This circuit is from a 90s American documentation. The circuit can use complementary pairs according to the power. The power voltage can be between 5 and 12 V.
This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power...
This circuit uses an optocoupler to obtain a solid state relay whose power depends on the Triac...
This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the...