This circuit was obtained from an old English book. Transistors are types of the time.
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...
