This simple logic probe circuit was found in the August 1980 issue of Radio Electronics magazine. The circuit works with both TTL and CMOS logic.
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...