This circuit was found in the August 1994 issue of Electronics Now magazine. The 4046 is uncommon these days and the frequency range is given by C1.
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...
This circuit releases a lock only if the correct 4-digit sequence is entered. The circuit uses...
Found in documentation from the 1980s, this circuit generates signals that can reach a few...