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how do i make an aluminum electrolytic capacitor?

i want to make a capacitor bank with high capacitance and i saw a lot of instructables for high voltage, but the most i got out of one was with aluminum foil and plastic wrap and i only got 14nf. i saw on some sites that the aluminum was electrocoated with aluminum oxide, but i couldn't find any specifics and nothing i tried so far has worked (it just created higher resistance, not capacitance). also, what's a good electrolyte solution, i'm just using water, salt and baking soda.

jtobako7 years ago
The more area and closer you can get the plates, the higher the capacitance.

I'm guessing that your current example is a Lydon jar (a bottle wrapped in foil) from the mention of an electrolyte. You should look into a plate capacitor, where sheets of aluminum foil are separated by plastic or other NON-conductors (salt water is a conductor).

Try http://wiki.answers.com/Q/Can_aluminum_foil_store_electricity .
LEYDEN jar.
orksecurity7 years ago
For what it's worth, aluminum is almost instantaneously coated with aluminum oxide when exposed to air. But since aluminum oxide is transparent and nonporous (unlike iron oxide), we don't normally notice it all that much. In fact, that protective layer of aluminum oxide is why aluminum pots don't corrode.
Aluminium oxide is usually deposited by electrolytic action, the process is called anodising, and is done in cold sulphuric or chromic acid baths by passing a current between a lead cathode and the aluminium workpiece anode. Steve