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 obtained in a 1984 publication, but it can be assembled using BC548 for TR1 and...
This circuit was found in an American documentation from 1969. The circuit memorizes when a...
This counter was found in the November 19983 issue of Radio Electronics magazine. The power supply...