This receiver, whose tuning range depends on L1 and L2, was found in the 1992 special edition of Radio Electronics Experimenter. The circuit is relatively simple and has good sensitivity.
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...