Teravolt.org – DIY High Voltage Capacitors… [via]
Sure making a cap out of paper is fun and all, but making a high voltage one is even more fun!
You don’t need lots of money to make high voltage capacitors, in fact some pretty decent ones can be made with some cheap and readily available materials. This is because capacitors are very simple devices; consisting only of a dielectric and two plates. Most often a capacitor’s plates are just aluminum foil, and reynold’s wrap is easy enough to obtain, but what about the dielectric?
Enter the overhead projector sheet. Transparencies as they are commonly known as are nothing but acetate film, and while this is not the ideal dielectric for a capacitor it still does quite a good job. Typically a four mil OHP sheet can withstand 14kV before breaking down. As for obtaining them, the cheapest I have found these sheets is $10 for a box of 100, enough for about 16 capacitors.
How you make the capacitors is a rather trivial task, all that needs to be done is some cutting, flattening and rolling. Below I have an image that explains the process. Multiple sheets of OHP sheet are used to increase the capacitor’s voltage rating, and two sets of sheets are used so the capacitor can be rolled up.
DIY High Voltage Capacitors – [Link]