This circuit activates a relay after a time given by C1 and R1. The circuit is from a Radio Electronics from December 1974. The relay voltage is the same as that used in the power supply.
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...