Using a 4046 PLL, which is uncommon today, this circuit was found in the October 1994 issue of Electronics Now magazine. The circuit can be modified by changing the capacitor.
Found in RCA documentation two years 70, this circuit triggers an incandescent lamp at dusk. The...
Found in Popular Electronics from the 90s, this circuit is based on a PLL567 and employs high-end or...
This circuit was obtained in an English publication of 1977. The operational is of the type with...