The use of a diac improves the performance of the two dimmers in the previous circuits. The circuit is from the same Radio Electronics magazine in an article that teaches how to use triacs.
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...