This classic windscreen wiper interval setup was found in American documentation from the 90s. The circuit can be found with variations at other points on this site.
Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The...
This proximity relay circuit was found in the July 1990 Radio Electronics magazine. The supply...
This circuit is from a 1970 publication. The time constant is given by 1.3R x C where R is the...