Electric Potential Sensor

Discussion in 'General Electronics Chat' started by cbecket13, Dec 10, 2014.

  1. cbecket13

    Thread Starter Member

    Nov 15, 2014
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  2. studiot

    AAC Fanatic!

    Nov 9, 2007
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    That works by capacitive coupling, like a touch switch.
     
  3. cbecket13

    Thread Starter Member

    Nov 15, 2014
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    What does the advertised "ultra high impedance" have to do with it?
     
  4. #12

    Expert

    Nov 30, 2010
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    If you (you being a sensor) don't need much current to sense something, you can sense things that have very little ability to supply current.
     
  5. studiot

    AAC Fanatic!

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    The capacitor value is very low so its impedance is very high, since the impedance is proportional to the reciprocal of capacitance.
     
  6. alfacliff

    Well-Known Member

    Dec 13, 2013
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    when measuring with an electrometer, either tube or fet, what is called impedance is actually resistance, they dont really measure ac, more likely the charge of a capacitor. the electrometer tubes are evacuated to a high vacuum, and the electrometer fets are designed for very low leakage. often used to measure radiation, as particals go through the partial atmosphere of an ion chamber., some more info here, http://www.techlib.com/
    several ion chamber projects and explations.
     
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