This alarm circuit triggers when S1 opens. The circuit from a January 1975 Radio Electronics magazine can be used with interrupt sensors connected in series.
We found this circuit in the Linear Applications Handbook by National Semiconductor. The circuit is...
This wide-range radiation monitor was found in a 1980s documentation. The circuit uses a diode as a...
This circuit is from an article that appeared in the June 1974 issue of Radio Electronics...