Differential Amplifier

Discussion in 'General Electronics Chat' started by dhpatil, Jun 18, 2007.

  1. dhpatil

    Thread Starter New Member

    Jun 18, 2007
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    0
    Hi All,
    I am using a differential amplifier. I had one doubt regarding input to the differential amplifier. Is it required to connect the circuit ground to the differential input common terminals? If i did so i am getting well stable data, and not then got so many fluctuations for output. So can any body guide me in this matter.


    Dhairyashil
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    It would be helpful if you provided a schematic of your differential amplifier.

    There are applications for differential amplifiers where the input signal source needs no ground. One such application is a magnetic read-head.

    hgmjr
     
  3. dhpatil

    Thread Starter New Member

    Jun 18, 2007
    5
    0
    Hi

    I am attaching the schematic for differential amplifier. The three stage classical Instrumentation amplifier is used in differential mode. Can you give me suggestions in this circuit. The amplifier works on +12V and -5V supply. Vinst_out is the output to be monitored.

    Dhairyashil
     
  4. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    1,437
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    where's the attachment? or are you having trouble uploading your schem?

    moz
     
  5. dhpatil

    Thread Starter New Member

    Jun 18, 2007
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    Attached the file. Can u see it?
     
  6. mozikluv

    AAC Fanatic!

    Jan 22, 2004
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    in what format have u place your schem? or have u used the "manage attachment" button to upload your file?

    moz
     
  7. dhpatil

    Thread Starter New Member

    Jun 18, 2007
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    0
    Hi

    I had used manage attachment at first and the file has format bmp.
     
  8. dhpatil

    Thread Starter New Member

    Jun 18, 2007
    5
    0
    Hi

    Can any body explain me how should i use instrumentation amplifier in Differential mode with input signal source ground isolated from circuit ground?
     
  9. Distort10n

    Active Member

    Dec 25, 2006
    429
    1
    You could use an isolation amplifier which isolates the two grounds. This will give you protection, and supply you with an input bias return path to ground for the instrumentation amplifer.

    What is your design?
     
  10. mozikluv

    AAC Fanatic!

    Jan 22, 2004
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    have you noticed that your bmp format must not exceed 2mb? if your file size is more than that, it's a no can do situation

    moz
     
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