This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is given by capacitor C1 and R2 which has the range of values indicated in the diagram.
This circuit was found in the April 1971 Radio Electronics magazine. It uses common transistors and can...
This voice scrambler and descrambler circuit was found in a Radio Electronics from July 1963....
Using a 4017 as a base, this circuit from a 1990s Popular Electronics generates low-frequency...