This basic relay configuration was found in a July 1994 Electronics Now. The relay is supposed to be sensitive, and the times are changed by changing C1.
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
This circuit was obtained in an old Elektor. It is a reference, since the integrated products of the...
This circuit was found in a European technical documentation from 1991. It is a circuit that must...