Overview: You will build a speaker consisting of two disposable plates face-to-face, joined at their edges with space in between. A magnet will be glued to the center of one plate, and attached to the other plate will be a coil of wire that extends up to and around the magnet.
Supplies needed: two disposable plates, magnet wire, magnets, a sheet of paper, tape, sandpaper, hot-glue gun, binder clips
Steps:
- Roll the paper into a tube, just a little larger than the magnet. Wrap several times — we need the tube to have some stiffness, because you’ll be wrapping wire around it.
- Cut the tube so it is just shorter than the distance between the two plates when touching rim to rim.
- Wind the magnet wire around the tube. Make sure both ends of the wire extend about 20 cm, not wrapped around the can. You can twist the two tails together, close to the cylinder, to keep the wire from loosening.
- Use the sandpaper to remove the lacquer insulation on the last 2cm of wire, on both ends.
- Glue the coil to the center of one of the plates, on the eating side.
- Glue the magnet to the center of the other plate, also on the eating side.
- Face the two plates toward each other and bring them together so they touch at the rims and the magnet is close to or inside the coil, with the coil tails sticking out. Use the binder clips to secure the two plates together. The speaker is now complete.
- Connect the two speaker leads to the output of an amplifier. Listen to music. Enjoy.
Here's a student-made video about speakers, including (from about two minutes in) a demonstration of building one from scratch. |
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