This circuit was found in a 1977 documentation. With it we have the direct indication, through LEDs of an ASCII signal. The circuit must be powered by a voltage of 5 V.
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...