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.
This circuit, from a 1988 publication, consists of a timer that activates a relay at the end of a...
Found a documentation for PC from 1992, this circuit is indicated for the English power grid of...
This conventional window comparator configuration was found in an old documentation. It is valid...