How to Choose Your Kind of Box Type Capacitors to Store Energy at Its Best

If you are from the Electrical Engineering discipline, you must agree with one thing that despite the scattered range of capacitors, you can easily put the last piece of the puzzle in place by their basic common physical laws. This way, it’s also easier for you to understand how the capacitors operate, with a choice of technologies, and their values.

In order to get a fair understanding of the various forms of capacitors and their usage, it is necessary to look at the basic theory behind capacitance.

In the following article, you will learn about film foil, non-inductive and axial capacitors. Remember, all of them are Box Type Capacitors.

The basic rule:

A capacitor’s ability to store energy doesn’t come from its chemical reactions, but from its physical design with two parallel metal plates, with a gap between them, that store potential energy through their mutual attraction when they are re-united.

This makes the capacitors very fast at charging and discharging, compared to batteries.

For ex. the film dielectric power capacitors save energy by reducing internal losses to half those of capacitors using conventional Film/Paper dielectric.

Film Foil Capacitors:

Film Foil Capacitor consists of two metal foil electrodes made of aluminium foil separated by a piece of plastic film. This plastic film can be of polyester, polypropylene or polycarbonate.

Film/foil capacitors, in general, are characterized by their good capacitance stability, low losses even at high frequencies, high insulation resistance and high pulse handling capabilities. They can be wound in two different ways – inductive and non-inductive.

Non-inductive Capacitors:

Non-Inductive Type Capacitors are wound in a similar manner to inductive capacitors except the foils here are oriented so that one side of each foil extends beyond the film.

Due to the very small lengths of these capacitors, a very low inductance is formed across them. The advantages of using these capacitors come from their suitability for low as well as high frequency.

Axial Capacitor:

Axial Capacitor is another polarized capacitor whose anode is made of a particular metal on which an insulating oxide layer is formed by anodization, simulating the dielectric of an electrolytic capacitor.

This kind of capacitor has, with a very thin dielectric oxide layer and enlarged anode surface, a much higher capacitance-voltage compared to other capacitors.

The large capacitance of this kind of capacitors makes them very suitable for passing or bypassing low-frequency signals, besides allowing them to store large amounts of energy.

You can also use them for decoupling, noise filtering, variable-frequency drives, and energy storing.