This is the basic full-scale circuit of an LM3914 for voltage measurement or voltage triggering and control. The power supply must be within the indicated range.
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....