This circuit was found in an Elektor from the 90s. It makes use of digital CMOS integrated devices common today. The signal is controlled automatically sequentially.
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. Some of...
This simple transistorized radio for listening on a crystal phone was found in a Japanese...
In the MEMs line of the ST available on Mouser Electronics we highlight the MP23AB01DH audio...