Basic principles of inductive components
Magnetism
The basis for understanding inductors is provided by magnetism and a few fundamental electromagnetic filed laws, revealing clear and fundamental knowledge of inductors and ferrites. The most important phenomena and laws will still perhaps be there from physics lessons:
Bar Magnet |
- Every magnet has a north and south pole (The earth is an enormous magnet!)
- If an existing magnet is divided , a new one is created. The magnet so created also has a north and south pole. This division can be performed down to the molecular level without losing the magnetic effect.
- Every magnet is surrounded by a magnetic field, which is represented by the field line model.
- Magnetic field lines are closed. They neither beginning nor end
- There are magnetizable materials(e.g iron) and non-magnetizable materials (e.g. aluminum).
Ferromagnetic Materials
The following analysis concerns a class of magnetizable materials, the ferromagnetic materials.
Every magnetic material is composed of finite number of smallest elementary magnets, configured randomly in the unmagnetized state. Therefore the sum of the magnetic effect is zero. These orientate under the influence of an external magnetic field.
Saturation |
If all elementary magnets are oriented in the magnetic field, one speaks of saturation of the material.
Once the externally applied magnetic field is removed, two effect can occur:
- The material becomes unmagnetic once again: One speaks of a soft magnetic
- The material remains magnetic: One speaks of a hard magnetic material
Ampere's Law
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