Difference Between Core Type and Shell Type Transformer

What is a Core-Type Transformer?

A core-type transformer is an electrical device that accepts an alternating current (AC) input and outputs an alternating current (AC) of a different voltage level. It is the most popular type of transformer widely used in power transmission and appliances to transform mains voltage to low voltage to power electronic devices. They come in a variety of power ratings ranging from mW to MW. The insulated laminations reduce eddy current losses in the iron core.


Science Quiz

Test your knowledge about topics related to science

1 / 5

An atom is considered to be ____________ when the number of protons and electrons are equal.

2 / 5

A chemical reaction where energy is released is called:

3 / 5

What is the function of root hair cells?

4 / 5

The substances that enter a chemical reaction are called __________.

5 / 5

A bond that occurs between nonmetals and nonmetals is called a/an _________.

Your score is


It is constructed with a core of high-grade steel laminations and two or more windings of insulated wire wrapped around it. It operates on the electromagnetic induction principle, in which a changing magnetic field formed by the input voltage induces a voltage in the output windings.

Power distribution, voltage regulation, industrial equipment, and audio equipment are among the applications for core-type transformers. They are often built to withstand greater voltage levels.

What is Shell-Type Transformer?

Shell-type transformers are power transformers built with a single steel frame or shell that houses all the windings and core. The capacity of this type of transformer to enable efficient cooling of the windings and core is its primary advantage. The windings are insulated copper strands arranged in a concentric pattern around the core.

The winding of a shell-type transformer is distributed type, so that heat can be naturally dissipated. Maintaining these transformers is complex, and mechanical strength is high.

Power distribution, control, and conversion are all ideal applications for shell-type transformers. It is used in various industries, including telecommunications, utilities, and manufacturing. It also provides power to electrical devices, such as computers, televisions, and radios.

The shell-type transformer’s key advantage is its ability to deliver efficient power transfer. It is also lightweight, making it easy to carry and install, and a good choice for use in regions with limited space because it can be quickly moved around.

Difference Between Core-Type and Shell-Type Transformers

  1. In core-type transformers, Cross-section may be square, cruciform, or three-stepped; on the other hand, in Shell-Type transformers, the cross-section is rectangular.
  2. The flux is equally distributed on the side limbs of the core in Core-Type Transformers, while in Shell-Type Transformers central limb carries the whole flux, and the side limbs carry half of the flux.
  3. The primary & secondary winding is placed on the side limbs in Core-Type Transformers, while in Shell-Type Transformers, the Primary and secondary windings are placed on the central limb.
  4. In core-type transformers, the lamination is cut in the form of the L strips, whereas lamination is cut in the form of the long strips of E and L in Shell-Type Transformers.
  5. There are two magnetic circuits in Core-type transformers, while in Shell-Type Transformers, there is only one.

Comparison Between Core-Type and Shell-Type Transformers

Parameters of ComparisonCore-Type TransformersShell-Type Transformers
MeaningThe winding surrounds the core in Core-Type Transformers.The core surrounds the winding in Shell-Type Transformers.
Alternate nameConcentric Winding or Cylindrical Winding.Sandwich or Disc Winding.
MaintenanceCore-Type Transformers have easy maintenance. Shell-Type Transformers have complex maintenance.
Mechanical strengthCore-Type Transformers have low mechanical strength.Shell-Type Transformers have high mechanical strength.  
InsulationInsulation is more in Core-Type Transformers.  Insulation is less in Shell-Type Transformers as compared to Core-Type Transformers.


  1. Calculation of leakage inductance of core-type transformers for power electronic circuits | IEEE Conference Publication | IEEE Xplore
  2. Electromechanical Analysis of Core- and Shell-Type Inductive Superconducting Fault Current Limiters Under General Fault Conditions | IEEE Journals & Magazine | IEEE Xplore
One request?

I’ve put so much effort writing this blog post to provide value to you. It’ll be very helpful for me, if you consider sharing it on social media or with your friends/family. SHARING IS ♥️