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How to Build a Circular Capacitor

A capacitor is an electric device that stores charge when voltage is applied to the capacitor's leads. Capacitors are used in AC circuits to alter the shape or period of the AC waveform. Capacitors can also be used in DC circuits as a storage device, or as a reservoir that can smooth out DC power that has been converted from AC.

Capacitors are generally available in polarized and non-polarized varieties. Many non-polarized capacitors are flat in shape, since the internal capacitor plates are identically sized and placed directly across from one another. Most polarized capacitors are available in a circular package that looks like a small can. You can build your own circular capacitor by using a few commonly-available materials.

Things You'll Need

Toilet paper roll core
Scissors
Aluminum foil
Wire cutters
Non-insulated copper wire
Vinyl electrical tape
Two-way adhesive tape

Instructions

- 1
  Use the scissors to cut the toilet paper roll core lengthwise. Open the toilet paper roll core until it lies nearly flat.
- 2
  Cut a piece of aluminum foil to line the inside of the toilet paper roll core. Cut a six-inch piece of electrical wire and tape the wire to this piece of foil by using the electrical tape.
- 3
  Place a piece of two-way tape on the inside of the toilet paper roll core. Lay the piece of foil over the inside of the toilet paper roll core so that the foil sticks to the inside of the toilet paper roll core.
- 4
  Roll up the toilet paper roll core so that it assumes its previous shape. Cover the outside of the toilet paper roll core with two-way tape.
- 5
  Cut a piece of aluminum foil to cover the outside surface of the toilet paper roll core. Cut a six-inch piece of electrical wire and tape the wire to this piece of foil by using the electrical tape. Ensure that the two wire segments do not come in contact with one another.
- 6
  Wrap the piece of foil over the outside of the toilet paper roll core. Make sure that this piece of foil does not come in contact with the foil on the inside of the core.
- 7
  Wrap the outside of the toilet paper roll core with electrical tape. No part of the foil must remain exposed. To use this capacitor, connect the wire that is taped to the inside piece of foil to the positive power source terminal. Connect the wire that is taped to the outside piece of foil to the negative power source terminal.

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