This circuit was found in an article about the 555 in the November 1992 Radio Electronics magazine. The circuit uses a 12 V relay and has two timing ranges.
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...