This version is one of many that can be found on our website. We found it in Radio Electronics from the 90s. Transistors support modern equivalents.
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...