This Kirlian machine circuit uses a car ignition coil. The circuit is from a Radio Electronics from May 1986. It is mentioned in an article that teaches how to obtain photographs.
This game was found in an old Popular Electronics. The unijunction transistor can be 2N2646. The...
This circuit interrupts the power supply when grounding is missing. The circuit is from an old...
In figure 1 we have a circuit that turns on after a certain time and then turns off, also after a...