About Transistors conducting


Joined Mar 24, 2008
It can be very small however. Small enough to treat as an open switch.

When discussing transistors it is important to remember there are several families. I assume you are talking BJT in this case, given you mentioned Collector and Emitter.

The early transistors, made from germanium, were much worse. The new ones are much better. BJTs are fundamentally analog devices, even if they can be run in their digital regions. Something to remember.


Joined Dec 20, 2007
Usually a transistor is turned off by something connecting its base to its emitter, maybe a resistor. Without something between the base and emitter then a very small collector to base leakage current is amplified by the transistor and it conducts much more current than with something connecting its base to its emitter.


Joined Mar 24, 2008
Just curious, are you going to school, or are you self taught? I was messing with electronics many years before I went into college. I had holes in what knew until a more formal education.

But I still had fun. I was even etching my own boards.

Thread Starter


Joined Jan 1, 2010
I am not learning electronics....
BTW, Im etching PCB also :)
With Toner Transfer method, or free drawing with marker....
BTW, Its great forum, fast answers, and very good people....