This circuit detects when an audio signal exceeds a certain level or even occurs due to an object falling, a door slamming or other. The circuit is from a Radio Electronics from January 1980.
This circuit was found in documentation from the 1980s. The circuit can be designed based on...
This circuit uses two operational amplifiers, which can be of the type 741, in a full wave...
Other series operational amplifiers, such as MC34072, MC34074, MC35071, MC35072, MC35074 d MC33071...