How does electricity reach our homes?
It all starts from the power station, which
gives a voltage of 20kV.
But, to transmit this voltage over longer
distances, it is stepped up (440kV) with the
help of Step-up transformer.
The transmission lines carry this voltage
(440kV) to the substations or distribution
stations, where the voltage gets transformed
from 440kV to 11kV,
which is (11kV) safer for distribution.
Again the voltage gets decreased one or two
steps with another Step-down transformer before
reaching our homes.
So, basically, transformers step up or down
the voltage before making its final way to the destination.
But, How it's done?
The transformer usually consists of an Iron
core.
The sides of the Iron core are wrapped up
with a coil, termed as Primary Winding and
Secondary Winding.
While for a stepdown transformer, the Primary
Winding has more turns than the Secondary
Winding.
Now when a high AC Voltage is given at the
Input, it excites the Primary Winding.
After this excitation, alternating current
circulates the winding and creates an alternating
magnetic flux, which passes through the magnetic
iron core.
This alternating magnetic flux induces a voltage
in the Secondary Winding.
Since the number of turns in the secondary
winding is less the induced voltage will be
low.
So, without making an electrical contact,
the voltage in the primary winding is transferred
to the secondary winding.
Simultaneously, for a step up transformer,
the number of winding turns in the primary
winding is less compared to the secondary
winding.
In our daily lives, transformers are everywhere
from the utility provider lines to the mobile
phone chargers, in this case, it steps
down in a small amount nothing but, incoming
voltage reduces to 5 voltages (tolerable voltage)
for charging your mobile phones.
