This transistor curve tracer was described in a December 1969 Radio Electronics article. It consists of a ladder-type signal generator that applies stepped voltages to the transistor under test.
This circuit makes use of a specific 80's component and was found in an American manual of the...
The circuit shown in the figure, generates a positive pulse whose duration depends on C1, from the...
We found this circuit on the internet. The components are current, and the time depends on C1...