Finding a voltage in an ideal op amp.

In summary, the conversation discusses a problem with solving an ideal op amp for V0 due to its structure and the lack of experience with this type of problem. The individual has attempted to solve it using nodal analysis, but is unsure of how to handle the bottom nodes. They share their attempt at solving it and ask for help with labeling certain points on the diagram. Additionally, the conversation touches on the ideal op-amp rules and how they can be used to deduce the voltage at the inverting input of the second op-amp, which then relates to V0 and other variables.
  • #1
gunnerrex
1
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
 
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  • #2
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?
 

Related to Finding a voltage in an ideal op amp.

1. What is an ideal op amp?

An ideal op amp, or operational amplifier, is an electronic device that amplifies an input voltage signal to a higher output voltage signal. It has two input terminals, a non-inverting (+) and an inverting (-) terminal, and one output terminal.

2. How does an ideal op amp work?

An ideal op amp works by using a high gain differential amplifier. The output voltage is calculated as the difference between the input voltages, multiplied by the gain of the amplifier. This allows for the op amp to amplify very small input voltages to a much larger output voltage.

3. What is the voltage gain of an ideal op amp?

The voltage gain of an ideal op amp is infinite, meaning that it can amplify the input voltage signal to an infinitely higher output voltage signal. This is because the op amp has a very high gain differential amplifier built in.

4. How do you find the output voltage of an ideal op amp?

The output voltage of an ideal op amp can be found by using the voltage gain equation, Vout = Av(V+ - V-), where Av is the voltage gain and V+ and V- are the input voltages at the non-inverting and inverting terminals respectively. In an ideal op amp, the voltage at the inverting and non-inverting terminals are equal, so V+ = V- = Vin. Therefore, the output voltage can be simplified to Vout = Av(Vin - Vin) = 0. This means that the output voltage of an ideal op amp is always 0, unless limited by the power supply.

5. Are there any limitations to finding a voltage in an ideal op amp?

Yes, there are a few limitations to finding a voltage in an ideal op amp. The main limitation is that an ideal op amp does not exist in reality. Real op amps have some limitations such as finite gain, input bias currents, and output impedance. Additionally, the power supply voltage can also limit the output voltage of an op amp.

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