Inductors are components to power electronic circuits that perform a significant, although somewhat complex, function. Practically every type of power electronic circuit will have some variation of an inductor on board. However, these components are difficult for some people to understand because they alter both the electric and the magnetic fields that surround them.
The inductance function that these components perform is derived from their coiled shape. When a current passes through the coil, a magnetic field is generated. The storage of electricity in the form of a magnetic field is what differentiates inductors from other electricity-storing components.
Depending upon the application you are looking to employ, the inductor that you choose will need to fit certain criteria. Here are four things for you to take into consideration when you are looking for an inductor for your project.
1. Core Type
The core of an inductor is one of the most important parts of these components. Nearly all inductors, in fact, are centralized on some sort of core that is composed of something that will support the generation of the magnetic field. Naturally, the type of core that an inductor has will directly impact the magnitude and scale of the magnetic field that is created.
Air core conductors, as the name would imply, use air as their core. This results in a low inductance and thus the capability to handle high frequencies. On the other hand, iron core inductors can only handle lower frequencies. Make sure that you take the core type into consideration when you are looking to purchase an inductor.
As you might have ascertained, the type of inductor that you go with will depend significantly upon the level of frequency that you will need it to handle. The frequency of the function will have an effect on the Q-factor of the inductor, its core type, and its tolerance level. Since frequency plays such an integral role here, it is something that cannot be left out of the picture when you are making your selection.
3. Self-Resonant Frequency
Each type of conductor will have its own self-resonant frequency, or SFR. The SFR of an inductor is the frequency at which the component stops working as an inductor. Each type of inductor that you come across will vary in this regard, and you don’t want to end up with a component that stops functioning when your application reaches its SRF. For this reason, it is important that you select a product that has an SRF that is significantly higher than the frequency at which your application will be running.
As with any other component that will be used in your application, you will need to select an inductor that suits the size requirements that you are working with. An inductor that is too large will obviously not be an option, but one that is too small might not operate to the extent that you need it to.