Found in a Hands On Electronics from the 80's this circuit allows the reading of low resistances in a common multimeter. The circuit consists of a constant current source.
We found this circuit in an old publication. The circuit can be implemented with modern equivalent...
Operational amplifiers used in this 80's circuit is not very common today, but the setting can be...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...