We found this circuit in an American documentation from 1975. The list of transistors that can be used is attached to the diagram. Modern types can be experienced.
This extremely slow circuit produces one pulse per month and can be used in a timer. We found it...
This circuit was found in a 1964 Electronic Design. The circuit delays the firing of a load for a...
Found in a documentation from the 90's, this circuit already includes an amplification stage. The...