How can a transistor amplify the current ??

[tefa921]

Plz, help me guys because i'm really confused .. now i know the circuit very well .. but still i can't understand how the npn transistor amplify the current where Ie = Ib + Ic .. what i mean is that Ic or the output is less than Ie or the input .. so this is not aplification at all .. So please please help me

 

[E-design]

Look at this simple explanation https://www.youtube.com/watch?v=WaHD7665NeM

 

[tgootee]

First, understand that the amplification factor is not required to be greater than unity. i.e. "Amplify" does not necessarily mean "make bigger". An amplifier can have a gain of less than one, or equal to one, or greater than one. They are all still called "amplifiers".

 

[thannara123]

Learn from here **broken link removed**

 

[dick_freebird]

It's a multi-port device, and each port-pair has a
gain (under or over unity, and often this depends
on bias-point), one with respect to the other. In
a particular pairing and configuration, current or
voltage or power gain can be realized. Not all are
obvious and not all are useful. But that doesn't
mean theory is wrong, just because you can't see
it offhand.

 

[godfreyl]

what i mean is that Ic or the output is less than Ie or the input .. so this is not aplification at all

If Ib is the input, then there is current gain.

Example: Ib=0.1mA, Ic=25mA, Ie=25.1mA
Ie = Ib + Ic
Current gain = Ic/Ib = 250