This trigger circuit was found in an American documentation from the 1980s. The amplifiers used can be replaced by equivalents with characteristics according to the frequency.
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...