transister question

[electronist]

if the CB junction is reverse biased to work in active reason how on earth do the electrons pass from the emitter-base junction to the collector (the CB junction is REVERSED BIAS) which should actually not allow any electron to flow. Even then amplification is taking place. How?
Now what am I doing wrong?

 

[samcheetah]

when the base-emitter junction of a transistor is forward biased and the collector-base junction of a transistor is reversed biased the transistor is said to be operating in the active mode. now here is what happens.

consider that we have an NPN transistor. due to the forward bias of the base-emitter junction electrons will enter from the emitter and go towards the base. there the electrons will recombine will the holes in the base region (P-material). but the base is usually very thin and the electrons entering from the emitter do not recombine with the holes in the base. instead of recombination they go into the reverse biased collector-base junction. now there the electrons are the minority carriers. and when minority carriers enter a reverse biased junction they are readily swept across it. which means that the moment the electrons enter the reverse biased collector base junction they will be attracted by the positive voltage on the collector.

for a detailed explanation go to http://amasci.com/amateur/transis.html

 

[budidharma]

http://amasci.com/amateur/transis.html

... awesome article. This definately sorted out a lot of stuff for me.