This circuit can be used as a shield for microcontrollers. The relay is power compliant, and the transistor is general purpose.
Found in Popular Electronics from the 90s, this circuit can be used as a warning shield for...
This simple logic test circuit with 3 LEDs was found in October 1985 Radio Electronics magazine. The...
This sophisticated digital timer was found in a 2002 documentation. Since CMOS integrated circuits are...