Film Capacitors

Film Capacitor Life Calculator

Calculator compliments of Illinois Capacitor

The operating conditions directly affect the life of an aluminum electolytic capacitor. The ambient temperature has the largest effect on life. The relationship between life and temperature follows a chemical reaction formula called Arrhenius' Law of Chemical Activity. The law put simply says that life of a capacitor doubles for every 10 degree Celsius decrease in temperature.

Voltage derating also increases the life of a capacitor but to a far lesser extent, as compared to temperature deratings. Internal heating caused by the applied ripple current, reduces the projected life of an aluminum electrolytic capacitor.

The relationship between capacitor life and the operating conditions is expressed by the following equations:

Film Capacitor Life Calculator

The operating conditions affect the life of a film capacitor in a very similar manner to aluminum electrolytic capacitors. Voltage derating has a greater effect on the life as compared to an aluminum electrolytic capacitor. The life expectancy formula for film capacitors is expressed by the following equation:

Film Capacitor Formula
L1 - Load Life Rating
Vr - Maximum Rated Voltage
Vo - Operating Voltage
Tm - Max.Temp.Rating of Capacitor
Ta - Ambient Temp.
 
 

Advertisement