This circuit was found in an Elektor from the 90s. Next to the circuit we have a table with the delays obtained when the circuit is connected according to the positions of the selector switches.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...