Originally, this circuit was created to monitor the liquid level in the reservoir of a car's windshield wiper. The circuit is from documentation from the 90s.
September 2016 - can already be purchased at Mouser Electronics the Robot Scribbler S3 from...
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
This simple transistorized game that appears in other versions in this section and website, was...