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How does a negative ion generator work?

  1. Mar 10, 2007 #1
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    I understand that it uses some sort of "needle assembly," and electric fields are stronger at sharp points in a conductor and then will ionize the surrounding air at a certain potential. But how exactly are the negative charges isolated in the first place? Some friends and I have discussed how this might happen, such as first charging a capacitor, then attaching the negative lead to such a needle assembly, then grounding the positive lead, but we're not exactly sure.
    Last edited: Mar 11, 2007
  2. jcsd
  3. Mar 12, 2007 #2


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    Gold Member

    I believe the ionisation is caused when an electron binds loosely with a gas molecule. If you put a high -ve voltage on a needle, electrons can escape from the point.

    That's about right. The voltage can come from any source, with the +ve grounded.
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