"gareth" wrote in
:

After studying (mainly BJTs, but with FETs in the final year) at Uni,
I was conversant with all the models, Hybrid-Pi, etc, and the use
of various matrical parameters, h, y, s, etc, for describing and
predicting transistor behaviour in circuit, but was puzzled on how it
actually worked, by which I mean, how did the base current control the
collector current?

(So many of the textbooks just glibly say that the part of the emitter
current
divides off to become the base current, but this does not describe the
low-level controlling action)

I found the answer about 18 years ago in these NG (ISTR
sci.electronics before its unnecessary split), but I wonder whether
anyone else puzzled over this, and what was their answer?



It's all perfectly simple: holes are just electrons with negative mass.