in this walkthrough:
http://www.explainth...istorswork.html
it says:
"the n-type has a surplus of electrons, the p-type has holes where electrons should be. Normally, the holes in the base act like a barrier, preventing any significant current flow flowing from the emitter to the collector"
I don't understand why/how electrons flow/stop-flowing in this scenario.
A - The language 'the holes.. act like a barrier'. if 'holes' are (lack of electrons/positive charge), doesn't that mean they are LOOKING FOR electrons (i.e. attracting them). How can they both 'attract' electrons but then also 'act like a barrier' / repel (those same electrons)?
B - what stops electrons from just going straight from the ntype plates to the Base as soon as the 'sandwhich' is glued together? Sort of seems like a transistor is a naturally closed circuit. i.e. The base wants electrons, and the ntype plates have them so why don't the electrons just head over? if the answer is 'they need energy to overcome (silicon's) natural resistance to electron flow', wouldn't applying energy to the Base cause both ntype plates to send their electrons straight to the Base until all three plates are balanced?
C - finally, how is there amplification in this? i.e. if I had only one 9V battery for input and the output was to, say, a lightbulb, how would those components connect with a transistor? Would I connect the battery positive to the Emitter and the battery negative to the Base and the output would come out the Collector? And then would that output be > 9V? ('amplified') or increased amps?
So I think electron-flow is the main puzzle piece I am trying to get. For example, regarding say, 100 electrons:
Battery: negative terminal sends 100 electrons to Base, Base has, say, 99 holes, so 1 extra electron wants to go somewhere, but it is surrounded by (ntype silicon) that already has too many electrons (repelling it). So how does it go anywhere?
or how does that one electron 'amplify' the electron flowing form the emitter to the collector? If the electron from the base just adds on the electron coming from the emitter, then '2' electrons would arrive at the collector, but isn't that just balanced? (no net gain of electrons?)
-al
