Introduction to Capacitors

This guide will present a very simplistic view of what a capacitor is and how it can be used in electronics. Capacitors have lots of different uses in electronics not presented here, but this guide should be enough to get you using them.

In general, a capacitor can be thought of as a tiny battery. They can provide power to your circuit when your battery can not, and help to stabilize your circuits operation. Most circuits can benefit from the addition of capacitors, as discussed at the end of this guide.

Polarized and Non Polarized

Capacitors come in 2 varieties: polarized and non-polarized. Recall that resistors are non-polarized, meaning it doesn't matter which way you hook a resistor up to a circuit, it will work either way. Batteries, on the other hand, are polarized because they have a + (positive) and - (negative) terminal. You have to be sure that you hook batteries up the way that they are intended.

Some capacitors are the same as batteries and some are not. You have to be sure that you know whether your capacitors are polarized or non-polarized. We will talk about each of them separately.

Non Polarized Capacitor Schematic	Ceramic Capacitor Image

Above is one possible schematic symbol for a capacitor. Next to the schematic symbol are some ceramic capacitors. These are very common, cheap capacitors. They are called non-polarized capacitors. You may notice that there is not a + or - sign next to either of the legs. These capacitors can be hooked up to a circuit either way.

Polarized Capacitor Schematic	Electrolytic Capacitor Image