Opto control for triac (CB20552E)

Found a documentation for PC from 1992, this circuit is indicated for the English power grid of 240 V.

Rectangular Generator With Active Cycle (CB10492E)
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...
Incandescent Lamps VU Meter (CB17345E)
This circuit triggers three incandescent light bulbs following the audio signal applied to its...
DC multiplier LM339 (CB15190E)
This circuit was obtained in the SGS manual of linear integrated circuits of 1982. The components used...