We found this circuit in an American documentation from the 80s. In it we have the way to control the amplifier gain by an input voltage.
Suggested by Harris in documentation from the 80s, this circuit uses components from that time. It...
The basis of this circuit is an LM380 that drives a speaker that emits sound when moisture is...
We found this circuit in a 1997 documentation. Its purpose is to turn a load on or off using...