Properly Grounding?

Discussion in 'The Projects Forum' started by teejusb, Jan 4, 2013.

  1. teejusb

    Thread Starter New Member

    Feb 25, 2012
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    Okay this might sound really trivial, but I am trying to find the best way to do this.

    So our University has a dance game arcade cabinet (In the Groove 2) which has a plastic pane about 1cm or so from the monitor. What happens, most notably in the wintertime, is that after a players' set when they touch the monitor, they discharge static electricity which makes the monitor flicker. The community seems to get a little worried about this so I had a few questions.

    I thought that by simply grounding the pane, it would stop this from happening. I mean my first course of action was electrical taping a wire from the pane to the negative pin of an outlet, but that seemed kind of ghetto to me. Is there a better solution and if so how should I do this?
     
  2. Brownout

    Well-Known Member

    Jan 10, 2012
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    Use the ground of the output rather than the negative pin. But being the pane is plastic, I don't think grounding it will work.
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    If it wasn't conductive the static wouldn't be a problem.
     
  4. wayneh

    Expert

    Sep 9, 2010
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    A length of flat wire wrapped around the perimeter might drain off any static without looking too bad. You could run a wire to wall ground, likely available on the back of the computer's power supply, but you might be able to use any open jack on the computer such as USB ground, audio (chassis) ground, whatever.
     
  5. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I like the idea of using the third green ground pin as the connection, I don't like directly connecting there.

    Use a series resistor of 1,000,000 ohms or such.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Yep treat the pane as a ESD mat..
     
  7. Brownout

    Well-Known Member

    Jan 10, 2012
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    I agree, but grounding something that's not conductive doesn't make sense. He might need a "grid" across the panel to make it conductive.
     
  8. wayneh

    Expert

    Sep 9, 2010
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    This is really the "problem", the perception that there is a problem. I don't think there is any real problem, and maybe all you need is a little note to that effect attached to the panel.
     
  9. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I once had a phone answering machine (way back when people actually had those things) that every winter I would touch it, spark it, and blow a 2 amp fuse inside. Wasn't a bad fix for me as I always have a screw driver and soldering iron handy, but would have been DOA for most folk.

    There's no real problem until someone gets hurt.
     
  10. DickCappels

    Moderator

    Aug 21, 2008
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    Is the display a cathode ray tube or an LCD screen?

    If its a cathode ray tube and the victim's hands are wiping off the surface charge, the only really good after-market solution is to place an antistatic filter over the screen. The antistatic filter is coated with a very thin layer (usually indium tin oxide) that is both conductive and nearly transparent. The conductive screens were very popular in the 1990's as people became concerned about the electric and magnetic fields from monitors, so there might be a lot of those screens in second-hand or surplus stores.

    Use of a fine conductive screen would probably work but there is a good chance of getting a moiré pattern because of the difference in the pitch of the picture elements if an LCD or the raster and dot/stripe pattern if a CRT. Another, perhaps more difficult problem with the screen (or mesh) is that the eye is very sensitive to the straightness and uniformly spaced in both axes, so its unlikely that such an approach would be done well.

    The coated glass plate mentioned above seems to be the best after-market solution.
     
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