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Does experiencing a static shock mean that you are grounded?

  1. Dec 6, 2014 #1
    If I built up static in me and then touch a doorknob and get shocked, am I then sufficiently grounded to be able to touch electrical components?
    Or was it just that the extra electrons were discharged and I should still ground myself in another way before touching electrical components?
     
  2. jcsd
  3. Dec 6, 2014 #2
    I believe a ground strap on your wrist is the proper method. Just moving around with clothes on can cause static electricity.
     
  4. Dec 6, 2014 #3

    Danger

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    I second that. One discharge clears you only until you build up more. Believe it or not, something as seemingly innocuous as sneezing can build a charge. Rather than buy a strap when I worked in the sign shop (and believe me, a rubber squeegee squishing vinyl ink through a polyester mesh onto a vinyl substrate creates something that will throw a spark more than 1/2 metre), I just disassembled one of my sets of handcuffs and reconnected them with coiled #10 automotive wire. One cuff on my wrist and one on the press cleared everything.

    Well... Occupational Health and Safety did actually (I'm serious) receive an anonymous tip that someone was being held as slave labour in a sign shop... My boss subsequently made me stop using it.

    edit: added a factor that I forgot the first time and corrected the spelling of "squeegee".
     
    Last edited: Dec 6, 2014
  5. Dec 6, 2014 #4

    jedishrfu

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    So were you handcuffed to your machine?
     
  6. Dec 6, 2014 #5

    Danger

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    Yeah. I removed the chain from my cuffs. Then I took a spool of #10 auto wire from my workbench (at home) and wound it around a 1/4" dowel to form it into a "spring" like an old-style telephone receiver cord. The last step was to connect one end of the wire to each cuff so as to make a complete circuit from one end to the other.
    To be clear, there was never any possibility of a mishap. For one thing, the wire was just wrapped around the chain-mount lanyard on each cuff with no soldering, so it would have torn away under any hint of force. Also, I used my "sex cuffs" :blushing: rather than my real ones; they had a small push-lever release so the key wasn't needed.
     
    Last edited: Dec 6, 2014
  7. Dec 7, 2014 #6

    NascentOxygen

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    You feel a jolt as there's a rapid sharing of electrons, but this doesn't necessarily mean you end up at zero volts. There is nothing in the building code that says all door knobs are to be solidly grounded. It just takes a metal body at a significantly different potential for you to feel a jolt as charge transfers. Besides, what is ground potential for you and the carpet may not be the ground for the electronic circuit you are contemplating handling. Before touching a delicate component you need to be grounded to that circuit's ground.
     
  8. Dec 7, 2014 #7

    Danger

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    Excellent point. I wasn't aware of that. (I don't mess with electronics.)
     
  9. Dec 7, 2014 #8

    Doug Huffman

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    You and your work's ground must be at the same potential. Use a grounding leash with a current limiting resistor in series.
     
  10. Dec 7, 2014 #9

    fedaykin

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    Keep in mind too, just because you don't feel a shock or later detect a failure of the circuit does not mean you have not damaged it too.
    This of course depends on the properties of the electronics you're working on.
     
  11. Dec 8, 2014 #10

    CWatters

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    No.

    If you can build up a static charge in the first place then you aren't really sufficiently earthed to be certain you won't damage electronic components.

    Any damage caused may not be immediately obvious either. It might only affect the life expectancy of the device. eg it might work fine now but die young.
     
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