Found in the December 1986 issue of Radio Electronics magazine, this circuit is designed to select 4 outputs with pulses from a pressure switch. The circuit includes LED indication.
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...