The circuit is from the Linear applications Handbook of the National Semiconductor of 1994. The components used are not common today.
Found in a 1977 publication this circuit can supply current up to about 20 mA set on the...
This circuit was obtained in Teledyne documentation from the 70s. The converter component is uncommon...
This variable bandpass filter was found in an American 1980s documentation. The power supply must be...