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== ASSIGNMENT 2 - == | == ASSIGNMENT 2 - VARIABLE RESISTANCE == | ||
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For the second assignment I started some research on the piezo and got interested in the fact that it doesn't work as an acoustic microphone but one that's depending on vibration. | |||
So my attempt for the beginning was to use it as an input into the 555 circuit in monostable mode (for some reasons it did not work at all in the astable mode). So there was a permanent sound of the circuit and whenever I touched the piezo it gave some really small extra sound, pushing it harder did make it a little bit louder. Instead of the loudspeaker I used a LED to see the changes better. In this case my body was working as a variable resistance. I wanted to get a stronger signal that I could also work with. In this class and in the following last block I was occupied with researching on some amplifyer circuits. | |||
There are some different amplifyers that I came across but I kept on working with the LM385N for my piezo research. | |||
In another course I printed loudspeakers by the silkscreen printing technique for which I used the LM 386N-1. | |||
[[File:lm386ayla.jpg]] | |||
The last OP-AMP I came across in my research is the 741, which I didn't tested already but I will add some schematics on this too. | |||