This TTL heads or tails circuit was found in the July 1973 Radio Electronics magazine. The LEDs are types of the time. Note the symbolic representation of this component.
The integrated circuit used in this project is not common today, but it can be implemented with more...
Found in an American publication from 1969, this circuit can be adapted to be used as a shield....
This current meter with many scales was found in a 80s American documentation. The operational amplifier...