This simple logic level tester was found in Radio Electronics from the 90s. The inverters are of the 4009 type and the power comes from the circuit being analyzed.
This circuit can be used as a rhythmic light or as a control shield for incandescent lamps from...
This NOR gate uses an uncommon operating system today but can be implemented with more modern...
This basic relay configuration was found in a July 1994 Electronics Now. The relay is supposed to be...