What are the voltage ratios in an op amp circuit?

In summary, the conversation revolves around finding the voltage ratios for ideal opamps with infinite gain and no current draw. The speaker correctly identifies that R2 and R5 are not involved in the analysis for the same reasons. However, a new attempt is needed with R5 replaced with a wire. The conversation ends with the speaker finding an algebra error in their calculation and correcting it, with the assurance that they are now good to go.
  • #1
gfd43tg
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I have to find both of the voltage ratios. This is just ugly algebra. Here is what I came up with, and was wondering if I was correct.
Thanks

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  • #2
If the opamps are ideal, they have infinite gain and their inputs draw no current.

You correctly saw that this means R2 is not involved in the analysis, but you failed to notice that R5 is not involved for the same reasons.

You'll need to redo your work with R5 replaced with a wire; no R5, in other words.
 
  • #3
Is it really that easy?

ImageUploadedByPhysics Forums1399705402.263499.jpg


Edit: Wait a minute, I remember the professor saying to never do KCL at the output of an op-amp, I will redo this.
 
  • #4
Ok here is my next attempt hopefully it's right

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  • #5
I found an algebra error in my Vout/Vin and fixed it

ImageUploadedByPhysics Forums1399709957.638376.jpg
 
  • #6
You're good to go!
 

1. What is an op amp circuit?

An op amp circuit, short for operational amplifier circuit, is a type of electronic circuit that uses an operational amplifier to amplify and process electronic signals. It typically consists of an input signal, an operational amplifier, and an output signal.

2. What is a voltage ratio in an op amp circuit?

A voltage ratio in an op amp circuit refers to the relationship between the input voltage and the output voltage of the circuit. It is typically expressed as a ratio or a gain value, and it determines the amplification or attenuation of the input signal by the operational amplifier.

3. How do you calculate the voltage ratio in an op amp circuit?

The voltage ratio in an op amp circuit can be calculated by dividing the output voltage by the input voltage. This is also known as the gain of the circuit and is typically denoted by the symbol "A". The gain can be determined by analyzing the circuit components and the feedback network of the op amp circuit.

4. What is the ideal voltage ratio for an op amp circuit?

The ideal voltage ratio for an op amp circuit is infinite, meaning that the output voltage is equal to the input voltage multiplied by infinity. This is because an ideal op amp has infinite gain and no signal loss, resulting in a perfect amplification of the input signal. However, in reality, op amp circuits have finite gain values and some signal loss due to imperfections in the components.

5. How can the voltage ratio in an op amp circuit be adjusted?

The voltage ratio in an op amp circuit can be adjusted by changing the feedback network of the circuit. This can be done by adding or removing resistors, capacitors, or other components in the circuit. By adjusting the feedback network, the gain of the op amp circuit can be increased or decreased to achieve the desired voltage ratio.

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