Hi everyone
I was looking for a solution for an electret microphone amp/peak detector and came across
this While I think the guy has made a great job at explaining this, I'm not sure I properly understand why he has intentionally introduced a DC offset on U1 by using virtual ground equal to Vcc/2 (
), an offset he has to cancel later on. Is it because the microphone signal could swing below ground or above Vcc (or could it? I'm not sure) otherwise? Or maybe it's there to bias the D3 diode above its Vf so the signal doesn't have to "shoot through" it, i.e. detector isn't effectively limited to V > 0.6V?
I'd appreciate any help in understanding this.