so this week’s assingment was to build a microphone. if you look at the videos and tutorials around the web it seems pretty easy, but it actually required a lot of testing to make sure that it is working. I decided I wanted to make a small microphone and therefore I got small ceramic magnets and found the rest of the material’s on the shop (although this made me think that I might haven’t got the exact materials/thought it might not make the mic work).
My first prototype was this one:
After putting all the components together, I connected it to the oscilloscope and it didn’t get any vibrance from the microphone. I had some help from one of my colleagues, who gave me some useful tipis such as: the coil can’t go crazy around the straw, the straw has to be fixed to the top surface (they were loose one from the other) and the magnet part had to be stable.
So I did a second version, trying to make a bigger area of contact (connected through tape) and to stabilize the lower part. The problem was that because of the eletric magnet field / magnets attraction the needle wouldn’t be centered the way I wanted to. Also, this one did not work:
And then I did my third and last shot – that worked!! I redid the coil wrap around the straw, I glued the needle + washer structure on the bottom of the cup and glued the straw to the plastic film. This worked! I was very glad/relieved/proud that I saw some vibrance variation on the oscilloscope (although I don’t get why the signwave is increasing, instead of ending on the same level as the beggining of it). Here’s a picture and some videos: