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The image shows an electrical transformer, viewed from the front, a static electrical device that transfers electricity from one primary circuit to a secondary one, while transforming the voltage of the electric current so as to adapt from the secondary circuit to the final consumer.

It consists of a square frame called the iron core of the transformer, rendered by an embossed square, blank in the middle.

On the left side of the core are wrapped around it the conductors, copper wires called primary winding, through which flows initially the primary alternating current, which may be of a certain primary voltage.

On the right side of the core are wrapped around it the conductors, the copper wires called secondary winding, through which flows the secondary current, which may be of a certain secondary voltage.

The high or low voltage is given by the number of windings of copper conductors on the sides of the transformer core.

So, changing the ratio of coils changes how much the voltage changes.

If there are twice as many secondary coils, meaning the secondary winding on the right side, then the voltage is twice as high on the secondary side.

The process can also be reversed, respectively the secondary current flowing through the right side with less secondary winding, than the primary one on the right, to be transformed into low secondary voltage current.

The winding is highlighted, left and right of the core, by thick curved lines.

The direction of current flow, influenced by the magnetic flux of the magnet in the core of the transformer, is from left to right, being illustrated by two arrows with the tip to the right, located in the upper left and right ends.

General information

Standing in line right after the electric generators and the connecting wires through which the electric power is transmitted, the next components of the electric network are the transformers. These devices carry on more efficiently the transmission of electrical power over long distances. The role of transformers is to increase or decrease the voltage, according to the intended consumer’s needs. The voltage is measured in volts. Examples of electric power consumers are household appliances, various types of industrial equipment, as well as electric means of transportation.

The main components of a transformer are: a coil, named primary winding, and a second coil, called secondary winding, an iron core that passes through the center of both coils; a metal case that encapsulates the metallic core and the coils.

Apart from the huge transformers of the electric network, there are appliances that have their own transformers, which are factory built-in. The home socket voltage is two hundred twenty volts. But there are appliances that need a higher voltage in order to properly function, for example the microwave oven. On the contrary, there are devices which need a lower voltage for charging, like, for instance, a laptop or a modern TV.

To conclude, an electrical transformer is a device that takes the electric power from a power source, a power station for example, and then feeds the converted electric current to a power-charged consumer. 


  1. http://itee.elth.pub.ro/~prejblil/transformatorul%20electric.doc
  2. https://ro.wikipedia.org/wiki/Transformator

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