Transformers

A device which is used in stepping up and stepping down the voltages is known as a transformer. It can step-up and step-down alternating voltage only.

 

 

A transformer is a static electric machine which transfers electrical energy from one circuit to another without any change in the frequency. The principle is based on the electromagnetic induction. The major parts of a transformer are primary windings, secondary windings and laminated iron core. The alternating current given to the coil is known as primary winding. The coil from which electricity is taken is known as secondary winding. The two coils are wrapped around an iron core. This set up is known as a transformer.

 

The transformer works on the principle of mutual induction. When an alternating current is supplied an electromotive force is created in the primary coil. This causes a electromotive force to get created in the secondary winding too. If there is a passage of load of current through the coils, the voltage gets transferred from one coil to another.

 

If the number of turns of wire in the secondary winding is more than that of the primary winding then the voltage transferred gets increased, hence it is known as a step up transformer. If the number of coils is more in the primary winding than that of the secondary, then it s known as a step down transformer.

 

The need for a step and step down transformer is called for during the transfer of voltage from the area of production of electricity to the area of consumption. The network of electricity transfer is as follows:

 

• Electricity is transferred from the hydro electric or thermal project through cables to a step down transformer. Here the voltage is stepped down and hence the current increases proportionally. After reaching the local distribution system, a step up transformer is used so that the voltage is reduced in transferring to homes where a low level of electricity is required.

• Sufficient amount of energy loss is due to the transfer through the coils. This is prevented by laminating the steel core around which the coils are wrapped to prevent loss of energy. Insulations are provided between the primary and secondary windings to prevent backward flow. Most small transformers have a rectangular cross section, while most of them are large and have a cruciform shaped cross section.

 

Applications of a transformer:

 

• Transformers are used extensively to increase and decrease voltage before transmitting electrical energy. By changing the form of power from the transmission back to the spot of consumption, when it can be economical transfer of power.

• Transformers are also used in electric goods that are suitable only for low voltage circuits. • Signal and audio transformers are to be decided through micro propagation. A balun transformer can convert any signal to ground. Sufficient numbers of transformers have to be placed in different locations based on the size and the amount of voltage to pass through it.