Kt Kingtronics Film Capacitor full introduction

◆ Summary of a Film Capacitor

The basic structure is that the dielectric material of PET or PP plastic film inserted between two electrodes.
The electric characteristic is different in kinds of dielectric film, and the size is also different according to the electrode structure. The figure for the device is as following.

The following is the schematic diagram for device.

◆ Film capacitor category 1) Classified by dielectric material

Name	Film’s category
Film’s category	Polyester film
PP film Capacitor	Polypropylene film
PPS film Capacitor	Polypropylene-sulfide film

2) Classified by Application

Name	Purpose
Serial Film Capacitor	Using in second electronic circuit
AC source generator Film Capacitor	Noise suppressor across the line
For Electrical machine Film Capacitor	improvement in motor rotation, light power factor

3) Classified by its structure

Name	Classify of electrodes	Winding method	Methods in connecting the leads
Foil type	Foil	Winding type	Inductive, non-inductive type
Metallized type	Deposited metal film	Winding type	Non-inductive type
		Layer type

4) Classified by external features
- Paper Dip type
- Paper mold type
- Non-Metallic case type
- Metallic case type

◆ The structure of a film capacitor

◆ Equivalent circuit of film capacitor

1) Equivalent circuit

An ideal capacitor doesn’t have any component changing the property of circuit, but in reality, lead wire and electrodes have resistance and inductance. The equivalent circuit is as following.

2) Characteristics

- The change of capacitance according to temperature change is little.
- High reliance is possible. (low error tolerance) is possible.
- Dissipation factor is small and it is possible to use for high frequency circuits.
- Can be used both AC and DC(Non-polarity)
- The Insulation resistance is excellent and has high reliability.