Found in a Popular Electronics from the 90's, this circuit is used to recognize the frequency of a modulated infrared signal. The LM567 circuit must not be supplied with voltages above 9 V.
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...