Hi Folks,
I'd like to make timegrapher to measure accuracy of watch. One element of project is sound sensor to collect "tic" "tac" sound from watch. I found ready to work project and I tried to figure out each part of it. Unfortunately I do not understand what is the marked with circle part of the circuit and why I have feedback from op amp positive with capacitor inside. Because I'm not very experienced in electronics I tried to match this element with:
-sallen key filter, band-pass filter, low or high pass filter
-kind of amplifier
but I couldn't find similiar example. Could anybody show me what kind of circuit is that and what is the purpose of having it in this place?
I'd like to make timegrapher to measure accuracy of watch. One element of project is sound sensor to collect "tic" "tac" sound from watch. I found ready to work project and I tried to figure out each part of it. Unfortunately I do not understand what is the marked with circle part of the circuit and why I have feedback from op amp positive with capacitor inside. Because I'm not very experienced in electronics I tried to match this element with:
-sallen key filter, band-pass filter, low or high pass filter
-kind of amplifier
but I couldn't find similiar example. Could anybody show me what kind of circuit is that and what is the purpose of having it in this place?