Electric energy can be received in many ways. The generators of direct and alternating current based on the principle of rotation and also chemical sources of current are the most widespread.
To understand the principle of operation of the device called the generator of electric current it is necessary to remember the law of electromagnetic induction at least a little. Exactly thanks to it the mankind freely uses all benefits of a civilization.
The principle of operation of the generator of the direct and alternating current using rotation
The law of electromagnetic induction says that in any closed conductor the size of the induced electromotive force is directly proportional to the speed of change of a magnetic flux.
When the magnetic field created by a permanent magnet rotates with a stable angular speed around an axis, electromotive force is excited in a frame. The vertical parties of a frame are active, and horizontal – inactive. It is defined by what parties cross lines of magnetic field in the concrete scheme. At the same time the electromotive force which is directly proportional to magnetic induction (B), length of the party (L) and linear speed of magnetic field (v) is excited in each of the parties: E1 = B*L*v*sin(w*t)E2=B*L*v*sin(w*t+π) = - B*L*v*sin(w*t) the Resulting electromotive force doubles, i.e.: Е = E1-E2 = 2*B*L*v*sin (w*t) because E1 and E2 work according to with each other. Graphic display of the resulting electromotive force is a sinusoid. It is alternating current. To receive a direct current, it is necessary to remove contacts from the working parties of a frame not to contact rings, and to half rings, there will be a straightening of voltage.
The principle of operation of the DC generator using chemical energy
Systems which turn chemical energy into electric are called the chemical sources of current (CSC). It happen primary and secondary. Primary are not capable to be recharged by CSC is batteries, secondary CSC are capable - it is accumulators.
The last 20 years there was a furor in the HIT area. It belongs to creation of Li-ion batteries. Their principle of action is similar to a rocking-chair: ions of lithium pass from the cathode to the anode, from the anode on the cathode.
The chemical source of current can work only when there are following elements: 1) Electrodes (cathode and anode).2) Electrolyte.3) External chain. The difference of potentials between electrodes is called electromotive force. The HIT generates electric energy in an external chain because with its help the oxidation-reduction process carried in space proceeds. On the negatively charged anode there is a reducer oxidation. Electrons which pass into an external chain are formed and go to the positively charged cathode. There is a restoration of oxidizer by means of these electrons. In the accumulator the process of oxidation and restoration can repeatedly be we will repeat.