In order to build a capacitor, you have to know what materials you have on hand. I had Lexan and some aluminum tape. They would be easy enough to use, so I picked them. If you are looking for aluminium tape, try a hardware store. It is used to repair ducts in the heating systems of homes. Now for the assembly.
If you want to make a capacitor for a hobby project, and you need it to have specific capacitance, odds are you will need more capacitance than a few picofarads. In order to get more capacitance, look at the formula from before: -Make the dielectric constant larger: Pick a new material that will give you a better result.
With 22 compartments in the capacitor box I have a place for everything from 10pF to 100 uF (I mix together anything higher because I use them so rarely). The resistor box is a bit more annoying since I need to pick through to find the exact value I need; I should upgrade it. I bought them at my local hardware store.
This model shows a capacitor in its simplest form. It consists of two conductive plates separated by a dielectric material. Now a dielectric is a fancy word that just means an insulator that reacts a certain way in the presence of an electric field. Something to be aware of is that the dielectric material will have a property called permittivity.
#1 Lesson: The major thing you need to know about capacitors is that they "love" to keep voltage steady, and will use current to make it happen. That may not make sense to you just yet, so let's take a look at a few other things next to make it much clearer. The key thing to know about capacitors is something called capacitance.
Another place they are seen often is in oscillator circuits. They are well suited for high frequencies and high current pulsing. Aluminum capacitors are part of the electrolytic family. These capacitors use aluminum oxide as the dielectric. This type is very common and fairly cheap.