This damped oscillator that mimics the sound of a gong was found in 90s American documentation. The circuit signal must be applied to an external amplifier.
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...