This circuit was found in a 1967 US documentation. The FET is general purpose and the 6V zener. The circuit has a very fast switching action.
This well-crafted speed game setup for two competitors was found in a 1998 Poptronics. The circuit...
This circuit is from a 2004 documentation. When the passenger presses CH01 the Sonalart will sound...
This circuit was found in a 80’s American documentation. The adjustment trimpot is from 47k to...