This circuit was found in the September 1984 issue of Radio Electronics magazine. The frequency is given by the capacitors. The diodes help in the starting process.
This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a...
Found in an old English publication and in other parts of this website in different versions, this...
This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be...