Montpelier examiner. [volume] (Montpelier, Idaho) 1895-1937, 1912-02-23
THE GENERATION AND APPLI-
CATION OF ELECTRIC power
BY ARTHUR JoBsON

small stepup transformer. In gener-
al practice coil No. 3 would be called
the primary coil in this small trans
former, and coil No. would be thu
secondary coil. This is because coil
No. is the one to which we have
assumed the current to be delivered
and coil No. | is the coil from which
we draw the current. Suppose now
that we deliver an alternating elec
trio current at pressure of 800 vots
to coil No. |, thus making it the pri-
mary coil, what would be the result
on coil No. 2? Since coil No. 2 is
wound with only one-fourth of the
number of turns of wire wound on
coil No. it is evident, from what
has been previously said, that the
voltage across the terminals of coil
No. 2 would be just one-fourth of the
voltage impressed OH coil No. |, or in
this particular case 125 volts. Hence
we have a stepdOwn transformer. 1t
will now be seen that any simple
may NC uSCN Aoi OiOiVA
raising or lowering the voltage of an
electric circuit, depending upon how
it is connected to the circuit. More
over the ratio of transformation of
voltage depends only upon the ratio
of the number of turns of wire in the
two separate windings; that is, If We
deliver current at a pressure of TO-
900 volts to one coil of a transformer
having ten times rs many turns as
the other coil, the voltage will be re-
duced to one-tenth of it's original
pressure or 1000 volts In the second
or secondary coil If we had an al
ternating current generator that gem
Grated current at a pressure Of 2,200
volts and we wished to step this volt
age up to A, 900 volts, we would re-
quire a transformer having 20 tim s
as many turns of wire in the secoad-
AIRY coils as there were turns in the
primary coil. The importance o!
raising the voltage of an electric
current will be explained later.
Let us inquire now into the effect
on an electric current when the volt
B age is raised or lowered by the use
of transformer. Take the case ol
the small transformer above men.
toned We assumed that a current
at pressure of 200 volts was deliver.
ed to coil No. of this transformer
: (coil No. in this case being the pri
mary COLI Suppose that when tht
/ current is being delivered at this volt
: age we find that coil No. 2 isdrawint
:. two amperes 1t is evident then tina
| the power delivered to the trans
= former would pc 1000 watts e Y 500
or one X w. 1t was explained tina
If current at a pressure of 500 volt
}, was delivered to coil No. 2 the volt
e age across the terminals of coil No.
j. would be 1900 volts. However, from
the law of the conservation of energ,
Z we could not obtain any more powe
# from coil No. l, than we delivered
) to coil No. 2, which, in this par
:. ticular case, is 1000 watts. Therefor
to determine the current flowing Il
y the circuit connected to the second
IL ary coil or coil No. l, we must di
,s vide the power iu watts delivered b.
y this coil to the circuit by the voltag
. or 1000 by 2O00. This gives us a cul
q rent of one half ampere in the seeon
2 Diary circuit. Hence In raisiug th
If voltage by the use of this transform
i, er from 500 to 1000 volts the currer
- was lowered from two amperes to on
AZ half ampere. This is what occurs |
no any commercial transformer. Wine
ri the voltage is raised in an electr
:. circuit by the use of a transform'
@ the current is corrsspondingly loy
s. cred, and when the voltage is lowe
7e ed the current Is raised.
in In the next paper the writer WI
= discuss the practical application
70 the transformer, and the reason 4
fe transmitting electricity at high vol
q are,