اهمية المغنطيسية .. الإلكترونيات

The importance of magnetism .. Electronics

The importance of magnetism

It is known that the particles of the non-magnetic rod are in motion (57 A), then it is soon concluded when the rod becomes magnetized (57 B) so that it takes a certain end and this rod is called the magnet (57 C) and there are two ends at its ends, one of which is north there. South. The magnet has gone in different shapes, including the shape of a horseshoe (57 D) or the shape of a ring (57 E).

And it is equal to the north approach of a magnet from the south pole of another magnet by virtue of a force that attracted between the poles • But if we bring the north end of a certain magnet closer to the north pole of another magnet, or if we bring the south pole of the first closer to the south pole of the second, and the pole between the two is calculated as a repulsive force to push the two rods away from part of it. It is known that all iron objects are attracted towards the magnet.

The following devices use magnets with special shapes (58). The magnet in Figure (18) has concave ends and embraces the moving coil for measurement. The same magnet (58b) is used for the wine itself. As for the magnet shown in the nose (58c), it is used in the loudspeaker or the moving coil microphone.

57 - Magnets.
58 - Shapes of magnets used in electronic devices.

As for a coil with a battery or any source of direct current, a specific magnetic field is generated by a coil (59a) that has two magnetic connections, one north and one south, and it remains continuous with the continuous flow of alternating current in the coil, meaning that the magnetic field is not created unless the control switch is closed and the alternating current begins to flow (9) H B). As for the circuit version, it collapses completely (59c). As a result of this change in the magnetic field, a driving force is generated in the coil, but with an electrical mechanism opposite to the polarity of the battery itself. Also, if the polarity of the source is reversed, the magnetic poles of the coil are also reversed. Note the coil that is connected to an alternating current source (Figure 60). The current passes through it back and forth, i.e. it passes through the positive transmission half in a certain direction and its direction is reversed in its negative half. Every time the direction of the alternating current is reversed, the magnetic field collapses and a new magnetic field is generated from it with a reversed shoulder. Most magnets have iron electric cores to concentrate the lines of magnetic force. This is because the passage of alternating current through the coil leads to the presence of a magnetic field in it.

The opposite is true, and now you have begun to seek this phenomenon by moving the coil in a magnetic field or so a magnet inside a certain coil or next to it. In all these cases, a magnetic field is generated in the coil by induction (61).

59 - Magnetic field of a closed circuit area of ​​an induction coil.
60 - An exposed coil with an iron core fed with alternating current.