you need
  • For AC generators need special, which occurs when the strength of electromagnetic induction.The design has a particular power magnet, i.e. the rotor and the fixed core - the stator.
AC, as the concept is an average value of zero for a given period of voltage and power.Its essence lies in the title is that it is constantly changing with respect to direction and magnitude, and they are carried out through equal time.It is used in such devices, which are due, ie radio, television, wire telephony.This versatility is based on the fact that the voltage and alternating current if required can be converted without loss of energy.
AC can be single-phase and multiphase.Of the latter, the most widely spread is the three-p
hase, which is a system of alternating voltage, which consists of three circuits of electricity.They have the same parameters of the electromotive force of the same frequency and phase-shifted by exactly 120 degrees.It used a similar system in the industry to supply the lighting facilities, and electric motors.
in the process of passing on a particular conductor AC gives the same amount of heat as a constant.The time during which one oscillation takes place, is called the period.Status of this tension at certain times called phases, and the number of cycles produced per second - rate.
For activities of industry, as well as for efficient lighting alternating current is obtained by special generators, which are driven by steam or water engines and combustion turbines.If you need to transfer high levels of power, but at a relatively lower current need pretty high voltage.For this reason, transport of electricity over long distances may be accomplished only at a high voltage.
a long time, in the electrical field of activity only used direct current, but at a certain time there is a need to transfer this energy quite long distances.Moreover, in a life is mostly used is an alternating current, since it has a suitable physical characteristics.The conversion process with minimal loss of a large volume of low voltage in the high voltage low rates or vice versa, may be done only by a special electromagnetic device - the transformer.For this reason, at the moment of the advantages of its use only alternating electrical current.