Found in an Electronic Design of 1964, this circuit can control up to 20 SCRs in a trigger system powered by 24 V. The SCR supports a modern equivalent.
This circuit is a from publication 1980, but still can be mounted with BC548 transistors for Q1...
This circuit for testing zener diodes by lifting their curve on an oscilloscope was presented in...
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....