This configuration similar to many of this site was found in 1965 General Electric documentation. Modern equivalent transistors can be used. LEDs can be used.
April 2017 - Mouser Electronics is making available this new component for open LED protection...
Found in a 1967 RCA documentation, this AC power grid contactor can be fitted with modern...
We found this circuit in a 1967 General Electric SCR manual. The time is set to R1 and depends on C1...