This circuit was published in a 90s Radio Electronics. The circuit uses the well-known LM386 that appears in a large number of projects on this site.
This old AM receiver with an integrated circuit came out in a documentation from the 80s. The...
Suggested by a 1966 publication, this circuit applies a 60 Hz signal to a transistor to test its...
This mini siren, found in a 2003 publication, powers a small piezoelectric transducer, but a...