Practice 2. Effects of increasing and decreasing RC

 In this practice, the effects of changing the value of RC will be examined. The practice includes 2 parts:

    a) increase the value of RC.

    b) decrease the value of RC.

 Following is the procedure for the practice, as well as analysis of the effects of changing the value of RC.

 a)      Increase the value of RC

 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 “RC” to increase the value of RC.

3.       Observe how each of the 5 curves (except the curve for ui) changes.


Analysis:

RC: increase =>

UB = Ucc*R2/(R1+R2): unchanged

            URE = UB - 0.7: unchanged

UC = Ucc - IC*RC: decrease

[because IC = IRE = URE/RE: unchanged]

uo = -40*IC0*RC*ui1: increase

[because IC = IRE = URE/RE: decrease]

Uout = UC + uo: decrease

[because although uo increases at the same time UC decreases, the decreased amount of UC is much larger than the increased amount of uo]

 b)      Decrease the value of RC

 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 “RC” to decrease the value of RC.

3.       Observe how each of the 5 curves (except the curve for ui) changes.

 Analysis:

 RC: decrease =>

UB: unchanged

            URE: unchanged

UC: increase

uo: decrease

Uout: increase