Hi All, I have tried everything, by now I probably spend over 16 hours and countless combinations of every prescription I found on net, trying to figure it out and I am just stuck, need push in right direction.
I am learning microphone circuits and I trying to connect simple capsule mic to read its output with oscilloscope and I am getting weird results. Here are the details:
The circuit that I am building is as simple as a very basic one out there, see attached illustration #1, power supply is 3V, resistor from power to positive pin is 2k and capacitor from positive pin to output currently is 1uF but I have tried many others 0.1uF, 4.7uF, 2uF, 10uF (ceramic capacitors)
When I clap or make other somewhat loud-ish sound, waveform is offset up, see illustration #2 and #3
When I connect microphone from Adafruit, waveform is nice and symmetric as you see in illustration #4
I have tried everything, DC coupling, AC coupling on oscilloscope and waveform is still offset except with DC coupling it is half supply voltage up of course, I tried running this through inverting op amp and still same result of course inverted. I tried different capacitors as already mentioned, different supply voltage 4.5v and 3v, directly from batterys or via voltage regulator, I am running out of ideas what I am doing wrong, can you please help?