This power stage with two transistors was found in Radio Electronics magazine from October 1963. The transistors must be equipped with heatsinks and the supply voltage is 12 V.
This simple circuit controls the brightness of an LED from LDRs, NTCs, PTCs or other resistive sensors....
We found this circuit in a 1990 documentation. It draws one out of 10 numbers and during the draw...
The circuit shown in figure 3 uses a programmable unijunction transistor (PUT) of the BRY39 type...