Opto control for triac (CB20552E)

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

Comparator with Hysteresis LM339 (CB15187E)
This is the basic configuration of many LM339 manuals, as a comparator with hysteresis. The font...
Parallel Multi-Loop Alarm CIR13989S CB6652E (CB6652E)
We found this circuit in a Popular Electronics of the 80's. The circuit can be used to drive...
Simple power supply (CB22216E)
This simple power supply for transistors was found in documentation from the 1940s. The...