Capacitors March 16, 2011

What is a Capacitor? Capacitor – A device used for storing electrical charges. A capacitor is like a warehouse…it stores electricity, but it can not create it. Dielectric – An electrical insulator that can be polarized by electric force.

What’s Inside Inside a capacitor, there are two pieces of metal separated by a thin piece of wax paper. Metal conducts Wax Paper insulates.

The electrons are on the right, and the protons are on the left.

As the circuit becomes complete, the electrons rush to the negative side of the capacitor. It won’t complete the circuit entirely though because it can’t get past that wax paper.

The electrons are built up to a point where it can’t take it anymore.

Then…IT EXPLODES, sending a brief amount of electrons past the insulator through the other side. The electrons quickly complete the circuit, but only for a brief moment as they neutralize. You are left with a quick flash, and then it will go out.

So, what’s it for? A capacitor is to hold a brief amount of electricity for the things that need the extra push/burst of electricity. This is why it is so dangerous to start taking apart old electronics because capacitors can hold electricity for a really long time, and the minute you don’t expect it, BAM…a blast of electricity shoots through your body. If you are going to open something up and take it apart…STAY AWAY FROM THE CAPICATORS.

Ok, I got that, but why doesn’t it keep flowing through the circuit? The reason is because once things are neutralized, then it can stop pushing. If you turn it around, it will give another blast of energy from the other side.

Camera Flash Take a camera flash for example. A flash needs a quick burst of electricity, so a capacitor stores it up and then sends it to a transformer that gives a quick burst of electrons. Hence, we have a flash! We couldn’t have that many volts flowing through constantly, because they we would have a really bright light that would stay on.

What Happens Again? A battery sends out electrons from the negative terminal and then sends it to a metal plate inside a capacitor. The electrons won’t keep flowing because there is an insulator so the electrons build up on that plate. The electrons build up so much, that it has to send out a burst of them in all directions…hence, you get a quick flash.

How they talk to one another. Positive Terminal + + + + + + + + + + + + + + + + + + + +…hey, don’t blow up please. Insulator (Wax Paper) Cause I am an Insulator Stupid Negative Terminal - - - - - - - - - - - - - - - - - - - - - …Why can’t I flow through?

Your Challenge 1st First…create a circuit including a capacitor, a lamp, and a battery. 2nd Second…observe the burst of electrons and how they quickly turn on the light. 3rd Third…flip it around and try it from the other side.