Found in a Popular Elecronics from the 90s, this circuit appears in other versions in this section and on the website. The circuit draws one of 10 LEDs and has a sound effect produced during the draw.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...