This circuit is from Motorola's Linear Interface ICs of 1993. The integrated circuit is not common and the Triac is chosen according to the power of the controlled load.
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...