What is a Step Up Transformer : Working & Its Applications

A transformer is a static electrical device, used to transfer the energy in electrical form between two or number of circuits. The main function of a transformer is to change the alternating current from one voltage to another voltage. The transformer doesn’t have any moving parts and works on the principle of magnetic induction. The transformer design is mainly for step-up otherwise step down the voltage. These are mainly available in two types based on the windings namely step up and step down transformer. The purpose of the step-up transformer is to increase the voltage whereas the step-down transformer function is to step down the voltage. The transformers ratings can be done based on the requirement like VA, or KVA or MVA. This article discusses an overview of the step-up transformer.

What is Step-up Transformer?

A transformer that is used to step up the output voltage by maintaining the flow of current stable without any variation is known as a step-up transformer. This kind of transformer is mainly used in the applications of power transmitting and power generating stations applications. This transformer includes two windings like primary and secondary. The primary winding has fewer turns as compared with the secondary winding.

Step up Transformer
Step-up Transformer

Construction of Step-up Transformer

The Step-up transformer diagram is shown below. The construction of the step-up transformer can be done using core and windings.


The designing of core in the transformer can be done using a high permeable material. This core material allows the magnetic flux to flow with less loss. The material of core includes high permeability as compared with the nearby air. So this core material will restrict the magnetic field lines within the core material. Thus, transformer efficiency can be enhanced by decreasing the transformer losses.

The magnetic cores allow the magnetic flux to flow across them and also they lead to losses in core like eddy current losses because of hysteresis. So, hysteresis & low coactivity materials are chosen to make the magnetic cores similar to ferrite or silicon steel.

To keep the eddy current losses at a minimal low, the transformer core can be laminated, so that the core heating can be prevented. When the core is heated, then there is some loss of electrical energy and transformer efficiency can be decreased.


The windings in the step-up transformer will help to transmit the current which are wounded on the transformer. These windings are mainly designed to make the transformer cool & resist the conditions of test and operational. The density of the wire at the primary winding side is thick but includes fewer turns. Similarly, the density of the wire at the secondary winding is thin but includes huge turns. The designing of this can be done like the primary winding carries less power voltage as compared with the secondary winding.

The winding material used in the transformer is Aluminium & copper. Here the cost of the Aluminium is less as compared with copper but by using copper material, the transformer life can be increased. There are different kinds of laminations available in the transformer which can reduce the eddy currents like EE type and EI type.

Working of Step-up Transformer

The step-up transformer symbolic representation is shown below. In the following figure, the input & output voltages are represented with V1 & V2 respectively. The turns on the windings of the transformer are T1 & T2. Here the input winding is primary whereas the output is secondary.

Construction Transformer
Construction Transformer

The output voltage is high as compared with input voltage because the turns of wire in the primary is less than secondary. Once the alternating current flows in a transformer then the current will flow in one direction, stops and changes the direction to flow in another direction.

The current flow will create a magnetic field in the region of the winding. The directions of the magnetic poles will be changed once the flow of the current changes its direction.

The voltage is induced into the windings through the magnetic field. Likewise, the voltage will be induced within the secondary coil once it is located in a moving magnetic field is known as mutual induction. So, the AC in the primary winding generates a moving magnetic field so that voltage can be induced in the secondary winding.

The main relationship between the number of turns in every coil and the voltage can be given by using this step-up transformer formula.

V2/V1 = T2/T1

Where ‘V2’ is the voltage in the secondary coil

‘V1’ is voltage is the primary coil

‘T2’ turns on the secondary coil

‘T1’ turns on the primary coil

Different Factors

There are different factors that need to check while selecting the step-up transformer. They are

  • Transformers Efficiency
  • Number of Phases
  • Transformers Rating
  • Cooling Medium
  • Material of Windings


The advantages of Step-up transformer include the following.

  • These are used in residential and commercial places
  • Power Transmitter
  • Maintenance
  • Efficiency
  • Continuous Working
  • Quick Start


The disadvantages of Step-up transformer include the following.

  • It requires a cooling system
  • Works for Alternate Current
  • Size of these transformers is huge.


The uses of Step-up Transformers include the following.

  • These transformers are applicable in electronic devices like Inverters & Stabilizers to stabilize the voltage from low to high.
  • It is used for distributing electrical power.
  • This transformer is used to change the high voltage in transmission lines which is generated from the alternator.
  • This transformer is also used to make an electric motor run, X-ray machines, microwave oven, etc.
  • It is used to boost electrical and electronic devices

Thus, this is all about Step up transformer theory. The function of the step-up transformer is to enhance the voltage as well as decrease the strength of the current. In this transformer, the no. of coils within the secondary winding is high as compared with the primary winding. So, the wire in the primary coil is strong when compared with the secondary coil. In transmission and power generation system, these transformers are essential, because from generating stations, they transmit the power to far off areas. Here is a question for you, what is a step-down transformer?