[General] Resistance Reflection Rule

[guravsid]

What is mean by Resistance Reflection Rule ?? How it is calculated ?? What is its significance ??

 

[KlausST]

Hi,

i googled and it took only 10 seconds to find this :

Resistance reflection rule: Resistance looking into the base is (b +1) times total emitter resistance.

it is from the document "BJT Amp.pdf"

In other words: an amplifying BJT with variable load at emitter will transform the load resistance back to the base of the BJT by multiplying it with the (BJT gain +1).
Imagine a BJT as emitter follower. lets say b = 100. So with a collector currrent of 100mA you need 1 mA at the transistor´s base, at emitter you will see 101mA.

(to be exact B is for DC, b or beta is for AC)


Klaus