Using of Film Capacitor – the Charge and Energy Option

Do you know about the Film dielectric capacitor? If you are searching to learn about these capacitors, then don't jump to this article. Here we will be discussing this capacitor, its types, uses, and advantages. So stay with us to gain in-depth knowledge-

What is Film dielectric capacitor?

Film dielectric capacitor, or polymer film-capacitor, is widely termed as 'Film Caps' and 'Power Film-Capacitor'. It is an electrical device that stores electrical energy in the electrical field with the insulating thin polymeric material (Plastic Film) as an electrical insulator, which can be polarized by applying an electric field.

Sometimes, the capacitor is combined with paper that acts as a carrier of the electrode (an electrical conductor used to connect with the circuit’s non-metallic part). 

How does it work?

Unlike those general purpose capacitors, polymer film-capacitors follow the same principle. In these capacitors, the present electrodes store the charge & the energy. 

Due to its non-polarized characteristics, it can be connected anywhere in the circuit. Whenever the supply is given, it gets charged.

The capacitor's electrodes may be metallized aluminium or zinc. Aluminium & zinc can be applied to the plastic film's surface directly or a separate metallic foil. It gets charged when the AC type energy is supplied for the positive part. Hence, it has the same working principle as other capacitors; the only difference is its dielectric chosen.

How many types are available?

On the basis of construction, Film Capacitor can be distinguished into two types-

• Film Foil Capacitor.

• Metalized Capacitor.

Film Foil Capacitor: This capacitor has two sheets of plastic and one-sheets of metal like aluminium. These sheets are grouped and folded to give a cylindrical shape. Hence those plastic sheets get attached with aluminium foil, and that aluminium sheet acts as the electrode. Plastic films are used as dielectric.

Metalized Capacitor: In this type, either aluminium or zinc metal is used. Here the aluminium or zinc sheets are replaced by a vacuum. Same Film Foil Capacitor, the metal sheet acts as an electrode and the plastic sheets of capacitors are used as the dielectric.

What are the advantages of using film caps?

It has several advantages rather than other capacitors. We are going to propose the list of benefits in the following points-

• It possesses the metallized construction and has unique self-healing features.

• It can work at high voltage.

• It contains a higher ripple current if compared with an Electrolytic capacitor.

• It has a long operational life span.

• There is no worry about the leakage of electrolyte.

Uses of Plastic Film Capacitors:

• The film caps are widely used in electronic devices where the main concerning area is 'Power'. It is used in analogue to digital converters, flashes of x-rays, etc.

• It is preferred to use as the energy storage component or unit.

• The capacitor is used to give the smoothing effect.

• It is popularly used in those circuits which are made to protect devices