This includes equipment such water heaters, pumps for
showers and whirlpool baths.18. Equipment
supplied from SELV source may installed bathroom shower-
room, provided that suitably enclosed and protected from the ingress
of moisture. Large power transformers, used electri-
cal distribution systems, can have efficiency better than 90%.
● The voltage both the primary and secondary windings propor-
tional the number turns. 5.
Very small transformers are used electronic applications.
VP VS
IS
IP
Primary
winding turns
Secondary
winding turns
Steel core
Magnetic circuit through core
FIGURE 5.
● This means that you increase the number secondary turns you
will increase the output voltage. sketch oil immersed transformer can be
seen Fig.
● Alternatively, reducing the number secondary turns will reduce the
output voltage.18
Typical oil filled power transformer. Because has moving parts, transformer can
have very high efficiency. This useful for low voltage supplies such domestic
bell transformers.
Try This
Have you seen any transformers action?
Were they big small what were they being used for?
Have you been close transmission tower, perhaps when you were walking
in the countryside?
.
Large power transformers need cooling take the heat generated away
from the core.
FIGURE 5. Small trans-
formers are used isolating transformers shaver sockets and can also
be used supply separated extra low voltage (SELV) sources. This has application power
distribution. This often achieved totally immersing the core and
windings insulating oil.Basic Electrical Installation Work
116
● alternating voltage applied the primary winding establishes an
alternating magnetic flux the core.
● The magnetic flux the core causes voltage induced the
secondary winding the transformers.17
A simple transformer
