AC1 Fundamentals Unit 5 – Transformers
UNIT 5 – TRANSFORMERS
UNIT OBJECTIVE
At the completion of this unit, you will be able to describe the transfer of electrical energy from
one circuit to another by mutual inductance.
UNIT FUNDAMENTALS
Suppose two inductors are placed in close proximity to one another, but no electrical connection
exists between them.
Suppose also that an ac voltage is applied to one of the inductors. As shown, the magnetic field
surrounding the inductor with the applied voltage (L1) induces a voltage into the other inductor
(L2).
This phenomenon is known as mutual inductance. Inductor coils arranged in this manner result
in a common electrical device called a transformer.
The coil, or winding, with the applied voltage is the primary. The coil that develops voltage
from the magnetic field is the secondary.
The amount of voltage induced in the secondary depends on the ratio of turns of wire between
the two windings.