Found in a 90s Radio Electrconics, this circuit is an operational one with a power stage using two transistors. The output current can reach several amps.
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...