We found this circuit in documentation from the 1980s. It is an input stage for a digital frequency meter. The circuit can operate with signals up to a few tens of megahertz.
This circuit was found in the November 1993 issue of Electronics Now magazine. The two-stage...
This circuit acts on a relay disconnecting the load when the input voltage exceeds the set limit....
This circuit is from a Radio Electronics from March 1970. The integrated circuit used is one of...