This is a series current negative feedback circuit given in the book. The resistance connected to the transistor emitter is AC and DC feedback resistance, β=40, input resistance rbe=1kΩ, signal source internal resistance is 0, and then find its voltage amplification multiple, And the magnification when the feedback resistor is not added.
Jamie 发表于 August 5, 2020
I probably know how to find the first one, but the open-loop magnification after removing the feedback resistor is not so sure?
Kendall 发表于 August 5, 2020
You missed an input resistance...
Quinn 发表于 August 5, 2020
Just remove the feedback resistance you calculated, -40*2*6/(2+6)/rbe=-60, so you can see that a single negative feedback will greatly reduce the magnification.
