AC1 Fundamentals Unit 5 – Transformers
Exercise 1 – Transformer Windings
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to determine the coil resistances of a
transformer by using a multimeter. You will verify your results with information found in this
exercise.
DISCUSSION
- Inductors have an inherent resistance because they are made of wire. The same is true for
transformer windings. - The resistance of the transformer windings can be measured using a multimeter.
- Since the two windings (primary and secondary) are electrically isolated, an open circuit
condition exists. - Resistance in each winding will depend on the number of turns (length), wire gauge, and the
type of wire. - An autotransformer consists of one continuous tapped winding that acts as both primary and
secondary. - Transformer taps may be placed anywhere along the windings. The most common place is at
the center (dividing the windings in half); this type of transformer is referred to as a center-
tapped transformer.