MrAl, Hello again
There are, of course, people who "have done it". People have done a lot of things. But - the question is if it makes sense or not. And I doubt, if the results "are really "usable".
Do you consider the temperature effects which even can destroy the transistor? I never have seen an amplifier stage in common emitter configuration without any dc feedback, did you?
If you don`t believe me - here are some statements to be found in the "electronic bible" (H&H, The Art of Electronics):
* "The grounded emitter amplifier should be avoided - eccept in circuits with overall negative feedback";
* "The grounded emitter amplifier is difficult to bias. It might be tempting just to apply a voltage that gives the right quiescent current. That won´t work because of the temperature dependence of Vbe.
* "Such unstable biasing is useless."
Sorry - I don`t understand what you mean because you always speak about "it". What is better than what?
I think, now we come to the "core" of the problem - and I am not sure if you aren`t mixing up two different things: (1) The physical truth and (2) the technical method.
1.) At first, there is the question, if the current Ic of a BJT is PHYSICALLY controlled by the voltage Vbe or by the base current Ib. Only one single answer is possible because the transistor physics cannot depend on external circuitry. I know, that two different explanations can be found in textbooks - however, only one can be correct. I think, the people who are "advocates" of voltage control (Ratch and myself) have some good arguments, see for example the link Ratch has given elsewhere (I think, a very useful link, in particular post#10):
https://cr4.globalspec.com/thread/68055/voltage-vs-current
If you are interested, I can give you a reference from Berkeley University explaining why the BJT is physically voltage controlled.
But - this question has nothing to do with the METHOD how the transistor is biased.
2.) There are two different methods a BJT can be biased: Voltage driven or current driven (not "controlled"). What means "current driven"? We use a large resistor Rb and a relatively large dc voltage to realize a voltage divider between Rb and the dc resistance Rbe of the B-E path. In our engineering community it is a common agreement to call this method "current driven", in spite of the fact that it is not really a current source.
The current Ib is primarily determined by the resistor Rb - that`s all. And, of course, there is a useful relationship Ic=B*Ib. But this formula does not mean that Ib controls Ic. It`s just a fixed relation.
However, the current Ic still is controlled by the voltage, which is developed across the B-E path.
Hello again,
Jony has explained what i am looking for here. If you like you can include a link to the Berkley info and i'll read it, but our view depends on what we are looking at so we also need to distinguish the internal circuit view from the external circuit view.
You said that we cant calculate the grounded emitter circuit because there is too much variation, although i would accept a variation.
But then i posted anther circuit in post #19 that has an emitter resistor, yet we can still see that Vbe is a factor and so we still have the same situation right? The only difference is the external circuit view, where we see a better circuit. But surely we still have to figure out a way to bias this circuit correct?