The manufacture of artificial magnets through the passage of electrical current through the coil of copper wire coils on a core of permeable metal magnetic flux, is the foundation that has allowed the development of electric motors.

MAGNETIC FIELDS

Figure 1 shows some artificial magnets in widespread use. Was observed to have two poles called north (N) and south (S). Act on other magnetic materials exert attractive or repulsive forces, without any physical contact in between.

Figure 1 - Artificial Iman

In Figure 2 we can see the magnetic field lines leaving the north pole and returning by the south pole. It is noted that this field has the ability to spread through the air and exercise its influence over any magnetically permeable material (steel, iron, another magnet, etc.)..

Figure 2 - Magnetic Field

Figure 3 shows the attractive forces (different poles attract) and repulsion (like poles of rejection) that are exerted between two magnets depending on the position of its poles. The term "air gap" means "air gap" translated into Spanish for business, but the translation technique is known as "air gap".

Figure 3 - Forces of attraction and repulsion

Figure 4 shows the generation of a magnetic field concentric conducting wire through which current flows. The direction of the magnetic field is determined by the "left hand rule." When you point your thumb in the direction of the electrons, the remaining fingers indicate the direction of the magnetic field.

Figure 4 - Generation of a magnetic field

In the case of AC is shown in Figure 5 the generation of magnetic field when alternating electric current passes through a conductor. We can see that the magnetic field is variable and depends on the instantaneous value is current. The magnetic field direction changes when the direction of current through the conductor.

Figure 5 - magnetic field when alternating electric current passes

From Figures 4 and 5 concludes that:

a) A constant magnetic field (in value and direction) is produced by passing DC current through a conductor.

b) A variable magnetic field (in value and direction) is produced by AC current passing through a conductor.

The electro-magnets are implemented with a magnetic core, wire coil driver and the continuous current flow through the wire. Figure 6 is drawn in transparent mode the core to see clearly the winding. The purpose of using the magnetic core is getting more intense magnetic field.