Difference between Polar and Non Polar Capacitors

[furqankaimkhani]

I am a learner in electronics. I am unaware but curious about the major constructional and working differences between the polar and the non-polar capacitors.

Although we had been given some insights into the capacitor construction and working in High school, but I think that was a simple non-polar capacitor.

When I asked someone, what is a polar capacitor? I got a naive answer that these have polarity and you have to put them in the right polarity. This I know too.

Pls! tell me more.

Furqankaimkhani

 

[kak111]

what is a polar capacitor?

Non-polarized fixed capacitor

A non-polarized ("non polar") capacitor is a type of capacitor that has no implicit polarity -- it can be connected either way in a circuit.
Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them "bipolar" capacitors.

Polarized fixed capacitor

A polarized ("polar") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit.
The positive lead is shown on the schematic (and often on the capacitor) with a little "+" symbol.
The negative lead is generally not shown on the schematic, but may be marked on the capacitor with a bar or "-" symbol.
Polarized capacitors are generally electrolytics.

Note that you really need to pay attention to correctly hooking a polarized capacitor up (both with respect to polarity,
as well as not pushing a capacitor past its rated voltage). If you "push" a polarized capacitor hard enough, it is possible to begin
"electrolyzing" the moist electrolyte. Modern electrolytic capacitors usually have a pressure relief vent to prevent catastrophic failure
of the aluminum can (but don't bet your eyesight on this).

General info

Types of capacitor - Wikipedia, the free encyclopedia

Here is a booklet on aluminum electrolytic capacitors.

**broken link removed**