does anyone know/have a circuit to detect sound. i would define sound as in for the finger snapping (i dont know what it`s actually called) or maybe clapping.
just a simple circuit would be ok, that is to trigger a relay or so when it detected that sound.
The detector you describe might be a microphone and an amplifier. It seems a common microphone element is the electret mic - Radio Shack used to sell them at low cost. An speaker can work as an amplifier. I know many of the Radio Shack and other introductory circuits books have nice, simple circuits for this - from relatively common parts. Sorry I don't have links but a quick google on audio amplifier ought to produce some results.