This circuit is used to sense temperatures in degrees Celsius and Fahrenheit. The circuit is from Special Projects from 1983 in Radio Electronics magazine.
With the configuration shown in the figure, we have the relay being activated when the microphone picks...
We found this circuit in a 1992 Poptronics. What it does is to activate LEDs sequentially,...
In the figure we have an application of a voltage comparator in a circuit that fires with the...