This circuit was found in American documentation from the 1980s. The integrated circuit used is a voltage comparator of the time. Modern equivalents can be tested.
Found in an American publication from 1968, this circuit can be made based on a TIP42 that must be...
This circuit was found in the February 1992 issue of Radio Electronics magazine. The circuit...
This is a conventional differentiator configuration with operational amplifier. In principle any...