Opto control for triac (CB20552E)

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

5-Range Microammeter (CB25229E)
This instrumentation circuit was found in the September 1989 Radio Electronics magazine. The...
Square Converter (CB3934E)
This circuit converts a signal from any waveform into a rectangular or square signal of the same...
1 V Precision Reference (CB1285E )
This circuit is from a 1975 Motorola manual. The FET can be the BF245 and the output voltage...