- on Education & Information
- Published in issue 2/2004 on page 0
Foil Capacitor Polarity
Which terminal of a foil capacitor acts as the screen?
As most of you will be able to confirm, an electrolytic capacitor has to be connected the right way around in an electronic circuit. If you get the connections wrong, the innards of the capacitor will greet you when the power is switched on — the capacitor can will rupture, spilling its liquid or partly vaporised contents across the circuit board or (in the case of older high-voltage electrolytics) spouting it high up into the air. The rupture is not a silent process either as most of you will have learned the hard way. Depending on the size of the capacitor, a small explosion may occur. By contrast, fixed capacitors are non-polarized components and therefore not prone to explode unless they are operated way beyond their specifications in respect of voltage or surge current.