This circuit for AC loads was found in February 1976, Radio Electronics magazine. The triac is common, and the times are given by the 20 MΩ resistor and the 1 uF capacitor.
This circuit is from a documentation from the 70s. The circuit uses logic gates of the time, which...
Found in the July 1968 Supertena Bulletin of a Popular Electronics, this receiver makes use of the...
The circuit shown was found in the February 1994 issue of Electronics Now magazine. The circuit...