Hello to everyone who actually reads this ^^
*BOOM* there goes the 100-follower-wall down. :D
SOOOO, today i'll teach you about capacitor and after that i'll give you a little preview on what we are going to build the next time :o
At first, capacitor have the unit farad. (wow, now everyone understood what capacitor are)
With that said, let me explain how a capacitor works.
There are 2 plates with a non-conductive material between them.
Now we put the + pole on one side and the - pole on the other on our power supply of a few volts.
(for the love of god, please dont put a condensator in your power socket. PLEASE DONT BE SO STUPID! The thing will explode before you even recorgnize it!!!)
You may think "there is no way that current could flow there, capacitor are non-conductive." Right and wrong.
Because of the 2 plates, electrons from the plus pole push on the one plate while electrons from the - pole are pulled out of the plate. Through the capacitor flows no current but everywhere else.
"Does that mean, there is a permanent flow of current because of that capacitor ?"
No! Remember what i wrote about voltage? Its the potential difference between 2 points and on the biggest resistance stands the biggest voltage.
=> The capacitor is non-conductive so it is the biggest resistance and so the condensator will charge up to the whole supply voltage.
"But how long does it take till the voltage stands on the capacitor or is this instantly?"
You can imagine the capacitor as a battery. It charges upon the supply voltage. That is determinated by this formula:
t (time) = R (resistance) x F (farad)
We have a capacitor with 1mF (MilliFarad) and a resistor with 1kOhm. Our supply voltage is 5V.
t = 1kOhm x 1mF
t = 1
After 5 times that time the capacitor is "fully charged". So you see, the bigger the resistance of the wire/resistor is and the higher the capacity is, the longer the capacitor charges.
And after the same formula the capacitor discharges itself if you connect the 2 poles of the condensator.
Some of you might think now: "2 plates with a non-conductive material between them... does that mean 2 simple cables are a capacitor, too?"
Yes, you are right. But the less the surface of one plate is and the higher the distance between those plates is, the less is the farad of our "capacitor".
There are areas of use where this is very important but not for our purposes.
With that we can make frequenzys, we can let things blink, we can have our own little battery and we have a little buzzer.
In my apprentienceship, me and the others charged capacitors with around 20 volt. You put the 2 poles on someones arm/leg/neck/whatever and brizzl, the poor victim gets a little electrical shock ^^
aaaaaaaaand now, the thing that could be your thing after you build the thing next time.
Tadaaaaaaa.... wait, what is that? Only one way to find that out ;D