This circuit recognizes a tone determined by the tuned input circuit (R3 / R4 / C2). The circuit was found in Radio Electronics from the 90s. The 4046 is not a common component today.
The circuit shown enables dynamic diode testing with an oscilloscope. We found this configuration in a...
The circuit shown in the figure is quite interesting in control and alarm applications. This...
This different power control circuit with SCR was obtained from a 1967 magazine. The SCR can be...