This circuit was found in Delco documentation from 1965. The transistor is of the time, but any current power PNP with at least 500 mA collector current and 100 V collector voltage can be used.
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...