We made our own microphones this week. However, mine didn't work out too well. I had to physically tap my microphone in order to create vibrations strong enough for the oscilloscope to pick up. As we learned, sounds are the product of vibrations, so my voice should have been enough to create vibrations for the oscilloscope to read.
However, I can think of a few reasons, mostly due to the materials, as to why my microphone failed:
- The diaphragm (in this case, a plastic cup) wasn't the best choice of material.
- The lid on the cup probably needs to be something that will better seal the diaphragm.
- There probably isn't enough space in the diaphragm for the coil to properly move up and down with the vibrations.
The components for this are magnet rings to act as the transducer, magnetic copper wire wrapped around a straw to act as a coil, and a plastic cup as a diaphragm. If I were to re-do this, I'd probably find a better diaphragm (perhaps a large tin coffee can would work well here?). Here's some images and video of me testing my failed microphone.