This wired intercom circuit was found in an English publication from the 80's. The integrated circuit can be replaced by an equivalent, just like the transistor which is a general-purpose type.
This circuit was found in the 1991 Electronics Experimenters handbook. It can be used to display RGB...
This circuit uses sensors to determine who is the first to cross the end line. The circuit was...
Found in a General Electric documentation from 1970, this circuit consists of a relaxation...