Finding a voltage in an ideal op amp.

Click For Summary
SUMMARY

The discussion focuses on solving for the output voltage (V0) in a circuit involving an ideal operational amplifier (op amp) using nodal analysis. The user initially calculated V0 as zero but expressed confusion regarding the handling of nodes in the circuit. Key equations derived include V0 = Va, 3Va + 2V2 - V0 = 0, and 5Vb - 4V1 - Va = 0. The user seeks clarification on labeling nodes Va and Vb to better understand the relationships between the voltages in the circuit.

PREREQUISITES
  • Understanding of ideal op amp rules, specifically V- = V+ and I- = I+
  • Proficiency in nodal analysis for circuit analysis
  • Familiarity with voltage relationships in multi-stage op amp circuits
  • Basic knowledge of circuit components such as resistors and their configurations
NEXT STEPS
  • Study the principles of nodal analysis in more complex circuits
  • Learn about the behavior of ideal op amps in non-inverting and inverting configurations
  • Explore how to label and analyze multiple nodes in op amp circuits
  • Investigate the impact of feedback in operational amplifier circuits
USEFUL FOR

Electrical engineering students, circuit designers, and anyone studying operational amplifier applications and analysis techniques.

gunnerrex
Messages
1
Reaction score
0

Homework Statement



Hello everyone. I tried solving this ideal op amp for V0 but kept becoming confused because of the structure at the bottom. I only have experience solving ideal op amp questions when they are grounded and have not encountered one like this before. All the data is given in the picture of the ideal op amp I made in photoshop. I believe the curved line behind the second stage means that it does not come into contact with the wire it passes.

Homework Equations



The only method I have for solving ideal op amps so far is nodal analysis. I am guessing that is what must be used to solve this ideal op amp as well.

The Attempt at a Solution



When I tried solving for V0 I got zero. I don't understand how to handle the bottom nodes. I drew the picture as given to me and have not labeled the extra nodes, but here is my attempt going from right to left of the ideal op amp:

(V0 - Va) / 10,000 = 0
[1] so V0 = Va

(Va + V2) / 5,000 + (Va - V0) / 10,000 = 0

[2] so 3Va + 2V2 - V0 = 0

(V2 - Vb) / 100,000 = 0

[3] so V2 = Vb

(Vb - V1) / 25,000 + (Vb - Va) / 100,000 = 0

[4] so 5Vb - 4V1 - Va = 0

and finally Vc +V1 = 0

[5] so Vc = -V1 = Vb because of ideal op amp rules.

After working backwards I get V0 = 0 volts, but I doubt this is right.
egrihatethisquestion.jpg
 
Physics news on Phys.org
Could you label Va and Vb on the diagram?

Given the two ideal op-amp rules relating V- to V+ and I- to I+, what can you deduce regarding the voltage at the inverting input of the second op-amp, and thus at non-inverting input of the second op-amp?

How does this relate V0 to V2, and thus to V1?
 

Similar threads

Replies
15
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 44 ·
2
Replies
44
Views
6K
Replies
4
Views
2K
Replies
1
Views
2K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K