Electric energy can be obtained in many ways.
The most common are generators of direct and alternating current, based on the principle of rotation, as well as chemical sources of current.
To understand the principle of the device,Called the generator of electric current, it is necessary to recall at least a little the law of electromagnetic induction. It is thanks to him that mankind freely uses all the benefits of civilization.
Principle of operation of the generator of direct and alternating current, using rotation
The law of electromagnetic induction states that in any closed conductor the magnitude of the induced electromotive force is directly proportional to the rate of change of the magnetic flux.
When the magnetic field created by a constantMagnet, rotates at a stable angular velocity around the axis, an electromotive force is excited in the frame. The vertical sides of the frame are active, and the horizontal ones are inactive. This is determined by which sides cross the lines of the magnetic field in a particular circuit. At the same time, each side has its own electromotive force, which is directly proportional to the magnetic induction (B), the length of the side (L) and the linear velocity of the magnetic field (v):
E1 = B * L * v * sin (w * t)
E2 = B * L * v * sin (w * t +?) = - B * L * v * sin (w * t)
The resultant electromotive force is doubled, ie: E = E1-E2 = 2 * B * L * v * sin (w * t), because E1 and E2 act according to each other.
Graphical display of the resultingElectromotive force is a sinusoid. This is an alternating current. In order to obtain a constant current, it is necessary to withdraw the contacts from the working sides of the frame not to the contact rings, but to the semirings, rectification of the electrical voltage will occur.
Principle of operation of the generator of a direct current using chemical energy
Systems that convert chemical energy intoElectric, are called chemical current sources (HIT). It can be primary and secondary. Primary HITs can not be recharged - they are batteries, secondary HITs are capable of - these are batteries.
The last 20 years there was a furore in the field of HIT. This refers to the creation of lithium-ion batteries. Their principle of operation is similar to a rocking chair: lithium ions then go from the cathode to the anode, then from the anode to the cathode.
A chemical current source can only work when there are the following elements:
1); Electrodes (cathode and anode).
3); External chain.
The potential difference between the electrodes is calledElectromotive force. The HIT generates electrical energy in the external circuit because it is accompanied by an oxidation-reduction process carried out in space. The oxidation of the reducing agent occurs on the negatively charged anode. Electrons are formed, which transform into an external circuit and are directed to a positively charged cathode. Here, the oxidant is reduced by these electrons. In the battery, the oxidation and reduction process can repeatedly be repeated.