This TTL circuit uses LED indicators and must be powered by a voltage of 5 V. The capacitor determines the speed of the draw. We found it in documentation from the 90s.
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...