Doubt in the circuit diagram

Discussion in 'General Electronics Chat' started by kavin6, Jan 12, 2009.

  1. kavin6

    Thread Starter Member

    Jan 2, 2009
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    Please check the circuit in the attachment and explain where the pointed node should be connected? What is that whole cylinder thing, my guess is that its just a lengthy connection.
    Thanks:)
     
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  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    The "cylinder" is the shielding braid in the cable between the "patient", and the amplifier input.

    Ken
     
  3. kavin6

    Thread Starter Member

    Jan 2, 2009
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    What exactly is a shielding braid?:confused:
     
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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  5. Audioguru

    New Member

    Dec 20, 2007
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    You could use shielded microphone cable.
     
  6. kavin6

    Thread Starter Member

    Jan 2, 2009
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    Ok but where do i connect the output from the amplifier???
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    To the EKG monitor, of course.
     
  8. kavin6

    Thread Starter Member

    Jan 2, 2009
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    Sgt I meant the output from OPA2604 I have pointed it with red pointer in the circuit diagram
     
  9. thingmaker3

    Retired Moderator

    May 16, 2005
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    Connect it to the drain wire of the shield.
     
  10. SgtWookie

    Expert

    Jul 17, 2007
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    Ahh, OK.

    The OPA2604 is a shield driver. It attempts to force the shield to be at the same voltage potential as Rg/2, the gain resistor of the INA118 instrumentation amplifier.

    This minimizes the influence of outside voltage potentials. Ideally, the voltage potential on the shield will be the same as Rg/2, which will minimize any impact (distortion) on the signal input to the INA118.
     
  11. kavin6

    Thread Starter Member

    Jan 2, 2009
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    Thanks to all:)
    Cheers
     
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