The Principle Structure Of Metallized Film Capacitor

Metallized film capacitor is a capacitor made of organic plastic film as the dielectric and metallized film as the electrode. Carbonate and the like have a laminated type in addition to a wound type. Among them, polyester film media and polypropylene film media are the most widely used.

A metallized film capacitor uses a polyester film or a polypropylene film as a medium, and a zinc-aluminum alloy is attached to the surface of the film by vacuum evaporation to form an electrode. Capacitors are formed by non-inductive stepless winding or lamination. Metallized film capacitor has high withstand voltage, high insulation resistance, good impedance frequency characteristics (smaller parasitic inductance), lower ESR, high capacity stability, and low loss tangent.

Metallized film capacitor is used in electric energy meter for signal transmission, coupling, voltage reduction and so on. As a coupling capacitor, metallized polyester film capacitor, due to its high insulation resistance, can couple AC signals or pulse signals to the subsequent stage without attenuation, without affecting the DC operating point of the subsequent stage. Metallized polypropylene film capacitor as a step-down capacitor due to its low loss tangent and high capacity stability (using a special process to prevent destructive corona from declining capacitance), can reduce AC high voltage to low AC that meets the requirements of the subsequent circuit The voltage replaces the original transformer, making the product smaller and more stable in performance.