There are two types of electric current: constant and variable. But only alternating current is widely used. It is connected with the fact that it can be transformed (to transform) with the minimum losses of energy.
Instruction
1. For a start we will understand what is electric current. The directed movement (stream) of charged particles is also called electric current. In alternating electric current through the section of the conductor for equivalent periods there passes various amount of charged particles. In constant the quantity of these particles for identical intervals of time is always equivalent.
2. Alternating current constantly changes the force, size or the direction. Also there are these changes always periodically, that is repeat through identical periods. For example, by means of alternating current it is impossible to charge the accumulator or it is impossible to use it for the similar technical purposes.
3. Unlike a direct current, variable has several additional values: - the period - temporary value of commission of a full cycle of indicators of alternating current; a half-cycle and frequency (quantity of cycles for a concrete interval of time); - amplitude – the highest value of alternating current; - instant value – value of current at present time.
4. Alternating current is more widespread and widely we apply. It is easier to transform it to alternating current of other tension, to change tension in electrical networks depending on necessary requirements. It can be done by means of the transformer. The transformer – the device transforming alternating current of one tension to the same current, but other tension with an identical frequency of current.
5. In addition, the advantage of alternating current to come down to the fact that electric motors which work at alternating current much more reliably and more effectively, than direct current motors. They do not need frequent service that does their operation inexpensive. And also what is very important, they have higher degree of protection.