What is the effect of feedback on input and output impedances?

  • Thread starter Thread starter tanaygupta2000
  • Start date Start date
  • Tags Tags
    Feedback Impedance
Click For Summary
SUMMARY

The discussion focuses on the effects of feedback on input and output impedances in electronic circuits. It highlights the importance of understanding how feedback alters voltage gain and the methodologies for measuring input and output impedances. The conversation emphasizes the need for a schematic representation of the circuit to accurately calculate these impedances and suggests that the feedback factor (βv) influences the gain compared to the non-feedback scenario. Participants are encouraged to consult relevant textbooks for foundational knowledge.

PREREQUISITES
  • Understanding of electronic feedback systems
  • Familiarity with voltage gain formulas
  • Knowledge of input and output impedance concepts
  • Ability to read and interpret circuit schematics
NEXT STEPS
  • Research the impact of feedback on input and output impedances in operational amplifiers
  • Learn how to measure input impedance using an oscilloscope and multimeter
  • Study the calculation of output impedance in feedback circuits
  • Explore textbooks on electronic circuit design for deeper insights
USEFUL FOR

Electronics engineers, students studying circuit design, and anyone involved in analyzing feedback systems in electronic circuits will benefit from this discussion.

tanaygupta2000
Messages
208
Reaction score
14
Homework Statement
An amplifier has a voltage gain Av = 1000 , input impedance 1 kΩ and output impedance 500Ω A
fraction βv = 0.1 of the output voltage is fed back in the series in opposition to the input voltage. The
input and output impedance after the feedback are given respectively by the approximate values ?
Relevant Equations
A' = A/(1-βA)
I know that when the feedback is connected, the voltage gain changes by the above formula. But I don't know how to find final values of input and output impedances.
 
Physics news on Phys.org
How do input and output impedance change when you apply feedback? Have you studied that point?
 
How would you measure the input impedance (i.e. what information about this circuit do you need to calculate this)? How would you measure the output impedance?
Have you drawn a schematic of this circuit yet?
 
  • Like
Likes   Reactions: berkeman
You have mentioned a formula for the gain A´ with feedback ...when you insert the mentioned value βv = 0.1 , will the gain be larger or smaller than A (without feedback)? What do you expect ?

(By the way: An answer to your question can be found in each relevant textbook...did you already spend some time for searchnig?)
 

Similar threads

  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
15
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 5 ·
Replies
5
Views
3K