This is a core type transformer in which the windings are wound on an iron core. The magnetic flux linkages are made strong and perfect with iron as core material. This is commonly seen in laboratories. The figure below shows an example of iron core transformer.

Advantages

• They have very high magnetic permeability.
• Iron core transformers has low reluctance.
• Mutual Inductance is high.
• These transformers are highly efficient.

Disadvantages

• These are a bit noisy compared to Air core transformers.
• The hysteresis and eddy current losses are a bit more than Air core transformers.

Applications

• As isolation transformers.
• High frequency radio transmissions.

The transformers are also classified according to the type of core they use. Some transformers use the core immersed in oil. This oil is cooled from outside by various methods. Such transformers are named as Wet core transformers, while the others such as ferrite core transformers, laminated core transformers, toroidal core transformers and cast resin transformers are Dry core transformers.

Based on the type of winding technique, we have another transformer which is very popular named as the Auto transformer.