The PA222 integrated circuit used in this project from an American 1967 documentation is not common today. The circuit can deliver higher power with lower fidelity.
This circuit can be found elsewhere on this site as part of alarms or sirens. The circuit given is...
This circuit can generate time base signals from 5 to 1500 Hz. We find it in a documentation about old neon...
This circuit was found in an American magazine 73 for radio amateurs of the 80s. It is an...