This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be changed. The load depends on the relay. The circuit is old, from 1988 documentation, but totally viable today.
This circuit was found in an article in Radio Electronics magazine from October 1962. At that...
The Exclusive-OR function is characterized by the truth table of the figure itself. We see then...
This circuit was found in an English magazine from 1976. The transistors can be the BC548. The...