Transistors

[frankw]

I need help understanding how a transistor actually works... I know what it "does" as in how it creates a replication of the base signal that is amplified, but I cannot understand how this actually happens.

So when I visualize a transistor I see it as two diodes facing opposite directions, the collector supply is hitting a reverse biased diode, while the base supply is situated in the middle of the two diodes. Apparently the base current forward biases the emitter diode and while the transistor is in "active region" the other diode is still reverse biased.

So the base current doesn't affect the collector diode?? The collector current is breaking down the collector diode somehow right? If this is so then how is the base current "amplified", like when that collector current joins with the base current wouldnt it just be the flat collector current with some spikes provided by the base current?

Thanks for help!

 

[Nigel Goodwin]

A transistor isn't two diodes, imagining it as such is confusing you.

 

[crutschow]

Transistor theory is not easy to visualize (unlike vacuum tubes) but here's a short description that may help -- Transistor theory.

 

[anita1984]

Logic gate

Hello Forum , please can someone help me to design the hardware of this table of logic (by the use of the logic gate) , the table is in the attachment.
Thanks in advance

 

[anita1984]

sorry , i wrote in the wrong place :-( , i don't know why i can't delete it , i am really sorry