This circuit can be used in measurement bridges. We found it in the September 1995 Electronics Now magazine. The meter can be from 50 uA to 1 mA and the power supply is simple.
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...