Electrical Transformers and Types

What is a Transformer?

Transformers are used to transmit electrical energy for one circuit to another via electromagnetic induction to increase or reduce the alternating voltages in electrical applications. The machines mainly carry a laminated magnetic core and windings wound over it. These elements are covered from the center, from each other. Picking the most ideally suitable device out of the different types of available requires precise knowledge.

Different Types of Transformers and Applications

Transformers are one of the most pioneering inventions in electrical engineering. It is an electrical tool used to transfer the electric power from one circuit to another without altering its features, like phase and frequency.


A dry-type or oil-cooled transformer is a crucial device in each electrical network system. It has two circuits; to name them the primary circuits and the secondary circuits.

Here are the 10 different types of transformers

1. Air-Core Transformer

An air-core transformer is the type of Transformer that includes plastic or air as its core. The windings in this device are either wrapped around the plastic core or have no physical core.

The air instead has low magnetic permeability. However, there is no linkage within the coils since they are attached to the air between them.

There is no ferromagnetic core like iron in an air-core transformer. However, it reduces the core losses, which increase with the frequency. Also, the ferromagnetic substance crushes high-speed signals. However, the air-core Transformer is adaptable for radiofrequency current.

One more plus point of air core transformers is that they are not heavy and are suitable for mobile electronic devices like radio transmitters.

2. Ferromagnetic/Iron Core Transformer

The iron core/ferromagnetic transformer is made-up of ferromagnetic material. A ferromagnetic core is employed to amplify its magnetic field. The force of this magnetic field relies on the magnetic permeability of the item used.

Furthermore, iron is a usual ferromagnetic substance in these transformers. Iron core transformers are operated for heavy load applications with a low frequency, like electricity supplies.

3. Step Up Transformer

Step Up Transformer is the type of transformer wherein the secondary winding voltage is far more prominent than the primary winding since the number of turns in the primary winding is less than the secondary winding. The input and output power of transformers are similar.

However, the step-up transformer increases the voltage. Besides, it also reduces the current from the primary to the secondary winding. Therefore, it maintains continuous power. A step-up transformer is primarily utilized in power transmission over a large area to lessen line losses. The line losses rely on current.

However, reducing the current while increasing its voltage decreases the loss and supplies adequate power transmission. Besides, a microwave uses a step-up Transformer to raise the household voltage supply (110 or 220) to 2000 volts.

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4. Step-Down Transformer

A Step-down transformer reduces the alternative current voltage – the output voltage is less than the input voltage. The number of turns is higher in the primary winding than the secondary winding.

The most common step-up transformers are useful in diminishing the 11kv voltage from power lines to the standard voltage needed for the domestic appliances. Each phone charger utilizes a step-down Transformer to lessen the domestic supply voltage.

5. Power Transformer

A power transformer is helpful in power transmission. It steps up and down the voltages in the power generation plant to get suitable transmission. To lower the line control, using a step-up power transformer, we can increase the line voltage.

The power transformer’s operating voltage is relatively high, ranging over 33KV and energy ratings beyond 200MVA. Their size is enormous, and they function at the highest load using 100% efficiency.

6. Distribution Transformers

Distribution transformers are adequate for the supply of power to the residential and commercial applications. This type of Transformer steps down the high line voltage to the typical domestic voltage.

When compared with power transformers, they are smaller in size and easy to fix. They have a lower voltage, and the power ratings are usually below 200MVA. Their efficiency stays below 70% since they never function at full load.

7. Isolation Transformers

isolation-transformerIsolation transformers are the type of devices used for electrically isolating a tool from the power mains to avoid an electric shock.

One end of this main of the Transformer is grounded. However, if you touch the bare head of the secondary side, you will not get electric shock since there will be no current flow.

The 1:1 turn ratio transformer is fundamentally employed as an isolation transformer, but it is also planned to step up or down the transformer sometimes. Isolation transformers incorporate a unique insulating material among windings that supports high AC voltages.

Owing to the capacitive coupling, it entirely obstructs the DC component. They are used to avoid any electric shocks or attaching two circuits that are not supposed to be connected electrically.

8. Auto Transformers

Autotransformers only have one winding per phase split into two parts; primary winding and secondary winding. The windings accommodate three tap points – two fixed, whereas one is a changeable tap point.

The changeable tap point is moveable to rise or reduce the number of secondary turns and increase or lessen the output voltage.

Also read: Difference Between Auto Transformer and Conventional Transformer

Autotransformers are very useful in configuration to step up or down the input voltage and current. The output voltage can lower down if the supply is attached to the fixed terminals. In the reverse setting, the output voltage will surpass the input voltage.

The secondary winding is joined to the primary. However, there isn’t any electrical isolation, but it reduces the magnetic leakage level.

9. Single Phase Transformer

A Single-phase transformer has two windings; one primary and one secondary. The device is beneficial for single-phase applications such as microwave or mobile charger.

They consist of two input terminals attached with primary windings and two output terminals fixed with the secondary winding.

Single-Phase vs. Three-Phase Power Explanation

10. Three Phase Transformers

Three-phase transformers contain six windings: three primary windings and three secondary windings for every phase.

It has 12 terminals, each separated evenly on either side two for each stage supporting the star and delta connection. If not a three-phase transformer, you can also use three single-phase transformers together.

These are the ten different types of transformers mentioned above. Hopefully, this crucial information can make it easier for you to get the right kind of Transformer.

If you need further assistant while buying specialty-custom transformers you can reach out to https://www.electpower.com who manufactures and supplies high-quality copper wound dry-type transformer in Canada and can offer you relevant details to help you make the right decision.

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