Question with my circuit in multisim dealing with op-amp

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    Circuit Op-amp
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Discussion Overview

The discussion revolves around troubleshooting a circuit involving an operational amplifier (op-amp) in Multisim. Participants are examining issues related to voltage measurements and circuit connections, specifically focusing on the configuration of power supplies and resistors.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant reports that their circuit is not yielding the expected results, specifically measuring a voltage (Vc) that is inconsistent with their design expectations.
  • Another participant points out that the potentiometer (V2) is incorrectly connected, suggesting that one end should be at +10 V instead of ground.
  • There is a mention of the power supply pins for the op-amp not being connected, which may affect circuit functionality.
  • After making adjustments to the circuit, the original poster observes minimal changes in voltage (about 88mV DC without power and 75mV DC with power connected) despite altering the resistor (R4), indicating potential ongoing issues.
  • A later post indicates that the original poster has resolved their issue, but the details of the resolution are not provided.

Areas of Agreement / Disagreement

Participants express differing views on the circuit's configuration, particularly regarding the connections of the potentiometer and power supply. The discussion remains unresolved until the original poster claims to have figured out the issue, though specifics are not shared.

Contextual Notes

There are limitations regarding the clarity of circuit connections and the specific nature of the adjustments made by the original poster. The discussion does not clarify the exact nature of the problem or the resolution.

ee1215
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I am drawing a circuit but not getting right result. I am to assemble the circuit below using +-10V supplies with all those specifications I have put in. I leave Node A open and adjust R4 to make Vc=0V. When I measure Vc originally it is about 10VDC(on the DVM). If I use a 100M resistor it only makes it about 3V. What is wrong with my circuit(the second link)?

Constructing:
http://i812.photobucket.com/albums/zz41/uofmx12/E21ckt.jpg

My circuit:
http://i812.photobucket.com/albums/zz41/uofmx12/E21ckt_2-1.jpg
 
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V2 is upside down. You are supposed to have one end of the potentiometer be at +10 V, but you connected the + end of the +10 V supply supply to ground.

Also, you have not connected anything to what I presume are the power supply pins for the amplifier symbol.
 
MisterX said:
V2 is upside down. You are supposed to have one end of the potentiometer be at +10 V, but you connected the + end of the +10 V supply supply to ground.

Also, you have not connected anything to what I presume are the power supply pins for the amplifier symbol.

Ok, so I changed the V2 supply. And I am getting about 88mV DC without the +-10 supply to the op amp and about 75mV DC with them connected. But for some reason when I change R4 resistor the the Vc voltage does not change from either 75mV or 88mV no matter what I change the resistor to. So I imagine something is still wrong.
 
I figured it out
 

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