We found this circuit in an old American documentation. SCRs can be modern equivalent types. The transformer has a 5 A current, according to the SCRs.
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...