My homemade capacitor?

Question

I made two capacitors and im a little confused about how to charge them.. i tried hooking it up to a battery for a while then i tested the voltage on a multimeter and it was a very small voltage.. even if i use a 9 volt battery.. and i tried charging it with the static from a tv screen while holding one end to ground it and i ended up shocking myself somehow.. i hadnt put the ends together or touch the end i was charging on the tv.. but since then i havnt been able to do tht again.. and id rather not be holding on to it so is there a better way to ground the wire? and an easier way to charge the capacitor would be nice also.. anyone know?

Answer 1

Most homemade capacitors will have capacitance values in the range of 1 nanoFarad (1 billionth of a Farad).  It is difficult to build anything much larger than that.  

You probably charged it up just fine with the 9V battery, but as soon as you tried to measure it with your meter, it discharged within a fraction of a second -- too quick for the meter to display any of that 9 volts.

Charging it with static from a TV is also possible, and you may very well have charged it to a certain extent.  But now the problem is... your capacitor may not be constructed to withstand 10,000 to 30,000 volts that the TV static exists at, and breakdown will occur in the dielectric (insulator of the capacitor), and you will get a shock from that static.

If the capacitor is constructed properly, as soon as you attach a 9V battery to the terminals, the capacitor will be charged.  I'm not sure what you want to do with your capacitor.  Any further answer, here will depend on your application(s) and exactly how the cap. is constructed.

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Answer 2

It is very likely that you have some sort of a short between the two plates and the dielectric material.  In order for a capacitor to function properly, it has to have the two plates 100% electrically isolated.  I know 100% is not realistic, but the closer to full isolation, the better your capacitor.