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.
This circuit incorporates the passive control of the previous circuit and was also found in the...
I found this circuit on a December 1976 Radio Elettronica. The Italian magazine no longer exists, but...
This circuit is like the previous one except that it can be triggered electronically. The circuit is...