With this circuit of a Popular Electronics from the 90's it is possible to test a diode with the oscilloscope visualizing its characteristic curve. The transformer can have currents starting from 100 mA.
This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an...
The transistors in this circuit from an English publication in 1980 may be the BC548. Operational...
This is one of many circuits of this type that can be found in this section. This one is taken from...