This circuit was found in a PE Hobbyst Handbook of 1989. It uses a black light fluorescent of the time. Small fluorescent black light from 1 to 4 W can be used.
Using the CA3140 in the figure we have a comparator that goes low in the window voltage space. The...
With this circuit it is possible to connect a comparator to a power stage via two wires. The...
This simple circuit was found in the May 1979 issue of Radio Electronics magazine. The circuit has the...