Opto control for triac (CB20552E)

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

TTL Logic Probe (CB1461E )
This circuit is from a 1977 documentation. It is powered by the power supply of the circuit under...
8-Bit D-A Converter (CB15962E)
This circuit is based on the integrated DAC0801 and has an accuracy better than 0.39% on the...
Auto Bias for FET (CB6125E)
This configuration is from a 1964 US documentation valid for any FET. The range of power voltages...