How Many Types of Transformers are There

Introduction

A transformer is a device widely used in the electrical domain. It is a device that works on the simple principle of electromagnetism. This principle of electromagnetism was discovered by Michael Faraday. Different types of transformers are used in different places. These transformers mainly differ in the way they are constructed, however, the principle of working remains the same. You can also construct your transformer with little effort however make sure that you follow the transformer protection techniques.

Types of Transformers

Transformers are classified depending on various factors. These are:

1. Depending on the Voltage level

2. Depending on the core material

3. Depending on the winding arrangement

Types of Transformers on a Voltage Level

Transformers have several types of construction. However, it doesn't need to have an electrical connection from one end to another. Even though the ends are not connected to electricity the two coils of transformers can conduct electricity through electromagnetic flux. A transformer might have multiple windings on the primary side as well as the secondary side. In various cases, the primary side has coils connected in series, this is called centre tapped.

Depending on voltage level, transformers are of two types.

1. Step-down transformers- Step-down transformers are used when we need to convert primary voltage to a lower-level voltage. This is achieved by the ratio of primary and secondary windings. When talking of a step-down transformer, the primary side must have more windings of the coil than the secondary side. This is done to assure that the ratio of primary windings to secondary windings remains more than 1. These transformers are used in efficient electrical distribution systems.

2. Step-up transformers- Step-up transformers are opposite to step-down transformers. They are used when a lower level of voltage needs to be converted to a high-level voltage. This is again obtained by the ratio between primary and secondary windings. When talking of a step-up transformer, the primary side must have lesser windings of the coil than the secondary side. The ratio between primary windings to secondary windings remains less than 1. These transformers are mainly used as inverters and stabilisers.

3. Isolation Transformers- The isolation Transformer does not change any voltage levels. The primary and secondary voltage in an isolation transformer always remains the same. The ratio of primary and secondary windings is always 1 which means the number of windings on the primary side is equal to that on the secondary side. It is only used for safety purposes and cancels out the noise that gets transferred from primary to secondary or vice-versa.

Types of Transformers on Core Material

The energy transfer in a transformer takes place through a core material. Different core materials when used generate different densities of flux. Depending on the core material, transformers can be classified as:

1. Iron core- This type of transformer uses soft iron. Multiple iron plates are used to generate flux. Due to the excellent magnetic properties of iron, the flux linkage of this type of transformer is extremely high. The iron core plates are available in different shapes and sizes. The coils of primary and secondary are wrapped around the coil former. This coil is then mounted on the soft iron core plates. The efficiency of a transformer that has an iron core is too high.

2. Ferrite core- Ferrite is used to make a ferrite core because it has high magnetic permeability. It is used in high-frequency applications because it offers very low losses. These are used in SMPS (Switch Mode Power Supply), RF-related applications, etc. Ferrite core transformers are also available in different shapes and sizes depending on the application in which it is required.

3. Toroidal core- These transformers use a toroidal-shaped core. This shape is used for superior electrical performance. These cores are doughnut-shaped or ring-shaped. These shapes are preferred to minimise the influx leakage and get high inductance.

4. Air core- These transformers do not use any kind of physical material to make their core. The core is entirely made using air in these types of transformers. In these transformers, the primary coil has an Alternating Current (AC) so that an electromagnetic field can be formed around it. Then the secondary coil is kept in this magnetic field. According to the law of Faraday secondary coil also gets induced with the magnetic field to power the load.

Types of Transformers on Winding Arrangement

Based on the winding arrangement transformer is:

1. Auto winding transformer- In these transformers, primary and secondary coils are connected in series and the centre-tapped node is made movable. Based on the centre tapped position the voltage of the secondary coil can be varied. The auto here doesn’t mean automatic but is indicative of a single coil. The most common use of this transformer is VARIAC. VARIAC is a device that is used to produce variable Alternating current. It is used for power transmission and distribution where there is a need to frequently change high-voltage lines.

Conclusion

Transformers are devices mainly used for the generation of electricity. What we read so far shows us that transformers and their types vary depending on various factors. Each transformer finds its application in a different domain. Transformers are used in measurement, electricity generation, and distribution, to produce electrical pulses, to generate audio output, and much more.