Transfomradores Electicos

ELECTRICAL TRANSFORMERS

Called transformer to an electrical device which can increase or decrease the tension (voltage) in an alternating current electrical circuit, while maintaining the power. The power coming into the team, in the case of an ideal transformer (ie, without loss of voltage or voltage) is equal to that obtained at the output. Actual machines have a small percentage of losses, depending on its design and size, among other factors.

The transformer is a device that converts AC power of a certain level of voltage, AC power of another voltage level, based on the phenomenon of electromagnetic induction. It comprises two coils of conductive material wound on a closed core of ferromagnetic material, but electrically isolated from each other. The only connection between the coils is the common magnetic flux established in the core.

Operation:

This electrical component is based on the phenomenon of electromagnetic induction, as if we apply an AC electromotive force in the primary winding due to the variation of the intensity and direction of the AC current, the induction of a variable magnetic flux is produced in the iron core.

This flow will cause electromagnetic induction, the appearance of an electromotive force in the secondary winding. The voltage in the secondary winding will depend directly upon the number of coils having windings and the voltage of the primary winding.

Relationship Transformation

The ratio indicates an increase or decrease experienced by the value of the output voltage with respect to the input voltage, this means, the relationship between the output voltage and the input.

The relationship between the electromotive force inducing (Ep), applied to the primary winding and the induced electromotive force (Es), obtained in the secondary is directly proportional to the number of turns of the primary winding (Np) and secondary (ns) , according to the equation:

The ratio (m) of the tension between the primary winding and the secondary winding depends on the numbers of turns having each. If the number of secondary turns is three times the primary, the secondary will have the triple voltage.

Where: (Vp) is the voltage across the primary winding or input voltage (Vs) is the voltage across the secondary winding or output voltage (Ip) is the current in the primary or input winding stream, and (Is ) is the current in the secondary winding or current output.

This feature is used in the transmission of electricity: power carriage in high voltages and small currents, the losses by Joule effect and decrease the cost of drivers is minimized.

Thus, if the number of windings (turns) of the secondary is 100 times larger than the primary, by applying an AC voltage of 230 volts in the primary, 23,000 volts (100 times a ratio obtained in the secondary, as is turns ratio). A relationship between the number of turns or windings of the primary and the secondary is called turns ratio of the transformer or transformation ratio.

However, as the electric power applied to the primary, if an ideal transformer, must be equal to that obtained in the secondary:

The product of the potential difference by the intensity (power) should be constant, so that for example, if the circulating current through the primary is 10 amps, the sub will be only 0.1 amperes (one hundredth).

Operating Principle

The principle of operation of the transformer is rooted in the theory of electromagnetism summarized in Maxwell's equations.

Parts of a transformer

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