This circuit is from General Electric documentation from 1970. The transistors can be of general-purpose types, except for the power that can be a BD136.
This interesting circuit for testing NPN and PNP transistors for general use and medium power was...
We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the...
Published in Radio Electronics in January 1963, this circuit uses 5 transistors of the time. The...