This telephone circuit was found on a 90's EDN. It keeps a flashing LED to indicate that there was a call in your absence. The components admit equivalents.
This circuit was found in a 1966’s American publication. What it does is to receive a pulse and...
This dual circuit was found in an 80s Siliconix documentation. The power source must be...
We found this circuit in a Radio Electronics from the 90s. Transistors admit current equivalents,...