What is a Step-Up Transformer? How Does It Work?

9 May 2023

How Does a Step-Up Transformer Work?

A step-up transformer is a device that increases or controls the output voltage extensively compared to the input voltage while keeping the current constant. It finds applications in power generation stations and power transmission systems.

What is a Step-Up Transformer?

A transformer is an electrostatic device that converts electrical energy from the primary winding into magnetic energy in the transformer’s core and then back into electrical energy in the secondary winding.

A step-up transformer, on the other hand, is a type of transformer that serves the function of converting low voltage and high current on the primary side to high voltage and low current on the secondary side of the transformer.

Components of a Step-Up Transformer

A step-up transformer consists of windings, transformer enclosure, and a core.


The core of a step-up transformer is designed using a material with high permeability. This material allows magnetic flux lines to pass through with minimal loss. The core material has higher permeability than air.

As a result, the material confines the magnetic field lines within it. This minimizes losses and enhances the performance of the transformer. The core material is laminated to reduce eddy currents, which can cause heating of the core. Keeping the core cool is essential because excessive heating can lead to significant energy losses.


The windings inside the step-up transformer help in transmitting current through the transformer. These windings are specially designed to keep the transformer cool and withstand testing and operational conditions.

The winding thickness used for the primary side is larger, and the number of turns is fewer compared to the secondary side. Similarly, a thinner coil is used on the secondary side, and it has more turns.

The primary winding is designed to handle a lower voltage than the secondary supply voltage.

Materials commonly used for transformer windings are copper or aluminum. While aluminum is cheaper, using copper can extend the transformer’s lifespan.

Different winding types, such as EE type and EI type, are available, which help reduce eddy currents in transformers.

How Does a Step-Up Transformer Work?

Because the number of turns in the primary winding is less than that in the secondary winding, the output voltage is higher than the input voltage. When alternating current flows through the transformer, current flows in one direction, stops, and then reverses to flow in the opposite direction.

The flow of electric current creates a magnetic field under the coil. When the direction of the current changes, the orientation of magnetic poles also changes.

Voltage is induced in coils due to the motion in a moving magnetic field. Similarly, a moving magnetic field in the primary coil induces voltage in the secondary coil through a phenomenon known as mutual induction. Therefore, the alternating current in the primary coil creates a moving magnetic field, inducing voltage in the secondary coil.

Advantages of Step-Up Transformers

The advantages of step-up transformers include:

  • Suitable for residential and commercial use.
  • Provides power amplification.
  • Easy maintenance and repair.
  • Efficient operating principle.
  • Suitable for continuous operation.
  • Quick startup.

Disadvantages of Step-Up Transformers

Step-up transformers require a cooling system to operate efficiently. They work only with alternating current (AC). Finally, they are relatively large compared to other transformers.

Applications of Step-Up Transformers

Step-up transformers can be used with electronic equipment such as inverters and voltage stabilizers to maintain low to high voltage stability.

They are used for changing high voltage from power generators to lower voltage levels for distribution in power transmission lines. They can also be preferred for running electric motors and X-ray machines.

What to Consider When Buying a Step-Up Transformer

When purchasing a step-up transformer, there are factors to consider and verify:

  • Efficiency of the transformer
  • Number of phases
  • Transformer rating
  • Cooling medium
  • Material used for windings

Trans-El is a reputable company in the industry, combining its experience in manufacturing with the strength of its technological lines, expert engineering team, qualified technical staff, and business partners to provide the highest quality of service.

For inquiries and support requests, you can call us at +90 505 204 88 30 or send your requests to trans-el@trans-el.com. Do not purchase a step-up transformer without receiving a quote from us.

Nano Medya