Inductor: The Misunderstood physical component
Inductor is an electromagnetic device employed in several applications. The principle of operation of this component, the basic of its physic and its design was explained in many textbooks. However, I can say that all references and textbooks failed to give a correct and accurate definition of this component.
As a fundamental step in science, when dealing with such component it is recommended to start by giving it a useful definition. Unfortunately, I did not find any accurate and meaningful definition of this component in the literature. In most references it is defined as a passive storage component. This definition is completely wrong and the adjectives "passive" is definitely meaningless. In the following, I will give general definition of this component from which its principle of operation and its design can be well understood.
Inductor is called "Inductor" because it is the component that induces a magnetic field through a changing electric field and vice versa. This phenomenon is known as the magnetic induction: The electric field produces a magnetic induction B and the magnetic induction B produces an electromotive force which itself opposes the electric charges. The fundamental physical quantity that characterizes this phenomenon is the magnetic flux density known also as the magnetic induction and noted by B. It is a continuous vector and its divergence is null (div B=0). The second fundamental physical component of this phenomenon is the magnetic field intensity H. Unlike B, the vector H is a force and can naturally be discontinuous. The change of the magnetic flux density B with respect to time through a closed area can produce an electromotive force. Similarly, a changing electric field can produce a magnetic induction B. The vector B is flux type vector which can be calculated by the integral of surface. The magnetic force H can be calculated by a line integral. B is independent on the propriety of the medium, however H it does depend.
Inductance is a scalar quantity that principally quantify the capacity of a electromagnetic component to generate magnetic induction. Inductance does not mean by anyway the capacity of energy that a component has. It is fundamentally size and material dependent ( Not as taught by some people in social media). L is equivalent to the mass and B is equivalent to the speed in Einstein equation. Any change in the magnetic inductance should lead to a change in the magnetic induction B and vice-versa. In other terms, any change of the inductance which does not incorporate a change in B is definitely a fake change. From this basic, last year I have, for the first time, raised the issue of the fake inductor produced in industry. It should always kept in mind that Inductor is not the physical component (core and winding )that is visible to you. Inductor is the magnetic induction phenomenon generated by the changing electric field and the reaction of B to the changing electric field.
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As I said, last year I gave a lecture about the design of the DC gapped inductor and at the end of my lecture I mentioned the fake inductor. Some people objected my view and started to inquire what is the meaning of a fake inductor. Some of them looked in google to verify the meaning of "fake" thinking that I do know the English meaning of "fake". I preferred not to respond them because it is useless to argue with people who understood the inductor from its visible physical shape and not from the physical magnetic phenomenon generated in this component. To explain the problem of the gapped inductor in a simple way, I should say the following. Let's suppose we have a given inductor that has a given gap. We excite this inductor by a DC source during certain time dT. During dT, there will be generation of magnetic induction B that depends only on the DC voltage, the cross section area of the core, the number of turns. Now, Let's demagnetize the core and then increase or decrease the gap length and then apply the same Dc voltage during same time dT. In this case, the same B will be generated because B is independent on the length and the propriety of the medium as I have explained above (it is a flux vector and not a force). If you put a secondary in the core and you measure the voltage in both tests, you will get the same voltage. In both tests, the magnetic field H is different. the vector H has nothing with the phenomenon of magnetic induction. It is a force vector which can be calculated by a line integral. To summarize, in the market, there are inductors of same size, same cross section, same number of turns, same materials which have different inductances (L) obtained by changing the gap length. One of these Inductor can be considered a true inductor and the remaining are all fake inductors. They are definitely inefficient and weakly designed and they are also fake inductor from the scientific view.
This is a small and narrow view of the inductor. I hope To explain more in the future about this topic.
If You would like to design a non-fake inductor, you need to follow the method that I have developed in my paper which can be found in the following link.