Comparator circuit

Thread Starter

Sardaukar

Joined Jun 19, 2009
6
I found a schematic for the audio signal detector circuit:

http://www.discovercircuits.com/H-Corner/audio-signal.htm

I use it to control an ISD1600B to start recording automatically when audio signal is present (I record the same audio signal as the one used to turn recording on).

Recording supposedly works fine, but when I press the play button (short one of ISD pins to ground), recording starts again for some reason. If after the recording I disconnect the diode, the sound played is very distorted (no noise, it sounds like sound is played faster or slower than normal).

ISD worked fine without this comparator circuit, so the problem is with it, but in order to locate it, I would like to ask someone to explain to me how it works (this particular comparator circuit).

Instead of comparator in the schematic I use L258N opamp.
 
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