Found in a 1967 EEE, this circuit generates a constant amplitude signal, stabilized by a zener diode. The circuit can operate with voltages from 18 to 22 V.
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...