Found in US documentation, this circuit changes the waveform and phase of a sine signal. The circuit is indicated for frequencies between 0.1 and 10 Hz. The power source must be symmetrical.
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...