In this circuit we have the way to use two transistors as a regenerative pair simulating an SCR. The circuit is from a 1965 General Electric documentation.
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...