Using a standard multimeter, this circuit from a 73 magazine for radio amateurs provides an output proportional to the inductance under test. The circuit is TTL and must be powered with 5 V.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...