Steve - at first, let me say that I totally agree with your first sentence:
"There are two (and probably more -- but let me simplify it to two) ways of teaching a topic like this."
I have some experience in teaching - and I know that it can be effective (and sometimes: necessary) to start with some - more or less - simplified explanations. To be more precise - nearly all of our explanantions are only simplified descriptions of the reality. But that is not a problem - as long as we as engineers know about these limitations.
Nevertheless, such simplified considerations must not bar the way to a later better (correct) understanding of things.
Many text writers like the motto “Keep it simple ...”. Do we really want to teach stuff that is wrong just because it is simple? (A. Einstein:
"Everything should be made as simple as possible, but not simpler".)
In the following, some specific comments from my side:
The other approach is to start with generalities, then step down into details, refining the previous understanding as we go.
I think that such a "refining" of "previous understandings" requires that the generalities are simplified descriptions that can be refined later on. I think, in the present example that is not the case
....it is acceptable to teach generalities that will later be shown to be incorrect.
....if viewed as a relationship some of the first steps are easier.
Doesn`t this contradict the previous mentioning of "refinement"?
Can incorrect explanations refined step by step?
Do we really want to teach stuff that is wrong just because it is "easier"?
There are lots of other examples that the fundamentalists allow themselves to ignore. For instance, every time KVL is mentioned, they fail to state that it is only an approximation which begins to fail as the wavelength of the signal starts to approach the scale of the circuit.
For my opinion, this is not a good example. The rules according to KVL are not wrong but they have a limited range of validity. That`s a big difference. More than that, similar considerations apply to all equations and effects in the world of electronics. We always make simplifications: No part or system has "linear" properties and no signal is a pure sinus. But we are using these terms - knowing about their limited meaning.
(not to mention the limited world of Isaac Newton).
Would it teach someone more that is immediately useful about transistors than an equivalent time studying semiconductor physics? Unquestionably, yes.
I don`t think so. The video creates a totally false impression on the function principle of the BJT - and this is certainly not a good starting point for a succeeding "refinement".
(Example: Pretty often we can read "
Why is Ic nearly independent on Vce? Why does Ohms law not apply?"
I think, those questions result from thinking that the BJT would be nothing else than a variable resistance, as mentioned in the video).
(Side note to our moderator
davenn: Note that I did not start another current / voltage debate)
