Transformers are known more than 100 years and are the integral element of power lines, are widely used in the radio-electronic equipment and various household appliances. Exactly thanks to effect of transformation it is possible to receive electric current with necessary parameters.
There are two main types of current – constant and variable. The ordinary electric battery, for example, gives a direct current of 1.5 volts, and in the power supply network the alternating electric current with voltage of 220 V works. Transformers are used only for transformation of alternating electric current. The direct current of transformation does not give in.
As transformation of current is carried out
In the simplest option the transformer consists of the metal core – for example, of Highway-shaped plates, and two windings, primary and secondary. Windings electrically are among themselves not connected, transfer of electric energy is carried out due to electromagnetic induction.
Why in general the transformer is necessary? It allows in necessary limits to change tension and current. For example, you have an electric bulb on 2.5 V. It cannot be connected directly to the power supply network 220 V, it immediately will burn down. That it normally worked, it is necessary to lower tension from 220 V to 2.5 V – that is to reduce it almost by 100 times. The transformer also allows to solve this task. Its primary winding has rather large number of rounds – for example, 1000. Thanks to it it easily maintains voltage of 220 V, inclusion of a winding in network does not cause short circuit. Over primary winding it is reeled up secondary, but the number of its rounds are much less. If in our example 1000 rounds are calculated on 220 V, then 0.22 V then are the share of 1 round. We need to count 2.5 V. Netrudno that for normal work of a bulb of 2.5 V it is necessary to reel up a secondary winding from 11-12 rounds.
Areas of application of transformers of electric current
To transfer the electric power to long distances, high-voltage power lines are used. Alternating current as by transfer constant losses of the electric power are too big is transferred. Losses decrease also with increase in tension therefore on the main directions tension in hundreds of thousands of volts is used. To receive high voltage for transfer on distance, and then again to transform it to necessary to consumers, and transformers are used. As a rule, it is the powerful oil transformers calculated on high voltage. Small transformers are used also in the radio-electronic equipment and household appliances, they allow to lower voltage of 220 V to electronic components, lower, necessary for food. Sometimes transformers use for a galvanic outcome – in this case the quantity of rounds in primary and secondary winding is identical. From a secondary winding remove the same stress which acts on primary winding, but it is already other chain which does not have direct electric link with primary winding. Today in many cases it is not possible to replace transformers of alternating current with any other devices. Therefore it is possible not to doubt that they will be used still very long time.