This symmetrical power supply uses two old filament transformers. The circuit was obtained in a documentation from the 80's and the diodes can be 1N4002.
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...