This oscillator uses a crystal to set the frequency. The operating limit of the unijunction is in the order of 100 kHz. Power supply can be between 10 and 20V.
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...