Electrical energy can be obtained in many ways.

The most common are the generators of direct and alternating current, based on the principle of rotation, as well as the chemical current sources.

To understand the principle of operation of the device,referred to as a generator of electric current must be at least a little to recall the law of electromagnetic induction. It is thanks to him mankind from enjoying all the benefits of civilization.

## The principle of operation of the generator AC and DC using rotation

The law of electromagnetic induction states that in any closed conductor magnitude of induced electromotive force is directly proportional to the rate of change of the magnetic flux.

When the magnetic field generated by the permanentmagnet rotates at a stable angular velocity about an axis in a frame electromotive force is excited. The vertical sides of the frame are active, and the horizontal - inactive. This depends on which side the magnetic field lines intersect in a specific pattern. At each of its sides is excited electromotive force which is directly proportional to the magnetic induction (B), the length of the sides (L) of the magnetic field and the linear velocity (v):
E1 = B * L * v * sin (w * t)
E2 = B * L * v * sin (w * t +?) = - B * L * v * sin (w * t)
The resulting electromotive force is doubled, ie .: E = E1-E2 = 2 * B * L * v * sin (w * t), because the E1 and E2 act in accordance with each other.
Graphical display of the resultingelectromotive force is a sinusoid. This is - an alternating current. To get a direct current, must be contacts on the operating side frame display is not to slip rings and half-rings to happen rectification voltage.

## The operating principle of DC generator that uses the chemical energy

Systems that convert chemical energy intoelectrical, called chemical current sources (HIT). He are primary and secondary. Primary HIT are not able to recharge - a battery, secondary HIT capable - this battery.

The last 20 years there has been a sensation in the field of CCS. This refers to the establishment of lithium-ion batteries. Their principle of operation is similar to the rocker: the lithium ions move from the cathode to the anode, from the anode to the cathode.

The chemical current source can operate only when there are the following elements:
1) The electrodes (cathode and anode).
2) electrolyte.
3) External circuit.
The difference in potential between the electrodes is calledelectromotive force. HIT generates electrical energy to an external circuit so that when it takes care redox process in space diversity. In a negatively charged anode, oxidation occurs reductant. Образуются электроны, которые переходят во внешнюю цепь и направляются к положительно заряженному катоду. Here comes oxidant recovery using these electrons. The battery oxidation and restore process can be repeated many times.