wound machine. A compound wound
machine OF this kind Is used in com.
bination with q constant speed ma
chine. A good example 81 such com.
bination il found IN some of the cider
types OF equipment manufactured by
Gray & Davis, Ia which the gener.
ators were driven at q constant speed
by means OF centrifugal clutch.
J A diagrammatic scheme Of connec-
tons for this type OF regulation Is
shown In Fig. 1. When there are no
lamps lighted the shunt winding Is
acting alone and sufficient pressure
is generated n the armature winding
to overcome the pressure of the hat
terry and produce a charging current.
When the lamps are turned on the
current through them passes through
the series field and Increases the mag
netic field IN which the armature is
rotating. thus Increasing the electrical
pressure generated. BY a proper adj
iustment Of the turns in the series
field In relation to the current taken
by the lamps Il IL possible to cause
the generator to carry the lamp load
and to continue to charge the battery
at the same rate Il was charging the
battery before the lamps were turned
on.
Differentiai Action o. Wlndings
When the magnetising action OF the
windings of q generator are in op-
posite directions the action is said to
he differentlal, and the generator is
called q differential compound wound
machine. A good example of in
herent regulation In which the shunt
and series fields produce opposing
magnetizing effects Is found In one
type Of equipment made by the Auto
Lite Company. A diagrammatic
scheme Of connections for this type OF
regulation is shown I'm Fig. g The
action. In brief. 10 as follows: The
voltage OF the machine is built up
with an increase In speed and shunt
field current until the cutout connects
the generator to the battery. After
this connection "a made current will
he established in the series field wind
ing in such direction that its mag
netixing action Is opposite to that
produced by the shunt field, and hence
the magnetic field is weakened.
With a. further increase In speed
there VII be an increase in gcher-
ated pressute In the armature OF the
generator. which mi cause an In
crease in the value OF the current pro-
duced in the series winding and bat
terry and also an increase in the cur
rent in the shunt held winding. Since
the magnetiking action of the series
field Il opposed 10 the magnetizing
action OF the shunt field the increase
in generated pressure due 70 an in
crease in speed viii not be as great
e1zYA. -,har