This control circuit using a low voltage switch was found in the September 1987 Radio Electronics magazine. The triac must be matched to the load and the mains voltage.
This basic configuration can be found in a lot of articles on this site. In this case, the relay...
This circuit is from American documentation from the 1980s. The transistors are general purpose...
The circuit is simple, as it uses only one transistor and a relay that can be MC2RC1 or MC2RC2,...