Homemade film capacitors
90nF film capacitor, made of aluminium kitchen foil and kitchen food wrap film
1. The
components that you need: Kitchen aluminium foil, kitchen food wrap
film, a pair of scissors and optionally two strips of copper.
2. Cut two sheets of 48mm x 8mm aluminium foil (maybe 52mm x 8mm for closer to 100nF). Make sure you do not crinkle them much.
3. Place one of these sheets on a clean flat desk.
4. Place a larger sheet of kitchen food wrap film onto the sheet. The film might electrostatically stick to the aluminium foil and the desk. Make sure you do not crinkle the film much.
5. Lift
up the film and the aluminium foil and insert the coper strip below the
foil. Instead of the copper strips, you can use aluminium foil, wrapped
a few times (for mechanical strength) to form a strip. After you do the
above, place another aluminium sheet on top of the film and align it to
the aluminium sheet below it.
6. Place the other strip above this second aluminium foil. Then put another sheet of film on top of the second aluminium foil.
7. Wrap the whole construction as shown, while making sure you do not crinkle it much.
8. When
finished, wrap a few more turns of film sheet around the whole
capacitor, to keep it mechanically stable. Then cut the excess film
from the ends, but not too close to the aluminium sheets. Leave some
excess foil at the sides.
The measured value of this particular capacitor was 90nF