In this practice, the effects of changing the value of RE will be examined. The practice includes 2 parts:
a) increase the value of RE.
b) decrease the value of RE.
Following is the procedure for the practice, as well as analysis
of the effects of changing the value of RE.
a)
Increase the value of RE
Procedure:
1.
Click “Continue” to start the simulation
2.
After a while (e.g. when the curves are reaching the 5th
grid), pull up the scaler in the scrollbar next to “RE” to increase
the value of RE.
3.
Observe how each of the 5 curves (except the curve for ui) changes.
Analysis:
RE: increase =>
UB
= Ucc*R2/(R1+R2): unchanged
URE
= UB - 0.7: unchanged
UC
= Ucc - IC*RC: increase
[because
IC = IRE = URE/RE: decrease]
uo
= -40*IC0*RC*ui1: decrease
[because
IC = IRE = URE/RE: decrease]
Uout
= UC + uo: increase
[because
although uo decreases at the same time UC increases, the increased amount of UC
is much larger than the decreased amount of uo]
b) Decrease the value of RE
Procedure:
1.
Click “Continue” to start the simulation
2.
After a while (e.g. when the curves are reaching the 5th
grid), pull down the scaler in the scrollbar next to “RE” to decrease the value of RE.
3.
Observe how each of the 5 curves (except the curve for ui) changes.
Analysis:
RE: decrease =>
UB:
unchanged
URE:
unchanged
UC:
decrease
uo:
increase
Uout:
decrease