Found in an old Popular Electronics this circuit appears in other variations on this site and in this section. It uses a 7-segment common anode LED display as an indicator.
This configuration for switching signals uses only common general-purpose diodes such as 1N4148. The...
This digital electronic game circuit was found in a 1982 publication. It randomly draws the...
This version works in the opposite way to the previous one, activating when the light falls on the...