This circuit is from an old documentation, making use of an operational of the time. The circuit can be adapted to use modern components. The power supply must be symmetrical.
This 3V-only circuit was found in old American documentation, but can be implemented with...
The output voltage of this circuit, which can regulate the current in a load between 0 and 1 A,...
This circuit was found in a Popular Electronics from the 90s. The circuit has temperature...